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mipmap.c

/*
** License Applicability. Except to the extent portions of this file are
** made subject to an alternative license as permitted in the SGI Free
** Software License B, Version 1.1 (the "License"), the contents of this
** file are subject only to the provisions of the License. You may not use
** this file except in compliance with the License. You may obtain a copy
** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
** 
** http://oss.sgi.com/projects/FreeB
** 
** Note that, as provided in the License, the Software is distributed on an
** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
** 
** Original Code. The Original Code is: OpenGL Sample Implementation,
** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
** Copyright in any portions created by third parties is as indicated
** elsewhere herein. All Rights Reserved.
** 
** Additional Notice Provisions: The application programming interfaces
** established by SGI in conjunction with the Original Code are The
** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
** Window System(R) (Version 1.3), released October 19, 1998. This software
** was created using the OpenGL(R) version 1.2.1 Sample Implementation
** published by SGI, but has not been independently verified as being
** compliant with the OpenGL(R) version 1.2.1 Specification.
**
*/
/* $XFree86: xc/extras/ogl-sample/main/gfx/lib/glu/libutil/mipmap.c,v 1.5 2002/02/22 21:32:49 dawes Exp $ */

#include "gluos.h"
#include <assert.h>
#include <GL/glu.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>           /* UINT_MAX */
#include <math.h>
#include "gluint.h"

typedef union {
    unsigned char ub[4];
    unsigned short us[2];
    unsigned int ui;
    char b[4];
    short s[2];
    int i;
    float f;
} Type_Widget;

/* Pixel storage modes */ 
typedef struct {
   GLint pack_alignment;
   GLint pack_row_length; 
   GLint pack_skip_rows;  
   GLint pack_skip_pixels;
   GLint pack_lsb_first;
   GLint pack_swap_bytes;
   GLint pack_skip_images;
   GLint pack_image_height;

   GLint unpack_alignment;
   GLint unpack_row_length;
   GLint unpack_skip_rows;
   GLint unpack_skip_pixels;
   GLint unpack_lsb_first;
   GLint unpack_swap_bytes;
   GLint unpack_skip_images;
   GLint unpack_image_height;
} PixelStorageModes;

static int gluBuild1DMipmapLevelsCore(GLenum, GLint, 
                              GLsizei,
                              GLsizei,
                              GLenum, GLenum, GLint, GLint, GLint, 
                              const void *);
static int gluBuild2DMipmapLevelsCore(GLenum, GLint, 
                              GLsizei, GLsizei, 
                              GLsizei, GLsizei, 
                              GLenum, GLenum, GLint, GLint, GLint, 
                              const void *);
static int gluBuild3DMipmapLevelsCore(GLenum, GLint, 
                              GLsizei, GLsizei, GLsizei,
                              GLsizei, GLsizei, GLsizei,
                              GLenum, GLenum, GLint, GLint, GLint, 
                              const void *);

/*
 * internal function declarations
 */
static GLfloat bytes_per_element(GLenum type);
static GLint elements_per_group(GLenum format, GLenum type);
static GLint is_index(GLenum format);
static GLint image_size(GLint width, GLint height, GLenum format, GLenum type);
static void fill_image(const PixelStorageModes *,
                   GLint width, GLint height, GLenum format, 
                   GLenum type, GLboolean index_format, 
                   const void *userdata, GLushort *newimage);
static void empty_image(const PixelStorageModes *,
                  GLint width, GLint height, GLenum format, 
                    GLenum type, GLboolean index_format, 
                  const GLushort *oldimage, void *userdata);
static void scale_internal(GLint components, GLint widthin, GLint heightin, 
                     const GLushort *datain, 
                     GLint widthout, GLint heightout, 
                     GLushort *dataout);

static void scale_internal_ubyte(GLint components, GLint widthin, 
                     GLint heightin, const GLubyte *datain, 
                     GLint widthout, GLint heightout, 
                     GLubyte *dataout, GLint element_size,
                     GLint ysize, GLint group_size);
static void scale_internal_byte(GLint components, GLint widthin,
                           GLint heightin, const GLbyte *datain,
                           GLint widthout, GLint heightout,
                           GLbyte *dataout, GLint element_size,
                           GLint ysize, GLint group_size);
static void scale_internal_ushort(GLint components, GLint widthin,
                           GLint heightin, const GLushort *datain,
                           GLint widthout, GLint heightout,
                           GLushort *dataout, GLint element_size,
                           GLint ysize, GLint group_size,
                           GLint myswap_bytes);
static void scale_internal_short(GLint components, GLint widthin,
                           GLint heightin, const GLshort *datain,
                           GLint widthout, GLint heightout,
                           GLshort *dataout, GLint element_size,
                           GLint ysize, GLint group_size,
                           GLint myswap_bytes);
static void scale_internal_uint(GLint components, GLint widthin,
                           GLint heightin, const GLuint *datain,
                           GLint widthout, GLint heightout,
                           GLuint *dataout, GLint element_size,
                           GLint ysize, GLint group_size,
                           GLint myswap_bytes);
static void scale_internal_int(GLint components, GLint widthin,
                           GLint heightin, const GLint *datain,
                           GLint widthout, GLint heightout,
                           GLint *dataout, GLint element_size,
                           GLint ysize, GLint group_size,
                           GLint myswap_bytes);
static void scale_internal_float(GLint components, GLint widthin,
                           GLint heightin, const GLfloat *datain,
                           GLint widthout, GLint heightout,
                           GLfloat *dataout, GLint element_size,
                           GLint ysize, GLint group_size,
                           GLint myswap_bytes);

static int checkMipmapArgs(GLenum, GLenum, GLenum);
static GLboolean legalFormat(GLenum);
static GLboolean legalType(GLenum);
static GLboolean isTypePackedPixel(GLenum);
static GLboolean isLegalFormatForPackedPixelType(GLenum, GLenum);
static GLboolean isLegalLevels(GLint, GLint, GLint, GLint);
static void closestFit(GLenum, GLint, GLint, GLint, GLenum, GLenum,
                   GLint *, GLint *);

/* all extract/shove routines must return double to handle unsigned ints */
static GLdouble extractUbyte(int, const void *);
static void shoveUbyte(GLdouble, int, void *);
static GLdouble extractSbyte(int, const void *);
static void shoveSbyte(GLdouble, int, void *);
static GLdouble extractUshort(int, const void *);
static void shoveUshort(GLdouble, int, void *);
static GLdouble extractSshort(int, const void *);
static void shoveSshort(GLdouble, int, void *);
static GLdouble extractUint(int, const void *);
static void shoveUint(GLdouble, int, void *);
static GLdouble extractSint(int, const void *);
static void shoveSint(GLdouble, int, void *);
static GLdouble extractFloat(int, const void *);
static void shoveFloat(GLdouble, int, void *);
static void halveImageSlice(int, GLdouble (*)(int, const void *),
                      void (*)(GLdouble, int, void *),
                      GLint, GLint, GLint,
                      const void *, void *,
                      GLint, GLint, GLint, GLint, GLint);
static void halveImage3D(int, GLdouble (*)(int, const void *),
                   void (*)(GLdouble, int, void *),
                   GLint, GLint, GLint,
                   const void *, void *,
                   GLint, GLint, GLint, GLint, GLint);

/* packedpixel type scale routines */
static void extract332(int,const void *, GLfloat []);
static void shove332(const GLfloat [],int ,void *);
static void extract233rev(int,const void *, GLfloat []);
static void shove233rev(const GLfloat [],int ,void *);
static void extract565(int,const void *, GLfloat []);
static void shove565(const GLfloat [],int ,void *);
static void extract565rev(int,const void *, GLfloat []);
static void shove565rev(const GLfloat [],int ,void *);
static void extract4444(int,const void *, GLfloat []);
static void shove4444(const GLfloat [],int ,void *);
static void extract4444rev(int,const void *, GLfloat []);
static void shove4444rev(const GLfloat [],int ,void *);
static void extract5551(int,const void *, GLfloat []);
static void shove5551(const GLfloat [],int ,void *);
static void extract1555rev(int,const void *, GLfloat []);
static void shove1555rev(const GLfloat [],int ,void *);
static void extract8888(int,const void *, GLfloat []);
static void shove8888(const GLfloat [],int ,void *);
static void extract8888rev(int,const void *, GLfloat []);
static void shove8888rev(const GLfloat [],int ,void *);
static void extract1010102(int,const void *, GLfloat []);
static void shove1010102(const GLfloat [],int ,void *);
static void extract2101010rev(int,const void *, GLfloat []);
static void shove2101010rev(const GLfloat [],int ,void *);
static void scaleInternalPackedPixel(int,
                             void (*)(int, const void *,GLfloat []),
                             void (*)(const GLfloat [],int, void *),
                             GLint,GLint, const void *,
                             GLint,GLint,void *,GLint,GLint,GLint);
static void halveImagePackedPixel(int,
                          void (*)(int, const void *,GLfloat []),
                          void (*)(const GLfloat [],int, void *),
                          GLint, GLint, const void *,
                          void *, GLint, GLint, GLint);
static void halve1DimagePackedPixel(int,
                            void (*)(int, const void *,GLfloat []),
                            void (*)(const GLfloat [],int, void *),
                            GLint, GLint, const void *,
                            void *, GLint, GLint, GLint);

static void halve1Dimage_ubyte(GLint, GLuint, GLuint,const GLubyte *,
                         GLubyte *, GLint, GLint, GLint);
static void halve1Dimage_byte(GLint, GLuint, GLuint,const GLbyte *, GLbyte *, 
                        GLint, GLint, GLint);
static void halve1Dimage_ushort(GLint, GLuint, GLuint, const GLushort *,
                        GLushort *, GLint, GLint, GLint, GLint);
static void halve1Dimage_short(GLint, GLuint, GLuint,const GLshort *, GLshort *, 
                         GLint, GLint, GLint, GLint);
static void halve1Dimage_uint(GLint, GLuint, GLuint, const GLuint *, GLuint *, 
                        GLint, GLint, GLint, GLint);
static void halve1Dimage_int(GLint, GLuint, GLuint, const GLint *, GLint *, 
                       GLint, GLint, GLint, GLint);
static void halve1Dimage_float(GLint, GLuint, GLuint, const GLfloat *, GLfloat *, 
                         GLint, GLint, GLint, GLint);

static GLint imageSize3D(GLint, GLint, GLint, GLenum,GLenum);
static void fillImage3D(const PixelStorageModes *, GLint, GLint, GLint,GLenum, 
                  GLenum, GLboolean, const void *, GLushort *);
static void emptyImage3D(const PixelStorageModes *,
                   GLint, GLint, GLint, GLenum, 
                   GLenum, GLboolean, 
                   const GLushort *, void *);
static void scaleInternal3D(GLint, GLint, GLint, GLint, const GLushort *, 
                      GLint, GLint, GLint, GLushort *);

static void retrieveStoreModes(PixelStorageModes *psm)
{
    glGetIntegerv(GL_UNPACK_ALIGNMENT, &psm->unpack_alignment);
    glGetIntegerv(GL_UNPACK_ROW_LENGTH, &psm->unpack_row_length);
    glGetIntegerv(GL_UNPACK_SKIP_ROWS, &psm->unpack_skip_rows);
    glGetIntegerv(GL_UNPACK_SKIP_PIXELS, &psm->unpack_skip_pixels);
    glGetIntegerv(GL_UNPACK_LSB_FIRST, &psm->unpack_lsb_first);
    glGetIntegerv(GL_UNPACK_SWAP_BYTES, &psm->unpack_swap_bytes);

    glGetIntegerv(GL_PACK_ALIGNMENT, &psm->pack_alignment);
    glGetIntegerv(GL_PACK_ROW_LENGTH, &psm->pack_row_length);
    glGetIntegerv(GL_PACK_SKIP_ROWS, &psm->pack_skip_rows);
    glGetIntegerv(GL_PACK_SKIP_PIXELS, &psm->pack_skip_pixels);
    glGetIntegerv(GL_PACK_LSB_FIRST, &psm->pack_lsb_first);
    glGetIntegerv(GL_PACK_SWAP_BYTES, &psm->pack_swap_bytes);
}

static void retrieveStoreModes3D(PixelStorageModes *psm)
{
    glGetIntegerv(GL_UNPACK_ALIGNMENT, &psm->unpack_alignment);
    glGetIntegerv(GL_UNPACK_ROW_LENGTH, &psm->unpack_row_length);
    glGetIntegerv(GL_UNPACK_SKIP_ROWS, &psm->unpack_skip_rows);
    glGetIntegerv(GL_UNPACK_SKIP_PIXELS, &psm->unpack_skip_pixels);
    glGetIntegerv(GL_UNPACK_LSB_FIRST, &psm->unpack_lsb_first);
    glGetIntegerv(GL_UNPACK_SWAP_BYTES, &psm->unpack_swap_bytes);
    glGetIntegerv(GL_UNPACK_SKIP_IMAGES, &psm->unpack_skip_images);
    glGetIntegerv(GL_UNPACK_IMAGE_HEIGHT, &psm->unpack_image_height);

    glGetIntegerv(GL_PACK_ALIGNMENT, &psm->pack_alignment);
    glGetIntegerv(GL_PACK_ROW_LENGTH, &psm->pack_row_length);
    glGetIntegerv(GL_PACK_SKIP_ROWS, &psm->pack_skip_rows);
    glGetIntegerv(GL_PACK_SKIP_PIXELS, &psm->pack_skip_pixels);
    glGetIntegerv(GL_PACK_LSB_FIRST, &psm->pack_lsb_first);
    glGetIntegerv(GL_PACK_SWAP_BYTES, &psm->pack_swap_bytes);
    glGetIntegerv(GL_PACK_SKIP_IMAGES, &psm->pack_skip_images);
    glGetIntegerv(GL_PACK_IMAGE_HEIGHT, &psm->pack_image_height);
}

static int computeLog(GLuint value)
{
    int i;

    i = 0;

    /* Error! */
    if (value == 0) return -1;

    for (;;) {
      if (value & 1) {
          /* Error ! */
          if (value != 1) return -1;
          return i;
      }
      value = value >> 1;
      i++;
    }
}

/* 
** Compute the nearest power of 2 number.  This algorithm is a little 
** strange, but it works quite well.
*/
static int nearestPower(GLuint value)
{
    int i;

    i = 1;

    /* Error! */
    if (value == 0) return -1;

    for (;;) {
      if (value == 1) {
          return i;
      } else if (value == 3) {
          return i*4;
      }
      value = value >> 1;
      i *= 2;
    }
}

#define __GLU_SWAP_2_BYTES(s)\
(GLushort)(((GLushort)((const GLubyte*)(s))[1])<<8 | ((const GLubyte*)(s))[0])

#define __GLU_SWAP_4_BYTES(s)\
(GLuint)(((GLuint)((const GLubyte*)(s))[3])<<24 | \
      ((GLuint)((const GLubyte*)(s))[2])<<16 | \
      ((GLuint)((const GLubyte*)(s))[1])<<8  | ((const GLubyte*)(s))[0])

static void halveImage(GLint components, GLuint width, GLuint height, 
                   const GLushort *datain, GLushort *dataout)
{
    int i, j, k;
    int newwidth, newheight;
    int delta;
    GLushort *s;
    const GLushort *t;

    newwidth = width / 2;
    newheight = height / 2;
    delta = width * components;
    s = dataout;
    t = datain;

    /* Piece o' cake! */
    for (i = 0; i < newheight; i++) {
      for (j = 0; j < newwidth; j++) {
          for (k = 0; k < components; k++) {
            s[0] = (t[0] + t[components] + t[delta] + 
                  t[delta+components] + 2) / 4;
            s++; t++;
          }
          t += components;
      }
      t += delta;
    }
}

static void halveImage_ubyte(GLint components, GLuint width, GLuint height, 
                  const GLubyte *datain, GLubyte *dataout,
                  GLint element_size, GLint ysize, GLint group_size)
{
    int i, j, k;
    int newwidth, newheight;
    GLubyte *s;
    const char *t;

    /* handle case where there is only 1 column/row */
    if (width == 1 || height == 1) {
       assert( !(width == 1 && height == 1) ); /* can't be 1x1 */
       halve1Dimage_ubyte(components,width,height,datain,dataout,
                    element_size,ysize,group_size);
       return;
    }

    newwidth = width / 2;
    newheight = height / 2;
    s = dataout;
    t = (const char *)datain;

    /* Piece o' cake! */
    for (i = 0; i < newheight; i++) {
      for (j = 0; j < newwidth; j++) {
          for (k = 0; k < components; k++) {
                s[0] = (*(const GLubyte*)t + 
                  *(const GLubyte*)(t+group_size) +
                        *(const GLubyte*)(t+ysize) +
                        *(const GLubyte*)(t+ysize+group_size) + 2) / 4;
                s++; t += element_size;
          }
          t += group_size;
      }
      t += ysize;
    }
}

/* */
static void halve1Dimage_ubyte(GLint components, GLuint width, GLuint height, 
                         const GLubyte *dataIn, GLubyte *dataOut, 
                         GLint element_size, GLint ysize, 
                         GLint group_size)
{
   GLint halfWidth= width / 2;
   GLint halfHeight= height / 2;
   const char *src= (const char *) dataIn;
   GLubyte *dest= dataOut;
   int jj;

   assert(width == 1 || height == 1); /* must be 1D */
   assert(width != height);   /* can't be square */

   if (height == 1) {         /* 1 row */
      assert(width != 1);     /* widthxheight can't be 1x1 */
      halfHeight= 1;

      for (jj= 0; jj< halfWidth; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
          *dest= (*(const GLubyte*)src +
             *(const GLubyte*)(src+group_size)) / 2;

          src+= element_size;
          dest++;  
       } 
       src+= group_size;      /* skip to next 2 */
      }
      {
       int padBytes= ysize - (width*group_size); 
       src+= padBytes;  /* for assertion only */
      }
   }
   else if (width == 1) {     /* 1 column */
      int padBytes= ysize - (width * group_size);
      assert(height != 1);    /* widthxheight can't be 1x1 */
      halfWidth= 1; 
      /* one vertical column with possible pad bytes per row */
      /* average two at a time */

      for (jj= 0; jj< halfHeight; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
          *dest= (*(const GLubyte*)src + *(const GLubyte*)(src+ysize)) / 2;

          src+= element_size;
          dest++;
       }  
       src+= padBytes; /* add pad bytes, if any, to get to end to row */
       src+= ysize;
      }
   }

   assert(src == &((const char *)dataIn)[ysize*height]);
   assert((char *)dest == &((char *)dataOut)
        [components * element_size * halfWidth * halfHeight]);
} /* halve1Dimage_ubyte() */

static void halveImage_byte(GLint components, GLuint width, GLuint height, 
                  const GLbyte *datain, GLbyte *dataout,
                  GLint element_size,
                  GLint ysize, GLint group_size)
{
    int i, j, k;
    int newwidth, newheight;
    GLbyte *s;
    const char *t;

    /* handle case where there is only 1 column/row */
    if (width == 1 || height == 1) {
       assert( !(width == 1 && height == 1) ); /* can't be 1x1 */
       halve1Dimage_byte(components,width,height,datain,dataout,
                   element_size,ysize,group_size);
       return;
    }

    newwidth = width / 2;
    newheight = height / 2;
    s = dataout;
    t = (const char *)datain;

    /* Piece o' cake! */
    for (i = 0; i < newheight; i++) {
      for (j = 0; j < newwidth; j++) {
          for (k = 0; k < components; k++) {
                s[0] = (*(const GLbyte*)t + 
                  *(const GLbyte*)(t+group_size) +
                        *(const GLbyte*)(t+ysize) +
                        *(const GLbyte*)(t+ysize+group_size) + 2) / 4;
                s++; t += element_size;
          }
          t += group_size;
      }
      t += ysize;
    }
}

static void halve1Dimage_byte(GLint components, GLuint width, GLuint height, 
                        const GLbyte *dataIn, GLbyte *dataOut, 
                        GLint element_size,GLint ysize, GLint group_size)
{
   GLint halfWidth= width / 2;
   GLint halfHeight= height / 2;
   const char *src= (const char *) dataIn;
   GLbyte *dest= dataOut;
   int jj;

   assert(width == 1 || height == 1); /* must be 1D */
   assert(width != height);   /* can't be square */

   if (height == 1) {         /* 1 row */
      assert(width != 1);     /* widthxheight can't be 1x1 */
      halfHeight= 1;

      for (jj= 0; jj< halfWidth; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
          *dest= (*(const GLbyte*)src + *(const GLbyte*)(src+group_size)) / 2;

          src+= element_size;
          dest++;  
       } 
       src+= group_size;      /* skip to next 2 */
      }
      {
       int padBytes= ysize - (width*group_size); 
       src+= padBytes;  /* for assertion only */
      }
   }
   else if (width == 1) {     /* 1 column */
      int padBytes= ysize - (width * group_size);
      assert(height != 1);    /* widthxheight can't be 1x1 */
      halfWidth= 1; 
      /* one vertical column with possible pad bytes per row */
      /* average two at a time */

      for (jj= 0; jj< halfHeight; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
          *dest= (*(const GLbyte*)src + *(const GLbyte*)(src+ysize)) / 2;

          src+= element_size;
          dest++;
       }  
       src+= padBytes; /* add pad bytes, if any, to get to end to row */
       src+= ysize;
      }

      assert(src == &((const char *)dataIn)[ysize*height]);
   }

   assert((char *)dest == &((char *)dataOut)
        [components * element_size * halfWidth * halfHeight]);
} /* halve1Dimage_byte() */

static void halveImage_ushort(GLint components, GLuint width, GLuint height, 
                    const GLushort *datain, GLushort *dataout,
                  GLint element_size, GLint ysize, GLint group_size,
                  GLint myswap_bytes)
{
    int i, j, k;
    int newwidth, newheight;
    GLushort *s;
    const char *t;

    /* handle case where there is only 1 column/row */
    if (width == 1 || height == 1) {
       assert( !(width == 1 && height == 1) ); /* can't be 1x1 */
       halve1Dimage_ushort(components,width,height,datain,dataout,
                     element_size,ysize,group_size, myswap_bytes);
       return;
    }

    newwidth = width / 2;
    newheight = height / 2;
    s = dataout;
    t = (const char *)datain;

    /* Piece o' cake! */
    if (!myswap_bytes)
    for (i = 0; i < newheight; i++) {
      for (j = 0; j < newwidth; j++) {
          for (k = 0; k < components; k++) {
            s[0] = (*(const GLushort*)t + 
                  *(const GLushort*)(t+group_size) + 
                  *(const GLushort*)(t+ysize) + 
                  *(const GLushort*)(t+ysize+group_size) + 2) / 4;
            s++; t += element_size;
          }
          t += group_size;
      }
      t += ysize;
    }
    else
    for (i = 0; i < newheight; i++) {
        for (j = 0; j < newwidth; j++) {
            for (k = 0; k < components; k++) {
            s[0] = (__GLU_SWAP_2_BYTES(t) +
                  __GLU_SWAP_2_BYTES(t+group_size) +
                  __GLU_SWAP_2_BYTES(t+ysize) +
                  __GLU_SWAP_2_BYTES(t+ysize+group_size)+ 2)/4;
                s++; t += element_size;
          }
          t += group_size;
        }
        t += ysize;
    }
}

static void halve1Dimage_ushort(GLint components, GLuint width, GLuint height, 
                        const GLushort *dataIn, GLushort *dataOut, 
                        GLint element_size, GLint ysize, 
                        GLint group_size, GLint myswap_bytes)
{
   GLint halfWidth= width / 2;
   GLint halfHeight= height / 2;
   const char *src= (const char *) dataIn;
   GLushort *dest= dataOut;
   int jj;

   assert(width == 1 || height == 1); /* must be 1D */
   assert(width != height);   /* can't be square */

   if (height == 1) {         /* 1 row */
      assert(width != 1);     /* widthxheight can't be 1x1 */
      halfHeight= 1;

      for (jj= 0; jj< halfWidth; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
#define BOX2 2
          GLushort ushort[BOX2];
          if (myswap_bytes) {
             ushort[0]= __GLU_SWAP_2_BYTES(src);
             ushort[1]= __GLU_SWAP_2_BYTES(src+group_size);
          }
          else {
             ushort[0]= *(const GLushort*)src;
             ushort[1]= *(const GLushort*)(src+group_size);
          }

          *dest= (ushort[0] + ushort[1]) / 2;
          src+= element_size;
          dest++;  
       } 
       src+= group_size;      /* skip to next 2 */
      }
      {
       int padBytes= ysize - (width*group_size); 
       src+= padBytes;  /* for assertion only */
      }
   }
   else if (width == 1) {     /* 1 column */
      int padBytes= ysize - (width * group_size);
      assert(height != 1);    /* widthxheight can't be 1x1 */
      halfWidth= 1; 
      /* one vertical column with possible pad bytes per row */
      /* average two at a time */

      for (jj= 0; jj< halfHeight; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
#define BOX2 2
          GLushort ushort[BOX2];
          if (myswap_bytes) {
             ushort[0]= __GLU_SWAP_2_BYTES(src);
             ushort[1]= __GLU_SWAP_2_BYTES(src+ysize);
          }
          else {
             ushort[0]= *(const GLushort*)src;
             ushort[1]= *(const GLushort*)(src+ysize);
          }
          *dest= (ushort[0] + ushort[1]) / 2;

          src+= element_size;
          dest++;
       }  
       src+= padBytes; /* add pad bytes, if any, to get to end to row */
       src+= ysize;
      }

      assert(src == &((const char *)dataIn)[ysize*height]);
   }

   assert((char *)dest == &((char *)dataOut)
        [components * element_size * halfWidth * halfHeight]);

} /* halve1Dimage_ushort() */


static void halveImage_short(GLint components, GLuint width, GLuint height, 
                  const GLshort *datain, GLshort *dataout,
                  GLint element_size, GLint ysize, GLint group_size,
                  GLint myswap_bytes)
{
    int i, j, k;
    int newwidth, newheight;
    GLshort *s;
    const char *t;

    /* handle case where there is only 1 column/row */
    if (width == 1 || height == 1) {
       assert( !(width == 1 && height == 1) ); /* can't be 1x1 */
       halve1Dimage_short(components,width,height,datain,dataout,
                    element_size,ysize,group_size, myswap_bytes);
       return;
    }

    newwidth = width / 2;
    newheight = height / 2;
    s = dataout;
    t = (const char *)datain;

    /* Piece o' cake! */
    if (!myswap_bytes)
    for (i = 0; i < newheight; i++) {
      for (j = 0; j < newwidth; j++) {
          for (k = 0; k < components; k++) {
            s[0] = (*(const GLshort*)t + 
                  *(const GLshort*)(t+group_size) + 
                  *(const GLshort*)(t+ysize) + 
                  *(const GLshort*)(t+ysize+group_size) + 2) / 4;
            s++; t += element_size;
          }
          t += group_size;
      }
      t += ysize;
    }
    else
    for (i = 0; i < newheight; i++) {
        for (j = 0; j < newwidth; j++) {
            for (k = 0; k < components; k++) {
            GLushort b;
            GLint buf;
                b = __GLU_SWAP_2_BYTES(t);
            buf = *(const GLshort*)&b;
                b = __GLU_SWAP_2_BYTES(t+group_size);
            buf += *(const GLshort*)&b;
                b = __GLU_SWAP_2_BYTES(t+ysize);
            buf += *(const GLshort*)&b;
                b = __GLU_SWAP_2_BYTES(t+ysize+group_size);
            buf += *(const GLshort*)&b;
            s[0] = (GLshort)((buf+2)/4);
                s++; t += element_size;
          }
          t += group_size;
        }
        t += ysize;
    }
}

static void halve1Dimage_short(GLint components, GLuint width, GLuint height, 
                        const GLshort *dataIn, GLshort *dataOut, 
                        GLint element_size, GLint ysize, 
                        GLint group_size, GLint myswap_bytes)
{
   GLint halfWidth= width / 2;
   GLint halfHeight= height / 2;
   const char *src= (const char *) dataIn;
   GLshort *dest= dataOut;
   int jj;

   assert(width == 1 || height == 1); /* must be 1D */
   assert(width != height);   /* can't be square */

   if (height == 1) {         /* 1 row */
      assert(width != 1);     /* widthxheight can't be 1x1 */
      halfHeight= 1;

      for (jj= 0; jj< halfWidth; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
#define BOX2 2
          GLshort sshort[BOX2];
          if (myswap_bytes) {
             sshort[0]= __GLU_SWAP_2_BYTES(src);
             sshort[1]= __GLU_SWAP_2_BYTES(src+group_size);
          }
          else {
             sshort[0]= *(const GLshort*)src;
             sshort[1]= *(const GLshort*)(src+group_size);
          }

          *dest= (sshort[0] + sshort[1]) / 2;
          src+= element_size;
          dest++;  
       } 
       src+= group_size;      /* skip to next 2 */
      }
      {
       int padBytes= ysize - (width*group_size); 
       src+= padBytes;  /* for assertion only */
      }
   }
   else if (width == 1) {     /* 1 column */
      int padBytes= ysize - (width * group_size);
      assert(height != 1);    /* widthxheight can't be 1x1 */
      halfWidth= 1; 
      /* one vertical column with possible pad bytes per row */
      /* average two at a time */

      for (jj= 0; jj< halfHeight; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
#define BOX2 2
          GLshort sshort[BOX2];
          if (myswap_bytes) {
             sshort[0]= __GLU_SWAP_2_BYTES(src);
             sshort[1]= __GLU_SWAP_2_BYTES(src+ysize);
          }
          else {
             sshort[0]= *(const GLshort*)src;
             sshort[1]= *(const GLshort*)(src+ysize);
          }
          *dest= (sshort[0] + sshort[1]) / 2;

          src+= element_size;
          dest++;
       }  
       src+= padBytes; /* add pad bytes, if any, to get to end to row */
       src+= ysize;
      }

      assert(src == &((const char *)dataIn)[ysize*height]);
   }

   assert((char *)dest == &((char *)dataOut)
        [components * element_size * halfWidth * halfHeight]);

} /* halve1Dimage_short() */


static void halveImage_uint(GLint components, GLuint width, GLuint height, 
                    const GLuint *datain, GLuint *dataout,
                  GLint element_size, GLint ysize, GLint group_size,
                  GLint myswap_bytes)
{
    int i, j, k;
    int newwidth, newheight;
    GLuint *s;
    const char *t;

    /* handle case where there is only 1 column/row */
    if (width == 1 || height == 1) {
       assert( !(width == 1 && height == 1) ); /* can't be 1x1 */
       halve1Dimage_uint(components,width,height,datain,dataout,
                   element_size,ysize,group_size, myswap_bytes);
       return;
    }

    newwidth = width / 2;
    newheight = height / 2;
    s = dataout;
    t = (const char *)datain;

    /* Piece o' cake! */
    if (!myswap_bytes) 
    for (i = 0; i < newheight; i++) {
      for (j = 0; j < newwidth; j++) {
          for (k = 0; k < components; k++) {
              /* need to cast to double to hold large unsigned ints */
            s[0] = ((double)*(const GLuint*)t + 
                  (double)*(const GLuint*)(t+group_size) + 
                    (double)*(const GLuint*)(t+ysize) + 
                    (double)*(const GLuint*)(t+ysize+group_size))/4 + 0.5;
            s++; t += element_size;

          }
          t += group_size;
      }
      t += ysize;
    }
    else
    for (i = 0; i < newheight; i++) {
        for (j = 0; j < newwidth; j++) {
            for (k = 0; k < components; k++) {
              /* need to cast to double to hold large unsigned ints */
            GLdouble buf;
                buf = (GLdouble)__GLU_SWAP_4_BYTES(t) +
                      (GLdouble)__GLU_SWAP_4_BYTES(t+group_size) +
                      (GLdouble)__GLU_SWAP_4_BYTES(t+ysize) +
                      (GLdouble)__GLU_SWAP_4_BYTES(t+ysize+group_size);
                s[0] = (GLuint)(buf/4 + 0.5);

            s++; t += element_size;
          }
          t += group_size;
        }
        t += ysize;
    }
}

/* */
static void halve1Dimage_uint(GLint components, GLuint width, GLuint height, 
                        const GLuint *dataIn, GLuint *dataOut, 
                        GLint element_size, GLint ysize, 
                        GLint group_size, GLint myswap_bytes)
{
   GLint halfWidth= width / 2;
   GLint halfHeight= height / 2;
   const char *src= (const char *) dataIn;
   GLuint *dest= dataOut;
   int jj;

   assert(width == 1 || height == 1); /* must be 1D */
   assert(width != height);   /* can't be square */

   if (height == 1) {         /* 1 row */
      assert(width != 1);     /* widthxheight can't be 1x1 */
      halfHeight= 1;

      for (jj= 0; jj< halfWidth; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
#define BOX2 2
          GLuint uint[BOX2];
          if (myswap_bytes) {
             uint[0]= __GLU_SWAP_4_BYTES(src);
             uint[1]= __GLU_SWAP_4_BYTES(src+group_size);
          }
          else {
             uint[0]= *(const GLuint*)src;
             uint[1]= *(const GLuint*)(src+group_size);
          }
          *dest= ((double)uint[0]+(double)uint[1])/2.0;   

          src+= element_size;
          dest++;  
       } 
       src+= group_size;      /* skip to next 2 */
      }
      {
       int padBytes= ysize - (width*group_size); 
       src+= padBytes;  /* for assertion only */
      }
   }
   else if (width == 1) {     /* 1 column */
      int padBytes= ysize - (width * group_size);
      assert(height != 1);    /* widthxheight can't be 1x1 */
      halfWidth= 1; 
      /* one vertical column with possible pad bytes per row */
      /* average two at a time */

      for (jj= 0; jj< halfHeight; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
#define BOX2 2
          GLuint uint[BOX2];
          if (myswap_bytes) {
             uint[0]= __GLU_SWAP_4_BYTES(src);
             uint[1]= __GLU_SWAP_4_BYTES(src+ysize);
          }
          else {
             uint[0]= *(const GLuint*)src;
             uint[1]= *(const GLuint*)(src+ysize);
          }
          *dest= ((double)uint[0]+(double)uint[1])/2.0;

          src+= element_size;
          dest++;
       }  
       src+= padBytes; /* add pad bytes, if any, to get to end to row */
       src+= ysize;
      }

      assert(src == &((const char *)dataIn)[ysize*height]);
   }

   assert((char *)dest == &((char *)dataOut)
        [components * element_size * halfWidth * halfHeight]);

