/* $Id: teximage.c,v 1.7 1996/12/02 18:59:54 brianp Exp $ */

/*
 * Mesa 3-D graphics library
 * Version:  2.0
 * Copyright (C) 1995-1996  Brian Paul
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */


/*
 * $Log: teximage.c,v $
 * Revision 1.7  1996/12/02 18:59:54  brianp
 * added code to handle GL_COLOR_INDEX textures, per Randy Frank
 *
 * Revision 1.6  1996/11/07 04:13:24  brianp
 * all new texture image handling, now pixel scale, bias, mapping work
 *
 * Revision 1.5  1996/09/27 01:29:57  brianp
 * removed unused variables, fixed cut&paste bug in color scaling
 *
 * Revision 1.4  1996/09/26 22:35:10  brianp
 * fixed a few compiler warnings from IRIX 6 -n32 and -64 compiler
 *
 * Revision 1.3  1996/09/15 14:18:55  brianp
 * now use GLframebuffer and GLvisual
 *
 * Revision 1.2  1996/09/15 01:48:58  brianp
 * removed #define NULL 0
 *
 * Revision 1.1  1996/09/13 01:38:16  brianp
 * Initial revision
 *
 */


#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "context.h"
#include "image.h"
#include "macros.h"
#include "pixel.h"
#include "span.h"
#include "teximage.h"
#include "types.h"



/*
 * NOTES:
 *
 * The internal texture storage convension is an array of N GLubytes
 * where N = width * height * components.  There is no padding.
 */




/*
 * Compute log base 2 of n.
 * If n isn't an exact power of two return -1.
 * If n<0 return -1.
 */
static int logbase2( int n )
{
   GLint m = n;
   GLint i = 1;
   GLint log2 = 0;

   if (n<0) {
      return -1;
   }

   while ( m > i ) {
      i *= 2;
      log2++;
   }
   if (m != n) {
      return -1;
   }
   else {
      return log2;
   }
}



/*
 * Given an internal texture format enum or 1, 2, 3, 4 return the
 * corresponding _base_ internal format:  GL_ALPHA, GL_LUMINANCE,
 * GL_LUMANCE_ALPHA, GL_INTENSITY, GL_RGB, or GL_RGBA.  Return -1 if
 * invalid enum.
 */
static GLint decode_internal_format( GLint format )
{
   switch (format) {
      case GL_ALPHA:
      case GL_ALPHA4:
      case GL_ALPHA8:
      case GL_ALPHA12:
      case GL_ALPHA16:
         return GL_ALPHA;
      case 1:
      case GL_LUMINANCE:
      case GL_LUMINANCE4:
      case GL_LUMINANCE8:
      case GL_LUMINANCE12:
      case GL_LUMINANCE16:
         return GL_LUMINANCE;
      case 2:
      case GL_LUMINANCE_ALPHA:
      case GL_LUMINANCE4_ALPHA4:
      case GL_LUMINANCE6_ALPHA2:
      case GL_LUMINANCE8_ALPHA8:
      case GL_LUMINANCE12_ALPHA4:
      case GL_LUMINANCE12_ALPHA12:
      case GL_LUMINANCE16_ALPHA16:
         return GL_LUMINANCE_ALPHA;
      case GL_INTENSITY:
      case GL_INTENSITY4:
      case GL_INTENSITY8:
      case GL_INTENSITY12:
      case GL_INTENSITY16:
         return GL_INTENSITY;
      case 3:
      case GL_RGB:
      case GL_R3_G3_B2:
      case GL_RGB4:
      case GL_RGB5:
      case GL_RGB8:
      case GL_RGB10:
      case GL_RGB12:
      case GL_RGB16:
         return GL_RGB;
      case 4:
      case GL_RGBA:
      case GL_RGBA2:
      case GL_RGBA4:
      case GL_RGB5_A1:
      case GL_RGBA8:
      case GL_RGB10_A2:
      case GL_RGBA12:
      case GL_RGBA16:
         return GL_RGBA;
      default:
         return -1;  /* error */
   }
}



/*
 * Given an internal texture format enum or 1, 2, 3, 4 return the
 * corresponding _base_ internal format:  GL_ALPHA, GL_LUMINANCE,
 * GL_LUMANCE_ALPHA, GL_INTENSITY, GL_RGB, or GL_RGBA.  Return the
 * number of components for the format.  Return -1 if invalid enum.
 */
static GLint components_in_intformat( GLint format )
{
   switch (format) {
      case GL_ALPHA:
      case GL_ALPHA4:
      case GL_ALPHA8:
      case GL_ALPHA12:
      case GL_ALPHA16:
         return 1;
      case 1:
      case GL_LUMINANCE:
      case GL_LUMINANCE4:
      case GL_LUMINANCE8:
      case GL_LUMINANCE12:
      case GL_LUMINANCE16:
         return 1;
      case 2:
      case GL_LUMINANCE_ALPHA:
      case GL_LUMINANCE4_ALPHA4:
      case GL_LUMINANCE6_ALPHA2:
      case GL_LUMINANCE8_ALPHA8:
      case GL_LUMINANCE12_ALPHA4:
      case GL_LUMINANCE12_ALPHA12:
      case GL_LUMINANCE16_ALPHA16:
         return 2;
      case GL_INTENSITY:
      case GL_INTENSITY4:
      case GL_INTENSITY8:
      case GL_INTENSITY12:
      case GL_INTENSITY16:
         return 1;
      case 3:
      case GL_RGB:
      case GL_R3_G3_B2:
      case GL_RGB4:
      case GL_RGB5:
      case GL_RGB8:
      case GL_RGB10:
      case GL_RGB12:
      case GL_RGB16:
         return 3;
      case 4:
      case GL_RGBA:
      case GL_RGBA2:
      case GL_RGBA4:
      case GL_RGB5_A1:
      case GL_RGBA8:
      case GL_RGB10_A2:
      case GL_RGBA12:
      case GL_RGBA16:
         return 4;
      default:
         return -1;  /* error */
   }
}



struct gl_texture_image *gl_alloc_texture_image( void )
{
   return calloc( 1, sizeof(struct gl_texture_image) );
}



void gl_free_texture_image( struct gl_texture_image *teximage )
{
   if (teximage->Data) {
      free( teximage->Data );
   }
   free( teximage );
}