} /* halve1Dimage_uint() */

static void halveImage_int(GLint components, GLuint width, GLuint height, 
                    const GLint *datain, GLint *dataout, GLint element_size,
                  GLint ysize, GLint group_size, GLint myswap_bytes)
{
    int i, j, k;
    int newwidth, newheight;
    GLint *s;
    const char *t;

    /* handle case where there is only 1 column/row */
    if (width == 1 || height == 1) {
       assert( !(width == 1 && height == 1) ); /* can't be 1x1 */
       halve1Dimage_int(components,width,height,datain,dataout,
                  element_size,ysize,group_size, myswap_bytes);
       return;
    }

    newwidth = width / 2;
    newheight = height / 2;
    s = dataout;
    t = (const char *)datain;

    /* Piece o' cake! */
    if (!myswap_bytes) 
    for (i = 0; i < newheight; i++) {
      for (j = 0; j < newwidth; j++) {
          for (k = 0; k < components; k++) {
            s[0] = ((float)*(const GLint*)t + 
                  (float)*(const GLint*)(t+group_size) + 
                  (float)*(const GLint*)(t+ysize) + 
                  (float)*(const GLint*)(t+ysize+group_size))/4 + 0.5;
            s++; t += element_size;
          }
          t += group_size;
      }
      t += ysize;
    }
    else 
    for (i = 0; i < newheight; i++) {
        for (j = 0; j < newwidth; j++) {
            for (k = 0; k < components; k++) {
            GLuint b;
                GLfloat buf;
                b = __GLU_SWAP_4_BYTES(t);
                buf = *(GLint*)&b;
                b = __GLU_SWAP_4_BYTES(t+group_size);
                buf += *(GLint*)&b;
                b = __GLU_SWAP_4_BYTES(t+ysize);
                buf += *(GLint*)&b;
                b = __GLU_SWAP_4_BYTES(t+ysize+group_size);
                buf += *(GLint*)&b;
                s[0] = (GLint)(buf/4 + 0.5);

                s++; t += element_size;
          }
          t += group_size;
        }
        t += ysize;
    }
}

/* */
static void halve1Dimage_int(GLint components, GLuint width, GLuint height, 
                       const GLint *dataIn, GLint *dataOut, 
                       GLint element_size, GLint ysize, 
                       GLint group_size, GLint myswap_bytes)
{
   GLint halfWidth= width / 2;
   GLint halfHeight= height / 2;
   const char *src= (const char *) dataIn;
   GLint *dest= dataOut;
   int jj;

   assert(width == 1 || height == 1); /* must be 1D */
   assert(width != height);   /* can't be square */

   if (height == 1) {         /* 1 row */
      assert(width != 1);     /* widthxheight can't be 1x1 */
      halfHeight= 1;

      for (jj= 0; jj< halfWidth; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
#define BOX2 2
          GLuint uint[BOX2];
          if (myswap_bytes) {
             uint[0]= __GLU_SWAP_4_BYTES(src);
             uint[1]= __GLU_SWAP_4_BYTES(src+group_size);
          }
          else {
             uint[0]= *(const GLuint*)src;
             uint[1]= *(const GLuint*)(src+group_size);
          }
          *dest= ((float)uint[0]+(float)uint[1])/2.0;

          src+= element_size;
          dest++;  
       } 
       src+= group_size;      /* skip to next 2 */
      }
      {
       int padBytes= ysize - (width*group_size); 
       src+= padBytes;  /* for assertion only */
      }
   }
   else if (width == 1) {     /* 1 column */
      int padBytes= ysize - (width * group_size);
      assert(height != 1);    /* widthxheight can't be 1x1 */
      halfWidth= 1; 
      /* one vertical column with possible pad bytes per row */
      /* average two at a time */

      for (jj= 0; jj< halfHeight; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
#define BOX2 2
          GLuint uint[BOX2];
          if (myswap_bytes) {
             uint[0]= __GLU_SWAP_4_BYTES(src);
             uint[1]= __GLU_SWAP_4_BYTES(src+ysize);
          }
          else {
             uint[0]= *(const GLuint*)src;
             uint[1]= *(const GLuint*)(src+ysize);
          }
          *dest= ((float)uint[0]+(float)uint[1])/2.0;

          src+= element_size;
          dest++;
       }  
       src+= padBytes; /* add pad bytes, if any, to get to end to row */
       src+= ysize;
      }

      assert(src == &((const char *)dataIn)[ysize*height]);
   }

   assert((char *)dest == &((char *)dataOut)
        [components * element_size * halfWidth * halfHeight]);

} /* halve1Dimage_int() */


static void halveImage_float(GLint components, GLuint width, GLuint height, 
                    const GLfloat *datain, GLfloat *dataout,
                  GLint element_size, GLint ysize, GLint group_size,
                  GLint myswap_bytes)
{
    int i, j, k;
    int newwidth, newheight;
    GLfloat *s;
    const char *t;

    /* handle case where there is only 1 column/row */
    if (width == 1 || height == 1) {
       assert( !(width == 1 && height == 1) ); /* can't be 1x1 */
       halve1Dimage_float(components,width,height,datain,dataout,
                    element_size,ysize,group_size, myswap_bytes);
       return;
    }

    newwidth = width / 2;
    newheight = height / 2;
    s = dataout;
    t = (const char *)datain;

    /* Piece o' cake! */
    if (!myswap_bytes)
    for (i = 0; i < newheight; i++) {
      for (j = 0; j < newwidth; j++) {
          for (k = 0; k < components; k++) {
            s[0] = (*(const GLfloat*)t + 
                  *(const GLfloat*)(t+group_size) + 
                  *(const GLfloat*)(t+ysize) + 
                  *(const GLfloat*)(t+ysize+group_size)) / 4;
            s++; t += element_size;
          }
          t += group_size;
      }
      t += ysize;
    }
    else 
    for (i = 0; i < newheight; i++) {
        for (j = 0; j < newwidth; j++) {
            for (k = 0; k < components; k++) {
            GLuint b;
                b = __GLU_SWAP_4_BYTES(t);
                s[0] = *(GLfloat*)&b;
                b = __GLU_SWAP_4_BYTES(t+group_size);
                s[0] += *(GLfloat*)&b;
                b = __GLU_SWAP_4_BYTES(t+ysize);
                s[0] += *(GLfloat*)&b;
                b = __GLU_SWAP_4_BYTES(t+ysize+group_size);
                s[0] += *(GLfloat*)&b;
            s[0] /= 4;
                s++; t += element_size;
          }
          t += group_size;
        }
        t += ysize;
    }
}

/* */
static void halve1Dimage_float(GLint components, GLuint width, GLuint height, 
                         const GLfloat *dataIn, GLfloat *dataOut, 
                         GLint element_size, GLint ysize, 
                         GLint group_size, GLint myswap_bytes)
{
   GLint halfWidth= width / 2;
   GLint halfHeight= height / 2;
   const char *src= (const char *) dataIn;
   GLfloat *dest= dataOut; 
   int jj;

   assert(width == 1 || height == 1); /* must be 1D */
   assert(width != height);   /* can't be square */

   if (height == 1) {         /* 1 row */
      assert(width != 1);     /* widthxheight can't be 1x1 */
      halfHeight= 1;

      for (jj= 0; jj< halfWidth; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
#define BOX2 2
          GLfloat sfloat[BOX2];
          if (myswap_bytes) {
             sfloat[0]= __GLU_SWAP_4_BYTES(src);
             sfloat[1]= __GLU_SWAP_4_BYTES(src+group_size);
          }
          else {
             sfloat[0]= *(const GLfloat*)src;
             sfloat[1]= *(const GLfloat*)(src+group_size);
          }

          *dest= (sfloat[0] + sfloat[1]) / 2.0;
          src+= element_size;
          dest++;  
       } 
       src+= group_size;      /* skip to next 2 */
      }
      {
       int padBytes= ysize - (width*group_size); 
       src+= padBytes;  /* for assertion only */
      }
   }
   else if (width == 1) {     /* 1 column */
      int padBytes= ysize - (width * group_size);
      assert(height != 1);    /* widthxheight can't be 1x1 */
      halfWidth= 1; 
      /* one vertical column with possible pad bytes per row */
      /* average two at a time */

      for (jj= 0; jj< halfHeight; jj++) {
       int kk;
       for (kk= 0; kk< components; kk++) {
#define BOX2 2
          GLfloat sfloat[BOX2];
          if (myswap_bytes) {
             sfloat[0]= __GLU_SWAP_4_BYTES(src);
             sfloat[1]= __GLU_SWAP_4_BYTES(src+ysize);
          }
          else {
             sfloat[0]= *(const GLfloat*)src;
             sfloat[1]= *(const GLfloat*)(src+ysize);
          }
          *dest= (sfloat[0] + sfloat[1]) / 2.0;

          src+= element_size;
          dest++;
       }  
       src+= padBytes; /* add pad bytes, if any, to get to end to row */
       src+= ysize;           /* skip to odd row */
      }
   }

   assert(src == &((const char *)dataIn)[ysize*height]);
   assert((char *)dest == &((char *)dataOut)
        [components * element_size * halfWidth * halfHeight]);
} /* halve1Dimage_float() */

static void scale_internal(GLint components, GLint widthin, GLint heightin, 
                     const GLushort *datain, 
                     GLint widthout, GLint heightout, 
                     GLushort *dataout)
{
    float x, lowx, highx, convx, halfconvx;
    float y, lowy, highy, convy, halfconvy;
    float xpercent,ypercent;
    float percent;
    /* Max components in a format is 4, so... */
    float totals[4];
    float area;
    int i,j,k,yint,xint,xindex,yindex;
    int temp;

    if (widthin == widthout*2 && heightin == heightout*2) {
      halveImage(components, widthin, heightin, datain, dataout);
      return;
    }
    convy = (float) heightin/heightout;
    convx = (float) widthin/widthout;
    halfconvx = convx/2;
    halfconvy = convy/2;
    for (i = 0; i < heightout; i++) {
      y = convy * (i+0.5);
      if (heightin > heightout) {
          highy = y + halfconvy;
          lowy = y - halfconvy;
      } else {
          highy = y + 0.5;
          lowy = y - 0.5;
      }
      for (j = 0; j < widthout; j++) {
          x = convx * (j+0.5);
          if (widthin > widthout) {
            highx = x + halfconvx;
            lowx = x - halfconvx;
          } else {
            highx = x + 0.5;
            lowx = x - 0.5;
          }

          /*
          ** Ok, now apply box filter to box that goes from (lowx, lowy)
          ** to (highx, highy) on input data into this pixel on output
          ** data.
          */
          totals[0] = totals[1] = totals[2] = totals[3] = 0.0;
          area = 0.0;

          y = lowy;
          yint = floor(y);
          while (y < highy) {
            yindex = (yint + heightin) % heightin;
            if (highy < yint+1) {
                ypercent = highy - y;
            } else {
                ypercent = yint+1 - y;
            }

            x = lowx;
            xint = floor(x);

            while (x < highx) {
                xindex = (xint + widthin) % widthin;
                if (highx < xint+1) {
                  xpercent = highx - x;
                } else {
                  xpercent = xint+1 - x;
                }

                percent = xpercent * ypercent;
                area += percent;
                temp = (xindex + (yindex * widthin)) * components;
                for (k = 0; k < components; k++) {
                  totals[k] += datain[temp + k] * percent;
                }

                xint++;
                x = xint;
            }
            yint++;
            y = yint;
          }

          temp = (j + (i * widthout)) * components;
          for (k = 0; k < components; k++) {
            /* totals[] should be rounded in the case of enlarging an RGB
             * ramp when the type is 332 or 4444
             */
            dataout[temp + k] = (totals[k]+0.5)/area;
          }
      }
    }
}

static void scale_internal_ubyte(GLint components, GLint widthin, 
                     GLint heightin, const GLubyte *datain, 
                     GLint widthout, GLint heightout, 
                     GLubyte *dataout, GLint element_size,
                     GLint ysize, GLint group_size)
{
    float convx;
    float convy;
    float percent;
    /* Max components in a format is 4, so... */
    float totals[4];
    float area;
    int i,j,k,xindex;

    const char *temp, *temp0;
    const char *temp_index;
    int outindex;

    int lowx_int, highx_int, lowy_int, highy_int;
    float x_percent, y_percent;
    float lowx_float, highx_float, lowy_float, highy_float;
    float convy_float, convx_float;
    int convy_int, convx_int;
    int l, m;
    const char *left, *right;

    if (widthin == widthout*2 && heightin == heightout*2) {
      halveImage_ubyte(components, widthin, heightin, 
      (const GLubyte *)datain, (GLubyte *)dataout, 
      element_size, ysize, group_size);
      return;
    }
    convy = (float) heightin/heightout;
    convx = (float) widthin/widthout;
    convy_int = floor(convy);
    convy_float = convy - convy_int;
    convx_int = floor(convx);
    convx_float = convx - convx_int;
   
    area = convx * convy;

    lowy_int = 0;
    lowy_float = 0;
    highy_int = convy_int;
    highy_float = convy_float;

    for (i = 0; i < heightout; i++) {
      lowx_int = 0;
      lowx_float = 0;
      highx_int = convx_int;
      highx_float = convx_float;

      for (j = 0; j < widthout; j++) {

          /*
          ** Ok, now apply box filter to box that goes from (lowx, lowy)
          ** to (highx, highy) on input data into this pixel on output
          ** data.
          */
          totals[0] = totals[1] = totals[2] = totals[3] = 0.0;

          /* calculate the value for pixels in the 1st row */
          xindex = lowx_int*group_size;
          if((highy_int>lowy_int) && (highx_int>lowx_int)) {

            y_percent = 1-lowy_float;
            temp = (const char *)datain + xindex + lowy_int * ysize;
            percent = y_percent * (1-lowx_float);
                  for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                  totals[k] += (GLubyte)(*(temp_index)) * percent;
              }
            left = temp;
            for(l = lowx_int+1; l < highx_int; l++) {
                temp += group_size;
                for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * y_percent;
                }
              }
            temp += group_size;
            right = temp;
            percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * percent;
                }

                /* calculate the value for pixels in the last row */          
            y_percent = highy_float;
            percent = y_percent * (1-lowx_float);
            temp = (const char *)datain + xindex + highy_int * ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * percent;
                }
            for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * y_percent;
                    }
                }
                temp += group_size;
            percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * percent;
                }


                /* calculate the value for pixels in the 1st and last column */
            for(m = lowy_int+1; m < highy_int; m++) {
                left += ysize;
                right += ysize;
                    for (k = 0; k < components; 
                     k++, left += element_size, right += element_size) {
                        totals[k] += (GLubyte)(*(left))*(1-lowx_float)
                        +(GLubyte)(*(right))*highx_float;
                }
            }
          } else if (highy_int > lowy_int) {
            x_percent = highx_float - lowx_float;
            percent = (1-lowy_float)*x_percent;
            temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * percent;
              }
            for(m = lowy_int+1; m < highy_int; m++) {
                temp += ysize;
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * x_percent;
                }
            }
            percent = x_percent * highy_float;
            temp += ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * percent;
                }
          } else if (highx_int > lowx_int) {
            y_percent = highy_float - lowy_float;
            percent = (1-lowx_float)*y_percent;
            temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * percent;
                }
            for (l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * y_percent;
                }
            }
            temp += group_size;
            percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * percent;
            }
          } else {
            percent = (highy_float-lowy_float)*(highx_float-lowx_float);
            temp = (const char *)datain + xindex + lowy_int * ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index)) * percent;
                }
          }



            /* this is for the pixels in the body */
          temp0 = (const char *)datain + xindex + group_size +
             (lowy_int+1)*ysize;
          for (m = lowy_int+1; m < highy_int; m++) {
            temp = temp0;
            for(l = lowx_int+1; l < highx_int; l++) {
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        totals[k] += (GLubyte)(*(temp_index));
                    }
                    temp += group_size;
                }
            temp0 += ysize;
          }

          outindex = (j + (i * widthout)) * components;
          for (k = 0; k < components; k++) {
            dataout[outindex + k] = totals[k]/area;
            /*printf("totals[%d] = %f\n", k, totals[k]);*/
          }
          lowx_int = highx_int;
          lowx_float = highx_float;
          highx_int += convx_int;
          highx_float += convx_float;
          if(highx_float > 1) {
            highx_float -= 1.0;
            highx_int++;
          }
      }
      lowy_int = highy_int;
      lowy_float = highy_float;
      highy_int += convy_int;
      highy_float += convy_float;
      if(highy_float > 1) {
          highy_float -= 1.0;
          highy_int++;
      }
    }
}

static void scale_internal_byte(GLint components, GLint widthin, 
                     GLint heightin, const GLbyte *datain, 
                     GLint widthout, GLint heightout, 
                     GLbyte *dataout, GLint element_size,
                     GLint ysize, GLint group_size)
{
    float convx;
    float convy;
    float percent;
    /* Max components in a format is 4, so... */
    float totals[4];
    float area;
    int i,j,k,xindex;

    const char *temp, *temp0;
    const char *temp_index;
    int outindex;

    int lowx_int, highx_int, lowy_int, highy_int;
    float x_percent, y_percent;
    float lowx_float, highx_float, lowy_float, highy_float;
    float convy_float, convx_float;
    int convy_int, convx_int;
    int l, m;
    const char *left, *right;

    if (widthin == widthout*2 && heightin == heightout*2) {
      halveImage_byte(components, widthin, heightin, 
      (const GLbyte *)datain, (GLbyte *)dataout, 
      element_size, ysize, group_size);
      return;
    }
    convy = (float) heightin/heightout;
    convx = (float) widthin/widthout;
    convy_int = floor(convy);
    convy_float = convy - convy_int;
    convx_int = floor(convx);
    convx_float = convx - convx_int;
   
    area = convx * convy;

    lowy_int = 0;
    lowy_float = 0;
    highy_int = convy_int;
    highy_float = convy_float;

    for (i = 0; i < heightout; i++) {
      lowx_int = 0;
      lowx_float = 0;
      highx_int = convx_int;
      highx_float = convx_float;

      for (j = 0; j < widthout; j++) {

          /*
          ** Ok, now apply box filter to box that goes from (lowx, lowy)
          ** to (highx, highy) on input data into this pixel on output
          ** data.
          */
          totals[0] = totals[1] = totals[2] = totals[3] = 0.0;

            /* calculate the value for pixels in the 1st row */
          xindex = lowx_int*group_size;
          if((highy_int>lowy_int) && (highx_int>lowx_int)) {

            y_percent = 1-lowy_float;
            temp = (const char *)datain + xindex + lowy_int * ysize;
            percent = y_percent * (1-lowx_float);
                  for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                  totals[k] += (GLbyte)(*(temp_index)) * percent;
              }
            left = temp;
            for(l = lowx_int+1; l < highx_int; l++) {
                temp += group_size;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * y_percent;
                }
              }
            temp += group_size;
            right = temp;
            percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * percent;
                }

                /* calculate the value for pixels in the last row */          
            y_percent = highy_float;
            percent = y_percent * (1-lowx_float);
            temp = (const char *)datain + xindex + highy_int * ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * percent;
                }
            for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * y_percent;
                    }
                }
                temp += group_size;
            percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * percent;
                }


                /* calculate the value for pixels in the 1st and last column */
            for(m = lowy_int+1; m < highy_int; m++) {
                left += ysize;
                right += ysize;
                    for (k = 0; k < components; 
                     k++, left += element_size, right += element_size) {
                        totals[k] += (GLbyte)(*(left))*(1-lowx_float)
                        +(GLbyte)(*(right))*highx_float;
                }
            }
          } else if (highy_int > lowy_int) {
            x_percent = highx_float - lowx_float;
            percent = (1-lowy_float)*x_percent;
            temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * percent;
              }
            for(m = lowy_int+1; m < highy_int; m++) {
                temp += ysize;
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * x_percent;
                }
            }
            percent = x_percent * highy_float;
            temp += ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * percent;
                }
          } else if (highx_int > lowx_int) {
            y_percent = highy_float - lowy_float;
            percent = (1-lowx_float)*y_percent;
            temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * percent;
                }
            for (l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * y_percent;
                }
            }
            temp += group_size;
            percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * percent;
            }
          } else {
            percent = (highy_float-lowy_float)*(highx_float-lowx_float);
            temp = (const char *)datain + xindex + lowy_int * ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index)) * percent;
                }
          }



            /* this is for the pixels in the body */
          temp0 = (const char *)datain + xindex + group_size + 
            (lowy_int+1)*ysize;
          for (m = lowy_int+1; m < highy_int; m++) {
            temp = temp0;
            for(l = lowx_int+1; l < highx_int; l++) {
                    for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                        totals[k] += (GLbyte)(*(temp_index));
                    }
                    temp += group_size;
                }
            temp0 += ysize;
          }

          outindex = (j + (i * widthout)) * components;
          for (k = 0; k < components; k++) {
            dataout[outindex + k] = totals[k]/area;
            /*printf("totals[%d] = %f\n", k, totals[k]);*/
          }
          lowx_int = highx_int;
          lowx_float = highx_float;
          highx_int += convx_int;
          highx_float += convx_float;
          if(highx_float > 1) {
            highx_float -= 1.0;
            highx_int++;
          }
      }
      lowy_int = highy_int;
      lowy_float = highy_float;
      highy_int += convy_int;
      highy_float += convy_float;
      if(highy_float > 1) {
          highy_float -= 1.0;
          highy_int++;
      }
    }
}

static void scale_internal_ushort(GLint components, GLint widthin, 
                     GLint heightin, const GLushort *datain, 
                     GLint widthout, GLint heightout, 
                     GLushort *dataout, GLint element_size,
                     GLint ysize, GLint group_size,
                     GLint myswap_bytes)
{
    float convx;
    float convy;
    float percent;
    /* Max components in a format is 4, so... */
    float totals[4];
    float area;
    int i,j,k,xindex;

    const char *temp, *temp0;
    const char *temp_index;
    int outindex;

    int lowx_int, highx_int, lowy_int, highy_int;
    float x_percent, y_percent;
    float lowx_float, highx_float, lowy_float, highy_float;
    float convy_float, convx_float;
    int convy_int, convx_int;
    int l, m;
    const char *left, *right;

    if (widthin == widthout*2 && heightin == heightout*2) {
      halveImage_ushort(components, widthin, heightin, 
      (const GLushort *)datain, (GLushort *)dataout, 
      element_size, ysize, group_size, myswap_bytes);
      return;
    }
    convy = (float) heightin/heightout;
    convx = (float) widthin/widthout;
    convy_int = floor(convy);
    convy_float = convy - convy_int;
    convx_int = floor(convx);
    convx_float = convx - convx_int;
   
    area = convx * convy;

    lowy_int = 0;
    lowy_float = 0;
    highy_int = convy_int;
    highy_float = convy_float;

    for (i = 0; i < heightout; i++) {
      lowx_int = 0;
      lowx_float = 0;
      highx_int = convx_int;
      highx_float = convx_float;

      for (j = 0; j < widthout; j++) {
          /*
          ** Ok, now apply box filter to box that goes from (lowx, lowy)
          ** to (highx, highy) on input data into this pixel on output
          ** data.
          */
          totals[0] = totals[1] = totals[2] = totals[3] = 0.0;

          /* calculate the value for pixels in the 1st row */
          xindex = lowx_int*group_size;
          if((highy_int>lowy_int) && (highx_int>lowx_int)) {

            y_percent = 1-lowy_float;
            temp = (const char *)datain + xindex + lowy_int * ysize;
            percent = y_percent * (1-lowx_float);
                  for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                if (myswap_bytes) {
                  totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                } else {
                    totals[k] += *(const GLushort*)temp_index * percent;
                }
              }
            left = temp;
            for(l = lowx_int+1; l < highx_int; l++) {
                temp += group_size;
                for (k = 0, temp_index = temp; k < components; 
                   k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                                 __GLU_SWAP_2_BYTES(temp_index) * y_percent;
                        } else {
                            totals[k] += *(const GLushort*)temp_index * y_percent;
                        }
                }
              }
            temp += group_size;
            right = temp;
            percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }

            /* calculate the value for pixels in the last row */        
            y_percent = highy_float;
            percent = y_percent * (1-lowx_float);
            temp = (const char *)datain + xindex + highy_int * ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }
            for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components; 
                   k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                                 __GLU_SWAP_2_BYTES(temp_index) * y_percent;
                        } else {
                            totals[k] += *(const GLushort*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
            percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }

            /* calculate the value for pixels in the 1st and last column */
            for(m = lowy_int+1; m < highy_int; m++) {
                left += ysize;
                right += ysize;
                    for (k = 0; k < components; 
                     k++, left += element_size, right += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                          __GLU_SWAP_2_BYTES(left) * (1-lowx_float) +
                          __GLU_SWAP_2_BYTES(right) * highx_float;
                        } else {
                            totals[k] += *(const GLushort*)left * (1-lowx_float)
                                       + *(const GLushort*)right * highx_float;
                        }
                }
            }
          } else if (highy_int > lowy_int) {
            x_percent = highx_float - lowx_float;
            percent = (1-lowy_float)*x_percent;
            temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
              }
            for(m = lowy_int+1; m < highy_int; m++) {
                temp += ysize;
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                        __GLU_SWAP_2_BYTES(temp_index) * x_percent;
                        } else {
                            totals[k] += *(const GLushort*)temp_index * x_percent;
                        }
                }
            }
            percent = x_percent * highy_float;
            temp += ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }
          } else if (highx_int > lowx_int) {
            y_percent = highy_float - lowy_float;
            percent = (1-lowx_float)*y_percent;
            temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }
            for (l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                          __GLU_SWAP_2_BYTES(temp_index) * y_percent;
                        } else {
                            totals[k] += *(const GLushort*)temp_index * y_percent;
                        }
                }
            }
            temp += group_size;
            percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
            }
          } else {
            percent = (highy_float-lowy_float)*(highx_float-lowx_float);
            temp = (const char *)datain + xindex + lowy_int * ysize;
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }
          }

          /* this is for the pixels in the body */
          temp0 = (const char *)datain + xindex + group_size +
             (lowy_int+1)*ysize;
          for (m = lowy_int+1; m < highy_int; m++) {
            temp = temp0;
            for(l = lowx_int+1; l < highx_int; l++) {
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += __GLU_SWAP_2_BYTES(temp_index);
                        } else {
                            totals[k] += *(const GLushort*)temp_index;
                        }
                    }
                    temp += group_size;
                }
            temp0 += ysize;
          }

          outindex = (j + (i * widthout)) * components;
          for (k = 0; k < components; k++) {
            dataout[outindex + k] = totals[k]/area;
            /*printf("totals[%d] = %f\n", k, totals[k]);*/
          }
          lowx_int = highx_int;
          lowx_float = highx_float;
          highx_int += convx_int;
          highx_float += convx_float;
          if(highx_float > 1) {
            highx_float -= 1.0;
            highx_int++;
          }
      }
      lowy_int = highy_int;
      lowy_float = highy_float;
      highy_int += convy_int;
      highy_float += convy_float;
      if(highy_float > 1) {
          highy_float -= 1.0;
          highy_int++;
      }
    }
}

static void scale_internal_short(GLint components, GLint widthin,
                           GLint heightin, const GLshort *datain,
                           GLint widthout, GLint heightout,
                           GLshort *dataout, GLint element_size,
                           GLint ysize, GLint group_size,
                           GLint myswap_bytes)
{
    float convx;
    float convy;
    float percent;
    /* Max components in a format is 4, so... */
    float totals[4];
    float area;
    int i,j,k,xindex;

    const char *temp, *temp0;
    const char *temp_index;
    int outindex;

    int lowx_int, highx_int, lowy_int, highy_int;
    float x_percent, y_percent;
    float lowx_float, highx_float, lowy_float, highy_float;
    float convy_float, convx_float;
    int convy_int, convx_int;
    int l, m;
    const char *left, *right;

    GLushort swapbuf;   /* unsigned buffer */

    if (widthin == widthout*2 && heightin == heightout*2) {
        halveImage_short(components, widthin, heightin,
        (const GLshort *)datain, (GLshort *)dataout,
        element_size, ysize, group_size, myswap_bytes);
        return;
    }
    convy = (float) heightin/heightout;
    convx = (float) widthin/widthout;
    convy_int = floor(convy);
    convy_float = convy - convy_int;
    convx_int = floor(convx);
    convx_float = convx - convx_int;

    area = convx * convy;

    lowy_int = 0;
    lowy_float = 0;
    highy_int = convy_int;
    highy_float = convy_float;

    for (i = 0; i < heightout; i++) {
        lowx_int = 0;
        lowx_float = 0;
        highx_int = convx_int;
        highx_float = convx_float;

        for (j = 0; j < widthout; j++) {
            /*
            ** Ok, now apply box filter to box that goes from (lowx, lowy)
            ** to (highx, highy) on input data into this pixel on output
            ** data.
            */
            totals[0] = totals[1] = totals[2] = totals[3] = 0.0;

            /* calculate the value for pixels in the 1st row */
            xindex = lowx_int*group_size;
            if((highy_int>lowy_int) && (highx_int>lowx_int)) {

                y_percent = 1-lowy_float;
                temp = (const char *)datain + xindex + lowy_int * ysize;
                percent = y_percent * (1-lowx_float);
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                        totals[k] += *(const GLshort*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLshort*)temp_index * percent;
                    }
                }
                left = temp;
                for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                            totals[k] += *(const GLshort*)&swapbuf * y_percent;
                        } else {
                            totals[k] += *(const GLshort*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                right = temp;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                        totals[k] += *(const GLshort*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLshort*)temp_index * percent;
                    }
                }

                /* calculate the value for pixels in the last row */
                y_percent = highy_float;
                percent = y_percent * (1-lowx_float);
                temp = (const char *)datain + xindex + highy_int * ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                        totals[k] += *(const GLshort*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLshort*)temp_index * percent;
                    }
                }
                for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                            totals[k] += *(const GLshort*)&swapbuf * y_percent;
                        } else {
                            totals[k] += *(const GLshort*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                        totals[k] += *(const GLshort*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLshort*)temp_index * percent;
                    }
                }

                /* calculate the value for pixels in the 1st and last column */
                for(m = lowy_int+1; m < highy_int; m++) {
                    left += ysize;
                    right += ysize;
                    for (k = 0; k < components;
                         k++, left += element_size, right += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_2_BYTES(left);
                            totals[k] += *(const GLshort*)&swapbuf * (1-lowx_float);
                      swapbuf = __GLU_SWAP_2_BYTES(right);
                      totals[k] += *(const GLshort*)&swapbuf * highx_float;
                        } else {
                            totals[k] += *(const GLshort*)left * (1-lowx_float)
                                       + *(const GLshort*)right * highx_float;
                        }
                    }
                }
            } else if (highy_int > lowy_int) {
                x_percent = highx_float - lowx_float;
                percent = (1-lowy_float)*x_percent;
                temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                        totals[k] += *(const GLshort*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLshort*)temp_index * percent;
                    }
                }
                for(m = lowy_int+1; m < highy_int; m++) {
                    temp += ysize;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                            totals[k] += *(const GLshort*)&swapbuf * x_percent;
                        } else {
                            totals[k] += *(const GLshort*)temp_index * x_percent;
                        }
                    }
                }
                percent = x_percent * highy_float;
                temp += ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                        totals[k] += *(const GLshort*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLshort*)temp_index * percent;
                    }
                }
            } else if (highx_int > lowx_int) {
                y_percent = highy_float - lowy_float;
                percent = (1-lowx_float)*y_percent;
   
             temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                        totals[k] += *(const GLshort*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLshort*)temp_index * percent;
                    }
                }
                for (l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                            totals[k] += *(const GLshort*)&swapbuf * y_percent;
                        } else {
                            totals[k] += *(const GLshort*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                        totals[k] += *(const GLshort*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLshort*)temp_index * percent;
                    }
                }
            } else {
                percent = (highy_float-lowy_float)*(highx_float-lowx_float);
                temp = (const char *)datain + xindex + lowy_int * ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                        totals[k] += *(const GLshort*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLshort*)temp_index * percent;
                    }
                }
            }

            /* this is for the pixels in the body */
            temp0 = (const char *)datain + xindex + group_size +
             (lowy_int+1)*ysize;
            for (m = lowy_int+1; m < highy_int; m++) {
                temp = temp0;
                for(l = lowx_int+1; l < highx_int; l++) {
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_2_BYTES(temp_index);
                            totals[k] += *(const GLshort*)&swapbuf; 
                        } else {
                            totals[k] += *(const GLshort*)temp_index;
                        }
                    }
                    temp += group_size;
                }
                temp0 += ysize;
            }

            outindex = (j + (i * widthout)) * components;
            for (k = 0; k < components; k++) {
                dataout[outindex + k] = totals[k]/area;
                /*printf("totals[%d] = %f\n", k, totals[k]);*/
            }
            lowx_int = highx_int;
            lowx_float = highx_float;
            highx_int += convx_int;
            highx_float += convx_float;
            if(highx_float > 1) {
                highx_float -= 1.0;
                highx_int++;
            }
        }
        lowy_int = highy_int;
        lowy_float = highy_float;
        highy_int += convy_int;
        highy_float += convy_float;
        if(highy_float > 1) {
            highy_float -= 1.0;
            highy_int++;
        }
    }
}

static void scale_internal_uint(GLint components, GLint widthin,
                           GLint heightin, const GLuint *datain,
                           GLint widthout, GLint heightout,
                           GLuint *dataout, GLint element_size,
                           GLint ysize, GLint group_size,
                           GLint myswap_bytes)
{
    float convx;
    float convy;
    float percent;
    /* Max components in a format is 4, so... */
    float totals[4];
    float area;
    int i,j,k,xindex;

    const char *temp, *temp0;
    const char *temp_index;
    int outindex;

    int lowx_int, highx_int, lowy_int, highy_int;
    float x_percent, y_percent;
    float lowx_float, highx_float, lowy_float, highy_float;
    float convy_float, convx_float;
    int convy_int, convx_int;
    int l, m;
    const char *left, *right;

    if (widthin == widthout*2 && heightin == heightout*2) {
        halveImage_uint(components, widthin, heightin,
        (const GLuint *)datain, (GLuint *)dataout,
        element_size, ysize, group_size, myswap_bytes);
        return;
    }
    convy = (float) heightin/heightout;
    convx = (float) widthin/widthout;
    convy_int = floor(convy);
    convy_float = convy - convy_int;
    convx_int = floor(convx);
    convx_float = convx - convx_int;

    area = convx * convy;

    lowy_int = 0;
    lowy_float = 0;
    highy_int = convy_int;
    highy_float = convy_float;

    for (i = 0; i < heightout; i++) {
        lowx_int = 0;
        lowx_float = 0;
        highx_int = convx_int;
        highx_float = convx_float;

        for (j = 0; j < widthout; j++) {
            /*
            ** Ok, now apply box filter to box that goes from (lowx, lowy)
            ** to (highx, highy) on input data into this pixel on output
            ** data.
            */
            totals[0] = totals[1] = totals[2] = totals[3] = 0.0;

            /* calculate the value for pixels in the 1st row */
            xindex = lowx_int*group_size;
            if((highy_int>lowy_int) && (highx_int>lowx_int)) {

                y_percent = 1-lowy_float;
                temp = (const char *)datain + xindex + lowy_int * ysize;
                percent = y_percent * (1-lowx_float);
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_4_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLuint*)temp_index * percent;
                    }
                }
                left = temp;
                for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                                 __GLU_SWAP_4_BYTES(temp_index) * y_percent;
                        } else {
                            totals[k] += *(const GLuint*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                right = temp;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_4_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLuint*)temp_index * percent;
                    }
                }

                /* calculate the value for pixels in the last row */
                y_percent = highy_float;
                percent = y_percent * (1-lowx_float);
                temp = (const char *)datain + xindex + highy_int * ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_4_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLuint*)temp_index * percent;
                    }
                }
                for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                                 __GLU_SWAP_4_BYTES(temp_index) * y_percent;
                        } else {
                            totals[k] += *(const GLuint*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_4_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLuint*)temp_index * percent;
                    }
                }

                /* calculate the value for pixels in the 1st and last column */
                for(m = lowy_int+1; m < highy_int; m++) {
                    left += ysize;
                    right += ysize;
                    for (k = 0; k < components;
                         k++, left += element_size, right += element_size) {
                        if (myswap_bytes) {
                            totals[k] +=
                                __GLU_SWAP_4_BYTES(left) * (1-lowx_float)
                              + __GLU_SWAP_4_BYTES(right) * highx_float;
                        } else {
                            totals[k] += *(const GLuint*)left * (1-lowx_float)
                                       + *(const GLuint*)right * highx_float;
                        }
                    }
                }
            } else if (highy_int > lowy_int) {
                x_percent = highx_float - lowx_float;
                percent = (1-lowy_float)*x_percent;
                temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_4_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLuint*)temp_index * percent;
                    }
                }
                for(m = lowy_int+1; m < highy_int; m++) {
                    temp += ysize;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                                 __GLU_SWAP_4_BYTES(temp_index) * x_percent;
                        } else {
                            totals[k] += *(const GLuint*)temp_index * x_percent;
                        }
                    }
                }
                percent = x_percent * highy_float;
                temp += ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_4_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLuint*)temp_index * percent;
                    }
                }
            } else if (highx_int > lowx_int) {
                y_percent = highy_float - lowy_float;
                percent = (1-lowx_float)*y_percent;
   
             temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_4_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLuint*)temp_index * percent;
                    }
                }
                for (l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                                 __GLU_SWAP_4_BYTES(temp_index) * y_percent;
                        } else {
                            totals[k] += *(const GLuint*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_4_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLuint*)temp_index * percent;
                    }
                }
            } else {
                percent = (highy_float-lowy_float)*(highx_float-lowx_float);
                temp = (const char *)datain + xindex + lowy_int * ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_4_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLuint*)temp_index * percent;
                    }
                }
            }

            /* this is for the pixels in the body */
            temp0 = (const char *)datain + xindex + group_size +
             (lowy_int+1)*ysize;
            for (m = lowy_int+1; m < highy_int; m++) {
                temp = temp0;
                for(l = lowx_int+1; l < highx_int; l++) {
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += __GLU_SWAP_4_BYTES(temp_index);
                        } else {
                            totals[k] += *(const GLuint*)temp_index;
                        }
                    }
                    temp += group_size;
                }
                temp0 += ysize;
            }

            outindex = (j + (i * widthout)) * components;
            for (k = 0; k < components; k++) {
              /* clamp at UINT_MAX */
              float value= totals[k]/area;
            if (value >= (float) UINT_MAX) {    /* need '=' */
              dataout[outindex + k] = UINT_MAX;
            }
                else dataout[outindex + k] = value;
          }
            lowx_int = highx_int;
            lowx_float = highx_float;
            highx_int += convx_int;
            highx_float += convx_float;
            if(highx_float > 1) {
                highx_float -= 1.0;
                highx_int++;
            }
        }
        lowy_int = highy_int;
        lowy_float = highy_float;
        highy_int += convy_int;
        highy_float += convy_float;
        if(highy_float > 1) {
            highy_float -= 1.0;
            highy_int++;
        }
    }
}



static void scale_internal_int(GLint components, GLint widthin,
                           GLint heightin, const GLint *datain,
                           GLint widthout, GLint heightout,
                           GLint *dataout, GLint element_size,
                           GLint ysize, GLint group_size,
                           GLint myswap_bytes)
{
    float convx;
    float convy;
    float percent;
    /* Max components in a format is 4, so... */
    float totals[4];
    float area;
    int i,j,k,xindex;

    const char *temp, *temp0;
    const char *temp_index;
    int outindex;

    int lowx_int, highx_int, lowy_int, highy_int;
    float x_percent, y_percent;
    float lowx_float, highx_float, lowy_float, highy_float;
    float convy_float, convx_float;
    int convy_int, convx_int;
    int l, m;
    const char *left, *right;

    GLuint swapbuf;     /* unsigned buffer */

    if (widthin == widthout*2 && heightin == heightout*2) {
        halveImage_int(components, widthin, heightin,
        (const GLint *)datain, (GLint *)dataout,
        element_size, ysize, group_size, myswap_bytes);
        return;
    }
    convy = (float) heightin/heightout;
    convx = (float) widthin/widthout;
    convy_int = floor(convy);
    convy_float = convy - convy_int;
    convx_int = floor(convx);
    convx_float = convx - convx_int;

    area = convx * convy;

    lowy_int = 0;
    lowy_float = 0;
    highy_int = convy_int;
    highy_float = convy_float;

    for (i = 0; i < heightout; i++) {
        lowx_int = 0;
        lowx_float = 0;
        highx_int = convx_int;
        highx_float = convx_float;

        for (j = 0; j < widthout; j++) {
            /*
            ** Ok, now apply box filter to box that goes from (lowx, lowy)
            ** to (highx, highy) on input data into this pixel on output
            ** data.
            */
            totals[0] = totals[1] = totals[2] = totals[3] = 0.0;

            /* calculate the value for pixels in the 1st row */
            xindex = lowx_int*group_size;
            if((highy_int>lowy_int) && (highx_int>lowx_int)) {

                y_percent = 1-lowy_float;
                temp = (const char *)datain + xindex + lowy_int * ysize;
                percent = y_percent * (1-lowx_float);
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLint*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLint*)temp_index * percent;
                    }
                }
                left = temp;
                for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                            totals[k] += *(const GLint*)&swapbuf * y_percent;
                        } else {
                            totals[k] += *(const GLint*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                right = temp;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLint*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLint*)temp_index * percent;
                    }
                }

                /* calculate the value for pixels in the last row */
                y_percent = highy_float;
                percent = y_percent * (1-lowx_float);
                temp = (const char *)datain + xindex + highy_int * ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLint*)&swapbuf  * percent;
                    } else {
                        totals[k] += *(const GLint*)temp_index * percent;
                    }
                }
                for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                            totals[k] += *(const GLint*)&swapbuf * y_percent;
                        } else {
                            totals[k] += *(const GLint*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLint*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLint*)temp_index * percent;
                    }
                }

                /* calculate the value for pixels in the 1st and last column */
                for(m = lowy_int+1; m < highy_int; m++) {
                    left += ysize;
                    right += ysize;
                    for (k = 0; k < components;
                         k++, left += element_size, right += element_size) {
                        if (myswap_bytes) {
                            swapbuf = __GLU_SWAP_4_BYTES(left);
                            totals[k] += *(const GLint*)&swapbuf * (1-lowx_float);
                            swapbuf = __GLU_SWAP_4_BYTES(right);
                            totals[k] += *(const GLint*)&swapbuf * highx_float;
                        } else {
                            totals[k] += *(const GLint*)left * (1-lowx_float)
                                       + *(const GLint*)right * highx_float;
                        }
                    }
                }
            } else if (highy_int > lowy_int) {
                x_percent = highx_float - lowx_float;
                percent = (1-lowy_float)*x_percent;
                temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLint*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLint*)temp_index * percent;
                    }
                }
                for(m = lowy_int+1; m < highy_int; m++) {
                    temp += ysize;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                            totals[k] += *(const GLint*)&swapbuf * x_percent;
                        } else {
                            totals[k] += *(const GLint*)temp_index * x_percent;
                        }
                    }
                }
                percent = x_percent * highy_float;
                temp += ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLint*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLint*)temp_index * percent;
                    }
                }
            } else if (highx_int > lowx_int) {
                y_percent = highy_float - lowy_float;
                percent = (1-lowx_float)*y_percent;
   
                 temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLint*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLint*)temp_index * percent;
                    }
                }
                for (l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                            totals[k] += *(const GLint*)&swapbuf * y_percent;
                        } else {
                            totals[k] += *(const GLint*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLint*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLint*)temp_index * percent;
                    }
                }
            } else {
                percent = (highy_float-lowy_float)*(highx_float-lowx_float);
                temp = (const char *)datain + xindex + lowy_int * ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLint*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLint*)temp_index * percent;
                    }
                }
            }

            /* this is for the pixels in the body */
            temp0 = (const char *)datain + xindex + group_size +
             (lowy_int+1)*ysize;
            for (m = lowy_int+1; m < highy_int; m++) {
                temp = temp0;
                for(l = lowx_int+1; l < highx_int; l++) {
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                            totals[k] += *(const GLint*)&swapbuf;
                        } else {
                            totals[k] += *(const GLint*)temp_index;
                        }
                    }
                    temp += group_size;
                }
                temp0 += ysize;
            }

            outindex = (j + (i * widthout)) * components;
            for (k = 0; k < components; k++) {
                dataout[outindex + k] = totals[k]/area;
                /*printf("totals[%d] = %f\n", k, totals[k]);*/
            }
            lowx_int = highx_int;
            lowx_float = highx_float;
            highx_int += convx_int;
            highx_float += convx_float;
            if(highx_float > 1) {
                highx_float -= 1.0;
                highx_int++;
            }
        }
        lowy_int = highy_int;
        lowy_float = highy_float;
        highy_int += convy_int;
        highy_float += convy_float;
        if(highy_float > 1) {
            highy_float -= 1.0;
            highy_int++;
        }
    }
}



static void scale_internal_float(GLint components, GLint widthin,
                           GLint heightin, const GLfloat *datain,
                           GLint widthout, GLint heightout,
                           GLfloat *dataout, GLint element_size,
                           GLint ysize, GLint group_size,
                           GLint myswap_bytes)
{
    float convx;
    float convy;
    float percent;
    /* Max components in a format is 4, so... */
    float totals[4];
    float area;
    int i,j,k,xindex;

    const char *temp, *temp0;
    const char *temp_index;
    int outindex;

    int lowx_int, highx_int, lowy_int, highy_int;
    float x_percent, y_percent;
    float lowx_float, highx_float, lowy_float, highy_float;
    float convy_float, convx_float;
    int convy_int, convx_int;
    int l, m;
    const char *left, *right;

    GLuint swapbuf;     /* unsigned buffer */

    if (widthin == widthout*2 && heightin == heightout*2) {
        halveImage_float(components, widthin, heightin,
        (const GLfloat *)datain, (GLfloat *)dataout,
        element_size, ysize, group_size, myswap_bytes);
        return;
    }
    convy = (float) heightin/heightout;
    convx = (float) widthin/widthout;
    convy_int = floor(convy);
    convy_float = convy - convy_int;
    convx_int = floor(convx);
    convx_float = convx - convx_int;

    area = convx * convy;

    lowy_int = 0;
    lowy_float = 0;
    highy_int = convy_int;
    highy_float = convy_float;

    for (i = 0; i < heightout; i++) {
        lowx_int = 0;
        lowx_float = 0;
        highx_int = convx_int;
        highx_float = convx_float;

        for (j = 0; j < widthout; j++) {
            /*
            ** Ok, now apply box filter to box that goes from (lowx, lowy)
            ** to (highx, highy) on input data into this pixel on output
            ** data.
            */
            totals[0] = totals[1] = totals[2] = totals[3] = 0.0;

            /* calculate the value for pixels in the 1st row */
            xindex = lowx_int*group_size;
            if((highy_int>lowy_int) && (highx_int>lowx_int)) {

                y_percent = 1-lowy_float;
                temp = (const char *)datain + xindex + lowy_int * ysize;
                percent = y_percent * (1-lowx_float);
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLfloat*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLfloat*)temp_index * percent;
                    }
                }
                left = temp;
                for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                            totals[k] += *(const GLfloat*)&swapbuf * y_percent;
                        } else {
                            totals[k] += *(const GLfloat*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                right = temp;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLfloat*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLfloat*)temp_index * percent;
                    }
                }

                /* calculate the value for pixels in the last row */
                y_percent = highy_float;
                percent = y_percent * (1-lowx_float);
                temp = (const char *)datain + xindex + highy_int * ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLfloat*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLfloat*)temp_index * percent;
                    }
                }
                for(l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                            totals[k] += *(const GLfloat*)&swapbuf * y_percent;
                        } else {
                            totals[k] += *(const GLfloat*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLfloat*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLfloat*)temp_index * percent;
                    }
                }

                /* calculate the value for pixels in the 1st and last column */
                for(m = lowy_int+1; m < highy_int; m++) {
                    left += ysize;
                    right += ysize;
                    for (k = 0; k < components;
                         k++, left += element_size, right += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_4_BYTES(left);
                            totals[k] += *(const GLfloat*)&swapbuf * (1-lowx_float);
                            swapbuf = __GLU_SWAP_4_BYTES(right);
                            totals[k] += *(const GLfloat*)&swapbuf * highx_float;
                        } else {
                            totals[k] += *(const GLfloat*)left * (1-lowx_float)
                                       + *(const GLfloat*)right * highx_float;
                        }
                    }
                }
            } else if (highy_int > lowy_int) {
                x_percent = highx_float - lowx_float;
                percent = (1-lowy_float)*x_percent;
                temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLfloat*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLfloat*)temp_index * percent;
                    }
                }
                for(m = lowy_int+1; m < highy_int; m++) {
                    temp += ysize;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                            totals[k] += *(const GLfloat*)&swapbuf * x_percent;
                        } else {
                            totals[k] += *(const GLfloat*)temp_index * x_percent;
                        }
                    }
                }
                percent = x_percent * highy_float;
                temp += ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLfloat*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLfloat*)temp_index * percent;
                    }
                }
            } else if (highx_int > lowx_int) {
                y_percent = highy_float - lowy_float;
                percent = (1-lowx_float)*y_percent;
   
             temp = (const char *)datain + xindex + lowy_int*ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLfloat*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLfloat*)temp_index * percent;
                    }
                }
                for (l = lowx_int+1; l < highx_int; l++) {
                    temp += group_size;
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                            totals[k] += *(const GLfloat*)&swapbuf * y_percent;
                        } else {
                            totals[k] += *(const GLfloat*)temp_index * y_percent;
                        }
                    }
                }
                temp += group_size;
                percent = y_percent * highx_float;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLfloat*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLfloat*)temp_index * percent;
                    }
                }
            } else {
                percent = (highy_float-lowy_float)*(highx_float-lowx_float);
                temp = (const char *)datain + xindex + lowy_int * ysize;
                for (k = 0, temp_index = temp; k < components;
                     k++, temp_index += element_size) {
                    if (myswap_bytes) {
                  swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                        totals[k] += *(const GLfloat*)&swapbuf * percent;
                    } else {
                        totals[k] += *(const GLfloat*)temp_index * percent;
                    }
                }
            }

            /* this is for the pixels in the body */
            temp0 = (const char *)datain + xindex + group_size +
             (lowy_int+1)*ysize;
            for (m = lowy_int+1; m < highy_int; m++) {
                temp = temp0;
                for(l = lowx_int+1; l < highx_int; l++) {
                    for (k = 0, temp_index = temp; k < components;
                         k++, temp_index += element_size) {
                        if (myswap_bytes) {
                      swapbuf = __GLU_SWAP_4_BYTES(temp_index);
                            totals[k] += *(const GLfloat*)&swapbuf;
                        } else {
                            totals[k] += *(const GLfloat*)temp_index;
                        }
                    }
                    temp += group_size;
                }
                temp0 += ysize;
            }

            outindex = (j + (i * widthout)) * components;
            for (k = 0; k < components; k++) {
                dataout[outindex + k] = totals[k]/area;
                /*printf("totals[%d] = %f\n", k, totals[k]);*/
            }
            lowx_int = highx_int;
            lowx_float = highx_float;
            highx_int += convx_int;
            highx_float += convx_float;
            if(highx_float > 1) {
                highx_float -= 1.0;
                highx_int++;
            }
        }
        lowy_int = highy_int;
        lowy_float = highy_float;
        highy_int += convy_int;
        highy_float += convy_float;
        if(highy_float > 1) {
            highy_float -= 1.0;
            highy_int++;
        }
    }
}

static int checkMipmapArgs(GLenum internalFormat, GLenum format, GLenum type)
{
    if (!legalFormat(format) || !legalType(type)) {
      return GLU_INVALID_ENUM;
    }
    if (format == GL_STENCIL_INDEX) {
      return GLU_INVALID_ENUM;
    }

    if (!isLegalFormatForPackedPixelType(format, type)) {
      return GLU_INVALID_OPERATION; 
    }

    return 0;
} /* checkMipmapArgs() */

static GLboolean legalFormat(GLenum format)
{
    switch(format) {
      case GL_COLOR_INDEX:
      case GL_STENCIL_INDEX:
      case GL_DEPTH_COMPONENT:
      case GL_RED:
      case GL_GREEN:
      case GL_BLUE:
      case GL_ALPHA:
      case GL_RGB:
      case GL_RGBA:
      case GL_LUMINANCE:
      case GL_LUMINANCE_ALPHA:
      case GL_BGR:
      case GL_BGRA:
      return GL_TRUE;
      default:
      return GL_FALSE;
    }
}

static GLboolean legalType(GLenum type)
{
    switch(type) {
      case GL_BITMAP:
      case GL_BYTE:
      case GL_UNSIGNED_BYTE:
      case GL_SHORT:
      case GL_UNSIGNED_SHORT:
      case GL_INT:
      case GL_UNSIGNED_INT:
      case GL_FLOAT:
      case GL_UNSIGNED_BYTE_3_3_2:
      case GL_UNSIGNED_BYTE_2_3_3_REV:    
      case GL_UNSIGNED_SHORT_5_6_5:
      case GL_UNSIGNED_SHORT_5_6_5_REV:
      case GL_UNSIGNED_SHORT_4_4_4_4:
      case GL_UNSIGNED_SHORT_4_4_4_4_REV:
      case GL_UNSIGNED_SHORT_5_5_5_1:
      case GL_UNSIGNED_SHORT_1_5_5_5_REV:
      case GL_UNSIGNED_INT_8_8_8_8:
      case GL_UNSIGNED_INT_8_8_8_8_REV:
      case GL_UNSIGNED_INT_10_10_10_2:
      case GL_UNSIGNED_INT_2_10_10_10_REV:
         return GL_TRUE;
      default:
      return GL_FALSE;
    }
}

/* */
static GLboolean isTypePackedPixel(GLenum type)
{
   assert(legalType(type));

   if (type == GL_UNSIGNED_BYTE_3_3_2 ||
       type == GL_UNSIGNED_BYTE_2_3_3_REV ||
       type == GL_UNSIGNED_SHORT_5_6_5 ||
       type == GL_UNSIGNED_SHORT_5_6_5_REV ||
       type == GL_UNSIGNED_SHORT_4_4_4_4 ||
       type == GL_UNSIGNED_SHORT_4_4_4_4_REV ||
       type == GL_UNSIGNED_SHORT_5_5_5_1 ||
       type == GL_UNSIGNED_SHORT_1_5_5_5_REV ||
       type == GL_UNSIGNED_INT_8_8_8_8 ||
       type == GL_UNSIGNED_INT_8_8_8_8_REV ||
       type == GL_UNSIGNED_INT_10_10_10_2 ||
       type == GL_UNSIGNED_INT_2_10_10_10_REV) {
      return 1;
   }
   else return 0;
} /* isTypePackedPixel() */

/* Determines if the packed pixel type is compatible with the format */
static GLboolean isLegalFormatForPackedPixelType(GLenum format, GLenum type)
{
   /* if not a packed pixel type then return true */
   if (!isTypePackedPixel(type)) {
      return GL_TRUE;
   }
   
   /* 3_3_2/2_3_3_REV & 5_6_5/5_6_5_REV are only compatible with RGB */
   if ((type == GL_UNSIGNED_BYTE_3_3_2 || type == GL_UNSIGNED_BYTE_2_3_3_REV|| 
      type == GL_UNSIGNED_SHORT_5_6_5|| type == GL_UNSIGNED_SHORT_5_6_5_REV)
       && format != GL_RGB)
      return GL_FALSE;
   
   /* 4_4_4_4/4_4_4_4_REV & 5_5_5_1/1_5_5_5_REV & 8_8_8_8/8_8_8_8_REV & 
    * 10_10_10_2/2_10_10_10_REV are only compatible with RGBA, BGRA & ABGR_EXT.
    */
   if ((type == GL_UNSIGNED_SHORT_4_4_4_4 ||
      type == GL_UNSIGNED_SHORT_4_4_4_4_REV ||
      type == GL_UNSIGNED_SHORT_5_5_5_1 ||
      type == GL_UNSIGNED_SHORT_1_5_5_5_REV ||
      type == GL_UNSIGNED_INT_8_8_8_8 ||
      type == GL_UNSIGNED_INT_8_8_8_8_REV ||
      type == GL_UNSIGNED_INT_10_10_10_2 ||
      type == GL_UNSIGNED_INT_2_10_10_10_REV) &&
       (format != GL_RGBA && 
      format != GL_BGRA)) {
      return GL_FALSE;
   }

   return GL_TRUE;
} /* isLegalFormatForPackedPixelType() */

static GLboolean isLegalLevels(GLint userLevel,GLint baseLevel,GLint maxLevel, 
                         GLint totalLevels)
{
   if (baseLevel < 0 || baseLevel < userLevel || maxLevel < baseLevel ||
       totalLevels < maxLevel)
      return GL_FALSE;
   else return GL_TRUE;
} /* isLegalLevels() */

/* Given user requested texture size, determine if it fits. If it
 * doesn't then halve both sides and make the determination again
 * until it does fit (for IR only). 
 * Note that proxy textures are not implemented in RE* even though
 * they advertise the texture extension.  
 * Note that proxy textures are implemented but not according to spec in
 * IMPACT*.
 */
static void closestFit(GLenum target, GLint width, GLint height, 
                   GLint internalFormat, GLenum format, GLenum type, 
                   GLint *newWidth, GLint *newHeight)
{
   /* Use proxy textures if OpenGL version is >= 1.1 */
   if ( (strtod((const char *)glGetString(GL_VERSION),NULL) >= 1.1)
      ) {
      GLint widthPowerOf2= nearestPower(width);
      GLint heightPowerOf2= nearestPower(height);     
      GLint proxyWidth;

      do {
       /* compute level 1 width & height, clamping each at 1 */
       GLint widthAtLevelOne= (widthPowerOf2 > 1) ?
                               widthPowerOf2 >> 1 :
                         widthPowerOf2;  
       GLint heightAtLevelOne= (heightPowerOf2 > 1) ?
                                heightPowerOf2 >> 1 :
                          heightPowerOf2;  
       GLenum proxyTarget;
       assert(widthAtLevelOne > 0); assert(heightAtLevelOne > 0);

       /* does width x height at level 1 & all their mipmaps fit? */
       if (target == GL_TEXTURE_2D || target == GL_PROXY_TEXTURE_2D) {
          proxyTarget = GL_PROXY_TEXTURE_2D;
          glTexImage2D(proxyTarget, 1, /* must be non-zero */
                   internalFormat,
                   widthAtLevelOne,heightAtLevelOne,0,format,type,NULL);
       } else
#if defined(GL_ARB_texture_cube_map)
         if ((target == GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB) ||
             (target == GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB) ||
             (target == GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB) ||
             (target == GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB) ||
             (target == GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB) ||
             (target == GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB)) {
             proxyTarget = GL_PROXY_TEXTURE_CUBE_MAP_ARB;
             glTexImage2D(proxyTarget, 1, /* must be non-zero */
                          internalFormat,
                          widthAtLevelOne,heightAtLevelOne,0,format,type,NULL);
         } else
#endif /* GL_ARB_texture_cube_map */
         {
          assert(target == GL_TEXTURE_1D || target == GL_PROXY_TEXTURE_1D);
          proxyTarget = GL_PROXY_TEXTURE_1D;
          glTexImage1D(proxyTarget, 1, /* must be non-zero */
                   internalFormat,widthAtLevelOne,0,format,type,NULL);
       }
       glGetTexLevelParameteriv(proxyTarget, 1,GL_TEXTURE_WIDTH,&proxyWidth);
       /* does it fit??? */
       if (proxyWidth == 0) { /* nope, so try again with these sizes */
          if (widthPowerOf2 == 1 && heightPowerOf2 == 1) {
             /* An 1x1 texture couldn't fit for some reason, so
            * break out.  This should never happen. But things
            * happen.  The disadvantage with this if-statement is
            * that we will never be aware of when this happens
            * since it will silently branch out.  
            */
             goto noProxyTextures;
          }
          widthPowerOf2= widthAtLevelOne;
          heightPowerOf2= heightAtLevelOne;
       } 
       /* else it does fit */
      } while (proxyWidth == 0);
      /* loop must terminate! */

      /* return the width & height at level 0 that fits */
      *newWidth= widthPowerOf2;
      *newHeight= heightPowerOf2;
/*printf("Proxy Textures\n");*/
   } /* if gluCheckExtension() */
   else {               /* no texture extension, so do this instead */
      GLint maxsize;

noProxyTextures:

      glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxsize);
      /* clamp user's texture sizes to maximum sizes, if necessary */
      *newWidth = nearestPower(width);
      if (*newWidth > maxsize) *newWidth = maxsize;
      *newHeight = nearestPower(height);
      if (*newHeight > maxsize) *newHeight = maxsize;
/*printf("NO proxy textures\n");*/
   }
} /* closestFit() */

GLint GLAPIENTRY
gluScaleImage(GLenum format, GLsizei widthin, GLsizei heightin, 
                GLenum typein, const void *datain, 
                GLsizei widthout, GLsizei heightout, GLenum typeout,
                void *dataout)
{
    int components;
    GLushort *beforeImage;
    GLushort *afterImage;
    PixelStorageModes psm;

    if (widthin == 0 || heightin == 0 || widthout == 0 || heightout == 0) {
      return 0;
    }
    if (widthin < 0 || heightin < 0 || widthout < 0 || heightout < 0) {
      return GLU_INVALID_VALUE;
    }
    if (!legalFormat(format) || !legalType(typein) || !legalType(typeout)) {
      return GLU_INVALID_ENUM;
    }
    if (!isLegalFormatForPackedPixelType(format, typein)) {
       return GLU_INVALID_OPERATION;
    }
    if (!isLegalFormatForPackedPixelType(format, typeout)) {
       return GLU_INVALID_OPERATION;
    }
    beforeImage =
      malloc(image_size(widthin, heightin, format, GL_UNSIGNED_SHORT)); 
    afterImage =
      malloc(image_size(widthout, heightout, format, GL_UNSIGNED_SHORT));
    if (beforeImage == NULL || afterImage == NULL) {
      return GLU_OUT_OF_MEMORY;
    }

    retrieveStoreModes(&psm);
    fill_image(&psm,widthin, heightin, format, typein, is_index(format),
          datain, beforeImage);
    components = elements_per_group(format, 0);
    scale_internal(components, widthin, heightin, beforeImage, 
          widthout, heightout, afterImage);
    empty_image(&psm,widthout, heightout, format, typeout, 
          is_index(format), afterImage, dataout);
    free((GLbyte *) beforeImage);
    free((GLbyte *) afterImage);

    return 0;
}

int gluBuild1DMipmapLevelsCore(GLenum target, GLint internalFormat,
                         GLsizei width,
                         GLsizei widthPowerOf2,
                         GLenum format, GLenum type, 
                         GLint userLevel, GLint baseLevel,GLint maxLevel,
                         const void *data)
{
    GLint newwidth;
    GLint level, levels;
    GLushort *newImage;
    GLint newImage_width;
    GLushort *otherImage;
    GLushort *imageTemp;
    GLint memreq;
    GLint cmpts;
    PixelStorageModes psm;

    assert(checkMipmapArgs(internalFormat,format,type) == 0);
    assert(width >= 1);

    otherImage = NULL;

    newwidth= widthPowerOf2;
    levels = computeLog(newwidth);

    levels+= userLevel;

    retrieveStoreModes(&psm);
    newImage = (GLushort *)
      malloc(image_size(width, 1, format, GL_UNSIGNED_SHORT)); 
    newImage_width = width;
    if (newImage == NULL) {
      return GLU_OUT_OF_MEMORY;
    }
    fill_image(&psm,width, 1, format, type, is_index(format),
          data, newImage);
    cmpts = elements_per_group(format,type);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 2);
    glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    /*
    ** If swap_bytes was set, swapping occurred in fill_image.
    */
    glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_FALSE);

    for (level = userLevel; level <= levels; level++) {
      if (newImage_width == newwidth) {
          /* Use newImage for this level */
          if (baseLevel <= level && level <= maxLevel) {
          glTexImage1D(target, level, internalFormat, newImage_width, 
                0, format, GL_UNSIGNED_SHORT, (void *) newImage);
          }
      } else {
          if (otherImage == NULL) {
            memreq = image_size(newwidth, 1, format, GL_UNSIGNED_SHORT);
            otherImage = (GLushort *) malloc(memreq);
            if (otherImage == NULL) {
                glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
                glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
                glPixelStorei(GL_UNPACK_SKIP_PIXELS,psm.unpack_skip_pixels);
                glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
                glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
                return GLU_OUT_OF_MEMORY;
            }
          }
          scale_internal(cmpts, newImage_width, 1, newImage, 
                newwidth, 1, otherImage);
          /* Swap newImage and otherImage */
          imageTemp = otherImage; 
          otherImage = newImage;
          newImage = imageTemp;

          newImage_width = newwidth;
          if (baseLevel <= level && level <= maxLevel) {
          glTexImage1D(target, level, internalFormat, newImage_width,
                0, format, GL_UNSIGNED_SHORT, (void *) newImage);
          }
      }
      if (newwidth > 1) newwidth /= 2;
    }
    glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
    glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
    glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);

    free((GLbyte *) newImage);
    if (otherImage) {
      free((GLbyte *) otherImage);
    }
    return 0;
}

GLint GLAPIENTRY
gluBuild1DMipmapLevels(GLenum target, GLint internalFormat, 
                       GLsizei width,
                       GLenum format, GLenum type, 
                       GLint userLevel, GLint baseLevel, GLint maxLevel,
                       const void *data)
{
   int levels;

   int rc= checkMipmapArgs(internalFormat,format,type);
   if (rc != 0) return rc;

   if (width < 1) {
       return GLU_INVALID_VALUE;
   }

   levels = computeLog(width);

   levels+= userLevel;
   if (!isLegalLevels(userLevel,baseLevel,maxLevel,levels)) 
      return GLU_INVALID_VALUE;

   return gluBuild1DMipmapLevelsCore(target, internalFormat, 
                             width,
                             width,format, type, 
                             userLevel, baseLevel, maxLevel,
                             data);
} /* gluBuild1DMipmapLevels() */