/*
 * Given a gl_image, apply the pixel transfer scale, bias, and mapping
 * to produce a gl_texture_image.
 * Input:  image - the incoming gl_image
 *         internalFormat - desired format of resultant texture
 *         border - texture border width (0 or 1)
 */
struct gl_texture_image *gl_image_to_texture( GLcontext *ctx,
                                              const struct gl_image *image,
                                              GLenum internalFormat,
                                              GLint border )
{
   GLint components;
   struct gl_texture_image *texImage;
   GLint numPixels, pixel;
   GLboolean scaleOrBias;

   internalFormat = decode_internal_format(internalFormat);
   components = components_in_intformat(internalFormat);
   numPixels = image->Width * image->Height;

   texImage = gl_alloc_texture_image();
   texImage->Format = internalFormat;
   texImage->Border = border;
   texImage->Width = image->Width;
   texImage->Height = image->Height;
   texImage->WidthLog2 = logbase2(image->Width);
   texImage->HeightLog2 = logbase2(image->Height);
   texImage->MaxLog2 = MAX2( texImage->WidthLog2, texImage->HeightLog2 );
   texImage->Data = (GLubyte *) malloc( numPixels * components );

   if (!texImage->Data) {
      /* out of memory */
      gl_free_texture_image( texImage );
      return NULL;
   }

   /* Determine if scaling and/or biasing is needed */
   if (ctx->Pixel.RedScale!=1.0F   || ctx->Pixel.RedBias!=0.0F ||
       ctx->Pixel.GreenScale!=1.0F || ctx->Pixel.GreenBias!=0.0F ||
       ctx->Pixel.BlueScale!=1.0F  || ctx->Pixel.BlueBias!=0.0F ||
       ctx->Pixel.AlphaScale!=1.0F || ctx->Pixel.AlphaBias!=0.0F) {
      scaleOrBias = GL_TRUE;
   }
   else {
      scaleOrBias = GL_FALSE;
   }

   switch (image->Type) {
      case GL_BITMAP:
         {
            GLint shift = ctx->Pixel.IndexShift;
            GLint offset = ctx->Pixel.IndexOffset;
            /* MapIto[RGBA]Size must be powers of two */
            GLint rMask = ctx->Pixel.MapItoRsize-1;
            GLint gMask = ctx->Pixel.MapItoGsize-1;
            GLint bMask = ctx->Pixel.MapItoBsize-1;
            GLint aMask = ctx->Pixel.MapItoAsize-1;
            GLint i, j;
            GLubyte *srcPtr = (GLubyte *) image->Data;

            assert( image->Format==GL_COLOR_INDEX );

            for (j=0; j<image->Height; j++) {
               GLubyte bitMask = 128;
               for (i=0; i<image->Width; i++) {
                  GLint index;
                  GLubyte red, green, blue, alpha;

                  /* Fetch image color index */
                  index = (*srcPtr & bitMask) ? 1 : 0;
                  bitMask = bitMask >> 1;
                  if (bitMask==0) {
                     bitMask = 128;
                     srcPtr++;
                  }
                  /* apply index shift and offset */
                  if (shift>=0) {
                     index = (index << shift) + offset;
                  }
                  else {
                     index = (index >> -shift) + offset;
                  }
                  /* convert index to RGBA */
                  red   = (GLint) (ctx->Pixel.MapItoR[index & rMask] * 255.0F);
                  green = (GLint) (ctx->Pixel.MapItoG[index & gMask] * 255.0F);
                  blue  = (GLint) (ctx->Pixel.MapItoB[index & bMask] * 255.0F);
                  alpha = (GLint) (ctx->Pixel.MapItoA[index & aMask] * 255.0F);

                  /* store texel (components are GLubytes in [0,255]) */
                  pixel = j * image->Width + i;
                  switch (internalFormat) {
                     case GL_ALPHA:
                        texImage->Data[pixel] = alpha;
                        break;
                     case GL_LUMINANCE:
                        texImage->Data[pixel] = red;
                        break;
                     case GL_LUMINANCE_ALPHA:
                        texImage->Data[pixel*2+0] = red;
                        texImage->Data[pixel*2+1] = alpha;
                        break;
                     case GL_INTENSITY:
                        texImage->Data[pixel] = red;
                        break;
                     case GL_RGB:
                        texImage->Data[pixel*3+0] = red;
                        texImage->Data[pixel*3+1] = green;
                        texImage->Data[pixel*3+2] = blue;
                        break;
                     case GL_RGBA:
                        texImage->Data[pixel*4+0] = red;
                        texImage->Data[pixel*4+1] = green;
                        texImage->Data[pixel*4+2] = blue;
                        texImage->Data[pixel*4+3] = alpha;
                        break;
                     default:
                        abort();
                  }
               }
               if (bitMask!=128) {
                  srcPtr++;
               }
            }
         }
         break;