GLint GLAPIENTRY
gluBuild1DMipmaps(GLenum target, GLint internalFormat, GLsizei width,
                  GLenum format, GLenum type, 
                  const void *data)
{
   GLint widthPowerOf2;
   int levels;
   GLint dummy;

   int rc= checkMipmapArgs(internalFormat,format,type);
   if (rc != 0) return rc;

   if (width < 1) {
       return GLU_INVALID_VALUE;
   }

   closestFit(target,width,1,internalFormat,format,type,&widthPowerOf2,&dummy);
   levels = computeLog(widthPowerOf2);

   return gluBuild1DMipmapLevelsCore(target,internalFormat,
                             width,
                             widthPowerOf2,
                             format,type,0,0,levels,data);
}

static int bitmapBuild2DMipmaps(GLenum target, GLint internalFormat,
                 GLint width, GLint height, GLenum format,
                     GLenum type, const void *data)
{
    GLint newwidth, newheight;
    GLint level, levels;
    GLushort *newImage;
    GLint newImage_width;
    GLint newImage_height;
    GLushort *otherImage;
    GLushort *imageTemp;
    GLint memreq;
#if 0
    GLint maxsize;
#endif
    GLint cmpts;
    PixelStorageModes psm;

    retrieveStoreModes(&psm);

#if 0
    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxsize);
    newwidth = nearestPower(width);
    if (newwidth > maxsize) newwidth = maxsize;
    newheight = nearestPower(height);
    if (newheight > maxsize) newheight = maxsize;
#else
    closestFit(target,width,height,internalFormat,format,type,
             &newwidth,&newheight);
#endif
    levels = computeLog(newwidth);
    level = computeLog(newheight);
    if (level > levels) levels=level;

    otherImage = NULL;
    newImage = (GLushort *)
        malloc(image_size(width, height, format, GL_UNSIGNED_SHORT));
    newImage_width = width;
    newImage_height = height;
    if (newImage == NULL) {
        return GLU_OUT_OF_MEMORY;
    }

    fill_image(&psm,width, height, format, type, is_index(format),
          data, newImage);

    cmpts = elements_per_group(format,type);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 2);
    glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    /*
    ** If swap_bytes was set, swapping occurred in fill_image.
    */
    glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_FALSE);

    for (level = 0; level <= levels; level++) {
        if (newImage_width == newwidth && newImage_height == newheight) {            /* Use newImage for this level */
            glTexImage2D(target, level, internalFormat, newImage_width,
                    newImage_height, 0, format, GL_UNSIGNED_SHORT,
                    (void *) newImage);
        } else {
            if (otherImage == NULL) {
                memreq =
                    image_size(newwidth, newheight, format, GL_UNSIGNED_SHORT);
                otherImage = (GLushort *) malloc(memreq);
                if (otherImage == NULL) {
                    glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
                    glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
                    glPixelStorei(GL_UNPACK_SKIP_PIXELS,psm.unpack_skip_pixels);
                    glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
                    glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
                    return GLU_OUT_OF_MEMORY;
                }
            }
            scale_internal(cmpts, newImage_width, newImage_height, newImage,
                    newwidth, newheight, otherImage);
            /* Swap newImage and otherImage */
            imageTemp = otherImage;
            otherImage = newImage;
            newImage = imageTemp;

            newImage_width = newwidth;
            newImage_height = newheight;
            glTexImage2D(target, level, internalFormat, newImage_width,
                    newImage_height, 0, format, GL_UNSIGNED_SHORT,
                    (void *) newImage);
        }
        if (newwidth > 1) newwidth /= 2;
        if (newheight > 1) newheight /= 2;
    }
    glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
    glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
    glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);

    free((GLbyte *) newImage);
    if (otherImage) {
        free((GLbyte *) otherImage);
    }
    return 0;
}

/* To make swapping images less error prone */
#define __GLU_INIT_SWAP_IMAGE void *tmpImage
#define __GLU_SWAP_IMAGE(a,b) tmpImage = a; a = b; b = tmpImage;

static int gluBuild2DMipmapLevelsCore(GLenum target, GLint internalFormat, 
                              GLsizei width, GLsizei height, 
                              GLsizei widthPowerOf2, 
                              GLsizei heightPowerOf2, 
                              GLenum format, GLenum type, 
                              GLint userLevel, 
                              GLint baseLevel,GLint maxLevel,
                              const void *data)
{
    GLint newwidth, newheight;
    GLint level, levels;
    const void *usersImage; /* passed from user. Don't touch! */
    void *srcImage, *dstImage; /* scratch area to build mipmapped images */
    __GLU_INIT_SWAP_IMAGE;
    GLint memreq;
    GLint cmpts;

    GLint myswap_bytes, groups_per_line, element_size, group_size;
    GLint rowsize, padding;
    PixelStorageModes psm;

    assert(checkMipmapArgs(internalFormat,format,type) == 0);
    assert(width >= 1 && height >= 1);

    if(type == GL_BITMAP) {
      return bitmapBuild2DMipmaps(target, internalFormat, width, height,
                format, type, data);
    }

    srcImage = dstImage = NULL;

    newwidth= widthPowerOf2;
    newheight= heightPowerOf2;
    levels = computeLog(newwidth);
    level = computeLog(newheight);
    if (level > levels) levels=level;

    levels+= userLevel;

    retrieveStoreModes(&psm);
    myswap_bytes = psm.unpack_swap_bytes;
    cmpts = elements_per_group(format,type);
    if (psm.unpack_row_length > 0) {
      groups_per_line = psm.unpack_row_length;
    } else {
      groups_per_line = width;
    }

    element_size = bytes_per_element(type);
    group_size = element_size * cmpts;
    if (element_size == 1) myswap_bytes = 0;

    rowsize = groups_per_line * group_size;
    padding = (rowsize % psm.unpack_alignment);
    if (padding) {
      rowsize += psm.unpack_alignment - padding;
    }
    usersImage = (const GLubyte *) data + psm.unpack_skip_rows * rowsize + 
      psm.unpack_skip_pixels * group_size;

    glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);

    level = userLevel;

    /* already power-of-two square */
    if (width == newwidth && height == newheight) {
      /* Use usersImage for level userLevel */
        if (baseLevel <= level && level <= maxLevel) { 
      glTexImage2D(target, level, internalFormat, width, 
            height, 0, format, type,
            usersImage);
      }
      if(levels == 0) { /* we're done. clean up and return */
        glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
        glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
        glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
        glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
        glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
        return 0;
      }
      {
         int nextWidth= newwidth/2;
         int nextHeight= newheight/2;

         /* clamp to 1 */
         if (nextWidth < 1) nextWidth= 1;
         if (nextHeight < 1) nextHeight= 1;
      memreq = image_size(nextWidth, nextHeight, format, type);
        }

      switch(type) {
      case GL_UNSIGNED_BYTE:
        dstImage = (GLubyte *)malloc(memreq);
        break;
      case GL_BYTE:
        dstImage = (GLbyte *)malloc(memreq);
        break;
      case GL_UNSIGNED_SHORT:
        dstImage = (GLushort *)malloc(memreq);
        break;
      case GL_SHORT:
        dstImage = (GLshort *)malloc(memreq);
        break;
      case GL_UNSIGNED_INT:
        dstImage = (GLuint *)malloc(memreq);
        break;
      case GL_INT:
        dstImage = (GLint *)malloc(memreq);
        break;
      case GL_FLOAT:
        dstImage = (GLfloat *)malloc(memreq);
        break;
        case GL_UNSIGNED_BYTE_3_3_2: 
        case GL_UNSIGNED_BYTE_2_3_3_REV: 
        dstImage = (GLubyte *)malloc(memreq);
        break;
        case GL_UNSIGNED_SHORT_5_6_5:
        case GL_UNSIGNED_SHORT_5_6_5_REV:
        case GL_UNSIGNED_SHORT_4_4_4_4:
        case GL_UNSIGNED_SHORT_4_4_4_4_REV:
        case GL_UNSIGNED_SHORT_5_5_5_1:
        case GL_UNSIGNED_SHORT_1_5_5_5_REV:
        dstImage = (GLushort *)malloc(memreq);
          break;
        case GL_UNSIGNED_INT_8_8_8_8:
        case GL_UNSIGNED_INT_8_8_8_8_REV:
        case GL_UNSIGNED_INT_10_10_10_2:
        case GL_UNSIGNED_INT_2_10_10_10_REV:
        dstImage = (GLuint *)malloc(memreq);      
        break;
      default:
        return GLU_INVALID_ENUM;
      }
      if (dstImage == NULL) {
        glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
        glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
        glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
        glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
        glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
        return GLU_OUT_OF_MEMORY;
      }
      else
        switch(type) {
        case GL_UNSIGNED_BYTE:
          halveImage_ubyte(cmpts, width, height,
                       (const GLubyte *)usersImage, (GLubyte *)dstImage, 
                       element_size, rowsize, group_size);
          break;
        case GL_BYTE:
          halveImage_byte(cmpts, width, height,
                      (const GLbyte *)usersImage, (GLbyte *)dstImage, 
                      element_size, rowsize, group_size);
          break;
        case GL_UNSIGNED_SHORT:
          halveImage_ushort(cmpts, width, height,
                        (const GLushort *)usersImage, (GLushort *)dstImage,
                        element_size, rowsize, group_size, myswap_bytes);
          break;
        case GL_SHORT:
          halveImage_short(cmpts, width, height,
                       (const GLshort *)usersImage, (GLshort *)dstImage, 
                       element_size, rowsize, group_size, myswap_bytes);
          break;
        case GL_UNSIGNED_INT:
          halveImage_uint(cmpts, width, height,
                      (const GLuint *)usersImage, (GLuint *)dstImage, 
                      element_size, rowsize, group_size, myswap_bytes);
          break;
        case GL_INT:
          halveImage_int(cmpts, width, height,
                     (const GLint *)usersImage, (GLint *)dstImage, 
                     element_size, rowsize, group_size, myswap_bytes);
          break;
        case GL_FLOAT:
          halveImage_float(cmpts, width, height,
                       (const GLfloat *)usersImage, (GLfloat *)dstImage,
                       element_size, rowsize, group_size, myswap_bytes);
          break;
        case GL_UNSIGNED_BYTE_3_3_2: 
          assert(format == GL_RGB);
          halveImagePackedPixel(3,extract332,shove332,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;
          case GL_UNSIGNED_BYTE_2_3_3_REV:
          assert(format == GL_RGB);
          halveImagePackedPixel(3,extract233rev,shove233rev,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;
          case GL_UNSIGNED_SHORT_5_6_5:
          halveImagePackedPixel(3,extract565,shove565,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;
          case GL_UNSIGNED_SHORT_5_6_5_REV:
          halveImagePackedPixel(3,extract565rev,shove565rev,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;
          case GL_UNSIGNED_SHORT_4_4_4_4:
          halveImagePackedPixel(4,extract4444,shove4444,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;          
          case GL_UNSIGNED_SHORT_4_4_4_4_REV:
          halveImagePackedPixel(4,extract4444rev,shove4444rev,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;          
          case GL_UNSIGNED_SHORT_5_5_5_1:
          halveImagePackedPixel(4,extract5551,shove5551,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;          
          case GL_UNSIGNED_SHORT_1_5_5_5_REV:
          halveImagePackedPixel(4,extract1555rev,shove1555rev,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;          
          case GL_UNSIGNED_INT_8_8_8_8:
          halveImagePackedPixel(4,extract8888,shove8888,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;          
          case GL_UNSIGNED_INT_8_8_8_8_REV:
          halveImagePackedPixel(4,extract8888rev,shove8888rev,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;          
          case GL_UNSIGNED_INT_10_10_10_2:
          halveImagePackedPixel(4,extract1010102,shove1010102,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;          
          case GL_UNSIGNED_INT_2_10_10_10_REV:
          halveImagePackedPixel(4,extract2101010rev,shove2101010rev,
                          width,height,usersImage,dstImage,
                          element_size,rowsize,myswap_bytes);
          break;          
          default:
          assert(0);
          break;
        }
      newwidth = width/2;
      newheight = height/2;
      /* clamp to 1 */
      if (newwidth < 1) newwidth= 1;
      if (newheight < 1) newheight= 1; 

      myswap_bytes = 0;
      rowsize = newwidth * group_size;
      memreq = image_size(newwidth, newheight, format, type);
      /* Swap srcImage and dstImage */
      __GLU_SWAP_IMAGE(srcImage,dstImage);
      switch(type) {
      case GL_UNSIGNED_BYTE:
        dstImage = (GLubyte *)malloc(memreq);
        break;
      case GL_BYTE:
        dstImage = (GLbyte *)malloc(memreq);
        break;
      case GL_UNSIGNED_SHORT:
        dstImage = (GLushort *)malloc(memreq);
        break;
      case GL_SHORT:
        dstImage = (GLshort *)malloc(memreq);
        break;
      case GL_UNSIGNED_INT:
        dstImage = (GLuint *)malloc(memreq);
        break;
      case GL_INT:
        dstImage = (GLint *)malloc(memreq);
        break;
      case GL_FLOAT:
        dstImage = (GLfloat *)malloc(memreq);
        break;
        case GL_UNSIGNED_BYTE_3_3_2:
        case GL_UNSIGNED_BYTE_2_3_3_REV:
        dstImage = (GLubyte *)malloc(memreq);
        break;
        case GL_UNSIGNED_SHORT_5_6_5:
        case GL_UNSIGNED_SHORT_5_6_5_REV:
        case GL_UNSIGNED_SHORT_4_4_4_4:
        case GL_UNSIGNED_SHORT_4_4_4_4_REV:
        case GL_UNSIGNED_SHORT_5_5_5_1:
        case GL_UNSIGNED_SHORT_1_5_5_5_REV:
        dstImage = (GLushort *)malloc(memreq);
        break;
        case GL_UNSIGNED_INT_8_8_8_8:
        case GL_UNSIGNED_INT_8_8_8_8_REV:
        case GL_UNSIGNED_INT_10_10_10_2:
        case GL_UNSIGNED_INT_2_10_10_10_REV:
        dstImage = (GLuint *)malloc(memreq);
        break;
      default:
        return GLU_INVALID_ENUM;
      }
      if (dstImage == NULL) {
        glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
        glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
        glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
        glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
        glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
        return GLU_OUT_OF_MEMORY;
      }
      /* level userLevel+1 is in srcImage; level userLevel already saved */
      level = userLevel+1;
    } else { /* user's image is *not* nice power-of-2 sized square */
      memreq = image_size(newwidth, newheight, format, type);
      switch(type) {
            case GL_UNSIGNED_BYTE:
                dstImage = (GLubyte *)malloc(memreq);
                break;
            case GL_BYTE:
                dstImage = (GLbyte *)malloc(memreq);
                break;
            case GL_UNSIGNED_SHORT:
                dstImage = (GLushort *)malloc(memreq);
                break;
            case GL_SHORT:
                dstImage = (GLshort *)malloc(memreq);
                break;
            case GL_UNSIGNED_INT:
                dstImage = (GLuint *)malloc(memreq);
                break;
            case GL_INT:
                dstImage = (GLint *)malloc(memreq);
                break;
            case GL_FLOAT:
                dstImage = (GLfloat *)malloc(memreq);
                break;
            case GL_UNSIGNED_BYTE_3_3_2:
            case GL_UNSIGNED_BYTE_2_3_3_REV:
                dstImage = (GLubyte *)malloc(memreq);
            break;
          case GL_UNSIGNED_SHORT_5_6_5:
          case GL_UNSIGNED_SHORT_5_6_5_REV:
          case GL_UNSIGNED_SHORT_4_4_4_4:
          case GL_UNSIGNED_SHORT_4_4_4_4_REV:
          case GL_UNSIGNED_SHORT_5_5_5_1:
          case GL_UNSIGNED_SHORT_1_5_5_5_REV:
            dstImage = (GLushort *)malloc(memreq);
            break;
          case GL_UNSIGNED_INT_8_8_8_8:
          case GL_UNSIGNED_INT_8_8_8_8_REV:
          case GL_UNSIGNED_INT_10_10_10_2:
          case GL_UNSIGNED_INT_2_10_10_10_REV:
            dstImage = (GLuint *)malloc(memreq);
            break;
            default:
                return GLU_INVALID_ENUM;
        }

      if (dstImage == NULL) {
          glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
          glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
          glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
          glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
          glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
          return GLU_OUT_OF_MEMORY;
      }

      switch(type) {
      case GL_UNSIGNED_BYTE:
          scale_internal_ubyte(cmpts, width, height,
                         (const GLubyte *)usersImage, newwidth, newheight,
                         (GLubyte *)dstImage, element_size,
                         rowsize, group_size);
          break;
      case GL_BYTE:
          scale_internal_byte(cmpts, width, height,
                        (const GLbyte *)usersImage, newwidth, newheight, 
                        (GLbyte *)dstImage, element_size,
                        rowsize, group_size);
          break;
      case GL_UNSIGNED_SHORT:
          scale_internal_ushort(cmpts, width, height,
                          (const GLushort *)usersImage, newwidth, newheight,
                          (GLushort *)dstImage, element_size,
                          rowsize, group_size, myswap_bytes);
          break;
      case GL_SHORT:
          scale_internal_short(cmpts, width, height,
                         (const GLshort *)usersImage, newwidth, newheight,
                         (GLshort *)dstImage, element_size,
                         rowsize, group_size, myswap_bytes);
          break;
      case GL_UNSIGNED_INT:
          scale_internal_uint(cmpts, width, height,
                        (const GLuint *)usersImage, newwidth, newheight,
                        (GLuint *)dstImage, element_size,
                        rowsize, group_size, myswap_bytes);
          break;
      case GL_INT:
          scale_internal_int(cmpts, width, height,
                         (const GLint *)usersImage, newwidth, newheight, 
                         (GLint *)dstImage, element_size,
                         rowsize, group_size, myswap_bytes);
          break;
      case GL_FLOAT:
          scale_internal_float(cmpts, width, height,
                         (const GLfloat *)usersImage, newwidth, newheight, 
                         (GLfloat *)dstImage, element_size,
                         rowsize, group_size, myswap_bytes);
          break;
        case GL_UNSIGNED_BYTE_3_3_2:
          scaleInternalPackedPixel(3,extract332,shove332,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_BYTE_2_3_3_REV:
          scaleInternalPackedPixel(3,extract233rev,shove233rev,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_SHORT_5_6_5:
          scaleInternalPackedPixel(3,extract565,shove565,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_SHORT_5_6_5_REV:
          scaleInternalPackedPixel(3,extract565rev,shove565rev,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_SHORT_4_4_4_4:
          scaleInternalPackedPixel(4,extract4444,shove4444,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_SHORT_4_4_4_4_REV:
          scaleInternalPackedPixel(4,extract4444rev,shove4444rev,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_SHORT_5_5_5_1:
          scaleInternalPackedPixel(4,extract5551,shove5551,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_SHORT_1_5_5_5_REV:
          scaleInternalPackedPixel(4,extract1555rev,shove1555rev,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_INT_8_8_8_8:
          scaleInternalPackedPixel(4,extract8888,shove8888,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_INT_8_8_8_8_REV:
          scaleInternalPackedPixel(4,extract8888rev,shove8888rev,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_INT_10_10_10_2:
          scaleInternalPackedPixel(4,extract1010102,shove1010102,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        case GL_UNSIGNED_INT_2_10_10_10_REV:
          scaleInternalPackedPixel(4,extract2101010rev,shove2101010rev,
                             width, height,usersImage,
                             newwidth,newheight,(void *)dstImage,
                             element_size,rowsize,myswap_bytes);
          break;
        default:
          assert(0);
          break;
      }
      myswap_bytes = 0;
      rowsize = newwidth * group_size;
      /* Swap dstImage and srcImage */
      __GLU_SWAP_IMAGE(srcImage,dstImage);

      if(levels != 0) { /* use as little memory as possible */
          {
           int nextWidth= newwidth/2;
           int nextHeight= newheight/2;
           if (nextWidth < 1) nextWidth= 1;
           if (nextHeight < 1) nextHeight= 1;        

        memreq = image_size(nextWidth, nextHeight, format, type);
          }

        switch(type) {
        case GL_UNSIGNED_BYTE:
          dstImage = (GLubyte *)malloc(memreq);
          break;
        case GL_BYTE:
          dstImage = (GLbyte *)malloc(memreq);
          break;
        case GL_UNSIGNED_SHORT:
          dstImage = (GLushort *)malloc(memreq);
          break;
        case GL_SHORT:
          dstImage = (GLshort *)malloc(memreq);
          break;
        case GL_UNSIGNED_INT:
          dstImage = (GLuint *)malloc(memreq);
          break;
        case GL_INT:
          dstImage = (GLint *)malloc(memreq);
          break;
        case GL_FLOAT:
          dstImage = (GLfloat *)malloc(memreq);
          break;
          case GL_UNSIGNED_BYTE_3_3_2:
          case GL_UNSIGNED_BYTE_2_3_3_REV:
          dstImage = (GLubyte *)malloc(memreq);
          break;
          case GL_UNSIGNED_SHORT_5_6_5:
          case GL_UNSIGNED_SHORT_5_6_5_REV:
        case GL_UNSIGNED_SHORT_4_4_4_4:
        case GL_UNSIGNED_SHORT_4_4_4_4_REV:
        case GL_UNSIGNED_SHORT_5_5_5_1:
        case GL_UNSIGNED_SHORT_1_5_5_5_REV:
          dstImage = (GLushort *)malloc(memreq);
          break;
        case GL_UNSIGNED_INT_8_8_8_8:
        case GL_UNSIGNED_INT_8_8_8_8_REV:
        case GL_UNSIGNED_INT_10_10_10_2:
        case GL_UNSIGNED_INT_2_10_10_10_REV:
          dstImage = (GLuint *)malloc(memreq);
          break;
        default:
          return GLU_INVALID_ENUM;
        }
        if (dstImage == NULL) {
          glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
          glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
          glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
          glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
          glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
          return GLU_OUT_OF_MEMORY;
        }
      }
      /* level userLevel is in srcImage; nothing saved yet */
      level = userLevel; 
    }

    glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_FALSE);
    if (baseLevel <= level && level <= maxLevel) {
    glTexImage2D(target, level, internalFormat, newwidth, newheight, 0, 
             format, type, (void *)srcImage);
    }

    level++; /* update current level for the loop */
    for (; level <= levels; level++) {
      switch(type) {
          case GL_UNSIGNED_BYTE:
            halveImage_ubyte(cmpts, newwidth, newheight,
            (GLubyte *)srcImage, (GLubyte *)dstImage, element_size,
            rowsize, group_size);
            break;
          case GL_BYTE:
            halveImage_byte(cmpts, newwidth, newheight,
            (GLbyte *)srcImage, (GLbyte *)dstImage, element_size,
            rowsize, group_size);
            break;
          case GL_UNSIGNED_SHORT:
            halveImage_ushort(cmpts, newwidth, newheight,
            (GLushort *)srcImage, (GLushort *)dstImage, element_size,
            rowsize, group_size, myswap_bytes);
            break;
          case GL_SHORT:
            halveImage_short(cmpts, newwidth, newheight,
            (GLshort *)srcImage, (GLshort *)dstImage, element_size,
            rowsize, group_size, myswap_bytes);
            break;
          case GL_UNSIGNED_INT:
            halveImage_uint(cmpts, newwidth, newheight,
            (GLuint *)srcImage, (GLuint *)dstImage, element_size,
            rowsize, group_size, myswap_bytes);
            break;
          case GL_INT:
            halveImage_int(cmpts, newwidth, newheight,
            (GLint *)srcImage, (GLint *)dstImage, element_size,
            rowsize, group_size, myswap_bytes);
            break;
          case GL_FLOAT:
            halveImage_float(cmpts, newwidth, newheight,
            (GLfloat *)srcImage, (GLfloat *)dstImage, element_size,
            rowsize, group_size, myswap_bytes);
            break;
            case GL_UNSIGNED_BYTE_3_3_2:
              halveImagePackedPixel(3,extract332,shove332,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
            break;
            case GL_UNSIGNED_BYTE_2_3_3_REV:
              halveImagePackedPixel(3,extract233rev,shove233rev,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
            break;
          case GL_UNSIGNED_SHORT_5_6_5:
              halveImagePackedPixel(3,extract565,shove565,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
              break;
          case GL_UNSIGNED_SHORT_5_6_5_REV:
              halveImagePackedPixel(3,extract565rev,shove565rev,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
              break;
            case GL_UNSIGNED_SHORT_4_4_4_4:
              halveImagePackedPixel(4,extract4444,shove4444,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
            break;
            case GL_UNSIGNED_SHORT_4_4_4_4_REV:
              halveImagePackedPixel(4,extract4444rev,shove4444rev,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
            break;
            case GL_UNSIGNED_SHORT_5_5_5_1:           
              halveImagePackedPixel(4,extract5551,shove5551,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
            break;
            case GL_UNSIGNED_SHORT_1_5_5_5_REV:             
              halveImagePackedPixel(4,extract1555rev,shove1555rev,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
            break;
            case GL_UNSIGNED_INT_8_8_8_8:
              halveImagePackedPixel(4,extract8888,shove8888,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
            break;
            case GL_UNSIGNED_INT_8_8_8_8_REV:
              halveImagePackedPixel(4,extract8888rev,shove8888rev,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
            break;
            case GL_UNSIGNED_INT_10_10_10_2:
              halveImagePackedPixel(4,extract1010102,shove1010102,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
            break;
            case GL_UNSIGNED_INT_2_10_10_10_REV:
              halveImagePackedPixel(4,extract2101010rev,shove2101010rev,
                              newwidth,newheight,
                              srcImage,dstImage,element_size,rowsize,
                              myswap_bytes);
            break;
          default:
              assert(0);
            break;
      }

      __GLU_SWAP_IMAGE(srcImage,dstImage);

      if (newwidth > 1) { newwidth /= 2; rowsize /= 2;}
      if (newheight > 1) newheight /= 2;
      {
       /* compute amount to pad per row, if any */
       int rowPad= rowsize % psm.unpack_alignment; 

       /* should row be padded? */
       if (rowPad == 0) {     /* nope, row should not be padded */
         /* call tex image with srcImage untouched since it's not padded */
         if (baseLevel <= level && level <= maxLevel) {
         glTexImage2D(target, level, internalFormat, newwidth, newheight, 0, 
         format, type, (void *) srcImage);
         }
       }
       else {                 /* yes, row should be padded */
        /* compute length of new row in bytes, including padding */
        int newRowLength= rowsize + psm.unpack_alignment - rowPad;
        int ii; unsigned char *dstTrav, *srcTrav; /* indices for copying */

        /* allocate new image for mipmap of size newRowLength x newheight */
        void *newMipmapImage= malloc((size_t) (newRowLength*newheight));
        if (newMipmapImage == NULL) {
           /* out of memory so return */
           glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
           glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
           glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
           glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
           glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
           return GLU_OUT_OF_MEMORY;
        }

        /* copy image from srcImage into newMipmapImage by rows */
        for (ii= 0,
             dstTrav= (unsigned char *) newMipmapImage,
             srcTrav= (unsigned char *) srcImage;
             ii< newheight; 
             ii++,
             dstTrav+= newRowLength, /* make sure the correct distance... */
             srcTrav+= rowsize) {    /* ...is skipped */
           memcpy(dstTrav,srcTrav,rowsize);
           /* note that the pad bytes are not visited and will contain
            * garbage, which is ok.
            */
        } 

        /* ...and use this new image for mipmapping instead */ 
        if (baseLevel <= level && level <= maxLevel) {
        glTexImage2D(target, level, internalFormat, newwidth, newheight, 0, 
                   format, type, newMipmapImage);
        }
        free(newMipmapImage); /* don't forget to free it! */
       } /* else */
      }
    } /* for level */
    glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
    glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
    glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);

    free(srcImage); /*if you get to here, a srcImage has always been malloc'ed*/
    if (dstImage) { /* if it's non-rectangular and only 1 level */
      free(dstImage);
    }
    return 0;
} /* gluBuild2DMipmapLevelsCore() */

GLint GLAPIENTRY
gluBuild2DMipmapLevels(GLenum target, GLint internalFormat, 
                       GLsizei width, GLsizei height, 
                       GLenum format, GLenum type, 
                       GLint userLevel, GLint baseLevel, GLint maxLevel,
                       const void *data)
{
   int level, levels;

   int rc= checkMipmapArgs(internalFormat,format,type);
   if (rc != 0) return rc;

   if (width < 1 || height < 1) {
       return GLU_INVALID_VALUE;
   }

   levels = computeLog(width);
   level = computeLog(height);
   if (level > levels) levels=level;

   levels+= userLevel;
   if (!isLegalLevels(userLevel,baseLevel,maxLevel,levels)) 
      return GLU_INVALID_VALUE;

   return gluBuild2DMipmapLevelsCore(target, internalFormat, 
                             width, height,
                             width, height,
                             format, type, 
                             userLevel, baseLevel, maxLevel,
                             data);
} /* gluBuild2DMipmapLevels() */

GLint GLAPIENTRY
gluBuild2DMipmaps(GLenum target, GLint internalFormat, 
                  GLsizei width, GLsizei height, 
                  GLenum format, GLenum type, 
                  const void *data)
{
   GLint widthPowerOf2, heightPowerOf2;
   int level, levels;

   int rc= checkMipmapArgs(internalFormat,format,type);
   if (rc != 0) return rc;

   if (width < 1 || height < 1) {
       return GLU_INVALID_VALUE;
   }

   closestFit(target,width,height,internalFormat,format,type,
            &widthPowerOf2,&heightPowerOf2);

   levels = computeLog(widthPowerOf2);
   level = computeLog(heightPowerOf2);
   if (level > levels) levels=level;

   return gluBuild2DMipmapLevelsCore(target,internalFormat,
                             width, height,
                             widthPowerOf2,heightPowerOf2,
                             format,type,
                             0,0,levels,data);
}  /* gluBuild2DMipmaps() */

#if 0
/*
** This routine is for the limited case in which
**    type == GL_UNSIGNED_BYTE && format != index  && 
**    unpack_alignment = 1 && unpack_swap_bytes == false
**
** so all of the work data can be kept as ubytes instead of shorts.
*/
static int fastBuild2DMipmaps(const PixelStorageModes *psm,
                   GLenum target, GLint components, GLint width, 
                 GLint height, GLenum format, 
                 GLenum type, void *data)
{
    GLint newwidth, newheight;
    GLint level, levels;
    GLubyte *newImage;
    GLint newImage_width;
    GLint newImage_height;
    GLubyte *otherImage;
    GLubyte *imageTemp;
    GLint memreq;
#if 0
    GLint maxsize;
#endif
    GLint cmpts;


#if 0
    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &maxsize);
    newwidth = nearestPower(width);
    if (newwidth > maxsize) newwidth = maxsize;
    newheight = nearestPower(height);
    if (newheight > maxsize) newheight = maxsize;
#else
    closestFit(target,width,height,components,format,type,
             &newwidth,&newheight);
#endif
    levels = computeLog(newwidth);
    level = computeLog(newheight);
    if (level > levels) levels=level;

    cmpts = elements_per_group(format,type);

    otherImage = NULL;
    /**
    ** No need to copy the user data if its in the packed correctly.
    ** Make sure that later routines don't change that data.
    */
    if (psm->unpack_skip_rows == 0 && psm->unpack_skip_pixels == 0) {
      newImage = (GLubyte *)data;
      newImage_width = width;
      newImage_height = height;
    } else {
      GLint rowsize;
      GLint groups_per_line;
      GLint elements_per_line;
      const GLubyte *start;
      const GLubyte *iter;
      GLubyte *iter2;
      GLint i, j;

      newImage = (GLubyte *) 
          malloc(image_size(width, height, format, GL_UNSIGNED_BYTE)); 
      newImage_width = width;
      newImage_height = height;
      if (newImage == NULL) {
          return GLU_OUT_OF_MEMORY;
      }

      /*
      ** Abbreviated version of fill_image for this restricted case.
      */
      if (psm->unpack_row_length > 0) {
          groups_per_line = psm->unpack_row_length;
      } else {
          groups_per_line = width;
      }
      rowsize = groups_per_line * cmpts;
      elements_per_line = width * cmpts;
      start = (const GLubyte *) data + psm->unpack_skip_rows * rowsize + 
            psm->unpack_skip_pixels * cmpts;
      iter2 = newImage;

      for (i = 0; i < height; i++) {
          iter = start;
          for (j = 0; j < elements_per_line; j++) {
            *iter2 = *iter;
            iter++;
            iter2++;
          }
          start += rowsize;
      }
    }


    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_FALSE);

    for (level = 0; level <= levels; level++) {
      if (newImage_width == newwidth && newImage_height == newheight) {
          /* Use newImage for this level */
          glTexImage2D(target, level, components, newImage_width, 
                newImage_height, 0, format, GL_UNSIGNED_BYTE, 
                (void *) newImage);
      } else {
          if (otherImage == NULL) {
            memreq = 
                image_size(newwidth, newheight, format, GL_UNSIGNED_BYTE);
            otherImage = (GLubyte *) malloc(memreq);
            if (otherImage == NULL) {
                glPixelStorei(GL_UNPACK_ALIGNMENT, psm->unpack_alignment);
                glPixelStorei(GL_UNPACK_SKIP_ROWS, psm->unpack_skip_rows);
                glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm->unpack_skip_pixels);
                glPixelStorei(GL_UNPACK_ROW_LENGTH,psm->unpack_row_length);
                glPixelStorei(GL_UNPACK_SWAP_BYTES,psm->unpack_swap_bytes);
                return GLU_OUT_OF_MEMORY;
            }
          }
/*
          scale_internal_ubyte(cmpts, newImage_width, newImage_height, 
                newImage, newwidth, newheight, otherImage);
*/
          /* Swap newImage and otherImage */
          imageTemp = otherImage; 
          otherImage = newImage;
          newImage = imageTemp;

          newImage_width = newwidth;
          newImage_height = newheight;
          glTexImage2D(target, level, components, newImage_width, 
                newImage_height, 0, format, GL_UNSIGNED_BYTE, 
                (void *) newImage);
      }
      if (newwidth > 1) newwidth /= 2;
      if (newheight > 1) newheight /= 2;
    }
    glPixelStorei(GL_UNPACK_ALIGNMENT, psm->unpack_alignment);
    glPixelStorei(GL_UNPACK_SKIP_ROWS, psm->unpack_skip_rows);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm->unpack_skip_pixels);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, psm->unpack_row_length);
    glPixelStorei(GL_UNPACK_SWAP_BYTES, psm->unpack_swap_bytes);

    if (newImage != (const GLubyte *)data) {
      free((GLbyte *) newImage);
    }
    if (otherImage && otherImage != (const GLubyte *)data) {
      free((GLbyte *) otherImage);
    }
    return 0;
}
#endif