      case GL_UNSIGNED_BYTE:
         for (pixel=0; pixel<numPixels; pixel++) {
            GLubyte red, green, blue, alpha;
            switch (image->Format) {
               case GL_COLOR_INDEX:
                  {
                     GLint index = ((GLubyte*)image->Data)[pixel];
                     red   = 255.0F * ctx->Pixel.MapItoR[index];
                     green = 255.0F * ctx->Pixel.MapItoG[index];
                     blue  = 255.0F * ctx->Pixel.MapItoB[index];
                     alpha = 255;
                  }
                  break;
               case GL_RGB:
                  /* Fetch image RGBA values */
                  red   = ((GLubyte*) image->Data)[pixel*3+0];
                  green = ((GLubyte*) image->Data)[pixel*3+1];
                  blue  = ((GLubyte*) image->Data)[pixel*3+2];
                  alpha = 255;
                  break;
               case GL_RGBA:
                  red   = ((GLubyte*) image->Data)[pixel*4+0];
                  green = ((GLubyte*) image->Data)[pixel*4+1];
                  blue  = ((GLubyte*) image->Data)[pixel*4+2];
                  alpha = ((GLubyte*) image->Data)[pixel*4+3];
                  break;
               case GL_RED:
                  red   = ((GLubyte*) image->Data)[pixel];
                  green = 0;
                  blue  = 0;
                  alpha = 255;
                  break;
               case GL_GREEN:
                  red   = 0;
                  green = ((GLubyte*) image->Data)[pixel];
                  blue  = 0;
                  alpha = 255;
                  break;
               case GL_BLUE:
                  red   = 0;
                  green = 0;
                  blue  = ((GLubyte*) image->Data)[pixel];
                  alpha = 255;
                  break;
               case GL_ALPHA:
                  red   = 0;
                  green = 0;
                  blue  = 0;
                  alpha = ((GLubyte*) image->Data)[pixel];
                  break;
               case GL_LUMINANCE: 
                  red   = ((GLubyte*) image->Data)[pixel];
                  green = red;
                  blue  = red;
                  alpha = 255;
                  break;
              case GL_LUMINANCE_ALPHA:
                  red   = ((GLubyte*) image->Data)[pixel*2+0];
                  green = red;
                  blue  = red;
                  alpha = ((GLubyte*) image->Data)[pixel*2+1];
                  break;
              default:
                  abort();
            }
            
            if (scaleOrBias || ctx->Pixel.MapColorFlag) {
               /* Apply RGBA scale and bias */
               GLfloat r = red   * (1.0F/255.0F);
               GLfloat g = green * (1.0F/255.0F);
               GLfloat b = blue * (1.0F/255.0F);
               GLfloat a = alpha * (1.0F/255.0F);
               if (scaleOrBias) {
                  /* r,g,b,a now in [0,1] */
                  r = r * ctx->Pixel.RedScale   + ctx->Pixel.RedBias;
                  g = g * ctx->Pixel.GreenScale + ctx->Pixel.GreenBias;
                  b = b * ctx->Pixel.BlueScale  + ctx->Pixel.BlueBias;
                  a = a * ctx->Pixel.AlphaScale + ctx->Pixel.AlphaBias;
                  r = CLAMP( r, 0.0F, 1.0F );
                  g = CLAMP( g, 0.0F, 1.0F );
                  b = CLAMP( b, 0.0F, 1.0F );
                  a = CLAMP( a, 0.0F, 1.0F );
               }
               /* Apply pixel maps */
               if (ctx->Pixel.MapColorFlag) {
                  GLint ir = (GLint) (r*ctx->Pixel.MapRtoRsize);
                  GLint ig = (GLint) (g*ctx->Pixel.MapGtoGsize);
                  GLint ib = (GLint) (b*ctx->Pixel.MapBtoBsize);
                  GLint ia = (GLint) (a*ctx->Pixel.MapAtoAsize);
                  r = ctx->Pixel.MapRtoR[ir];
                  g = ctx->Pixel.MapGtoG[ig];
                  b = ctx->Pixel.MapBtoB[ib];
                  a = ctx->Pixel.MapAtoA[ia];
               }
               red   = (GLint) (r * 255.0F);
               green = (GLint) (g * 255.0F);
               blue  = (GLint) (b * 255.0F);
               alpha = (GLint) (a * 255.0F);
            }

            /* store texel (components are GLubytes in [0,255]) */
            switch (internalFormat) {
               case GL_ALPHA:
                  texImage->Data[pixel] = alpha;
                  break;
               case GL_LUMINANCE:
                  texImage->Data[pixel] = red;
                  break;
               case GL_LUMINANCE_ALPHA:
                  texImage->Data[pixel*2+0] = red;
                  texImage->Data[pixel*2+1] = alpha;
                  break;
               case GL_INTENSITY:
                  texImage->Data[pixel] = red;
                  break;
               case GL_RGB:
                  texImage->Data[pixel*3+0] = red;
                  texImage->Data[pixel*3+1] = green;
                  texImage->Data[pixel*3+2] = blue;
                  break;
               case GL_RGBA:
                  texImage->Data[pixel*4+0] = red;
                  texImage->Data[pixel*4+1] = green;
                  texImage->Data[pixel*4+2] = blue;
                  texImage->Data[pixel*4+3] = alpha;
                  break;
               default:
                  abort();
            }
         }
         break;