/*
 * Utility Routines
 */
static GLint elements_per_group(GLenum format, GLenum type) 
{
    /*
     * Return the number of elements per group of a specified format
     */

    /* If the type is packedpixels then answer is 1 (ignore format) */
    if (type == GL_UNSIGNED_BYTE_3_3_2 || 
      type == GL_UNSIGNED_BYTE_2_3_3_REV ||
      type == GL_UNSIGNED_SHORT_5_6_5 ||
      type == GL_UNSIGNED_SHORT_5_6_5_REV ||
      type == GL_UNSIGNED_SHORT_4_4_4_4 ||
      type == GL_UNSIGNED_SHORT_4_4_4_4_REV ||
      type == GL_UNSIGNED_SHORT_5_5_5_1  ||
      type == GL_UNSIGNED_SHORT_1_5_5_5_REV  ||
      type == GL_UNSIGNED_INT_8_8_8_8 ||
      type == GL_UNSIGNED_INT_8_8_8_8_REV ||
      type == GL_UNSIGNED_INT_10_10_10_2 ||
      type == GL_UNSIGNED_INT_2_10_10_10_REV) {
        return 1;
    }

    /* Types are not packed pixels, so get elements per group */
    switch(format) {
      case GL_RGB:
      case GL_BGR:
      return 3;
      case GL_LUMINANCE_ALPHA:
      return 2;
      case GL_RGBA:
      case GL_BGRA:
      return 4;
      default:
      return 1;
    }
}

static GLfloat bytes_per_element(GLenum type) 
{
    /*
     * Return the number of bytes per element, based on the element type
     */
    switch(type) {
      case GL_BITMAP:
      return 1.0 / 8.0;
      case GL_UNSIGNED_SHORT:
      return(sizeof(GLushort));
      case GL_SHORT:
      return(sizeof(GLshort));
      case GL_UNSIGNED_BYTE:
      return(sizeof(GLubyte));
      case GL_BYTE:
      return(sizeof(GLbyte));
      case GL_INT:
      return(sizeof(GLint));
      case GL_UNSIGNED_INT:
      return(sizeof(GLuint));
      case GL_FLOAT:
      return(sizeof(GLfloat));
      case GL_UNSIGNED_BYTE_3_3_2:
      case GL_UNSIGNED_BYTE_2_3_3_REV:    
      return(sizeof(GLubyte));
      case GL_UNSIGNED_SHORT_5_6_5:
      case GL_UNSIGNED_SHORT_5_6_5_REV:
      case GL_UNSIGNED_SHORT_4_4_4_4:
      case GL_UNSIGNED_SHORT_4_4_4_4_REV:
      case GL_UNSIGNED_SHORT_5_5_5_1:
      case GL_UNSIGNED_SHORT_1_5_5_5_REV:
      return(sizeof(GLushort));
      case GL_UNSIGNED_INT_8_8_8_8:
      case GL_UNSIGNED_INT_8_8_8_8_REV:
      case GL_UNSIGNED_INT_10_10_10_2:
      case GL_UNSIGNED_INT_2_10_10_10_REV:
      return(sizeof(GLuint));
      default:
      return 4;
    }
}

static GLint is_index(GLenum format) 
{
    return format == GL_COLOR_INDEX || format == GL_STENCIL_INDEX;
}

/*
** Compute memory required for internal packed array of data of given type
** and format.
*/
static GLint image_size(GLint width, GLint height, GLenum format, GLenum type) 
{
    int bytes_per_row;
    int components;

assert(width > 0);
assert(height > 0);
    components = elements_per_group(format,type);
    if (type == GL_BITMAP) {
      bytes_per_row = (width + 7) / 8;
    } else {
      bytes_per_row = bytes_per_element(type) * width;
    }
    return bytes_per_row * height * components;
}

/*
** Extract array from user's data applying all pixel store modes.
** The internal format used is an array of unsigned shorts.
*/
static void fill_image(const PixelStorageModes *psm,
                   GLint width, GLint height, GLenum format, 
                   GLenum type, GLboolean index_format, 
                   const void *userdata, GLushort *newimage)
{
    GLint components;
    GLint element_size;
    GLint rowsize;
    GLint padding;
    GLint groups_per_line;
    GLint group_size;
    GLint elements_per_line;
    const GLubyte *start;
    const GLubyte *iter;
    GLushort *iter2;
    GLint i, j, k;
    GLint myswap_bytes;

    myswap_bytes = psm->unpack_swap_bytes;
    components = elements_per_group(format,type);
    if (psm->unpack_row_length > 0) {
      groups_per_line = psm->unpack_row_length;
    } else {
      groups_per_line = width;
    }

    /* All formats except GL_BITMAP fall out trivially */
    if (type == GL_BITMAP) {
      GLint bit_offset;
      GLint current_bit;

      rowsize = (groups_per_line * components + 7) / 8;
      padding = (rowsize % psm->unpack_alignment);
      if (padding) {
          rowsize += psm->unpack_alignment - padding;
      }
      start = (const GLubyte *) userdata + psm->unpack_skip_rows * rowsize + 
            (psm->unpack_skip_pixels * components / 8);
      elements_per_line = width * components;
      iter2 = newimage;
      for (i = 0; i < height; i++) {
          iter = start;
          bit_offset = (psm->unpack_skip_pixels * components) % 8;
          for (j = 0; j < elements_per_line; j++) {
            /* Retrieve bit */
            if (psm->unpack_lsb_first) {
                current_bit = iter[0] & (1 << bit_offset);
            } else {
                current_bit = iter[0] & (1 << (7 - bit_offset));
            }
            if (current_bit) {
                if (index_format) {
                  *iter2 = 1;
                } else {
                  *iter2 = 65535;
                }
            } else {
                *iter2 = 0;
            }
            bit_offset++;
            if (bit_offset == 8) {
                bit_offset = 0;
                iter++;
            }
            iter2++;
          }
          start += rowsize;
      }
    } else {
      element_size = bytes_per_element(type);
      group_size = element_size * components;
      if (element_size == 1) myswap_bytes = 0;

      rowsize = groups_per_line * group_size;
      padding = (rowsize % psm->unpack_alignment);
      if (padding) {
          rowsize += psm->unpack_alignment - padding;
      }
      start = (const GLubyte *) userdata + psm->unpack_skip_rows * rowsize + 
            psm->unpack_skip_pixels * group_size;
      elements_per_line = width * components;

      iter2 = newimage;
      for (i = 0; i < height; i++) {
          iter = start;
          for (j = 0; j < elements_per_line; j++) {
            Type_Widget widget;
            float extractComponents[4];

            switch(type) {
              case GL_UNSIGNED_BYTE_3_3_2:
                extract332(0,iter,extractComponents);
                for (k = 0; k < 3; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
              case GL_UNSIGNED_BYTE_2_3_3_REV:  
                extract233rev(0,iter,extractComponents);
                for (k = 0; k < 3; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
              case GL_UNSIGNED_BYTE:
                if (index_format) {
                  *iter2++ = *iter;
                } else {
                  *iter2++ = (*iter) * 257;
                }
                break;
              case GL_BYTE:
                if (index_format) {
                  *iter2++ = *((const GLbyte *) iter);
                } else {
                  /* rough approx */
                  *iter2++ = (*((const GLbyte *) iter)) * 516;
                }
                break;
              case GL_UNSIGNED_SHORT_5_6_5:                           
                extract565(myswap_bytes,iter,extractComponents);
                for (k = 0; k < 3; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
              case GL_UNSIGNED_SHORT_5_6_5_REV:                       
                extract565rev(myswap_bytes,iter,extractComponents);
                for (k = 0; k < 3; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
                  case GL_UNSIGNED_SHORT_4_4_4_4:               
                extract4444(myswap_bytes,iter,extractComponents);
                for (k = 0; k < 4; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
                  case GL_UNSIGNED_SHORT_4_4_4_4_REV:           
                extract4444rev(myswap_bytes,iter,extractComponents);
                for (k = 0; k < 4; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
                  case GL_UNSIGNED_SHORT_5_5_5_1:               
                extract5551(myswap_bytes,iter,extractComponents);
                for (k = 0; k < 4; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
              case GL_UNSIGNED_SHORT_1_5_5_5_REV:
                extract1555rev(myswap_bytes,iter,extractComponents);
                for (k = 0; k < 4; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
              case GL_UNSIGNED_SHORT:
              case GL_SHORT:
                if (myswap_bytes) {
                  widget.ub[0] = iter[1];
                  widget.ub[1] = iter[0];
                } else {
                  widget.ub[0] = iter[0];
                  widget.ub[1] = iter[1];
                }
                if (type == GL_SHORT) {
                  if (index_format) {
                      *iter2++ = widget.s[0];
                  } else {
                      /* rough approx */
                      *iter2++ = widget.s[0]*2;
                  }
                } else {
                  *iter2++ = widget.us[0];
                }
                break;
                  case GL_UNSIGNED_INT_8_8_8_8:           
                extract8888(myswap_bytes,iter,extractComponents);
                for (k = 0; k < 4; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
                  case GL_UNSIGNED_INT_8_8_8_8_REV:             
                extract8888rev(myswap_bytes,iter,extractComponents);
                for (k = 0; k < 4; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
                  case GL_UNSIGNED_INT_10_10_10_2:              
                extract1010102(myswap_bytes,iter,extractComponents);
                for (k = 0; k < 4; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
              case GL_UNSIGNED_INT_2_10_10_10_REV:
                extract2101010rev(myswap_bytes,iter,extractComponents);
                for (k = 0; k < 4; k++) {
                  *iter2++ = (GLushort)(extractComponents[k]*65535);
                }
                break;
              case GL_INT:
              case GL_UNSIGNED_INT:
              case GL_FLOAT:
                if (myswap_bytes) {
                  widget.ub[0] = iter[3];
                  widget.ub[1] = iter[2];
                  widget.ub[2] = iter[1];
                  widget.ub[3] = iter[0];
                } else {
                  widget.ub[0] = iter[0];
                  widget.ub[1] = iter[1];
                  widget.ub[2] = iter[2];
                  widget.ub[3] = iter[3];
                }
                if (type == GL_FLOAT) {
                  if (index_format) {
                      *iter2++ = widget.f;
                  } else {
                      *iter2++ = 65535 * widget.f;
                  }
                } else if (type == GL_UNSIGNED_INT) {
                  if (index_format) {
                      *iter2++ = widget.ui;
                  } else {
                      *iter2++ = widget.ui >> 16;
                  }
                } else {
                  if (index_format) {
                      *iter2++ = widget.i;
                  } else {
                      *iter2++ = widget.i >> 15;
                  }
                }
                break;
            }
            iter += element_size;
          } /* for j */
          start += rowsize;
#if 1
          /* want 'iter' pointing at start, not within, row for assertion
           * purposes
           */
          iter= start;  
#endif
      } /* for i */

       /* iterators should be one byte past end */
       if (!isTypePackedPixel(type)) {
        assert(iter2 == &newimage[width*height*components]);
       }
       else {
        assert(iter2 == &newimage[width*height*
                            elements_per_group(format,0)]);
       }
       assert( iter == &((const GLubyte *)userdata)[rowsize*height +
                              psm->unpack_skip_rows * rowsize + 
                              psm->unpack_skip_pixels * group_size] );

    } /* else */
} /* fill_image() */

/*
** Insert array into user's data applying all pixel store modes.
** The internal format is an array of unsigned shorts.
** empty_image() because it is the opposite of fill_image().
*/
static void empty_image(const PixelStorageModes *psm,
                  GLint width, GLint height, GLenum format, 
                    GLenum type, GLboolean index_format, 
                  const GLushort *oldimage, void *userdata)
{
    GLint components;
    GLint element_size;
    GLint rowsize;
    GLint padding;
    GLint groups_per_line;
    GLint group_size;
    GLint elements_per_line;
    GLubyte *start;
    GLubyte *iter;
    const GLushort *iter2;
    GLint i, j, k;
    GLint myswap_bytes;

    myswap_bytes = psm->pack_swap_bytes;
    components = elements_per_group(format,type);
    if (psm->pack_row_length > 0) {
      groups_per_line = psm->pack_row_length;
    } else {
      groups_per_line = width;
    }

    /* All formats except GL_BITMAP fall out trivially */
    if (type == GL_BITMAP) {
      GLint bit_offset;
      GLint current_bit;

      rowsize = (groups_per_line * components + 7) / 8;
      padding = (rowsize % psm->pack_alignment);
      if (padding) {
          rowsize += psm->pack_alignment - padding;
      }
      start = (GLubyte *) userdata + psm->pack_skip_rows * rowsize + 
            (psm->pack_skip_pixels * components / 8);
      elements_per_line = width * components;
      iter2 = oldimage;
      for (i = 0; i < height; i++) {
          iter = start;
          bit_offset = (psm->pack_skip_pixels * components) % 8;
          for (j = 0; j < elements_per_line; j++) {
            if (index_format) {
                current_bit = iter2[0] & 1;
            } else {
                if (iter2[0] > 32767) {
                  current_bit = 1;
                } else {
                  current_bit = 0;
                }
            }

            if (current_bit) {
                if (psm->pack_lsb_first) {
                  *iter |= (1 << bit_offset);
                } else {
                  *iter |= (1 << (7 - bit_offset));
                }
            } else {
                if (psm->pack_lsb_first) {
                  *iter &= ~(1 << bit_offset);
                } else {
                  *iter &= ~(1 << (7 - bit_offset));
                }
            }

            bit_offset++;
            if (bit_offset == 8) {
                bit_offset = 0;
                iter++;
            }
            iter2++;
          }
          start += rowsize;
      }
    } else {
        float shoveComponents[4];

      element_size = bytes_per_element(type);
      group_size = element_size * components;
      if (element_size == 1) myswap_bytes = 0;

      rowsize = groups_per_line * group_size;
      padding = (rowsize % psm->pack_alignment);
      if (padding) {
          rowsize += psm->pack_alignment - padding;
      }
      start = (GLubyte *) userdata + psm->pack_skip_rows * rowsize + 
            psm->pack_skip_pixels * group_size;
      elements_per_line = width * components;

      iter2 = oldimage;
      for (i = 0; i < height; i++) {
          iter = start;
          for (j = 0; j < elements_per_line; j++) {
            Type_Widget widget;

            switch(type) {
              case GL_UNSIGNED_BYTE_3_3_2: 
                for (k = 0; k < 3; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove332(shoveComponents,0,(void *)iter);
                break;
              case GL_UNSIGNED_BYTE_2_3_3_REV:
                for (k = 0; k < 3; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove233rev(shoveComponents,0,(void *)iter);
                break; 
              case GL_UNSIGNED_BYTE:
                if (index_format) {
                  *iter = *iter2++;
                } else {
                  *iter = *iter2++ >> 8;
                }
                break;
              case GL_BYTE:
                if (index_format) {
                  *((GLbyte *) iter) = *iter2++;
                } else {
                  *((GLbyte *) iter) = *iter2++ >> 9;
                }
                break;
              case GL_UNSIGNED_SHORT_5_6_5:               
                for (k = 0; k < 3; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove565(shoveComponents,0,(void *)&widget.us[0]);
                if (myswap_bytes) {
                   iter[0] = widget.ub[1];
                   iter[1] = widget.ub[0];
                }
                else {
                   *(GLushort *)iter = widget.us[0];
                }
                break;
              case GL_UNSIGNED_SHORT_5_6_5_REV:           
                for (k = 0; k < 3; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove565rev(shoveComponents,0,(void *)&widget.us[0]);
                if (myswap_bytes) {
                   iter[0] = widget.ub[1];
                   iter[1] = widget.ub[0];
                }
                else {
                   *(GLushort *)iter = widget.us[0];
                }
                break;
                  case GL_UNSIGNED_SHORT_4_4_4_4:
                for (k = 0; k < 4; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove4444(shoveComponents,0,(void *)&widget.us[0]);
                if (myswap_bytes) {
                   iter[0] = widget.ub[1];
                   iter[1] = widget.ub[0];
                } else {
                   *(GLushort *)iter = widget.us[0];
                }
                break;
                  case GL_UNSIGNED_SHORT_4_4_4_4_REV:
                for (k = 0; k < 4; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove4444rev(shoveComponents,0,(void *)&widget.us[0]);
                if (myswap_bytes) {
                   iter[0] = widget.ub[1];
                   iter[1] = widget.ub[0];
                } else {
                   *(GLushort *)iter = widget.us[0];
                }
                break;
              case GL_UNSIGNED_SHORT_5_5_5_1:
                for (k = 0; k < 4; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove5551(shoveComponents,0,(void *)&widget.us[0]);
                if (myswap_bytes) {
                   iter[0] = widget.ub[1];
                   iter[1] = widget.ub[0];
                } else {
                   *(GLushort *)iter = widget.us[0];
                }
                break;
              case GL_UNSIGNED_SHORT_1_5_5_5_REV:
                for (k = 0; k < 4; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove1555rev(shoveComponents,0,(void *)&widget.us[0]);
                if (myswap_bytes) {
                   iter[0] = widget.ub[1];
                   iter[1] = widget.ub[0];
                } else {
                   *(GLushort *)iter = widget.us[0];
                }
                break;
              case GL_UNSIGNED_SHORT:
              case GL_SHORT:
                if (type == GL_SHORT) {
                  if (index_format) {
                      widget.s[0] = *iter2++;
                  } else {
                      widget.s[0] = *iter2++ >> 1;
                  }
                } else {
                  widget.us[0] = *iter2++;
                }
                if (myswap_bytes) {
                  iter[0] = widget.ub[1];
                  iter[1] = widget.ub[0];
                } else {
                  iter[0] = widget.ub[0];
                  iter[1] = widget.ub[1];
                }
                break;
              case GL_UNSIGNED_INT_8_8_8_8:  
                for (k = 0; k < 4; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove8888(shoveComponents,0,(void *)&widget.ui);
                if (myswap_bytes) {
                  iter[3] = widget.ub[0];
                  iter[2] = widget.ub[1];
                  iter[1] = widget.ub[2];
                  iter[0] = widget.ub[3];
                } else {
                    *(GLuint *)iter= widget.ui;
                }

                break;
              case GL_UNSIGNED_INT_8_8_8_8_REV:  
                for (k = 0; k < 4; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove8888rev(shoveComponents,0,(void *)&widget.ui);
                if (myswap_bytes) {
                  iter[3] = widget.ub[0];
                  iter[2] = widget.ub[1];
                  iter[1] = widget.ub[2];
                  iter[0] = widget.ub[3];
                } else {
                    *(GLuint *)iter= widget.ui;
                }
                break;
              case GL_UNSIGNED_INT_10_10_10_2:  
                for (k = 0; k < 4; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove1010102(shoveComponents,0,(void *)&widget.ui);
                if (myswap_bytes) {
                  iter[3] = widget.ub[0];
                  iter[2] = widget.ub[1];
                  iter[1] = widget.ub[2];
                  iter[0] = widget.ub[3];
                } else {
                    *(GLuint *)iter= widget.ui;
                }
                break;
              case GL_UNSIGNED_INT_2_10_10_10_REV:
                for (k = 0; k < 4; k++) {
                   shoveComponents[k]= *iter2++ / 65535.0;
                } 
                shove2101010rev(shoveComponents,0,(void *)&widget.ui);
                if (myswap_bytes) {
                  iter[3] = widget.ub[0];
                  iter[2] = widget.ub[1];
                  iter[1] = widget.ub[2];
                  iter[0] = widget.ub[3];
                } else {
                    *(GLuint *)iter= widget.ui;
                }
                break;
              case GL_INT:
              case GL_UNSIGNED_INT:
              case GL_FLOAT:
                if (type == GL_FLOAT) {
                  if (index_format) {
                      widget.f = *iter2++;
                  } else {
                      widget.f = *iter2++ / (float) 65535.0;
                  }
                } else if (type == GL_UNSIGNED_INT) {
                  if (index_format) {
                      widget.ui = *iter2++;
                  } else {
                      widget.ui = (unsigned int) *iter2++ * 65537;
                  }
                } else {
                  if (index_format) {
                      widget.i = *iter2++;
                  } else {
                      widget.i = ((unsigned int) *iter2++ * 65537)/2;
                  }
                }
                if (myswap_bytes) {
                  iter[3] = widget.ub[0];
                  iter[2] = widget.ub[1];
                  iter[1] = widget.ub[2];
                  iter[0] = widget.ub[3];
                } else {
                  iter[0] = widget.ub[0];
                  iter[1] = widget.ub[1];
                  iter[2] = widget.ub[2];
                  iter[3] = widget.ub[3];
                }
                break;
            }
            iter += element_size;
          } /* for j */
          start += rowsize;
#if 1
          /* want 'iter' pointing at start, not within, row for assertion
           * purposes
           */
          iter= start;  
#endif
      } /* for i */

      /* iterators should be one byte past end */
      if (!isTypePackedPixel(type)) {
         assert(iter2 == &oldimage[width*height*components]);
      }
      else {
         assert(iter2 == &oldimage[width*height*
                             elements_per_group(format,0)]);
      }
      assert( iter == &((GLubyte *)userdata)[rowsize*height +
                              psm->pack_skip_rows * rowsize + 
                              psm->pack_skip_pixels * group_size] );

    } /* else */
} /* empty_image() */

/*--------------------------------------------------------------------------
 * Decimation of packed pixel types 
 *--------------------------------------------------------------------------
 */ 
static void extract332(int isSwap,
                   const void *packedPixel, GLfloat extractComponents[])
{
   GLubyte ubyte= *(const GLubyte *)packedPixel;

   isSwap= isSwap;            /* turn off warnings */

   /* 11100000 == 0xe0 */
   /* 00011100 == 0x1c */
   /* 00000011 == 0x03 */

   extractComponents[0]=   (float)((ubyte & 0xe0)  >> 5) / 7.0;
   extractComponents[1]=   (float)((ubyte & 0x1c)  >> 2) / 7.0; /* 7 = 2^3-1 */
   extractComponents[2]=   (float)((ubyte & 0x03)      ) / 3.0;   /* 3 = 2^2-1 */
} /* extract332() */

static void shove332(const GLfloat shoveComponents[], 
                 int index, void *packedPixel)         
{
   /* 11100000 == 0xe0 */
   /* 00011100 == 0x1c */
   /* 00000011 == 0x03 */

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLubyte *)packedPixel)[index]  = 
     ((GLubyte)((shoveComponents[0] * 7)+0.5)  << 5) & 0xe0;
   ((GLubyte *)packedPixel)[index] |= 
     ((GLubyte)((shoveComponents[1] * 7)+0.5)  << 2) & 0x1c;
   ((GLubyte *)packedPixel)[index]  |=
     ((GLubyte)((shoveComponents[2] * 3)+0.5)      ) & 0x03;
} /* shove332() */

static void extract233rev(int isSwap,
                    const void *packedPixel, GLfloat extractComponents[])
{
   GLubyte ubyte= *(const GLubyte *)packedPixel;

   isSwap= isSwap;            /* turn off warnings */

   /* 0000,0111 == 0x07 */
   /* 0011,1000 == 0x38 */  
   /* 1100,0000 == 0xC0 */

   extractComponents[0]= (float)((ubyte & 0x07)     ) / 7.0;
   extractComponents[1]= (float)((ubyte & 0x38) >> 3) / 7.0;
   extractComponents[2]= (float)((ubyte & 0xC0) >> 6) / 3.0;
} /* extract233rev() */

static void shove233rev(const GLfloat shoveComponents[], 
                  int index, void *packedPixel)        
{
   /* 0000,0111 == 0x07 */
   /* 0011,1000 == 0x38 */  
   /* 1100,0000 == 0xC0 */

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLubyte *)packedPixel)[index] = 
     ((GLubyte)((shoveComponents[0] * 7.0)+0.5)     ) & 0x07;
   ((GLubyte *)packedPixel)[index]|= 
     ((GLubyte)((shoveComponents[1] * 7.0)+0.5) << 3) & 0x38;
   ((GLubyte *)packedPixel)[index]|= 
     ((GLubyte)((shoveComponents[2] * 3.0)+0.5) << 6) & 0xC0;
} /* shove233rev() */

static void extract565(int isSwap,
                   const void *packedPixel, GLfloat extractComponents[])
{
   GLushort ushort= *(const GLushort *)packedPixel; 

   if (isSwap) {
     ushort= __GLU_SWAP_2_BYTES(packedPixel);
   }
   else {
     ushort= *(const GLushort *)packedPixel;
   }

   /* 11111000,00000000 == 0xf800 */
   /* 00000111,11100000 == 0x07e0 */
   /* 00000000,00011111 == 0x001f */

   extractComponents[0]=(float)((ushort & 0xf800) >> 11) / 31.0;/* 31 = 2^5-1*/
   extractComponents[1]=(float)((ushort & 0x07e0) >>  5) / 63.0;/* 63 = 2^6-1*/
   extractComponents[2]=(float)((ushort & 0x001f)      ) / 31.0;
} /* extract565() */

static void shove565(const GLfloat shoveComponents[],
                 int index,void *packedPixel)
{
   /* 11111000,00000000 == 0xf800 */
   /* 00000111,11100000 == 0x07e0 */
   /* 00000000,00011111 == 0x001f */

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLushort *)packedPixel)[index] = 
     ((GLushort)((shoveComponents[0] * 31)+0.5) << 11) & 0xf800;
   ((GLushort *)packedPixel)[index]|= 
     ((GLushort)((shoveComponents[1] * 63)+0.5) <<  5) & 0x07e0;
   ((GLushort *)packedPixel)[index]|= 
     ((GLushort)((shoveComponents[2] * 31)+0.5)      ) & 0x001f;
} /* shove565() */

static void extract565rev(int isSwap,
                    const void *packedPixel, GLfloat extractComponents[])
{
   GLushort ushort= *(const GLushort *)packedPixel; 

   if (isSwap) {
     ushort= __GLU_SWAP_2_BYTES(packedPixel);
   }
   else {
     ushort= *(const GLushort *)packedPixel;
   }

   /* 00000000,00011111 == 0x001f */
   /* 00000111,11100000 == 0x07e0 */
   /* 11111000,00000000 == 0xf800 */

   extractComponents[0]= (float)((ushort & 0x001F)      ) / 31.0;
   extractComponents[1]= (float)((ushort & 0x07E0) >>  5) / 63.0;
   extractComponents[2]= (float)((ushort & 0xF800) >> 11) / 31.0;
} /* extract565rev() */

static void shove565rev(const GLfloat shoveComponents[],
                  int index,void *packedPixel)
{
   /* 00000000,00011111 == 0x001f */
   /* 00000111,11100000 == 0x07e0 */
   /* 11111000,00000000 == 0xf800 */

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLushort *)packedPixel)[index] = 
     ((GLushort)((shoveComponents[0] * 31.0)+0.5)      ) & 0x001F;
   ((GLushort *)packedPixel)[index]|=   
     ((GLushort)((shoveComponents[1] * 63.0)+0.5) <<  5) & 0x07E0;
   ((GLushort *)packedPixel)[index]|=   
     ((GLushort)((shoveComponents[2] * 31.0)+0.5) << 11) & 0xF800;
} /* shove565rev() */

static void extract4444(int isSwap,const void *packedPixel, 
                  GLfloat extractComponents[])
{
   GLushort ushort;

   if (isSwap) {
     ushort= __GLU_SWAP_2_BYTES(packedPixel);
   }
   else {
     ushort= *(const GLushort *)packedPixel;
   }

   /* 11110000,00000000 == 0xf000 */  
   /* 00001111,00000000 == 0x0f00 */  
   /* 00000000,11110000 == 0x00f0 */  
   /* 00000000,00001111 == 0x000f */  

   extractComponents[0]= (float)((ushort & 0xf000) >> 12) / 15.0;/* 15=2^4-1 */
   extractComponents[1]= (float)((ushort & 0x0f00) >>  8) / 15.0;
   extractComponents[2]= (float)((ushort & 0x00f0) >>  4) / 15.0;
   extractComponents[3]= (float)((ushort & 0x000f)      ) / 15.0;
} /* extract4444() */

static void shove4444(const GLfloat shoveComponents[],
                  int index,void *packedPixel)
{
   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);
   assert(0.0 <= shoveComponents[3] && shoveComponents[3] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLushort *)packedPixel)[index] = 
     ((GLushort)((shoveComponents[0] * 15)+0.5) << 12) & 0xf000;
   ((GLushort *)packedPixel)[index]|= 
     ((GLushort)((shoveComponents[1] * 15)+0.5) <<  8) & 0x0f00;
   ((GLushort *)packedPixel)[index]|= 
     ((GLushort)((shoveComponents[2] * 15)+0.5) <<  4) & 0x00f0;
   ((GLushort *)packedPixel)[index]|= 
     ((GLushort)((shoveComponents[3] * 15)+0.5)      ) & 0x000f;
} /* shove4444() */

static void extract4444rev(int isSwap,const void *packedPixel, 
                     GLfloat extractComponents[])
{
   GLushort ushort;

   if (isSwap) {
     ushort= __GLU_SWAP_2_BYTES(packedPixel);
   }
   else {
     ushort= *(const GLushort *)packedPixel;
   }

   /* 00000000,00001111 == 0x000f */  
   /* 00000000,11110000 == 0x00f0 */  
   /* 00001111,00000000 == 0x0f00 */  
   /* 11110000,00000000 == 0xf000 */  

   /* 15 = 2^4-1 */
   extractComponents[0]= (float)((ushort & 0x000F)      ) / 15.0;
   extractComponents[1]= (float)((ushort & 0x00F0) >>  4) / 15.0;
   extractComponents[2]= (float)((ushort & 0x0F00) >>  8) / 15.0;
   extractComponents[3]= (float)((ushort & 0xF000) >> 12) / 15.0;
} /* extract4444rev() */

static void shove4444rev(const GLfloat shoveComponents[],
                   int index,void *packedPixel)
{
   /* 00000000,00001111 == 0x000f */  
   /* 00000000,11110000 == 0x00f0 */  
   /* 00001111,00000000 == 0x0f00 */  
   /* 11110000,00000000 == 0xf000 */  

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);
   assert(0.0 <= shoveComponents[3] && shoveComponents[3] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLushort *)packedPixel)[index] =   
     ((GLushort)((shoveComponents[0] * 15)+0.5)      ) & 0x000F;
   ((GLushort *)packedPixel)[index]|=   
     ((GLushort)((shoveComponents[1] * 15)+0.5) <<  4) & 0x00F0;
   ((GLushort *)packedPixel)[index]|=   
     ((GLushort)((shoveComponents[2] * 15)+0.5) <<  8) & 0x0F00;
   ((GLushort *)packedPixel)[index]|=   
     ((GLushort)((shoveComponents[3] * 15)+0.5) << 12) & 0xF000;
} /* shove4444rev() */

static void extract5551(int isSwap,const void *packedPixel, 
                  GLfloat extractComponents[])
{
   GLushort ushort;

   if (isSwap) {
     ushort= __GLU_SWAP_2_BYTES(packedPixel);
   }
   else {
     ushort= *(const GLushort *)packedPixel;
   }

   /* 11111000,00000000 == 0xf800 */  
   /* 00000111,11000000 == 0x07c0 */  
   /* 00000000,00111110 == 0x003e */  
   /* 00000000,00000001 == 0x0001 */  

   extractComponents[0]=(float)((ushort & 0xf800) >> 11) / 31.0;/* 31 = 2^5-1*/
   extractComponents[1]=(float)((ushort & 0x07c0) >>  6) / 31.0;
   extractComponents[2]=(float)((ushort & 0x003e) >>  1) / 31.0;
   extractComponents[3]=(float)((ushort & 0x0001)      );
} /* extract5551() */

static void shove5551(const GLfloat shoveComponents[],
                  int index,void *packedPixel)
{
   /* 11111000,00000000 == 0xf800 */  
   /* 00000111,11000000 == 0x07c0 */  
   /* 00000000,00111110 == 0x003e */  
   /* 00000000,00000001 == 0x0001 */  

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);
   assert(0.0 <= shoveComponents[3] && shoveComponents[3] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLushort *)packedPixel)[index]  = 
     ((GLushort)((shoveComponents[0] * 31)+0.5) << 11) & 0xf800;
   ((GLushort *)packedPixel)[index]|= 
     ((GLushort)((shoveComponents[1] * 31)+0.5) <<  6) & 0x07c0;
   ((GLushort *)packedPixel)[index]|= 
     ((GLushort)((shoveComponents[2] * 31)+0.5) <<  1) & 0x003e;
   ((GLushort *)packedPixel)[index]|= 
     ((GLushort)((shoveComponents[3])+0.5)           ) & 0x0001;
} /* shove5551() */

static void extract1555rev(int isSwap,const void *packedPixel, 
                     GLfloat extractComponents[])
{
   GLushort ushort;

   if (isSwap) {
     ushort= __GLU_SWAP_2_BYTES(packedPixel);
   }
   else {
     ushort= *(const GLushort *)packedPixel;
   }

   /* 00000000,00011111 == 0x001F */  
   /* 00000011,11100000 == 0x03E0 */  
   /* 01111100,00000000 == 0x7C00 */  
   /* 10000000,00000000 == 0x8000 */  

   /* 31 = 2^5-1 */
   extractComponents[0]= (float)((ushort & 0x001F)      ) / 31.0;  
   extractComponents[1]= (float)((ushort & 0x03E0) >>  5) / 31.0;
   extractComponents[2]= (float)((ushort & 0x7C00) >> 10) / 31.0;
   extractComponents[3]= (float)((ushort & 0x8000) >> 15);
} /* extract1555rev() */

static void shove1555rev(const GLfloat shoveComponents[],
                   int index,void *packedPixel)
{
   /* 00000000,00011111 == 0x001F */  
   /* 00000011,11100000 == 0x03E0 */  
   /* 01111100,00000000 == 0x7C00 */  
   /* 10000000,00000000 == 0x8000 */  