      case GL_FLOAT:
         for (pixel=0; pixel<numPixels; pixel++) {
            GLfloat red, green, blue, alpha;
            switch (image->Format) {
               case GL_COLOR_INDEX:
                  {
                     GLint shift = ctx->Pixel.IndexShift;
                     GLint offset = ctx->Pixel.IndexOffset;
                     /* MapIto[RGBA]Size must be powers of two */
                     GLint rMask = ctx->Pixel.MapItoRsize-1;
                     GLint gMask = ctx->Pixel.MapItoGsize-1;
                     GLint bMask = ctx->Pixel.MapItoBsize-1;
                     GLint aMask = ctx->Pixel.MapItoAsize-1;
                     /* Fetch image color index */
                     GLint index = (GLint) ((GLfloat*) image->Data)[pixel];
                     /* apply index shift and offset */
                     if (shift>=0) {
                        index = (index << shift) + offset;
                     }
                     else {
                        index = (index >> -shift) + offset;
                     }
                     /* convert index to RGBA */
                     red   = ctx->Pixel.MapItoR[index & rMask];
                     green = ctx->Pixel.MapItoG[index & gMask];
                     blue  = ctx->Pixel.MapItoB[index & bMask];
                     alpha = ctx->Pixel.MapItoA[index & aMask];
                  }
                  break;
               case GL_RGB:
                  /* Fetch image RGBA values */
                  red   = ((GLfloat*) image->Data)[pixel*3+0];
                  green = ((GLfloat*) image->Data)[pixel*3+1];
                  blue  = ((GLfloat*) image->Data)[pixel*3+2];
                  alpha = 1.0;
                  break;
               case GL_RGBA:
                  red   = ((GLfloat*) image->Data)[pixel*4+0];
                  green = ((GLfloat*) image->Data)[pixel*4+1];
                  blue  = ((GLfloat*) image->Data)[pixel*4+2];
                  alpha = ((GLfloat*) image->Data)[pixel*4+3];
                  break;
               case GL_RED:
                  red   = ((GLfloat*) image->Data)[pixel];
                  green = 0.0;
                  blue  = 0.0;
                  alpha = 1.0;
                  break;
               case GL_GREEN:
                  red   = 0.0;
                  green = ((GLfloat*) image->Data)[pixel];
                  blue  = 0.0;
                  alpha = 1.0;
                  break;
               case GL_BLUE:
                  red   = 0.0;
                  green = 0.0;
                  blue  = ((GLfloat*) image->Data)[pixel];
                  alpha = 1.0;
                  break;
               case GL_ALPHA:
                  red   = 0.0;
                  green = 0.0;
                  blue  = 0.0;
                  alpha = ((GLfloat*) image->Data)[pixel];
                  break;
               case GL_LUMINANCE: 
                  red   = ((GLfloat*) image->Data)[pixel];
                  green = red;
                  blue  = red;
                  alpha = 1.0;
                  break;
              case GL_LUMINANCE_ALPHA:
                  red   = ((GLfloat*) image->Data)[pixel*2+0];
                  green = red;
                  blue  = red;
                  alpha = ((GLfloat*) image->Data)[pixel*2+1];
                  break;
               default:
                  abort();
            }
            
            if (image->Format!=GL_COLOR_INDEX) {
               /* Apply RGBA scale and bias */
               if (scaleOrBias) {
                  red   = red   * ctx->Pixel.RedScale   + ctx->Pixel.RedBias;
                  green = green * ctx->Pixel.GreenScale + ctx->Pixel.GreenBias;
                  blue  = blue  * ctx->Pixel.BlueScale  + ctx->Pixel.BlueBias;
                  alpha = alpha * ctx->Pixel.AlphaScale + ctx->Pixel.AlphaBias;
                  red   = CLAMP( red,    0.0F, 1.0F );
                  green = CLAMP( green,  0.0F, 1.0F );
                  blue  = CLAMP( blue,   0.0F, 1.0F );
                  alpha = CLAMP( alpha,  0.0F, 1.0F );
               }
               /* Apply pixel maps */
               if (ctx->Pixel.MapColorFlag) {
                  GLint ir = (GLint) (red  *ctx->Pixel.MapRtoRsize);
                  GLint ig = (GLint) (green*ctx->Pixel.MapGtoGsize);
                  GLint ib = (GLint) (blue *ctx->Pixel.MapBtoBsize);
                  GLint ia = (GLint) (alpha*ctx->Pixel.MapAtoAsize);
                  red   = ctx->Pixel.MapRtoR[ir];
                  green = ctx->Pixel.MapGtoG[ig];
                  blue  = ctx->Pixel.MapBtoB[ib];
                  alpha = ctx->Pixel.MapAtoA[ia];
               }
            }

            /* store texel (components are GLubytes in [0,255]) */
            switch (internalFormat) {
               case GL_ALPHA:
                  texImage->Data[pixel] = (GLint) (alpha * 255.0F);
                  break;
               case GL_LUMINANCE:
                  texImage->Data[pixel] = (GLint) (red * 255.0F);
                  break;
               case GL_LUMINANCE_ALPHA:
                  texImage->Data[pixel*2+0] = (GLint) (red * 255.0F);
                  texImage->Data[pixel*2+1] = (GLint) (alpha * 255.0F);
                  break;
               case GL_INTENSITY:
                  texImage->Data[pixel] = (GLint) (red * 255.0F);
                  break;
               case GL_RGB:
                  texImage->Data[pixel*3+0] = (GLint) (red   * 255.0F);
                  texImage->Data[pixel*3+1] = (GLint) (green * 255.0F);
                  texImage->Data[pixel*3+2] = (GLint) (blue  * 255.0F);
                  break;
               case GL_RGBA:
                  texImage->Data[pixel*4+0] = (GLint) (red   * 255.0F);
                  texImage->Data[pixel*4+1] = (GLint) (green * 255.0F);
                  texImage->Data[pixel*4+2] = (GLint) (blue  * 255.0F);
                  texImage->Data[pixel*4+3] = (GLint) (alpha * 255.0F);
                  break;
               default:
                  abort();
            }
         }
         break;

      default:
         abort();
   }

   return texImage;
}




/*
 * Test glTexImagee1D() parameters for errors.
 */
static GLboolean texture_1d_error_check( GLcontext *ctx, GLenum target,
                                         GLint level, GLenum internalFormat,
                                         GLenum format, GLenum type,
                                         GLint width, GLint border )
{
   GLint iformat;
   if (target!=GL_TEXTURE_1D && target!=GL_PROXY_TEXTURE_1D) {
      gl_error( ctx, GL_INVALID_ENUM, "glTexImage1D" );
      return GL_TRUE;
   }
   if (level<0 || level>=MAX_TEXTURE_LEVELS) {
      gl_error( ctx, GL_INVALID_VALUE, "glTexImage1D(level)" );
      return GL_TRUE;
   }
   iformat = decode_internal_format( internalFormat );
   if (iformat<0) {
      gl_error( ctx, GL_INVALID_VALUE, "glTexImage1D(internalFormat)" );
      return GL_TRUE;
   }
   if (width<2*border || width>2+MAX_TEXTURE_SIZE) {
      if (target!=GL_PROXY_TEXTURE_1D) {
         gl_error( ctx, GL_INVALID_VALUE, "glTexImage1D(width)" );
      }
      return GL_TRUE;
   }
   if (border!=0 && border!=1) {
      if (target!=GL_PROXY_TEXTURE_1D) {
         gl_error( ctx, GL_INVALID_VALUE, "glTexImage1D(border)" );
      }
      return GL_TRUE;
   }
   if (logbase2( width-2*border )<0) {
      gl_error( ctx, GL_INVALID_VALUE,
               "glTexImage1D(width != 2^k + 2*border))");
      return GL_TRUE;
   }
   switch (format) {
      case GL_COLOR_INDEX:
      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:
         /* OK */
         break;
      default:
         gl_error( ctx, GL_INVALID_ENUM, "glTexImage1D(format)" );
         return GL_TRUE;
   }
   switch (type) {
      case GL_UNSIGNED_BYTE:
      case GL_BYTE:
      case GL_UNSIGNED_SHORT:
      case GL_SHORT:
      case GL_FLOAT:
         /* OK */
         break;
      default:
         gl_error( ctx, GL_INVALID_ENUM, "glTexImage1D(type)" );
         return GL_TRUE;
   }
   return GL_FALSE;
}


/*
 * Test glTexImagee2D() parameters for errors.
 */
static GLboolean texture_2d_error_check( GLcontext *ctx, GLenum target,
                                         GLint level, GLenum internalFormat,
                                         GLenum format, GLenum type,
                                         GLint width, GLint height,
                                         GLint border )
{
   GLint iformat;
   if (target!=GL_TEXTURE_2D && target!=GL_PROXY_TEXTURE_2D) {
      gl_error( ctx, GL_INVALID_ENUM, "glTexImage2D(target)" );
      return GL_TRUE;
   }
   if (level<0 || level>=MAX_TEXTURE_LEVELS) {
      gl_error( ctx, GL_INVALID_VALUE, "glTexImage2D(level)" );
      return GL_TRUE;
   }
   iformat = decode_internal_format( internalFormat );
   if (iformat<0) {
      gl_error( ctx, GL_INVALID_VALUE, "glTexImage2D(internalFormat)" );
      return GL_TRUE;
   }
   if (width<2*border || width>2+MAX_TEXTURE_SIZE) {
      if (target!=GL_PROXY_TEXTURE_2D) {
         gl_error( ctx, GL_INVALID_VALUE, "glTexImage2D(width)" );
      }
      return GL_TRUE;
   }
   if (height<2*border || height>2+MAX_TEXTURE_SIZE) {
      if (target!=GL_PROXY_TEXTURE_2D) {
         gl_error( ctx, GL_INVALID_VALUE, "glTexImage2D(height)" );
      }
      return GL_TRUE;
   }
   if (border!=0 && border!=1) {
      if (target!=GL_PROXY_TEXTURE_2D) {
         gl_error( ctx, GL_INVALID_VALUE, "glTexImage2D(border)" );
      }
      return GL_TRUE;
   }
   if (logbase2( width-2*border )<0) {
      gl_error( ctx,GL_INVALID_VALUE,
               "glTexImage2D(width != 2^k + 2*border))");
      return GL_TRUE;
   }
   if (logbase2( height-2*border )<0) {
      gl_error( ctx,GL_INVALID_VALUE,
               "glTexImage2D(height != 2^k + 2*border))");
      return GL_TRUE;
   }
   switch (format) {
      case GL_COLOR_INDEX:
      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:
         /* OK */
         break;
      default:
         gl_error( ctx, GL_INVALID_ENUM, "glTexImage2D(format)" );
         return GL_TRUE;
   }
   switch (type) {
      case GL_UNSIGNED_BYTE:
      case GL_BYTE:
      case GL_UNSIGNED_SHORT:
      case GL_SHORT:
      case GL_UNSIGNED_INT:
      case GL_INT:
      case GL_FLOAT:
         /* OK */
         break;
      default:
         gl_error( ctx, GL_INVALID_ENUM, "glTexImage2D(type)" );
         return GL_TRUE;
   }
   return GL_FALSE;
}