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);
   assert(0.0 <= shoveComponents[3] && shoveComponents[3] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLushort *)packedPixel)[index] =   
     ((GLushort)((shoveComponents[0] * 31)+0.5)      ) & 0x001F;
   ((GLushort *)packedPixel)[index]|=   
     ((GLushort)((shoveComponents[1] * 31)+0.5) <<  5) & 0x03E0;
   ((GLushort *)packedPixel)[index]|=   
     ((GLushort)((shoveComponents[2] * 31)+0.5) << 10) & 0x7C00;
   ((GLushort *)packedPixel)[index]|=   
     ((GLushort)((shoveComponents[3])+0.5)      << 15) & 0x8000;
} /* shove1555rev() */ 

static void extract8888(int isSwap,
                  const void *packedPixel, GLfloat extractComponents[])
{
   GLuint uint;

   if (isSwap) {
     uint= __GLU_SWAP_4_BYTES(packedPixel);
   }
   else {
     uint= *(const GLuint *)packedPixel;
   }

   /* 11111111,00000000,00000000,00000000 == 0xff000000 */  
   /* 00000000,11111111,00000000,00000000 == 0x00ff0000 */  
   /* 00000000,00000000,11111111,00000000 == 0x0000ff00 */  
   /* 00000000,00000000,00000000,11111111 == 0x000000ff */  

   /* 255 = 2^8-1 */
   extractComponents[0]= (float)((uint & 0xff000000) >> 24) / 255.0;
   extractComponents[1]= (float)((uint & 0x00ff0000) >> 16) / 255.0;
   extractComponents[2]= (float)((uint & 0x0000ff00) >>  8) / 255.0;
   extractComponents[3]= (float)((uint & 0x000000ff)      ) / 255.0;
} /* extract8888() */

static void shove8888(const GLfloat shoveComponents[],
                  int index,void *packedPixel)
{
   /* 11111111,00000000,00000000,00000000 == 0xff000000 */  
   /* 00000000,11111111,00000000,00000000 == 0x00ff0000 */  
   /* 00000000,00000000,11111111,00000000 == 0x0000ff00 */  
   /* 00000000,00000000,00000000,11111111 == 0x000000ff */  

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);
   assert(0.0 <= shoveComponents[3] && shoveComponents[3] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLuint *)packedPixel)[index] = 
     ((GLuint)((shoveComponents[0] * 255)+0.5) << 24) & 0xff000000;
   ((GLuint *)packedPixel)[index]|= 
     ((GLuint)((shoveComponents[1] * 255)+0.5) << 16) & 0x00ff0000;
   ((GLuint *)packedPixel)[index]|=    
     ((GLuint)((shoveComponents[2] * 255)+0.5) <<  8) & 0x0000ff00;
   ((GLuint *)packedPixel)[index]|=    
     ((GLuint)((shoveComponents[3] * 255)+0.5)      ) & 0x000000ff;
} /* shove8888() */

static void extract8888rev(int isSwap,
                     const void *packedPixel,GLfloat extractComponents[])
{
   GLuint uint;

   if (isSwap) {
     uint= __GLU_SWAP_4_BYTES(packedPixel);
   }
   else {
     uint= *(const GLuint *)packedPixel;
   }

   /* 00000000,00000000,00000000,11111111 == 0x000000ff */  
   /* 00000000,00000000,11111111,00000000 == 0x0000ff00 */  
   /* 00000000,11111111,00000000,00000000 == 0x00ff0000 */  
   /* 11111111,00000000,00000000,00000000 == 0xff000000 */  

   /* 255 = 2^8-1 */
   extractComponents[0]= (float)((uint & 0x000000FF)      ) / 255.0; 
   extractComponents[1]= (float)((uint & 0x0000FF00) >>  8) / 255.0;
   extractComponents[2]= (float)((uint & 0x00FF0000) >> 16) / 255.0;
   extractComponents[3]= (float)((uint & 0xFF000000) >> 24) / 255.0;
} /* extract8888rev() */

static void shove8888rev(const GLfloat shoveComponents[],
                   int index,void *packedPixel)
{
   /* 00000000,00000000,00000000,11111111 == 0x000000ff */  
   /* 00000000,00000000,11111111,00000000 == 0x0000ff00 */  
   /* 00000000,11111111,00000000,00000000 == 0x00ff0000 */  
   /* 11111111,00000000,00000000,00000000 == 0xff000000 */  

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);
   assert(0.0 <= shoveComponents[3] && shoveComponents[3] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLuint *)packedPixel)[index] = 
     ((GLuint)((shoveComponents[0] * 255)+0.5)      ) & 0x000000FF;
   ((GLuint *)packedPixel)[index]|= 
     ((GLuint)((shoveComponents[1] * 255)+0.5) <<  8) & 0x0000FF00;
   ((GLuint *)packedPixel)[index]|= 
     ((GLuint)((shoveComponents[2] * 255)+0.5) << 16) & 0x00FF0000;
   ((GLuint *)packedPixel)[index]|= 
     ((GLuint)((shoveComponents[3] * 255)+0.5) << 24) & 0xFF000000;
} /* shove8888rev() */

static void extract1010102(int isSwap,
                     const void *packedPixel,GLfloat extractComponents[])
{
   GLuint uint;

   if (isSwap) {
     uint= __GLU_SWAP_4_BYTES(packedPixel);
   }
   else {
     uint= *(const GLuint *)packedPixel;
   }

   /* 11111111,11000000,00000000,00000000 == 0xffc00000 */  
   /* 00000000,00111111,11110000,00000000 == 0x003ff000 */  
   /* 00000000,00000000,00001111,11111100 == 0x00000ffc */  
   /* 00000000,00000000,00000000,00000011 == 0x00000003 */  

   /* 1023 = 2^10-1 */
   extractComponents[0]= (float)((uint & 0xffc00000) >> 22) / 1023.0; 
   extractComponents[1]= (float)((uint & 0x003ff000) >> 12) / 1023.0;
   extractComponents[2]= (float)((uint & 0x00000ffc) >>  2) / 1023.0;
   extractComponents[3]= (float)((uint & 0x00000003)      ) / 3.0;
} /* extract1010102() */

static void shove1010102(const GLfloat shoveComponents[],
                   int index,void *packedPixel)
{
   /* 11111111,11000000,00000000,00000000 == 0xffc00000 */  
   /* 00000000,00111111,11110000,00000000 == 0x003ff000 */  
   /* 00000000,00000000,00001111,11111100 == 0x00000ffc */  
   /* 00000000,00000000,00000000,00000011 == 0x00000003 */  

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);
   assert(0.0 <= shoveComponents[3] && shoveComponents[3] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLuint *)packedPixel)[index] = 
     ((GLuint)((shoveComponents[0] * 1023)+0.5) << 22) & 0xffc00000;
   ((GLuint *)packedPixel)[index]|= 
     ((GLuint)((shoveComponents[1] * 1023)+0.5) << 12) & 0x003ff000;
   ((GLuint *)packedPixel)[index]|= 
     ((GLuint)((shoveComponents[2] * 1023)+0.5) <<  2) & 0x00000ffc;
   ((GLuint *)packedPixel)[index]|= 
     ((GLuint)((shoveComponents[3] * 3)+0.5)         ) & 0x00000003;
} /* shove1010102() */ 

static void extract2101010rev(int isSwap,
                        const void *packedPixel,
                        GLfloat extractComponents[])
{
   GLuint uint;

   if (isSwap) {
     uint= __GLU_SWAP_4_BYTES(packedPixel);
   }
   else {
     uint= *(const GLuint *)packedPixel;
   }

   /* 00000000,00000000,00000011,11111111 == 0x000003FF */  
   /* 00000000,00001111,11111100,00000000 == 0x000FFC00 */  
   /* 00111111,11110000,00000000,00000000 == 0x3FF00000 */  
   /* 11000000,00000000,00000000,00000000 == 0xC0000000 */  

   /* 1023 = 2^10-1 */
   extractComponents[0]= (float)((uint & 0x000003FF)      ) / 1023.0;  
   extractComponents[1]= (float)((uint & 0x000FFC00) >> 10) / 1023.0;
   extractComponents[2]= (float)((uint & 0x3FF00000) >> 20) / 1023.0;
   extractComponents[3]= (float)((uint & 0xC0000000) >> 30) / 3.0;  
   /* 3 = 2^2-1 */
} /* extract2101010rev() */

static void shove2101010rev(const GLfloat shoveComponents[],
                      int index,void *packedPixel)
{
   /* 00000000,00000000,00000011,11111111 == 0x000003FF */  
   /* 00000000,00001111,11111100,00000000 == 0x000FFC00 */  
   /* 00111111,11110000,00000000,00000000 == 0x3FF00000 */  
   /* 11000000,00000000,00000000,00000000 == 0xC0000000 */  

   assert(0.0 <= shoveComponents[0] && shoveComponents[0] <= 1.0);
   assert(0.0 <= shoveComponents[1] && shoveComponents[1] <= 1.0);
   assert(0.0 <= shoveComponents[2] && shoveComponents[2] <= 1.0);
   assert(0.0 <= shoveComponents[3] && shoveComponents[3] <= 1.0);

   /* due to limited precision, need to round before shoving */
   ((GLuint *)packedPixel)[index] = 
     ((GLuint)((shoveComponents[0] * 1023)+0.5)      ) & 0x000003FF;
   ((GLuint *)packedPixel)[index]|= 
     ((GLuint)((shoveComponents[1] * 1023)+0.5) << 10) & 0x000FFC00;
   ((GLuint *)packedPixel)[index]|= 
     ((GLuint)((shoveComponents[2] * 1023)+0.5) << 20) & 0x3FF00000;
   ((GLuint *)packedPixel)[index]|= 
     ((GLuint)((shoveComponents[3] * 3)+0.5)    << 30) & 0xC0000000;
} /* shove2101010rev() */

static void scaleInternalPackedPixel(int components,
                             void (*extractPackedPixel)
                             (int, const void *,GLfloat []),
                             void (*shovePackedPixel)
                             (const GLfloat [], int, void *),
                             GLint widthIn,GLint heightIn, 
                             const void *dataIn,
                             GLint widthOut,GLint heightOut,
                             void *dataOut,
                             GLint pixelSizeInBytes,
                             GLint rowSizeInBytes,GLint isSwap)
{
    float convx;
    float convy;
    float percent;

    /* Max components in a format is 4, so... */
    float totals[4];
    float extractTotals[4], extractMoreTotals[4], shoveTotals[4];

    float area;
    int i,j,k,xindex;

    const char *temp, *temp0;
#if 0
    const char *temp_index;
#endif
    int outindex;

    int lowx_int, highx_int, lowy_int, highy_int;
    float x_percent, y_percent;
    float lowx_float, highx_float, lowy_float, highy_float;
    float convy_float, convx_float;
    int convy_int, convx_int;
    int l, m;
    const char *left, *right;

    if (widthIn == widthOut*2 && heightIn == heightOut*2) {
      halveImagePackedPixel(components,extractPackedPixel,shovePackedPixel,
                        widthIn, heightIn, dataIn, dataOut,
                        pixelSizeInBytes,rowSizeInBytes,isSwap);
      return;
    }
    convy = (float) heightIn/heightOut;
    convx = (float) widthIn/widthOut;
    convy_int = floor(convy);
    convy_float = convy - convy_int;
    convx_int = floor(convx);
    convx_float = convx - convx_int;
   
    area = convx * convy;

    lowy_int = 0;
    lowy_float = 0;
    highy_int = convy_int;
    highy_float = convy_float;

    for (i = 0; i < heightOut; i++) {
      lowx_int = 0;
      lowx_float = 0;
      highx_int = convx_int;
      highx_float = convx_float;

      for (j = 0; j < widthOut; j++) {
          /*
          ** Ok, now apply box filter to box that goes from (lowx, lowy)
          ** to (highx, highy) on input data into this pixel on output
          ** data.
          */
          totals[0] = totals[1] = totals[2] = totals[3] = 0.0;

          /* calculate the value for pixels in the 1st row */
          xindex = lowx_int*pixelSizeInBytes;
          if((highy_int>lowy_int) && (highx_int>lowx_int)) {

            y_percent = 1-lowy_float;
            temp = (const char *)dataIn + xindex + lowy_int * rowSizeInBytes;
            percent = y_percent * (1-lowx_float);
#if 0
                  for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                if (myswap_bytes) {
                  totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                } else {
                    totals[k] += *(const GLushort*)temp_index * percent;
                }
              }
#else
            (*extractPackedPixel)(isSwap,temp,extractTotals);
            for (k = 0; k < components; k++) {
               totals[k]+= extractTotals[k] * percent;
            } 
#endif
            left = temp;
            for(l = lowx_int+1; l < highx_int; l++) {
                temp += pixelSizeInBytes;
#if 0
                for (k = 0, temp_index = temp; k < components; 
                   k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                                 __GLU_SWAP_2_BYTES(temp_index) * y_percent;
                        } else {
                            totals[k] += *(const GLushort*)temp_index * y_percent;
                        }
                }
#else
                (*extractPackedPixel)(isSwap,temp,extractTotals);
                for (k = 0; k < components; k++) {
                   totals[k]+= extractTotals[k] * y_percent;
                } 
#endif
              }
            temp += pixelSizeInBytes;
            right = temp;
            percent = y_percent * highx_float;
#if 0
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }
#else
            (*extractPackedPixel)(isSwap,temp,extractTotals);
            for (k = 0; k < components; k++) {
               totals[k]+= extractTotals[k] * percent;
            } 
#endif

            /* calculate the value for pixels in the last row */
            
            y_percent = highy_float;
            percent = y_percent * (1-lowx_float);
            temp = (const char *)dataIn + xindex + highy_int * rowSizeInBytes;
#if 0
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }
#else
            (*extractPackedPixel)(isSwap,temp,extractTotals);
            for (k = 0; k < components; k++) {
               totals[k]+= extractTotals[k] * percent;
            } 
#endif
            for(l = lowx_int+1; l < highx_int; l++) {
                    temp += pixelSizeInBytes;
#if 0
                    for (k = 0, temp_index = temp; k < components; 
                   k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                                 __GLU_SWAP_2_BYTES(temp_index) * y_percent;
                        } else {
                            totals[k] += *(const GLushort*)temp_index * y_percent;
                        }
                    }
#else
                (*extractPackedPixel)(isSwap,temp,extractTotals);
                for (k = 0; k < components; k++) {
                   totals[k]+= extractTotals[k] * y_percent;
                } 
#endif

                }
                temp += pixelSizeInBytes;
            percent = y_percent * highx_float;
#if 0
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }
#else
            (*extractPackedPixel)(isSwap,temp,extractTotals);
            for (k = 0; k < components; k++) {
               totals[k]+= extractTotals[k] * percent;
            } 
#endif

            /* calculate the value for pixels in the 1st and last column */
            for(m = lowy_int+1; m < highy_int; m++) {
                left += rowSizeInBytes;
                right += rowSizeInBytes;
#if 0
                    for (k = 0; k < components; 
                     k++, left += element_size, right += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                          __GLU_SWAP_2_BYTES(left) * (1-lowx_float) +
                          __GLU_SWAP_2_BYTES(right) * highx_float;
                        } else {
                            totals[k] += *(const GLushort*)left * (1-lowx_float)
                                       + *(const GLushort*)right * highx_float;
                        }
                }
#else
                (*extractPackedPixel)(isSwap,left,extractTotals);
                (*extractPackedPixel)(isSwap,right,extractMoreTotals);
                for (k = 0; k < components; k++) {
                   totals[k]+= (extractTotals[k]*(1-lowx_float) +
                             extractMoreTotals[k]*highx_float);
                }
#endif
            }
          } else if (highy_int > lowy_int) {
            x_percent = highx_float - lowx_float;
            percent = (1-lowy_float)*x_percent;
            temp = (const char *)dataIn + xindex + lowy_int*rowSizeInBytes;
#if 0
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
              }
#else
            (*extractPackedPixel)(isSwap,temp,extractTotals);
            for (k = 0; k < components; k++) {
               totals[k]+= extractTotals[k] * percent;
            } 
#endif
            for(m = lowy_int+1; m < highy_int; m++) {
                temp += rowSizeInBytes;
#if 0
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                        __GLU_SWAP_2_BYTES(temp_index) * x_percent;
                        } else {
                            totals[k] += *(const GLushort*)temp_index * x_percent;
                        }
                }
#else
                (*extractPackedPixel)(isSwap,temp,extractTotals);
                for (k = 0; k < components; k++) {
                   totals[k]+= extractTotals[k] * x_percent;
                } 
#endif
            }
            percent = x_percent * highy_float;
            temp += rowSizeInBytes;
#if 0
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }
#else
            (*extractPackedPixel)(isSwap,temp,extractTotals);
            for (k = 0; k < components; k++) {
               totals[k]+= extractTotals[k] * percent;
            } 
#endif
          } else if (highx_int > lowx_int) {
            y_percent = highy_float - lowy_float;
            percent = (1-lowx_float)*y_percent;
            temp = (const char *)dataIn + xindex + lowy_int*rowSizeInBytes;
#if 0
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }
#else
            (*extractPackedPixel)(isSwap,temp,extractTotals);
            for (k = 0; k < components; k++) {
               totals[k]+= extractTotals[k] * percent;
            } 
#endif
            for (l = lowx_int+1; l < highx_int; l++) {
                    temp += pixelSizeInBytes;
#if 0
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += 
                          __GLU_SWAP_2_BYTES(temp_index) * y_percent;
                        } else {
                            totals[k] += *(const GLushort*)temp_index * y_percent;
                        }
                }
#else
            (*extractPackedPixel)(isSwap,temp,extractTotals);
            for (k = 0; k < components; k++) {
               totals[k]+= extractTotals[k] * y_percent;
            } 
#endif
            }
            temp += pixelSizeInBytes;
            percent = y_percent * highx_float;
#if 0
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
            }
#else
            (*extractPackedPixel)(isSwap,temp,extractTotals);
            for (k = 0; k < components; k++) {
               totals[k]+= extractTotals[k] * percent;
            } 
#endif
          } else {
            percent = (highy_float-lowy_float)*(highx_float-lowx_float);
            temp = (const char *)dataIn + xindex + lowy_int * rowSizeInBytes;
#if 0
                for (k = 0, temp_index = temp; k < components; 
                 k++, temp_index += element_size) {
                    if (myswap_bytes) {
                        totals[k] += __GLU_SWAP_2_BYTES(temp_index) * percent;
                    } else {
                        totals[k] += *(const GLushort*)temp_index * percent;
                    }
                }
#else
            (*extractPackedPixel)(isSwap,temp,extractTotals);
            for (k = 0; k < components; k++) {
               totals[k]+= extractTotals[k] * percent;
            } 
#endif
          }

          /* this is for the pixels in the body */
          temp0 = (const char *)dataIn + xindex + pixelSizeInBytes + (lowy_int+1)*rowSizeInBytes;
          for (m = lowy_int+1; m < highy_int; m++) {
            temp = temp0;
            for(l = lowx_int+1; l < highx_int; l++) {
#if 0
                    for (k = 0, temp_index = temp; k < components; 
                     k++, temp_index += element_size) {
                        if (myswap_bytes) {
                            totals[k] += __GLU_SWAP_2_BYTES(temp_index);
                        } else {
                            totals[k] += *(const GLushort*)temp_index;
                        }
                    }
#else
                (*extractPackedPixel)(isSwap,temp,extractTotals);
                for (k = 0; k < components; k++) {
                   totals[k]+= extractTotals[k];
                } 
#endif
                    temp += pixelSizeInBytes;
                }
            temp0 += rowSizeInBytes;
          }

          outindex = (j + (i * widthOut)); /* * (components == 1) */
#if 0
          for (k = 0; k < components; k++) {
            dataout[outindex + k] = totals[k]/area;
            /*printf("totals[%d] = %f\n", k, totals[k]);*/
          }
#else
          for (k = 0; k < components; k++) {
              shoveTotals[k]= totals[k]/area;
          }
          (*shovePackedPixel)(shoveTotals,outindex,(void *)dataOut);
#endif
          lowx_int = highx_int;
          lowx_float = highx_float;
          highx_int += convx_int;
          highx_float += convx_float;
          if(highx_float > 1) {
            highx_float -= 1.0;
            highx_int++;
          }
      }
      lowy_int = highy_int;
      lowy_float = highy_float;
      highy_int += convy_int;
      highy_float += convy_float;
      if(highy_float > 1) {
          highy_float -= 1.0;
          highy_int++;
      }
    }

    assert(outindex == (widthOut*heightOut - 1));
} /* scaleInternalPackedPixel() */

/* rowSizeInBytes is at least the width (in bytes) due to padding on 
 *  inputs; not always equal. Output NEVER has row padding.  
 */
static void halveImagePackedPixel(int components,
                          void (*extractPackedPixel)
                          (int, const void *,GLfloat []),
                          void (*shovePackedPixel)
                          (const GLfloat [],int, void *),
                          GLint width, GLint height, 
                          const void *dataIn, void *dataOut,
                          GLint pixelSizeInBytes, 
                          GLint rowSizeInBytes, GLint isSwap)
{
   /* handle case where there is only 1 column/row */
   if (width == 1 || height == 1) {
      assert(!(width == 1 && height == 1)); /* can't be 1x1 */
      halve1DimagePackedPixel(components,extractPackedPixel,shovePackedPixel,
                        width,height,dataIn,dataOut,pixelSizeInBytes,
                        rowSizeInBytes,isSwap);
      return;
   }

   {
      int ii, jj;

      int halfWidth= width / 2;
      int halfHeight= height / 2;
      const char *src= (const char *) dataIn;
      int padBytes= rowSizeInBytes - (width*pixelSizeInBytes);
      int outIndex= 0;

      for (ii= 0; ii< halfHeight; ii++) {
       for (jj= 0; jj< halfWidth; jj++) {
#define BOX4 4
          float totals[4];    /* 4 is maximum components */
          float extractTotals[BOX4][4]; /* 4 is maximum components */
          int cc;

          (*extractPackedPixel)(isSwap,src,
                          &extractTotals[0][0]);
          (*extractPackedPixel)(isSwap,(src+pixelSizeInBytes),
                          &extractTotals[1][0]);
          (*extractPackedPixel)(isSwap,(src+rowSizeInBytes),
                          &extractTotals[2][0]);
          (*extractPackedPixel)(isSwap,
                          (src+rowSizeInBytes+pixelSizeInBytes),
                          &extractTotals[3][0]);
          for (cc = 0; cc < components; cc++) { 
             int kk;

             /* grab 4 pixels to average */
             totals[cc]= 0.0;
             /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED]+
            *              extractTotals[2][RED]+extractTotals[3][RED];
            * totals[RED]/= 4.0;
            */
             for (kk = 0; kk < BOX4; kk++) {
              totals[cc]+= extractTotals[kk][cc];
             }
             totals[cc]/= (float)BOX4;
          }
          (*shovePackedPixel)(totals,outIndex,dataOut);

          outIndex++;
          /* skip over to next square of 4 */
          src+= pixelSizeInBytes + pixelSizeInBytes;
       }
       /* skip past pad bytes, if any, to get to next row */
       src+= padBytes;

       /* src is at beginning of a row here, but it's the second row of
        * the square block of 4 pixels that we just worked on so we
        * need to go one more row.  
        * i.e.,             
        *                   OO... 
        *           here -->OO...
        *       but want -->OO...
        *                   OO... 
        *                   ...
        */
       src+= rowSizeInBytes;
      }

      /* both pointers must reach one byte after the end */
      assert(src == &((const char *)dataIn)[rowSizeInBytes*height]);
      assert(outIndex == halfWidth * halfHeight);
   }
} /* halveImagePackedPixel() */

static void halve1DimagePackedPixel(int components,
                            void (*extractPackedPixel)
                            (int, const void *,GLfloat []),
                            void (*shovePackedPixel)
                            (const GLfloat [],int, void *),
                            GLint width, GLint height, 
                            const void *dataIn, void *dataOut,
                            GLint pixelSizeInBytes, 
                            GLint rowSizeInBytes, GLint isSwap)
{
   int halfWidth= width / 2;
   int halfHeight= height / 2;
   const char *src= (const char *) dataIn;
   int jj;

   assert(width == 1 || height == 1); /* must be 1D */
   assert(width != height);   /* can't be square */

   if (height == 1) {   /* 1 row */
      int outIndex= 0;

      assert(width != 1);     /* widthxheight can't be 1x1 */
      halfHeight= 1;

      /* one horizontal row with possible pad bytes */

      for (jj= 0; jj< halfWidth; jj++) {
#define BOX2 2
       float totals[4]; /* 4 is maximum components */
       float extractTotals[BOX2][4]; /* 4 is maximum components */
       int cc;

       /* average two at a time, instead of four */
       (*extractPackedPixel)(isSwap,src,
                         &extractTotals[0][0]);
       (*extractPackedPixel)(isSwap,(src+pixelSizeInBytes),
                         &extractTotals[1][0]);                    
       for (cc = 0; cc < components; cc++) { 
          int kk;

          /* grab 2 pixels to average */
          totals[cc]= 0.0;
          /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED];
           * totals[RED]/= 2.0;
           */
          for (kk = 0; kk < BOX2; kk++) {
             totals[cc]+= extractTotals[kk][cc];
          }
          totals[cc]/= (float)BOX2;
       }
       (*shovePackedPixel)(totals,outIndex,dataOut);

       outIndex++;
       /* skip over to next group of 2 */
       src+= pixelSizeInBytes + pixelSizeInBytes;
      }

      {
       int padBytes= rowSizeInBytes - (width*pixelSizeInBytes); 
       src+= padBytes;  /* for assertion only */
      }
      assert(src == &((const char *)dataIn)[rowSizeInBytes]);
      assert(outIndex == halfWidth * halfHeight);
   }
   else if (width == 1) { /* 1 column */
      int outIndex= 0;

      assert(height != 1);    /* widthxheight can't be 1x1 */
      halfWidth= 1;
      /* one vertical column with possible pad bytes per row */
      /* average two at a time */

      for (jj= 0; jj< halfHeight; jj++) {
#define BOX2 2
       float totals[4]; /* 4 is maximum components */
       float extractTotals[BOX2][4]; /* 4 is maximum components */
       int cc;

       /* average two at a time, instead of four */
       (*extractPackedPixel)(isSwap,src,
                         &extractTotals[0][0]);
       (*extractPackedPixel)(isSwap,(src+rowSizeInBytes),
                         &extractTotals[1][0]);                    
       for (cc = 0; cc < components; cc++) { 
          int kk;

          /* grab 2 pixels to average */
          totals[cc]= 0.0;
          /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED];
           * totals[RED]/= 2.0;
           */
          for (kk = 0; kk < BOX2; kk++) {
             totals[cc]+= extractTotals[kk][cc];
          }
          totals[cc]/= (float)BOX2;
       }
       (*shovePackedPixel)(totals,outIndex,dataOut);

       outIndex++;
       src+= rowSizeInBytes + rowSizeInBytes; /* go to row after next */
      }

      assert(src == &((const char *)dataIn)[rowSizeInBytes*height]);
      assert(outIndex == halfWidth * halfHeight);
   }
} /* halve1DimagePackedPixel() */

/*===========================================================================*/

static GLint imageSize3D(GLint width, GLint height, GLint depth,
                   GLenum format, GLenum type) 
{
    int components= elements_per_group(format,type);
    int bytes_per_row=  bytes_per_element(type) * width;

assert(width > 0 && height > 0 && depth > 0);
assert(type != GL_BITMAP);

    return bytes_per_row * height * depth * components;
} /* imageSize3D() */

static void fillImage3D(const PixelStorageModes *psm, 
                  GLint width, GLint height, GLint depth, GLenum format, 
                  GLenum type, GLboolean indexFormat, 
                  const void *userImage, GLushort *newImage)
{
   int myswapBytes;
   int components;
   int groupsPerLine;
   int elementSize;
   int groupSize;
   int rowSize;
   int padding;
   int elementsPerLine;
   int rowsPerImage;
   int imageSize;
   const GLubyte *start, *rowStart, *iter; 
   GLushort *iter2;
   int ww, hh, dd, k; 
   
   myswapBytes= psm->unpack_swap_bytes;
   components= elements_per_group(format,type);
   if (psm->unpack_row_length > 0) {
      groupsPerLine= psm->unpack_row_length;
   }
   else {
      groupsPerLine= width;
   }
   elementSize= bytes_per_element(type);
   groupSize= elementSize * components;
   if (elementSize == 1) myswapBytes= 0;

   /* 3dstuff begin */
   if (psm->unpack_image_height > 0) { 
      rowsPerImage= psm->unpack_image_height; 
   }
   else {
      rowsPerImage= height;
   }
   /* 3dstuff end */

   rowSize= groupsPerLine * groupSize;
   padding= rowSize % psm->unpack_alignment;
   if (padding) {
      rowSize+= psm->unpack_alignment - padding;
   }

   imageSize= rowsPerImage * rowSize; /* 3dstuff */

   start= (const GLubyte *)userImage + psm->unpack_skip_rows * rowSize + 
                                 psm->unpack_skip_pixels * groupSize +
                                 /*3dstuff*/
                                 psm->unpack_skip_images * imageSize;
   elementsPerLine = width * components;

   iter2= newImage;
   for (dd= 0; dd < depth; dd++) {
      rowStart= start;

      for (hh= 0; hh < height; hh++) {
       iter= rowStart;

       for (ww= 0; ww < elementsPerLine; ww++) {
          Type_Widget widget;
          float extractComponents[4];

          switch(type) {
          case GL_UNSIGNED_BYTE:
            if (indexFormat) {
              *iter2++ = *iter;
            } else {
              *iter2++ = (*iter) * 257;
            }
            break;
          case GL_BYTE:
            if (indexFormat) {
              *iter2++ = *((const GLbyte *) iter);
            } else {
              /* rough approx */
              *iter2++ = (*((const GLbyte *) iter)) * 516;
            }
            break;
          case GL_UNSIGNED_BYTE_3_3_2:
            extract332(0,iter,extractComponents);
            for (k = 0; k < 3; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_BYTE_2_3_3_REV:  
            extract233rev(0,iter,extractComponents);
            for (k = 0; k < 3; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_SHORT_5_6_5:                               
            extract565(myswapBytes,iter,extractComponents);
            for (k = 0; k < 3; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_SHORT_5_6_5_REV:                           
            extract565rev(myswapBytes,iter,extractComponents);
            for (k = 0; k < 3; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_SHORT_4_4_4_4:           
            extract4444(myswapBytes,iter,extractComponents);
            for (k = 0; k < 4; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_SHORT_4_4_4_4_REV:             
            extract4444rev(myswapBytes,iter,extractComponents);
            for (k = 0; k < 4; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_SHORT_5_5_5_1:           
            extract5551(myswapBytes,iter,extractComponents);
            for (k = 0; k < 4; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_SHORT_1_5_5_5_REV:
            extract1555rev(myswapBytes,iter,extractComponents);
            for (k = 0; k < 4; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_SHORT:
          case GL_SHORT:
            if (myswapBytes) {
              widget.ub[0] = iter[1];
              widget.ub[1] = iter[0];
            } else {
              widget.ub[0] = iter[0];
              widget.ub[1] = iter[1];
            }
            if (type == GL_SHORT) {
              if (indexFormat) {
                  *iter2++ = widget.s[0];
              } else {
                  /* rough approx */
                  *iter2++ = widget.s[0]*2;
              }
            } else {
              *iter2++ = widget.us[0];
            }
            break;
          case GL_UNSIGNED_INT_8_8_8_8:             
            extract8888(myswapBytes,iter,extractComponents);
            for (k = 0; k < 4; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_INT_8_8_8_8_REV:               
            extract8888rev(myswapBytes,iter,extractComponents);
            for (k = 0; k < 4; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_INT_10_10_10_2:                
            extract1010102(myswapBytes,iter,extractComponents);
            for (k = 0; k < 4; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_UNSIGNED_INT_2_10_10_10_REV:
            extract2101010rev(myswapBytes,iter,extractComponents);
            for (k = 0; k < 4; k++) {
            *iter2++ = (GLushort)(extractComponents[k]*65535);
            }
            break;
          case GL_INT:
          case GL_UNSIGNED_INT:
          case GL_FLOAT:
            if (myswapBytes) {
              widget.ub[0] = iter[3];
              widget.ub[1] = iter[2];
              widget.ub[2] = iter[1];
              widget.ub[3] = iter[0];
            } else {
              widget.ub[0] = iter[0];
              widget.ub[1] = iter[1];
              widget.ub[2] = iter[2];
              widget.ub[3] = iter[3];
            }
            if (type == GL_FLOAT) {
              if (indexFormat) {
                  *iter2++ = widget.f;
              } else {
                  *iter2++ = 65535 * widget.f;
              }
            } else if (type == GL_UNSIGNED_INT) {
              if (indexFormat) {
                  *iter2++ = widget.ui;
              } else {
                  *iter2++ = widget.ui >> 16;
              }
            } else {
              if (indexFormat) {
                  *iter2++ = widget.i;
              } else {
                  *iter2++ = widget.i >> 15;
              }
            }
            break;
            default:
            assert(0);
          }

          iter+= elementSize;
       } /* for ww */
       rowStart+= rowSize;

       iter= rowStart;  /* for assertion purposes */
      } /* for hh */

      start+= imageSize;
   } /* for dd */

   /* iterators should be one byte past end */
   if (!isTypePackedPixel(type)) {
      assert(iter2 == &newImage[width*height*depth*components]);
   }
   else {
      assert(iter2 == &newImage[width*height*depth*
                        elements_per_group(format,0)]);
   }
   assert( iter == &((const GLubyte *)userImage)[rowSize*height*depth +
                              psm->unpack_skip_rows * rowSize + 
                              psm->unpack_skip_pixels * groupSize +
                              /*3dstuff*/
                              psm->unpack_skip_images * imageSize] );
} /* fillImage3D () */

static void scaleInternal3D(GLint components, 
                      GLint widthIn, GLint heightIn, GLint depthIn,
                      const GLushort *dataIn,
                      GLint widthOut, GLint heightOut, GLint depthOut,
                      GLushort *dataOut)
{
    float x, lowx, highx, convx, halfconvx;
    float y, lowy, highy, convy, halfconvy;
    float z, lowz, highz, convz, halfconvz;
    float xpercent,ypercent,zpercent; 
    float percent;
    /* Max components in a format is 4, so... */
    float totals[4];
    float volume;
    int i,j,d,k,zint,yint,xint,xindex,yindex,zindex;
    int temp;

    convz = (float) depthIn/depthOut;
    convy = (float) heightIn/heightOut;
    convx = (float) widthIn/widthOut;
    halfconvx = convx/2;
    halfconvy = convy/2;
    halfconvz = convz/2;
    for (d = 0; d < depthOut; d++) { 
       z = convz * (d+0.5);
       if (depthIn > depthOut) {
         highz = z + halfconvz;
         lowz = z - halfconvz;
       } else {
         highz = z + 0.5;
         lowz = z - 0.5;
       }
       for (i = 0; i < heightOut; i++) {
         y = convy * (i+0.5);
         if (heightIn > heightOut) {
             highy = y + halfconvy;
             lowy = y - halfconvy;
         } else {
             highy = y + 0.5;
             lowy = y - 0.5;
         }
         for (j = 0; j < widthOut; j++) {
             x = convx * (j+0.5);
             if (widthIn > widthOut) {
               highx = x + halfconvx;
               lowx = x - halfconvx;
             } else {
               highx = x + 0.5;
               lowx = x - 0.5;
             }