/*
 * Called from the API.  Note that width includes the border.
 */
void gl_TexImage1D( GLcontext *ctx,
                    GLenum target, GLint level, GLint internalformat,
		    GLsizei width, GLint border, GLenum format,
		    GLenum type, struct gl_image *image )
{
   if (INSIDE_BEGIN_END(ctx)) {
      gl_error( ctx, GL_INVALID_OPERATION, "glTexImage1D" );
      return;
   }

   if (image) {
      /* if image is not NULL then it must be valid */
      if (target==GL_TEXTURE_1D) {
         struct gl_texture_image *teximage;
         /* free current texture image, if any */
         if (ctx->Texture.Current1D->Image[level]) {
            gl_free_texture_image( ctx->Texture.Current1D->Image[level] );
         }
         /* install new texture image */
         teximage = gl_image_to_texture( ctx, image, internalformat, border );
         ctx->Texture.Current1D->Image[level] = teximage;
         ctx->NewState |= NEW_TEXTURING;
      }
      else if (target==GL_PROXY_TEXTURE_1D) {
         /* Proxy texture: check for errors and update proxy state */
         if (texture_1d_error_check( ctx, target, level, internalformat,
                                     format, type, width, border )) {
            if (level>=0 && level<MAX_TEXTURE_LEVELS) {
               MEMSET( ctx->Texture.Proxy1D->Image[level], 0,
                      sizeof(struct gl_texture_image) );
            }
         }
         else {
            ctx->Texture.Proxy1D->Image[level]->Format = internalformat;
            ctx->Texture.Proxy1D->Image[level]->Border = border;
            ctx->Texture.Proxy1D->Image[level]->Width = width;
            ctx->Texture.Proxy1D->Image[level]->Height = 1;
         }
      }
      else {
         gl_error( ctx, GL_INVALID_ENUM, "glTexImage1D(target)" );
         return;
      }
   }
   else {
      /* An error must have occured during texture unpacking.  Record the
       * error now.
       */
      (void) texture_1d_error_check( ctx, target, level, internalformat,
                                     format, type, width, border );
   }
}




/*
 * Called by the API or display list executor.
 * Note that width and height include the border.
 */
void gl_TexImage2D( GLcontext *ctx,
                    GLenum target, GLint level, GLint internalformat,
                    GLsizei width, GLsizei height, GLint border,
                    GLenum format, GLenum type,
                    struct gl_image *image )
{
   if (INSIDE_BEGIN_END(ctx)) {
      gl_error( ctx, GL_INVALID_OPERATION, "glTexImage2D" );
      return;
   }

   if (image) {
      /* if image is not NULL then it must be valid */
      if (target==GL_TEXTURE_2D) {
         struct gl_texture_image *teximage;
         /* free current texture image, if any */
         if (ctx->Texture.Current2D->Image[level]) {
            gl_free_texture_image( ctx->Texture.Current2D->Image[level] );
         }
         /* install new texture image */
         teximage = gl_image_to_texture( ctx, image, internalformat, border );
         ctx->Texture.Current2D->Image[level] = teximage;
         ctx->NewState |= NEW_TEXTURING;
      }
      else if (target==GL_PROXY_TEXTURE_2D) {
         /* Proxy texture: check for errors and update proxy state */
         if (texture_2d_error_check( ctx, target, level, internalformat,
                                     format, type, width, height, border )) {
            if (level>=0 && level<MAX_TEXTURE_LEVELS) {
               MEMSET( ctx->Texture.Proxy2D->Image[level], 0,
                      sizeof(struct gl_texture_image) );
            }
         }
         else {
            ctx->Texture.Proxy2D->Image[level]->Format = internalformat;
            ctx->Texture.Proxy2D->Image[level]->Border = border;
            ctx->Texture.Proxy2D->Image[level]->Width = width;
            ctx->Texture.Proxy2D->Image[level]->Height = height;
         }
      }
      else {
         gl_error( ctx, GL_INVALID_ENUM, "glTexImage2D(target)" );
         return;
      }
   }
   else {
      /*
       * An error must have occured during texture unpacking.
       * Take care of reporting the error now.
       */
      (void) texture_2d_error_check( ctx, target, level, internalformat,
                                     format, type, width, height, border );
   }
}



void gl_GetTexImage( GLcontext *ctx, GLenum target, GLint level, GLenum format,
                     GLenum type, GLvoid *pixels )
{
   /* TODO */
}





/*
 * GL_EXT_copy_texture
 */



/*
 * Unpack the image data given to glTexSubImage[12]D.
 */
struct gl_image *
gl_unpack_texsubimage( GLcontext *ctx, GLint width, GLint height,
                       GLenum format, GLenum type, const GLvoid *pixels )
{
   GLint components;
   GLenum desttype;

   if (width<0 || height<0 || !pixels) {
      return NULL;
   }

   if (type==GL_BITMAP && format!=GL_COLOR_INDEX) {
      return NULL;
   }

   components = components_in_intformat( format );
   if (components<0 || format==GL_STENCIL_INDEX || format==GL_DEPTH_COMPONENT){
      return NULL;
   }

   if (gl_sizeof_type(type)<=0) {
      return NULL;
   }

   if (type==GL_UNSIGNED_BYTE) {
      desttype = GL_UNSIGNED_BYTE;
   }
   else {
      desttype = GL_FLOAT;
   }
   
   return gl_unpack_image( ctx, width, height, format, type,
                           desttype, pixels, GL_FALSE );
}






void gl_TexSubImage1D( GLcontext *ctx,
                       GLenum target, GLint level, GLint xoffset,
                       GLsizei width, GLenum format, GLenum type,
                       struct gl_image *image )
{
   struct gl_texture_image *teximage;

   if (target!=GL_TEXTURE_1D) {
      gl_error( ctx, GL_INVALID_ENUM, "glTexSubImage1D(target)" );
      return;
   }
   if (level<0 || level>=MAX_TEXTURE_LEVELS) {
      gl_error( ctx, GL_INVALID_ENUM, "glTexSubImage1D(level)" );
      return;
   }

   teximage = ctx->Texture.Current1D->Image[level];
   if (!teximage) {
      gl_error( ctx, GL_INVALID_OPERATION, "glTexSubImage1D" );
      return;
   }

   if (xoffset < -teximage->Border) {
      gl_error( ctx, GL_INVALID_VALUE, "glTexSubImage1D(xoffset)" );
      return;
   }
   if (xoffset + width > teximage->Width+teximage->Border) {
      gl_error( ctx, GL_INVALID_VALUE, "glTexSubImage1D(xoffset+width)" );
      return;
   }

   if (image) {
      /* unpacking must have been error-free */
      GLint texcomponents, i, k;
      GLubyte *dst, *src;

      /* TODO: this is temporary.  If Type==GL_FLOAT or scale&bias needed */
      /* then do more work. */
	  if (image->Type==GL_FLOAT) {
		  gl_warning( ctx, "unimplemented texture type in glTexSubImage1D" );
		  return;
	  }

      texcomponents = components_in_intformat(teximage->Format);

      dst = teximage->Data + texcomponents * xoffset;

      if (texcomponents == image->Components) {
         MEMCPY( dst, image->Data, width * texcomponents );
      }
      else {
         /* TODO: this is a hack */
         gl_warning( ctx, "component mismatch in glTexSubImage1D" );
         for (i=0;i<width;i++) {
            for (k=0;k<texcomponents;k++) {
               dst[k] = src[k];
            }
            dst += texcomponents;
            src += image->Components;
         }
      }
   }
   else {
      /* if no image, an error must have occured, do more testing now */
      GLint components, size;

      if (width<0) {
         gl_error( ctx, GL_INVALID_VALUE, "glTexSubImage1D(width)" );
         return;
      }
      if (type==GL_BITMAP && format!=GL_COLOR_INDEX) {
         gl_error( ctx, GL_INVALID_ENUM, "glTexSubImage1D(format)" );
         return;
      }
      components = components_in_intformat( format );
      if (components<0 || format==GL_STENCIL_INDEX
          || format==GL_DEPTH_COMPONENT){
         gl_error( ctx, GL_INVALID_ENUM, "glTexSubImage1D(format)" );
         return;
      }
      size = gl_sizeof_type( type );
      if (size<=0) {
         gl_error( ctx, GL_INVALID_ENUM, "glTexSubImage1D(type)" );
         return;
      }
      /* if we get here, probably ran out of memory during unpacking */
      gl_error( ctx, GL_OUT_OF_MEMORY, "glTexSubImage1D" );
   }
}



void gl_TexSubImage2D( GLcontext *ctx,
                       GLenum target, GLint level,
                       GLint xoffset, GLint yoffset,
                       GLsizei width, GLsizei height,
                       GLenum format, GLenum type,
                       struct gl_image *image )
{
   struct gl_texture_image *teximage;

   if (target!=GL_TEXTURE_2D) {
      gl_error( ctx, GL_INVALID_ENUM, "glTexSubImage2D(target)" );
      return;
   }
   if (level<0 || level>=MAX_TEXTURE_LEVELS) {
      gl_error( ctx, GL_INVALID_ENUM, "glTexSubImage2D(level)" );
      return;
   }

   teximage = ctx->Texture.Current2D->Image[level];
   if (!teximage) {
      gl_error( ctx, GL_INVALID_OPERATION, "glTexSubImage2D" );
      return;
   }

   if (xoffset < -teximage->Border) {
      gl_error( ctx, GL_INVALID_VALUE, "glTexSubImage2D(xoffset)" );
      return;
   }
   if (yoffset < -teximage->Border) {
      gl_error( ctx, GL_INVALID_VALUE, "glTexSubImage2D(yoffset)" );
      return;
   }
   if (xoffset + width > teximage->Width+teximage->Border) {
      gl_error( ctx, GL_INVALID_VALUE, "glTexSubImage2D(xoffset+width)" );
      return;
   }
   if (yoffset + height > teximage->Height+teximage->Border) {
      gl_error( ctx, GL_INVALID_VALUE, "glTexSubImage2D(yoffset+height)" );
      return;
   }

   if (image) {
      /* unpacking must have been error-free */
      GLint texcomponents, i, j, k;
      GLubyte *dst, *src;

      /* TODO: this is temporary.  If Type==GL_FLOAT or scale&bias needed */
      /* then do more work. */
	  if (image->Type==GL_FLOAT) {
		  gl_warning( ctx, "unimplemented texture type in glTexSubImage2D" );
		  return;
	  }

      texcomponents = components_in_intformat(teximage->Format);

      if (texcomponents == image->Components) {
         dst = teximage->Data 
               + (yoffset * teximage->Width + xoffset) * texcomponents;
         src = image->Data;
         for (j=0;j<height;j++) {
            MEMCPY( dst, src, width * texcomponents );
            dst += teximage->Width * texcomponents;
            src += width * texcomponents;
         }
      }
      else {
         /* TODO: this is a hack */
         gl_warning( ctx, "component mismatch in glTexSubImage2D" );

         for (j=0;j<height;j++) {
            dst = teximage->Data 
               + ((yoffset+j) * teximage->Width + xoffset) * texcomponents;
            src = (GLubyte *) image->Data + j * width * image->Components;
            for (i=0;i<width;i++) {
               for (k=0;k<texcomponents;k++) {
                  dst[k] = src[k];
               }
               dst += texcomponents;
               src += image->Components;
            }
         }
      }
   }
   else {
      /* if no image, an error must have occured, do more testing now */
      GLint components, size;

      if (width<0) {
         gl_error( ctx, GL_INVALID_VALUE, "glTexSubImage2D(width)" );
         return;
      }
      if (height<0) {
         gl_error( ctx, GL_INVALID_VALUE, "glTexSubImage2D(height)" );
         return;
      }
      if (type==GL_BITMAP && format!=GL_COLOR_INDEX) {
         gl_error( ctx, GL_INVALID_ENUM, "glTexSubImage1D(format)" );
         return;
      }
      components = components_in_intformat( format );
      if (components<0 || format==GL_STENCIL_INDEX
          || format==GL_DEPTH_COMPONENT){
         gl_error( ctx, GL_INVALID_ENUM, "glTexSubImage2D(format)" );
         return;
      }
      size = gl_sizeof_type( type );
      if (size<=0) {
         gl_error( ctx, GL_INVALID_ENUM, "glTexSubImage2D(type)" );
         return;
      }
      /* if we get here, probably ran out of memory during unpacking */
      gl_error( ctx, GL_OUT_OF_MEMORY, "glTexSubImage2D" );
   }
}