             /*
             ** Ok, now apply box filter to box that goes from (lowx, lowy,
             ** lowz) to (highx, highy, highz) on input data into this pixel
             ** on output data.
             */
             totals[0] = totals[1] = totals[2] = totals[3] = 0.0;
             volume = 0.0;

             z = lowz;
             zint = floor(z);
             while (z < highz) {
              zindex = (zint + depthIn) % depthIn;
              if (highz < zint+1) {
                  zpercent = highz - z;
              } else {
                  zpercent = zint+1 - z;
              }

              y = lowy;
              yint = floor(y);
              while (y < highy) {
                  yindex = (yint + heightIn) % heightIn;
                  if (highy < yint+1) {
                    ypercent = highy - y;
                  } else {
                    ypercent = yint+1 - y;
                  }

                  x = lowx;
                  xint = floor(x);

                  while (x < highx) {
                    xindex = (xint + widthIn) % widthIn;
                    if (highx < xint+1) {
                        xpercent = highx - x;
                    } else {
                        xpercent = xint+1 - x;
                    }

                    percent = xpercent * ypercent * zpercent;
                    volume += percent;

                    temp = (xindex + (yindex*widthIn) + 
                          (zindex*widthIn*heightIn)) * components;
                    for (k = 0; k < components; k++) {
                        assert(0 <= (temp+k) && 
                             (temp+k) < 
                             (widthIn*heightIn*depthIn*components));
                        totals[k] += dataIn[temp + k] * percent;
                    }

                    xint++;
                    x = xint;
                  } /* while x */

                  yint++;
                  y = yint;
              } /* while y */

              zint++;
              z = zint;
             } /* while z */

             temp = (j + (i * widthOut) + 
                   (d*widthOut*heightOut)) * components;
             for (k = 0; k < components; k++) {
               /* totals[] should be rounded in the case of enlarging an 
                * RGB ramp when the type is 332 or 4444
                */
               assert(0 <= (temp+k) && 
                    (temp+k) < (widthOut*heightOut*depthOut*components));
               dataOut[temp + k] = (totals[k]+0.5)/volume;
             }
         } /* for j */
       } /* for i */
    } /* for d */
} /* scaleInternal3D() */

static void emptyImage3D(const PixelStorageModes *psm,
                   GLint width, GLint height, GLint depth,
                   GLenum format, GLenum type, GLboolean indexFormat,
                   const GLushort *oldImage, void *userImage)
{
   int myswapBytes;
   int components;
   int groupsPerLine;
   int elementSize;
   int groupSize;
   int rowSize;
   int padding;
   GLubyte *start, *rowStart, *iter;
   int elementsPerLine;
   const GLushort *iter2;
   int ii, jj, dd, k;
   int rowsPerImage;
   int imageSize;

   myswapBytes= psm->pack_swap_bytes;
   components = elements_per_group(format,type);
   if (psm->pack_row_length > 0) {
      groupsPerLine = psm->pack_row_length;
   }
   else {
      groupsPerLine = width;
   }

   elementSize= bytes_per_element(type);
   groupSize= elementSize * components;
   if (elementSize == 1) myswapBytes= 0;
   
   /* 3dstuff begin */
   if (psm->pack_image_height > 0) {
      rowsPerImage= psm->pack_image_height;
   }
   else {
      rowsPerImage= height;
   }

   /* 3dstuff end */   

   rowSize = groupsPerLine * groupSize;
   padding = rowSize % psm->pack_alignment;
   if (padding) {
      rowSize+= psm->pack_alignment - padding;
   }
   
   imageSize= rowsPerImage * rowSize; /* 3dstuff */

   start = (GLubyte *)userImage + psm->pack_skip_rows * rowSize +
                                  psm->pack_skip_pixels * groupSize +
                                  /*3dstuff*/
                                  psm->pack_skip_images * imageSize;
   elementsPerLine= width * components;

   iter2 = oldImage;
   for (dd= 0; dd < depth; dd++) { 
      rowStart= start;

      for (ii= 0; ii< height; ii++) {
       iter = rowStart;

       for (jj = 0; jj < elementsPerLine; jj++) {
          Type_Widget widget;
          float shoveComponents[4];

          switch(type){
          case GL_UNSIGNED_BYTE:
            if (indexFormat) {
              *iter = *iter2++;
            } else {
              *iter = *iter2++ >> 8;
            }
            break;
          case GL_BYTE:
            if (indexFormat) {
              *((GLbyte *) iter) = *iter2++;
            } else {
              *((GLbyte *) iter) = *iter2++ >> 9;
            }
            break;
          case GL_UNSIGNED_BYTE_3_3_2: 
            for (k = 0; k < 3; k++) {
             shoveComponents[k]= *iter2++ / 65535.0;
            } 
            shove332(shoveComponents,0,(void *)iter);
            break;
          case GL_UNSIGNED_BYTE_2_3_3_REV:
            for (k = 0; k < 3; k++) {
             shoveComponents[k]= *iter2++ / 65535.0;
            } 
            shove233rev(shoveComponents,0,(void *)iter);
            break; 
          case GL_UNSIGNED_SHORT_5_6_5:             
            for (k = 0; k < 3; k++) {
             shoveComponents[k]= *iter2++ / 65535.0;
            } 
            shove565(shoveComponents,0,(void *)&widget.us[0]);
            if (myswapBytes) {
             iter[0] = widget.ub[1];
             iter[1] = widget.ub[0];
            }
            else {
             *(GLushort *)iter = widget.us[0];
            }
            break;
          case GL_UNSIGNED_SHORT_5_6_5_REV:               
            for (k = 0; k < 3; k++) {
             shoveComponents[k]= *iter2++ / 65535.0;
            } 
            shove565rev(shoveComponents,0,(void *)&widget.us[0]);
            if (myswapBytes) {
             iter[0] = widget.ub[1];
             iter[1] = widget.ub[0];
            }
            else {
             *(GLushort *)iter = widget.us[0];
            }
            break;
          case GL_UNSIGNED_SHORT_4_4_4_4:
            for (k = 0; k < 4; k++) {
             shoveComponents[k]= *iter2++ / 65535.0;
            } 
            shove4444(shoveComponents,0,(void *)&widget.us[0]);
            if (myswapBytes) {
             iter[0] = widget.ub[1];
             iter[1] = widget.ub[0];
            } else {
             *(GLushort *)iter = widget.us[0];
            }
            break;
          case GL_UNSIGNED_SHORT_4_4_4_4_REV:
            for (k = 0; k < 4; k++) {
             shoveComponents[k]= *iter2++ / 65535.0;
            } 
            shove4444rev(shoveComponents,0,(void *)&widget.us[0]);
            if (myswapBytes) {
             iter[0] = widget.ub[1];
             iter[1] = widget.ub[0];
            } else {
             *(GLushort *)iter = widget.us[0];
            }
            break;
          case GL_UNSIGNED_SHORT_5_5_5_1:
            for (k = 0; k < 4; k++) {
             shoveComponents[k]= *iter2++ / 65535.0;
            } 
            shove5551(shoveComponents,0,(void *)&widget.us[0]);
            if (myswapBytes) {
             iter[0] = widget.ub[1];
             iter[1] = widget.ub[0];
            } else {
             *(GLushort *)iter = widget.us[0];
            }
            break;
          case GL_UNSIGNED_SHORT_1_5_5_5_REV:
            for (k = 0; k < 4; k++) {
             shoveComponents[k]= *iter2++ / 65535.0;
            } 
            shove1555rev(shoveComponents,0,(void *)&widget.us[0]);
            if (myswapBytes) {
             iter[0] = widget.ub[1];
             iter[1] = widget.ub[0];
            } else {
             *(GLushort *)iter = widget.us[0];
            }
            break;
          case GL_UNSIGNED_SHORT:
          case GL_SHORT:
            if (type == GL_SHORT) {
              if (indexFormat) {
                  widget.s[0] = *iter2++;
              } else {
                  widget.s[0] = *iter2++ >> 1;
              }
            } else {
              widget.us[0] = *iter2++;
            }
            if (myswapBytes) {
              iter[0] = widget.ub[1];
              iter[1] = widget.ub[0];
            } else {
              iter[0] = widget.ub[0];
              iter[1] = widget.ub[1];
            }
            break;
          case GL_UNSIGNED_INT_8_8_8_8:
             for (k = 0; k < 4; k++) {
              shoveComponents[k]= *iter2++ / 65535.0;
             } 
             shove8888(shoveComponents,0,(void *)&widget.ui);
             if (myswapBytes) {
               iter[3] = widget.ub[0];
               iter[2] = widget.ub[1];
               iter[1] = widget.ub[2];
               iter[0] = widget.ub[3];
             } else {
               *(GLuint *)iter= widget.ui;
             }
             break;
          case GL_UNSIGNED_INT_8_8_8_8_REV:
             for (k = 0; k < 4; k++) {
              shoveComponents[k]= *iter2++ / 65535.0;
             } 
             shove8888rev(shoveComponents,0,(void *)&widget.ui);
             if (myswapBytes) {
               iter[3] = widget.ub[0];
               iter[2] = widget.ub[1];
               iter[1] = widget.ub[2];
               iter[0] = widget.ub[3];
             } else {
               *(GLuint *)iter= widget.ui;
             }
             break;
          case GL_UNSIGNED_INT_10_10_10_2:  
             for (k = 0; k < 4; k++) {
              shoveComponents[k]= *iter2++ / 65535.0;
             } 
             shove1010102(shoveComponents,0,(void *)&widget.ui);
             if (myswapBytes) {
               iter[3] = widget.ub[0];
               iter[2] = widget.ub[1];
               iter[1] = widget.ub[2];
               iter[0] = widget.ub[3];
             } else {
               *(GLuint *)iter= widget.ui;
             }
             break;
          case GL_UNSIGNED_INT_2_10_10_10_REV:  
             for (k = 0; k < 4; k++) {
              shoveComponents[k]= *iter2++ / 65535.0;
             } 
             shove2101010rev(shoveComponents,0,(void *)&widget.ui);
             if (myswapBytes) {
               iter[3] = widget.ub[0];
               iter[2] = widget.ub[1];
               iter[1] = widget.ub[2];
               iter[0] = widget.ub[3];
             } else {
               *(GLuint *)iter= widget.ui;
             }
             break;
          case GL_INT:
          case GL_UNSIGNED_INT:
          case GL_FLOAT:
            if (type == GL_FLOAT) {
              if (indexFormat) {
                  widget.f = *iter2++;
              } else {
                  widget.f = *iter2++ / (float) 65535.0;
              }
            } else if (type == GL_UNSIGNED_INT) {
              if (indexFormat) {
                  widget.ui = *iter2++;
              } else {
                  widget.ui = (unsigned int) *iter2++ * 65537;
              }
            } else {
              if (indexFormat) {
                  widget.i = *iter2++;
              } else {
                  widget.i = ((unsigned int) *iter2++ * 65537)/2;
              }
            }
            if (myswapBytes) {
              iter[3] = widget.ub[0];
              iter[2] = widget.ub[1];
              iter[1] = widget.ub[2];
              iter[0] = widget.ub[3];
            } else {
              iter[0] = widget.ub[0];
              iter[1] = widget.ub[1];
              iter[2] = widget.ub[2];
              iter[3] = widget.ub[3];
            }
            break;
          default:
             assert(0);
          }

          iter+= elementSize;
       }  /* for jj */

       rowStart+= rowSize;
      } /* for ii */

      start+= imageSize;
   } /* for dd */

   /* iterators should be one byte past end */
   if (!isTypePackedPixel(type)) {
      assert(iter2 == &oldImage[width*height*depth*components]);
   }
   else {
      assert(iter2 == &oldImage[width*height*depth*
                        elements_per_group(format,0)]);
   }
   assert( iter == &((GLubyte *)userImage)[rowSize*height*depth +
                              psm->unpack_skip_rows * rowSize + 
                              psm->unpack_skip_pixels * groupSize +
                              /*3dstuff*/
                              psm->unpack_skip_images * imageSize] );
} /* emptyImage3D() */

int gluScaleImage3D(GLenum format, 
                GLint widthIn, GLint heightIn, GLint depthIn,
                GLenum typeIn, const void *dataIn, 
                GLint widthOut, GLint heightOut, GLint depthOut,
                GLenum typeOut, void *dataOut)
{
   int components;
   GLushort *beforeImage, *afterImage;
   PixelStorageModes psm;

   if (widthIn == 0 || heightIn == 0 || depthIn == 0 || 
       widthOut == 0 || heightOut == 0 || depthOut == 0) {
      return 0;
   }

   if (widthIn < 0 || heightIn < 0 || depthIn < 0 || 
       widthOut < 0 || heightOut < 0 || depthOut < 0) {
      return GLU_INVALID_VALUE;
   }
      
   if (!legalFormat(format) || !legalType(typeIn) || !legalType(typeOut) ||
       typeIn == GL_BITMAP || typeOut == GL_BITMAP) {
      return GLU_INVALID_ENUM;
   }
   if (!isLegalFormatForPackedPixelType(format, typeIn)) {
      return GLU_INVALID_OPERATION;
   }
   if (!isLegalFormatForPackedPixelType(format, typeOut)) {
      return GLU_INVALID_OPERATION;
   }

   beforeImage = malloc(imageSize3D(widthIn, heightIn, depthIn, format,
                            GL_UNSIGNED_SHORT)); 
   afterImage = malloc(imageSize3D(widthOut, heightOut, depthOut, format, 
                           GL_UNSIGNED_SHORT));
   if (beforeImage == NULL || afterImage == NULL) {
       return GLU_OUT_OF_MEMORY;
   } 
   retrieveStoreModes3D(&psm);

   fillImage3D(&psm,widthIn,heightIn,depthIn,format,typeIn, is_index(format),
             dataIn, beforeImage);
   components = elements_per_group(format,0);
   scaleInternal3D(components,widthIn,heightIn,depthIn,beforeImage,
               widthOut,heightOut,depthOut,afterImage);
   emptyImage3D(&psm,widthOut,heightOut,depthOut,format,typeOut,
            is_index(format),afterImage, dataOut);
   free((void *) beforeImage);
   free((void *) afterImage);

   return 0;
} /* gluScaleImage3D() */

static void closestFit3D(GLenum target, GLint width, GLint height, GLint depth,
                   GLint internalFormat, GLenum format, GLenum type, 
                   GLint *newWidth, GLint *newHeight, GLint *newDepth)
{
   GLint widthPowerOf2= nearestPower(width);
   GLint heightPowerOf2= nearestPower(height);        
   GLint depthPowerOf2= nearestPower(depth);
   GLint proxyWidth;

   do {
      /* compute level 1 width & height & depth, clamping each at 1 */
      GLint widthAtLevelOne= (widthPowerOf2 > 1) ?
                        widthPowerOf2 >> 1 :
                        widthPowerOf2;  
      GLint heightAtLevelOne= (heightPowerOf2 > 1) ?
                         heightPowerOf2 >> 1 :
                         heightPowerOf2;  
      GLint depthAtLevelOne= (depthPowerOf2 > 1) ?
                        depthPowerOf2 >> 1 :
                        depthPowerOf2;  
      GLenum proxyTarget = 0;
      assert(widthAtLevelOne > 0); 
      assert(heightAtLevelOne > 0);
      assert(depthAtLevelOne > 0);

      /* does width x height x depth at level 1 & all their mipmaps fit? */
      if (target == GL_TEXTURE_3D || target == GL_PROXY_TEXTURE_3D) {
       proxyTarget = GL_PROXY_TEXTURE_3D;
       glTexImage3D(proxyTarget, 1, /* must be non-zero */
                  internalFormat,
                  widthAtLevelOne,heightAtLevelOne,depthAtLevelOne,
                  0,format,type,NULL);
      }
      glGetTexLevelParameteriv(proxyTarget, 1,GL_TEXTURE_WIDTH,&proxyWidth);
      /* does it fit??? */
      if (proxyWidth == 0) { /* nope, so try again with these sizes */
       if (widthPowerOf2 == 1 && heightPowerOf2 == 1 &&
           depthPowerOf2 == 1) {
          *newWidth= *newHeight= *newDepth= 1; /* must fit 1x1x1 texture */
          return;
       }
       widthPowerOf2= widthAtLevelOne;
       heightPowerOf2= heightAtLevelOne;
       depthPowerOf2= depthAtLevelOne;
      } 
      /* else it does fit */
   } while (proxyWidth == 0);
   /* loop must terminate! */

   /* return the width & height at level 0 that fits */
   *newWidth= widthPowerOf2;
   *newHeight= heightPowerOf2;
   *newDepth= depthPowerOf2;
/*printf("Proxy Textures\n");*/
} /* closestFit3D() */

static void halveImagePackedPixelSlice(int components,
                               void (*extractPackedPixel)
                               (int, const void *,GLfloat []),
                               void (*shovePackedPixel)
                               (const GLfloat [],int, void *),
                               GLint width, GLint height, GLint depth,
                               const void *dataIn, void *dataOut,
                               GLint pixelSizeInBytes, 
                               GLint rowSizeInBytes, 
                               GLint imageSizeInBytes,
                               GLint isSwap)
{
   int ii, jj;
   int halfWidth= width / 2;
   int halfHeight= height / 2;
   int halfDepth= depth / 2;
   const char *src= (const char *)dataIn;
   int outIndex= 0;

   assert((width == 1 || height == 1) && depth >= 2);

   if (width == height) {     /* a 1-pixel column viewed from top */
      assert(width == 1 && height == 1);
      assert(depth >= 2);

      for (ii= 0; ii< halfDepth; ii++) {
       float totals[4];
       float extractTotals[BOX2][4];
       int cc;

       (*extractPackedPixel)(isSwap,src,&extractTotals[0][0]);
       (*extractPackedPixel)(isSwap,(src+imageSizeInBytes),
                         &extractTotals[1][0]);
       for (cc = 0; cc < components; cc++) {
          int kk;

          /* average 2 pixels since only a column */
          totals[cc]= 0.0;
          /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED];
           * totals[RED]/= 2.0;
           */
          for (kk = 0; kk < BOX2; kk++) {
            totals[cc]+= extractTotals[kk][cc];
          }
          totals[cc]/= (float)BOX2;
       } /* for cc */
       
       (*shovePackedPixel)(totals,outIndex,dataOut);
       outIndex++;
       /* skip over to next group of 2 */
       src+= imageSizeInBytes + imageSizeInBytes;
      } /* for ii */
   }
   else if (height == 1) {    /* horizontal slice viewed from top */
      assert(width != 1);

      for (ii= 0; ii< halfDepth; ii++) {
       for (jj= 0; jj< halfWidth; jj++) {
           float totals[4];
           float extractTotals[BOX4][4]; 
           int cc;

           (*extractPackedPixel)(isSwap,src,
                           &extractTotals[0][0]);
           (*extractPackedPixel)(isSwap,(src+pixelSizeInBytes),
                           &extractTotals[1][0]);
           (*extractPackedPixel)(isSwap,(src+imageSizeInBytes),
                           &extractTotals[2][0]);
           (*extractPackedPixel)(isSwap,
                           (src+imageSizeInBytes+pixelSizeInBytes),
                           &extractTotals[3][0]);
           for (cc = 0; cc < components; cc++) {
              int kk;

            /* grab 4 pixels to average */
            totals[cc]= 0.0;
            /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED]+
             *              extractTotals[2][RED]+extractTotals[3][RED];
             * totals[RED]/= 4.0;
             */
            for (kk = 0; kk < BOX4; kk++) {
               totals[cc]+= extractTotals[kk][cc];
            }
            totals[cc]/= (float)BOX4;
           }
           (*shovePackedPixel)(totals,outIndex,dataOut);

           outIndex++;
           /* skip over to next horizontal square of 4 */
           src+= imageSizeInBytes + imageSizeInBytes;
       }
      }

      /* assert() */
   }
   else if (width == 1) {     /* vertical slice viewed from top */
      assert(height != 1);

      for (ii= 0; ii< halfDepth; ii++) {
       for (jj= 0; jj< halfHeight; jj++) {
          float totals[4];
          float extractTotals[BOX4][4];
          int cc;

          (*extractPackedPixel)(isSwap,src,
                          &extractTotals[0][0]);
          (*extractPackedPixel)(isSwap,(src+rowSizeInBytes),
                          &extractTotals[1][0]);
          (*extractPackedPixel)(isSwap,(src+imageSizeInBytes),
                          &extractTotals[2][0]);
          (*extractPackedPixel)(isSwap,
                          (src+imageSizeInBytes+rowSizeInBytes),
                          &extractTotals[3][0]);
          for (cc = 0; cc < components; cc++) {
             int kk;

             /* grab 4 pixels to average */
             totals[cc]= 0.0;
             /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED]+
            *              extractTotals[2][RED]+extractTotals[3][RED];
            * totals[RED]/= 4.0;
            */
             for (kk = 0; kk < BOX4; kk++) {
              totals[cc]+= extractTotals[kk][cc];
             }
             totals[cc]/= (float)BOX4;
          }
          (*shovePackedPixel)(totals,outIndex,dataOut);

          outIndex++;

          /* skip over to next vertical square of 4 */
          src+= imageSizeInBytes + imageSizeInBytes;
       }
      } 
      /* assert() */
   }

} /* halveImagePackedPixelSlice() */

static void halveImagePackedPixel3D(int components,
                            void (*extractPackedPixel)
                            (int, const void *,GLfloat []),
                            void (*shovePackedPixel)
                            (const GLfloat [],int, void *),
                            GLint width, GLint height, GLint depth,
                            const void *dataIn, void *dataOut,
                            GLint pixelSizeInBytes, 
                            GLint rowSizeInBytes, 
                            GLint imageSizeInBytes,
                            GLint isSwap)
{
   if (depth == 1) {
      assert(1 <= width && 1 <= height);

      halveImagePackedPixel(components,extractPackedPixel,shovePackedPixel,
                      width,height,dataIn,dataOut,pixelSizeInBytes,
                      rowSizeInBytes,isSwap);
      return;
   }
   /* a horizontal or vertical slice viewed from top */
   else if (width == 1 || height == 1) { 
      assert(1 <= depth);

      halveImagePackedPixelSlice(components,
                         extractPackedPixel,shovePackedPixel,
                         width, height, depth, dataIn, dataOut,
                         pixelSizeInBytes, rowSizeInBytes, 
                         imageSizeInBytes, isSwap);
      return;
   }
   {
      int ii, jj, dd;

      int halfWidth= width / 2;
      int halfHeight= height / 2;
      int halfDepth= depth / 2;  
      const char *src= (const char *) dataIn;
      int padBytes= rowSizeInBytes - (width*pixelSizeInBytes);
      int outIndex= 0;

      for (dd= 0; dd < halfDepth; dd++) {
       for (ii= 0; ii< halfHeight; ii++) {
          for (jj= 0; jj< halfWidth; jj++) {
#define BOX8 8
             float totals[4]; /* 4 is maximum components */
             float extractTotals[BOX8][4]; /* 4 is maximum components */
             int cc;

             (*extractPackedPixel)(isSwap,src,
                             &extractTotals[0][0]);
             (*extractPackedPixel)(isSwap,(src+pixelSizeInBytes),
                             &extractTotals[1][0]);
             (*extractPackedPixel)(isSwap,(src+rowSizeInBytes),
                             &extractTotals[2][0]);
             (*extractPackedPixel)(isSwap,
                             (src+rowSizeInBytes+pixelSizeInBytes),
                             &extractTotals[3][0]);

             (*extractPackedPixel)(isSwap,(src+imageSizeInBytes),
                             &extractTotals[4][0]);
             (*extractPackedPixel)(isSwap,(src+pixelSizeInBytes+imageSizeInBytes),
                             &extractTotals[5][0]);
             (*extractPackedPixel)(isSwap,(src+rowSizeInBytes+imageSizeInBytes),
                             &extractTotals[6][0]);
             (*extractPackedPixel)(isSwap,
                             (src+rowSizeInBytes+pixelSizeInBytes+imageSizeInBytes),
                             &extractTotals[7][0]);
             for (cc = 0; cc < components; cc++) { 
              int kk;

              /* grab 8 pixels to average */
              totals[cc]= 0.0;
              /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED]+
               *              extractTotals[2][RED]+extractTotals[3][RED]+
               *              extractTotals[4][RED]+extractTotals[5][RED]+
               *              extractTotals[6][RED]+extractTotals[7][RED];
               * totals[RED]/= 8.0;
               */
              for (kk = 0; kk < BOX8; kk++) {
                 totals[cc]+= extractTotals[kk][cc];
              }
              totals[cc]/= (float)BOX8;
             }
             (*shovePackedPixel)(totals,outIndex,dataOut);

             outIndex++;
             /* skip over to next square of 4 */
             src+= pixelSizeInBytes + pixelSizeInBytes;
          }
          /* skip past pad bytes, if any, to get to next row */
          src+= padBytes;

          /* src is at beginning of a row here, but it's the second row of
           * the square block of 4 pixels that we just worked on so we
           * need to go one more row.  
           * i.e.,             
           *                   OO... 
           *           here -->OO...
           *       but want -->OO...
           *                   OO... 
           *                   ...
           */
          src+= rowSizeInBytes;
       }

       src+= imageSizeInBytes; 
      } /* for dd */

      /* both pointers must reach one byte after the end */
      assert(src == &((const char *)dataIn)[rowSizeInBytes*height*depth]);
      assert(outIndex == halfWidth * halfHeight * halfDepth);
   } /* for dd */

} /* halveImagePackedPixel3D() */

static int gluBuild3DMipmapLevelsCore(GLenum target, GLint internalFormat, 
                              GLsizei width, 
                              GLsizei height, 
                              GLsizei depth,
                              GLsizei widthPowerOf2, 
                              GLsizei heightPowerOf2, 
                              GLsizei depthPowerOf2,
                              GLenum format, GLenum type, 
                              GLint userLevel,
                              GLint baseLevel,GLint maxLevel,
                              const void *data)
{
   GLint newWidth, newHeight, newDepth;
   GLint level, levels;
   const void *usersImage;
   void *srcImage, *dstImage;
   __GLU_INIT_SWAP_IMAGE;
   GLint memReq;
   GLint cmpts;

   GLint myswapBytes, groupsPerLine, elementSize, groupSize;
   GLint rowsPerImage, imageSize;
   GLint rowSize, padding;
   PixelStorageModes psm;

   assert(checkMipmapArgs(internalFormat,format,type) == 0);
   assert(width >= 1 && height >= 1 && depth >= 1);
   assert(type != GL_BITMAP);

   srcImage = dstImage = NULL;

   newWidth= widthPowerOf2;
   newHeight= heightPowerOf2;
   newDepth= depthPowerOf2;
   levels = computeLog(newWidth);
   level = computeLog(newHeight);
   if (level > levels) levels=level;
   level = computeLog(newDepth);
   if (level > levels) levels=level;

   levels+= userLevel;

   retrieveStoreModes3D(&psm);
   myswapBytes = psm.unpack_swap_bytes;
   cmpts = elements_per_group(format,type);
   if (psm.unpack_row_length > 0) {
       groupsPerLine = psm.unpack_row_length;
   } else {
       groupsPerLine = width;
   }

   elementSize = bytes_per_element(type);
   groupSize = elementSize * cmpts;
   if (elementSize == 1) myswapBytes = 0;

   /* 3dstuff begin */
   if (psm.unpack_image_height > 0) { 
      rowsPerImage= psm.unpack_image_height; 
   }
   else {
      rowsPerImage= height;
   }

   /* 3dstuff end */
   rowSize = groupsPerLine * groupSize;
   padding = (rowSize % psm.unpack_alignment);
   if (padding) {
       rowSize += psm.unpack_alignment - padding;
   }

   imageSize= rowsPerImage * rowSize; /* 3dstuff */

   usersImage = (const GLubyte *)data + psm.unpack_skip_rows * rowSize + 
                          psm.unpack_skip_pixels * groupSize +
                          /* 3dstuff */
                          psm.unpack_skip_images * imageSize;      

   glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
   glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
   glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
   glPixelStorei(GL_UNPACK_SKIP_IMAGES, 0);
   glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, 0);

   level = userLevel;

   if (width == newWidth && height == newHeight && depth == newDepth) {
       /* Use usersImage for level userLevel */
       if (baseLevel <= level && level <= maxLevel) {
          glTexImage3D(target, level, internalFormat, width, 
                   height, depth, 0, format, type,
                   usersImage);
       }
       if(levels == 0) { /* we're done. clean up and return */
       glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
       glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
       glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
       glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
       glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
       glPixelStorei(GL_UNPACK_SKIP_IMAGES, psm.unpack_skip_images);
       glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, psm.unpack_image_height);
       return 0;
       }
       {
        int nextWidth= newWidth/2;
        int nextHeight= newHeight/2;
        int nextDepth= newDepth/2;

        /* clamp to 1 */
        if (nextWidth < 1) nextWidth= 1;
        if (nextHeight < 1) nextHeight= 1;
        if (nextDepth < 1) nextDepth= 1;     
       memReq = imageSize3D(nextWidth, nextHeight, nextDepth, format, type);
       }
       switch(type) {
       case GL_UNSIGNED_BYTE:
       dstImage = (GLubyte *)malloc(memReq);
       break;
       case GL_BYTE:
       dstImage = (GLbyte *)malloc(memReq);
       break;
       case GL_UNSIGNED_SHORT:
       dstImage = (GLushort *)malloc(memReq);
       break;
       case GL_SHORT:
       dstImage = (GLshort *)malloc(memReq);
       break;
       case GL_UNSIGNED_INT:
       dstImage = (GLuint *)malloc(memReq);
       break;
       case GL_INT:
       dstImage = (GLint *)malloc(memReq);
       break;
       case GL_FLOAT:
       dstImage = (GLfloat *)malloc(memReq);
       break;
       case GL_UNSIGNED_BYTE_3_3_2: 
       case GL_UNSIGNED_BYTE_2_3_3_REV: 
       dstImage = (GLubyte *)malloc(memReq);
       break;
       case GL_UNSIGNED_SHORT_5_6_5:
       case GL_UNSIGNED_SHORT_5_6_5_REV:
       case GL_UNSIGNED_SHORT_4_4_4_4:
       case GL_UNSIGNED_SHORT_4_4_4_4_REV:
       case GL_UNSIGNED_SHORT_5_5_5_1:
       case GL_UNSIGNED_SHORT_1_5_5_5_REV:
       dstImage = (GLushort *)malloc(memReq);
       break;
       case GL_UNSIGNED_INT_8_8_8_8:
       case GL_UNSIGNED_INT_8_8_8_8_REV:
       case GL_UNSIGNED_INT_10_10_10_2:
       case GL_UNSIGNED_INT_2_10_10_10_REV:
       dstImage = (GLuint *)malloc(memReq);       
       break;
       default:
       return GLU_INVALID_ENUM; /* assertion */
       }
       if (dstImage == NULL) {
       glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
       glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
       glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
       glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
       glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
       glPixelStorei(GL_UNPACK_SKIP_IMAGES, psm.unpack_skip_images);
       glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, psm.unpack_image_height);
       return GLU_OUT_OF_MEMORY;
       }
       else
       switch(type) {
       case GL_UNSIGNED_BYTE:
         if (depth > 1) {
           halveImage3D(cmpts,extractUbyte,shoveUbyte,
                    width,height,depth,
                    usersImage,dstImage,elementSize,groupSize,rowSize,
                    imageSize,myswapBytes);
         }
         else {
           halveImage_ubyte(cmpts,width,height,usersImage,dstImage,
                        elementSize,rowSize,groupSize);
         }
         break;
       case GL_BYTE:
         if (depth > 1) {
         halveImage3D(cmpts,extractSbyte,shoveSbyte,
                  width,height,depth,
                  usersImage,dstImage,elementSize,groupSize,rowSize,
                  imageSize,myswapBytes);
         }
         else {
           halveImage_byte(cmpts,width,height,usersImage,dstImage,
                       elementSize,rowSize,groupSize);
         }
         break;
       case GL_UNSIGNED_SHORT:
         if (depth > 1) {
         halveImage3D(cmpts,extractUshort,shoveUshort,
                  width,height,depth,
                  usersImage,dstImage,elementSize,groupSize,rowSize,
                  imageSize,myswapBytes);
         }
         else {
           halveImage_ushort(cmpts,width,height,usersImage,dstImage,
                         elementSize,rowSize,groupSize,myswapBytes);
         }
         break;
       case GL_SHORT:
           if (depth > 1) { 
         halveImage3D(cmpts,extractSshort,shoveSshort,
                  width,height,depth,
                  usersImage,dstImage,elementSize,groupSize,rowSize,
                  imageSize,myswapBytes);
         }
         else {
           halveImage_short(cmpts,width,height,usersImage,dstImage,
                        elementSize,rowSize,groupSize,myswapBytes);
         }
         break;
       case GL_UNSIGNED_INT:
         if (depth > 1) { 
         halveImage3D(cmpts,extractUint,shoveUint,
                  width,height,depth,
                  usersImage,dstImage,elementSize,groupSize,rowSize,
                  imageSize,myswapBytes);
         }
         else {
           halveImage_uint(cmpts,width,height,usersImage,dstImage,
                       elementSize,rowSize,groupSize,myswapBytes);
         }
         break;
       case GL_INT:
         if (depth > 1) { 
         halveImage3D(cmpts,extractSint,shoveSint,
                  width,height,depth,
                  usersImage,dstImage,elementSize,groupSize,rowSize,
                  imageSize,myswapBytes);
         }
         else {
           halveImage_int(cmpts,width,height,usersImage,dstImage,
                      elementSize,rowSize,groupSize,myswapBytes);
         }
         break;
       case GL_FLOAT:
         if (depth > 1 ) {
         halveImage3D(cmpts,extractFloat,shoveFloat,
                  width,height,depth,
                  usersImage,dstImage,elementSize,groupSize,rowSize,
                  imageSize,myswapBytes);
         }
         else {
           halveImage_float(cmpts,width,height,usersImage,dstImage,
                        elementSize,rowSize,groupSize,myswapBytes);
         }
         break;
       case GL_UNSIGNED_BYTE_3_3_2: 
         assert(format == GL_RGB);
         halveImagePackedPixel3D(3,extract332,shove332,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;
       case GL_UNSIGNED_BYTE_2_3_3_REV:
         assert(format == GL_RGB);
         halveImagePackedPixel3D(3,extract233rev,shove233rev,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;
       case GL_UNSIGNED_SHORT_5_6_5:
         halveImagePackedPixel3D(3,extract565,shove565,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;
       case GL_UNSIGNED_SHORT_5_6_5_REV:
         halveImagePackedPixel3D(3,extract565rev,shove565rev,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;
       case GL_UNSIGNED_SHORT_4_4_4_4:
         halveImagePackedPixel3D(4,extract4444,shove4444,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;          
       case GL_UNSIGNED_SHORT_4_4_4_4_REV:
         halveImagePackedPixel3D(4,extract4444rev,shove4444rev,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;          
       case GL_UNSIGNED_SHORT_5_5_5_1:
         halveImagePackedPixel3D(4,extract5551,shove5551,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;          
       case GL_UNSIGNED_SHORT_1_5_5_5_REV:
         halveImagePackedPixel3D(4,extract1555rev,shove1555rev,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;          
       case GL_UNSIGNED_INT_8_8_8_8:
         halveImagePackedPixel3D(4,extract8888,shove8888,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;          
       case GL_UNSIGNED_INT_8_8_8_8_REV:
         halveImagePackedPixel3D(4,extract8888rev,shove8888rev,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;          
       case GL_UNSIGNED_INT_10_10_10_2:
         halveImagePackedPixel3D(4,extract1010102,shove1010102,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;          
       case GL_UNSIGNED_INT_2_10_10_10_REV:
         halveImagePackedPixel3D(4,extract2101010rev,shove2101010rev,
                           width,height,depth,usersImage,dstImage,
                           elementSize,rowSize,imageSize,myswapBytes);
         break;          
       default:
         assert(0);
         break;
       }
       newWidth = width/2;
       newHeight = height/2;
       newDepth = depth/2;
       /* clamp to 1 */
       if (newWidth < 1) newWidth= 1;
       if (newHeight < 1) newHeight= 1; 
       if (newDepth < 1) newDepth= 1;

       myswapBytes = 0;
       rowSize = newWidth * groupSize;
       imageSize= rowSize * newHeight; /* 3dstuff */
       memReq = imageSize3D(newWidth, newHeight, newDepth, format, type);
       /* Swap srcImage and dstImage */
       __GLU_SWAP_IMAGE(srcImage,dstImage);
       switch(type) {
       case GL_UNSIGNED_BYTE:
       dstImage = (GLubyte *)malloc(memReq);
       break;
       case GL_BYTE:
       dstImage = (GLbyte *)malloc(memReq);
       break;
       case GL_UNSIGNED_SHORT:
       dstImage = (GLushort *)malloc(memReq);
       break;
       case GL_SHORT:
       dstImage = (GLshort *)malloc(memReq);
       break;
       case GL_UNSIGNED_INT:
       dstImage = (GLuint *)malloc(memReq);
       break;
       case GL_INT:
       dstImage = (GLint *)malloc(memReq);
       break;
       case GL_FLOAT:
       dstImage = (GLfloat *)malloc(memReq);
       break;
       case GL_UNSIGNED_BYTE_3_3_2:
       case GL_UNSIGNED_BYTE_2_3_3_REV:
       dstImage = (GLubyte *)malloc(memReq);
       break;
       case GL_UNSIGNED_SHORT_5_6_5:
       case GL_UNSIGNED_SHORT_5_6_5_REV:
       case GL_UNSIGNED_SHORT_4_4_4_4:
       case GL_UNSIGNED_SHORT_4_4_4_4_REV:
       case GL_UNSIGNED_SHORT_5_5_5_1:
       case GL_UNSIGNED_SHORT_1_5_5_5_REV:
       dstImage = (GLushort *)malloc(memReq);
       break;
       case GL_UNSIGNED_INT_8_8_8_8:
       case GL_UNSIGNED_INT_8_8_8_8_REV:
       case GL_UNSIGNED_INT_10_10_10_2:
       case GL_UNSIGNED_INT_2_10_10_10_REV:
       dstImage = (GLuint *)malloc(memReq);
       break;
       default:
       return GLU_INVALID_ENUM; /* assertion */
       }
       if (dstImage == NULL) {
       glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
       glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
       glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
       glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
       glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
       glPixelStorei(GL_UNPACK_SKIP_IMAGES, psm.unpack_skip_images);
       glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, psm.unpack_image_height);
       return GLU_OUT_OF_MEMORY;
       }
       /* level userLevel+1 is in srcImage; level userLevel already saved */
       level = userLevel+1; 
   } else {/* user's image is *not* nice power-of-2 sized square */
       memReq = imageSize3D(newWidth, newHeight, newDepth, format, type);
       switch(type) {
         case GL_UNSIGNED_BYTE:
             dstImage = (GLubyte *)malloc(memReq);
             break;
         case GL_BYTE:
             dstImage = (GLbyte *)malloc(memReq);
             break;
         case GL_UNSIGNED_SHORT:
             dstImage = (GLushort *)malloc(memReq);
             break;
         case GL_SHORT:
             dstImage = (GLshort *)malloc(memReq);
             break;
         case GL_UNSIGNED_INT:
             dstImage = (GLuint *)malloc(memReq);
             break;
         case GL_INT:
             dstImage = (GLint *)malloc(memReq);
             break;
         case GL_FLOAT:
             dstImage = (GLfloat *)malloc(memReq);
             break;
         case GL_UNSIGNED_BYTE_3_3_2:
         case GL_UNSIGNED_BYTE_2_3_3_REV:
             dstImage = (GLubyte *)malloc(memReq);
             break;
         case GL_UNSIGNED_SHORT_5_6_5:
         case GL_UNSIGNED_SHORT_5_6_5_REV:
         case GL_UNSIGNED_SHORT_4_4_4_4:
         case GL_UNSIGNED_SHORT_4_4_4_4_REV:
         case GL_UNSIGNED_SHORT_5_5_5_1:
         case GL_UNSIGNED_SHORT_1_5_5_5_REV:
             dstImage = (GLushort *)malloc(memReq);
             break;
         case GL_UNSIGNED_INT_8_8_8_8:
         case GL_UNSIGNED_INT_8_8_8_8_REV:
         case GL_UNSIGNED_INT_10_10_10_2:
         case GL_UNSIGNED_INT_2_10_10_10_REV:
             dstImage = (GLuint *)malloc(memReq);
             break;
         default:
             return GLU_INVALID_ENUM;     /* assertion */
       }

       if (dstImage == NULL) {
         glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
         glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
         glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
         glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
         glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
         glPixelStorei(GL_UNPACK_SKIP_IMAGES, psm.unpack_skip_images);
         glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, psm.unpack_image_height);
         return GLU_OUT_OF_MEMORY;
       }
       /*printf("Build3DMipmaps(): ScaleImage3D %d %d %d->%d %d %d\n",
       width,height,depth,newWidth,newHeight,newDepth);*/

       gluScaleImage3D(format, width, height, depth, type, usersImage,
                   newWidth, newHeight, newDepth, type, dstImage);

       myswapBytes = 0;
       rowSize = newWidth * groupSize;
       imageSize = rowSize * newHeight; /* 3dstuff */
       /* Swap dstImage and srcImage */
       __GLU_SWAP_IMAGE(srcImage,dstImage);

       if(levels != 0) { /* use as little memory as possible */
       {
          int nextWidth= newWidth/2;
          int nextHeight= newHeight/2;
          int nextDepth= newDepth/2;
          if (nextWidth < 1) nextWidth= 1;
          if (nextHeight < 1) nextHeight= 1;         
          if (nextDepth < 1) nextDepth= 1;           

       memReq = imageSize3D(nextWidth, nextHeight, nextDepth, format, type);
       }
       switch(type) {
       case GL_UNSIGNED_BYTE:
         dstImage = (GLubyte *)malloc(memReq);
         break;
       case GL_BYTE:
         dstImage = (GLbyte *)malloc(memReq);
         break;
       case GL_UNSIGNED_SHORT:
         dstImage = (GLushort *)malloc(memReq);
         break;
       case GL_SHORT:
         dstImage = (GLshort *)malloc(memReq);
         break;
       case GL_UNSIGNED_INT:
         dstImage = (GLuint *)malloc(memReq);
         break;
       case GL_INT:
         dstImage = (GLint *)malloc(memReq);
         break;
       case GL_FLOAT:
         dstImage = (GLfloat *)malloc(memReq);
         break;
       case GL_UNSIGNED_BYTE_3_3_2:
       case GL_UNSIGNED_BYTE_2_3_3_REV:
         dstImage = (GLubyte *)malloc(memReq);
         break;
       case GL_UNSIGNED_SHORT_5_6_5:
       case GL_UNSIGNED_SHORT_5_6_5_REV:
       case GL_UNSIGNED_SHORT_4_4_4_4:
       case GL_UNSIGNED_SHORT_4_4_4_4_REV:
       case GL_UNSIGNED_SHORT_5_5_5_1:
       case GL_UNSIGNED_SHORT_1_5_5_5_REV:
         dstImage = (GLushort *)malloc(memReq);
         break;
       case GL_UNSIGNED_INT_8_8_8_8:
       case GL_UNSIGNED_INT_8_8_8_8_REV:
       case GL_UNSIGNED_INT_10_10_10_2:
       case GL_UNSIGNED_INT_2_10_10_10_REV:
         dstImage = (GLuint *)malloc(memReq);
         break;
       default:
         return GLU_INVALID_ENUM; /* assertion */
       }
       if (dstImage == NULL) {
         glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
         glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
         glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
         glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
         glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
         glPixelStorei(GL_UNPACK_SKIP_IMAGES, psm.unpack_skip_images);
         glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, psm.unpack_image_height);
         return GLU_OUT_OF_MEMORY;
       }
       }
       /* level userLevel is in srcImage; nothing saved yet */
       level = userLevel;     
   }

   glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_FALSE);
   if (baseLevel <= level && level <= maxLevel) {
     glTexImage3D(target, level, internalFormat, newWidth, newHeight, newDepth,
              0,format, type, (void *)srcImage);
   }
   level++; /* update current level for the loop */
   for (; level <= levels; level++) {
       switch(type) {
         case GL_UNSIGNED_BYTE:
             if (newDepth > 1) {
             halveImage3D(cmpts,extractUbyte,shoveUbyte,
                      newWidth,newHeight,newDepth,
                      srcImage,dstImage,elementSize,groupSize,rowSize,
                      imageSize,myswapBytes);
             }
             else {
             halveImage_ubyte(cmpts,newWidth,newHeight,srcImage,dstImage,
                          elementSize,rowSize,groupSize);
             }
             break;
         case GL_BYTE:
             if (newDepth > 1) {
             halveImage3D(cmpts,extractSbyte,shoveSbyte,
                      newWidth,newHeight,newDepth,
                      srcImage,dstImage,elementSize,groupSize,rowSize,
                      imageSize,myswapBytes);
             }
             else {
             halveImage_byte(cmpts,newWidth,newHeight,srcImage,dstImage,
                          elementSize,rowSize,groupSize);
             }
             break;
         case GL_UNSIGNED_SHORT:
             if (newDepth > 1) { 
             halveImage3D(cmpts,extractUshort,shoveUshort,
                      newWidth,newHeight,newDepth,
                      srcImage,dstImage,elementSize,groupSize,rowSize,
                      imageSize,myswapBytes);
             }
             else {
             halveImage_ushort(cmpts,newWidth,newHeight,srcImage,dstImage,
                           elementSize,rowSize,groupSize,myswapBytes);
             }
             break;
         case GL_SHORT:
             if (newDepth > 1) {
             halveImage3D(cmpts,extractSshort,shoveSshort,
                      newWidth,newHeight,newDepth,
                      srcImage,dstImage,elementSize,groupSize,rowSize,
                      imageSize,myswapBytes);
             }
             else {
             halveImage_short(cmpts,newWidth,newHeight,srcImage,dstImage,
                          elementSize,rowSize,groupSize,myswapBytes);
             }
             break;
         case GL_UNSIGNED_INT:
             if (newDepth > 1) {
             halveImage3D(cmpts,extractUint,shoveUint,
                      newWidth,newHeight,newDepth,
                      srcImage,dstImage,elementSize,groupSize,rowSize,
                      imageSize,myswapBytes);
             }
             else {
             halveImage_uint(cmpts,newWidth,newHeight,srcImage,dstImage,
                         elementSize,rowSize,groupSize,myswapBytes);
             }
             break;
         case GL_INT:
             if (newDepth > 1) {
             halveImage3D(cmpts,extractSint,shoveSint,
                      newWidth,newHeight,newDepth,
                      srcImage,dstImage,elementSize,groupSize,rowSize,
                      imageSize,myswapBytes);
             }
             else {
             halveImage_int(cmpts,newWidth,newHeight,srcImage,dstImage,
                        elementSize,rowSize,groupSize,myswapBytes);
             }
             break;
         case GL_FLOAT:
             if (newDepth > 1) {
             halveImage3D(cmpts,extractFloat,shoveFloat,
                      newWidth,newHeight,newDepth,
                      srcImage,dstImage,elementSize,groupSize,rowSize,
                      imageSize,myswapBytes);
             }
             else {
             halveImage_float(cmpts,newWidth,newHeight,srcImage,dstImage,
                          elementSize,rowSize,groupSize,myswapBytes);
             }
             break;
         case GL_UNSIGNED_BYTE_3_3_2:
             halveImagePackedPixel3D(3,extract332,shove332,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_BYTE_2_3_3_REV:
             halveImagePackedPixel3D(3,extract233rev,shove233rev,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_SHORT_5_6_5:
             halveImagePackedPixel3D(3,extract565,shove565,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_SHORT_5_6_5_REV:
             halveImagePackedPixel3D(3,extract565rev,shove565rev,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_SHORT_4_4_4_4:
             halveImagePackedPixel3D(4,extract4444,shove4444,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_SHORT_4_4_4_4_REV:
             halveImagePackedPixel3D(4,extract4444rev,shove4444rev,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_SHORT_5_5_5_1:        
             halveImagePackedPixel3D(4,extract5551,shove5551,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_SHORT_1_5_5_5_REV:          
             halveImagePackedPixel3D(4,extract1555rev,shove1555rev,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_INT_8_8_8_8:
             halveImagePackedPixel3D(4,extract8888,shove8888,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_INT_8_8_8_8_REV:
             halveImagePackedPixel3D(4,extract8888rev,shove8888rev,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_INT_10_10_10_2:
             halveImagePackedPixel3D(4,extract1010102,shove1010102,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         case GL_UNSIGNED_INT_2_10_10_10_REV:
             halveImagePackedPixel3D(4,extract2101010rev,shove2101010rev,
                               newWidth,newHeight,newDepth,
                               srcImage,dstImage,elementSize,rowSize,
                               imageSize,myswapBytes);
             break;
         default:
             assert(0);
             break;
       }

       __GLU_SWAP_IMAGE(srcImage,dstImage);

       if (newWidth > 1) { newWidth /= 2; rowSize /= 2;}
       if (newHeight > 1) { newHeight /= 2; imageSize = rowSize * newHeight; }
       if (newDepth > 1) newDepth /= 2;
       {
        /* call tex image with srcImage untouched since it's not padded */
        if (baseLevel <= level && level <= maxLevel) {
          glTexImage3D(target, level, internalFormat, newWidth, newHeight,
                   newDepth,0, format, type, (void *) srcImage);
        }
       }
   } /* for level */
   glPixelStorei(GL_UNPACK_ALIGNMENT, psm.unpack_alignment);
   glPixelStorei(GL_UNPACK_SKIP_ROWS, psm.unpack_skip_rows);
   glPixelStorei(GL_UNPACK_SKIP_PIXELS, psm.unpack_skip_pixels);
   glPixelStorei(GL_UNPACK_ROW_LENGTH, psm.unpack_row_length);
   glPixelStorei(GL_UNPACK_SWAP_BYTES, psm.unpack_swap_bytes);
   glPixelStorei(GL_UNPACK_SKIP_IMAGES, psm.unpack_skip_images);
   glPixelStorei(GL_UNPACK_IMAGE_HEIGHT, psm.unpack_image_height);

   free(srcImage); /*if you get to here, a srcImage has always been malloc'ed*/
   if (dstImage) { /* if it's non-rectangular and only 1 level */
     free(dstImage);
   }
   return 0;
} /* gluBuild3DMipmapLevelsCore() */

GLint GLAPIENTRY
gluBuild3DMipmapLevels(GLenum target, GLint internalFormat, 
                       GLsizei width, GLsizei height, GLsizei depth,
                       GLenum format, GLenum type, 
                       GLint userLevel, GLint baseLevel, GLint maxLevel,
                       const void *data)
{
   int level, levels;

   int rc= checkMipmapArgs(internalFormat,format,type);
   if (rc != 0) return rc;

   if (width < 1 || height < 1 || depth < 1) {
       return GLU_INVALID_VALUE;
   }

   if(type == GL_BITMAP) {
      return GLU_INVALID_ENUM;
   }

   levels = computeLog(width);
   level = computeLog(height);
   if (level > levels) levels=level;
   level = computeLog(depth);
   if (level > levels) levels=level;

   levels+= userLevel;
   if (!isLegalLevels(userLevel,baseLevel,maxLevel,levels)) 
      return GLU_INVALID_VALUE;

   return gluBuild3DMipmapLevelsCore(target, internalFormat, 
                             width, height, depth,
                             width, height, depth,
                             format, type, 
                             userLevel, baseLevel, maxLevel,
                             data);
} /* gluBuild3DMipmapLevels() */

GLint GLAPIENTRY
gluBuild3DMipmaps(GLenum target, GLint internalFormat, 
                  GLsizei width, GLsizei height, GLsizei depth,
                  GLenum format, GLenum type, const void *data)
{
   GLint widthPowerOf2, heightPowerOf2, depthPowerOf2;
   int level, levels;

   int rc= checkMipmapArgs(internalFormat,format,type);
   if (rc != 0) return rc;

   if (width < 1 || height < 1 || depth < 1) {
       return GLU_INVALID_VALUE;
   }

   if(type == GL_BITMAP) {
      return GLU_INVALID_ENUM;
   }

   closestFit3D(target,width,height,depth,internalFormat,format,type,
            &widthPowerOf2,&heightPowerOf2,&depthPowerOf2);

   levels = computeLog(widthPowerOf2);
   level = computeLog(heightPowerOf2);
   if (level > levels) levels=level;
   level = computeLog(depthPowerOf2);
   if (level > levels) levels=level;

   return gluBuild3DMipmapLevelsCore(target, internalFormat, 
                             width, height, depth,
                             widthPowerOf2, heightPowerOf2, 
                             depthPowerOf2,
                             format, type, 0, 0, levels,
                             data);
} /* gluBuild3DMipmaps() */

static GLdouble extractUbyte(int isSwap, const void *ubyte)
{
   isSwap= isSwap;            /* turn off warnings */

   assert(*((const GLubyte *)ubyte) <= 255);

   return (GLdouble)(*((const GLubyte *)ubyte));
} /* extractUbyte() */

static void shoveUbyte(GLdouble value, int index, void *data)
{
   assert(0.0 <= value && value < 256.0);

   ((GLubyte *)data)[index]= (GLubyte)value;
} /* shoveUbyte() */

static GLdouble extractSbyte(int isSwap, const void *sbyte)
{
   isSwap= isSwap;            /* turn off warnings */

   assert(*((const GLbyte *)sbyte) <= 127);

   return (GLdouble)(*((const GLbyte *)sbyte));
} /* extractSbyte() */

static void shoveSbyte(GLdouble value, int index, void *data)
{
   ((GLbyte *)data)[index]= (GLbyte)value;
} /* shoveSbyte() */

static GLdouble extractUshort(int isSwap, const void *uitem)
{
   GLushort ushort;

   if (isSwap) {
     ushort= __GLU_SWAP_2_BYTES(uitem);
   }
   else {
     ushort= *(const GLushort *)uitem;
   }

   assert(ushort <= 65535);  

   return (GLdouble)ushort;
} /* extractUshort() */

static void shoveUshort(GLdouble value, int index, void *data)
{
   assert(0.0 <= value && value < 65536.0);

   ((GLushort *)data)[index]= (GLushort)value;
} /* shoveUshort() */

static GLdouble extractSshort(int isSwap, const void *sitem)
{
   GLshort sshort;

   if (isSwap) {
     sshort= __GLU_SWAP_2_BYTES(sitem);
   }
   else {
     sshort= *(const GLshort *)sitem;
   }

   assert(sshort <= 32767);  

   return (GLdouble)sshort;
} /* extractSshort() */

static void shoveSshort(GLdouble value, int index, void *data)
{
   assert(0.0 <= value && value < 32768.0);

   ((GLshort *)data)[index]= (GLshort)value;
} /* shoveSshort() */

static GLdouble extractUint(int isSwap, const void *uitem)
{
   GLuint uint;

   if (isSwap) {
     uint= __GLU_SWAP_4_BYTES(uitem);
   }
   else {
     uint= *(const GLuint *)uitem;
   }

   assert(uint <= 0xffffffff);  

   return (GLdouble)uint;
} /* extractUint() */

static void shoveUint(GLdouble value, int index, void *data)
{
   assert(0.0 <= value && value <= (GLdouble) UINT_MAX); 

   ((GLuint *)data)[index]= (GLuint)value;
} /* shoveUint() */

static GLdouble extractSint(int isSwap, const void *sitem)
{
   GLint sint;

   if (isSwap) {
     sint= __GLU_SWAP_4_BYTES(sitem);
   }
   else {
     sint= *(const GLint *)sitem;
   }

   assert(sint <= 0x7fffffff);  

   return (GLdouble)sint;
} /* extractSint() */

static void shoveSint(GLdouble value, int index, void *data)
{
   assert(0.0 <= value && value <= (GLdouble) INT_MAX); 

   ((GLint *)data)[index]= (GLint)value;
} /* shoveSint() */

static GLdouble extractFloat(int isSwap, const void *item)
{
   GLfloat ffloat;

   if (isSwap) {
     ffloat= __GLU_SWAP_4_BYTES(item);
   }
   else {
     ffloat= *(const GLfloat *)item;
   }

   assert(ffloat <= 1.0);  

   return (GLdouble)ffloat;
} /* extractFloat() */

static void shoveFloat(GLdouble value, int index, void *data)
{
   assert(0.0 <= value && value <= 1.0);

   ((GLfloat *)data)[index]= value;
} /* shoveFloat() */

static void halveImageSlice(int components,
                      GLdouble (*extract)(int, const void *),
                      void (*shove)(GLdouble, int, void *),
                      GLint width, GLint height, GLint depth,
                      const void *dataIn, void *dataOut,
                      GLint elementSizeInBytes,
                      GLint groupSizeInBytes, 
                      GLint rowSizeInBytes, 
                      GLint imageSizeInBytes,
                      GLint isSwap)
{
   int ii, jj;
   int halfWidth= width / 2;
   int halfHeight= height / 2;
   int halfDepth= depth / 2;
   const char *src= (const char *)dataIn;
   int padBytes= rowSizeInBytes - (width * groupSizeInBytes);
   int outIndex= 0;

   assert((width == 1 || height == 1) && depth >= 2);

   if (width == height) {     /* a 1-pixel column viewed from top */
      /* printf("1-column\n");*/
      assert(width == 1 && height == 1);
      assert(depth >= 2);

      for (ii= 0; ii< halfDepth; ii++) {
       int cc;

       for (cc = 0; cc < components; cc++) {
          double totals[4];
          double extractTotals[BOX2][4];
          int kk;

          extractTotals[0][cc]= (*extract)(isSwap,src);
          extractTotals[1][cc]= (*extract)(isSwap,(src+imageSizeInBytes));

          /* average 2 pixels since only a column */
          totals[cc]= 0.0;
          /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED];
           * totals[RED]/= 2.0;
           */
          for (kk = 0; kk < BOX2; kk++) {
            totals[cc]+= extractTotals[kk][cc];
          }
          totals[cc]/= (double)BOX2;

          (*shove)(totals[cc],outIndex,dataOut);
          outIndex++;
          src+= elementSizeInBytes;
       } /* for cc */

       /* skip over to next group of 2 */
       src+= rowSizeInBytes;
      } /* for ii */

      assert(src == &((const char *)dataIn)[rowSizeInBytes*height*depth]);
      assert(outIndex == halfDepth * components);
   }
   else if (height == 1) {    /* horizontal slice viewed from top */
      /* printf("horizontal slice\n"); */
      assert(width != 1);

      for (ii= 0; ii< halfDepth; ii++) {
       for (jj= 0; jj< halfWidth; jj++) {
          int cc;

          for (cc = 0; cc < components; cc++) {
             int kk;
             double totals[4];
             double extractTotals[BOX4][4]; 

             extractTotals[0][cc]=(*extract)(isSwap,src);
             extractTotals[1][cc]=(*extract)(isSwap,
                                     (src+groupSizeInBytes));
             extractTotals[2][cc]=(*extract)(isSwap,
                                     (src+imageSizeInBytes));
             extractTotals[3][cc]=(*extract)(isSwap,
                                     (src+imageSizeInBytes+groupSizeInBytes));

             /* grab 4 pixels to average */
             totals[cc]= 0.0;
             /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED]+
            *              extractTotals[2][RED]+extractTotals[3][RED];
            * totals[RED]/= 4.0;
            */
             for (kk = 0; kk < BOX4; kk++) {
              totals[cc]+= extractTotals[kk][cc];
             }
             totals[cc]/= (double)BOX4;

             (*shove)(totals[cc],outIndex,dataOut);
             outIndex++;

             src+= elementSizeInBytes;
          } /* for cc */ 

          /* skip over to next horizontal square of 4 */
          src+= groupSizeInBytes;
       } /* for jj */
       src+= padBytes;

       src+= rowSizeInBytes;
      } /* for ii */

      assert(src == &((const char *)dataIn)[rowSizeInBytes*height*depth]);
      assert(outIndex == halfWidth * halfDepth * components);
   } 
   else if (width == 1) {     /* vertical slice viewed from top */
      /* printf("vertical slice\n"); */
      assert(height != 1);

      for (ii= 0; ii< halfDepth; ii++) {
       for (jj= 0; jj< halfHeight; jj++) {
          int cc;

          for (cc = 0; cc < components; cc++) {
             int kk;
             double totals[4];
             double extractTotals[BOX4][4];

             extractTotals[0][cc]=(*extract)(isSwap,src);
             extractTotals[1][cc]=(*extract)(isSwap,
                                     (src+rowSizeInBytes));
             extractTotals[2][cc]=(*extract)(isSwap,
                                     (src+imageSizeInBytes));
             extractTotals[3][cc]=(*extract)(isSwap,
                                     (src+imageSizeInBytes+rowSizeInBytes));

             /* grab 4 pixels to average */
             totals[cc]= 0.0;
             /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED]+
            *              extractTotals[2][RED]+extractTotals[3][RED];
            * totals[RED]/= 4.0;
            */
             for (kk = 0; kk < BOX4; kk++) {
              totals[cc]+= extractTotals[kk][cc];
             }
             totals[cc]/= (double)BOX4;

             (*shove)(totals[cc],outIndex,dataOut);
             outIndex++;

             src+= elementSizeInBytes;
          } /* for cc */
          src+= padBytes;

          /* skip over to next vertical square of 4 */
          src+= rowSizeInBytes;
       } /* for jj */

       src+= imageSizeInBytes;
      } /* for ii */ 

      assert(src == &((const char *)dataIn)[rowSizeInBytes*height*depth]);
      assert(outIndex == halfHeight * halfDepth * components);
   }

} /* halveImageSlice() */

static void halveImage3D(int components,
                   GLdouble (*extract)(int, const void *),
                   void (*shove)(GLdouble, int, void *),
                   GLint width, GLint height, GLint depth,
                   const void *dataIn, void *dataOut,
                   GLint elementSizeInBytes,
                   GLint groupSizeInBytes, 
                   GLint rowSizeInBytes, 
                   GLint imageSizeInBytes,
                   GLint isSwap)
{
   assert(depth > 1); 

   /* a horizontal/vertical/one-column slice viewed from top */
   if (width == 1 || height == 1) { 
      assert(1 <= depth);

      halveImageSlice(components,extract,shove, width, height, depth, 
                  dataIn, dataOut, elementSizeInBytes, groupSizeInBytes, 
                  rowSizeInBytes, imageSizeInBytes, isSwap);
      return;
   }
   {
      int ii, jj, dd;

      int halfWidth= width / 2;
      int halfHeight= height / 2;
      int halfDepth= depth / 2;  
      const char *src= (const char *) dataIn;
      int padBytes= rowSizeInBytes - (width*groupSizeInBytes);
      int outIndex= 0;

      for (dd= 0; dd < halfDepth; dd++) {
       for (ii= 0; ii< halfHeight; ii++) {
          for (jj= 0; jj< halfWidth; jj++) {
             int cc;

             for (cc= 0; cc < components; cc++) {
              int kk;
#define BOX8 8
              double totals[4];     /* 4 is maximum components */
              double extractTotals[BOX8][4]; /* 4 is maximum components */

              extractTotals[0][cc]= (*extract)(isSwap,src);
              extractTotals[1][cc]= (*extract)(isSwap,
                                       (src+groupSizeInBytes));
              extractTotals[2][cc]= (*extract)(isSwap,
                                       (src+rowSizeInBytes));
              extractTotals[3][cc]= (*extract)(isSwap,
                                       (src+rowSizeInBytes+groupSizeInBytes));

              extractTotals[4][cc]= (*extract)(isSwap,
                                       (src+imageSizeInBytes));

              extractTotals[5][cc]= (*extract)(isSwap,
                                       (src+groupSizeInBytes+imageSizeInBytes));
              extractTotals[6][cc]= (*extract)(isSwap,
                                       (src+rowSizeInBytes+imageSizeInBytes));
              extractTotals[7][cc]= (*extract)(isSwap,
                                       (src+rowSizeInBytes+groupSizeInBytes+imageSizeInBytes));

              totals[cc]= 0.0;

              /* totals[RED]= extractTotals[0][RED]+extractTotals[1][RED]+
               *              extractTotals[2][RED]+extractTotals[3][RED]+
               *              extractTotals[4][RED]+extractTotals[5][RED]+
               *              extractTotals[6][RED]+extractTotals[7][RED];
               * totals[RED]/= 8.0;
               */
              for (kk = 0; kk < BOX8; kk++) {
                 totals[cc]+= extractTotals[kk][cc];
              }
              totals[cc]/= (double)BOX8;

              (*shove)(totals[cc],outIndex,dataOut);

              outIndex++;

              src+= elementSizeInBytes; /* go to next component */
             } /* for cc */

             /* skip over to next square of 4 */
             src+= groupSizeInBytes;
          } /* for jj */
          /* skip past pad bytes, if any, to get to next row */
          src+= padBytes;

          /* src is at beginning of a row here, but it's the second row of
           * the square block of 4 pixels that we just worked on so we
           * need to go one more row.  
           * i.e.,             
           *                   OO... 
           *           here -->OO...
           *       but want -->OO...
           *                   OO... 
           *                   ...
           */
          src+= rowSizeInBytes;
       } /* for ii */

       src+= imageSizeInBytes; 
      } /* for dd */

      /* both pointers must reach one byte after the end */
      assert(src == &((const char *)dataIn)[rowSizeInBytes*height*depth]);
      assert(outIndex == halfWidth * halfHeight * halfDepth * components);
   }
} /* halveImage3D() */



/*** mipmap.c ***/


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