/*
 * Read an RGBA image from the frame buffer.
 * Input:  ctx - the context
 *         x, y - lower left corner
 *         width, height - size of region to read
 *         format - one of GL_RED, GL_RGB, GL_LUMINANCE, etc.
 * Return: gl_image pointer or NULL if out of memory
 */
struct gl_image *gl_read_color_image( GLcontext *ctx, GLint x, GLint y,
                                      GLsizei width, GLsizei height,
                                      GLint format )
{
   struct gl_image *image;
   GLubyte *imgptr;
   GLint components;
   GLint i, j;

   components = components_in_intformat( format );

   /*
    * Allocate image struct and image data buffer
    */
   image = (struct gl_image *) malloc( sizeof(struct gl_image) );
   if (image) {
      image->Width = width;
      image->Height = height;
      image->Components = components;
      image->Format = format;
      image->Type = GL_UNSIGNED_BYTE;
      image->Interleaved = GL_FALSE;
      image->Data = (GLubyte *) malloc( width * height * components );
      if (!image->Data) {
         free(image);
         return NULL;
      }
   }
   else {
      return NULL;
   }

   imgptr = image->Data;

   /* Select buffer to read from */
   (void) (*ctx->Driver.SetBuffer)( ctx, ctx->Pixel.ReadBuffer );

   for (j=0;j<height;j++) {
      GLubyte red[MAX_WIDTH], green[MAX_WIDTH];
      GLubyte blue[MAX_WIDTH], alpha[MAX_WIDTH];
      gl_read_color_span( ctx, width, x, y+j, red, green, blue, alpha );

      if (!ctx->Visual->EightBitColor) {
         /* scale red, green, blue, alpha values to range [0,255] */
         GLfloat rscale = 255.0f * ctx->Visual->InvRedScale;
         GLfloat gscale = 255.0f * ctx->Visual->InvGreenScale;
         GLfloat bscale = 255.0f * ctx->Visual->InvBlueScale;
         GLfloat ascale = 255.0f * ctx->Visual->InvAlphaScale;
         for (i=0;i<width;i++) {
            red[i]   = (GLubyte) (GLint) (red[i]   * rscale);
            green[i] = (GLubyte) (GLint) (green[i] * gscale);
            blue[i]  = (GLubyte) (GLint) (blue[i]  * bscale);
            alpha[i] = (GLubyte) (GLint) (alpha[i] * ascale);
         }
      }

      switch (format) {
         case GL_ALPHA:
            for (i=0;i<width;i++) {
               *imgptr++ = alpha[i];
            }
            break;
         case GL_LUMINANCE:
            for (i=0;i<width;i++) {
               *imgptr++ = red[i];
            }
            break;
         case GL_LUMINANCE_ALPHA:
            for (i=0;i<width;i++) {
               *imgptr++ = red[i];
               *imgptr++ = alpha[i];
            }
            break;
         case GL_INTENSITY:
            for (i=0;i<width;i++) {
               *imgptr++ = red[i];
            }
            break;
         case GL_RGB:
            for (i=0;i<width;i++) {
               *imgptr++ = red[i];
               *imgptr++ = green[i];
               *imgptr++ = blue[i];
            }
            break;
         case GL_RGBA:
            for (i=0;i<width;i++) {
               *imgptr++ = red[i];
               *imgptr++ = green[i];
               *imgptr++ = blue[i];
               *imgptr++ = alpha[i];
            }
            break;
      } /*switch*/

   } /*for*/         

   /* Restore drawing buffer */
   (void) (*ctx->Driver.SetBuffer)( ctx, ctx->Color.DrawBuffer );

   return image;
}




void gl_CopyTexImage1D( GLcontext *ctx,
                        GLenum target, GLint level,
                        GLenum internalformat,
                        GLint x, GLint y,
                        GLsizei width, GLint border )
{
   GLint format;
   struct gl_image *teximage;

   if (INSIDE_BEGIN_END(ctx)) {
      gl_error( ctx, GL_INVALID_OPERATION, "glCopyTexImage1D" );
      return;
   }
   if (target!=GL_TEXTURE_1D) {
      gl_error( ctx, GL_INVALID_ENUM, "glCopyTexImage1D(target)" );
      return;
   }
   if (level<0 || level>=MAX_TEXTURE_LEVELS) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexImage1D(level)" );
      return;
   }
   if (border!=0 && border!=1) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexImage1D(border)" );
      return;
   }
   if (width<2*border || width>2+MAX_TEXTURE_SIZE || width<0) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexImage1D(width)" );
      return;
   }
   format = decode_internal_format( internalformat );
   if (format<0 || (internalformat>=1 && internalformat<=4)) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexImage1D(format)" );
      return;
   }

   teximage = gl_read_color_image( ctx, x, y, width, 1, format );
   if (!teximage) {
      gl_error( ctx, GL_OUT_OF_MEMORY, "glCopyTexImage1D" );
      return;
   }

   gl_TexImage1D( ctx, target, level, internalformat, width,
                  border, GL_RGBA, GL_UNSIGNED_BYTE, teximage );

   gl_free_image( teximage );
}



void gl_CopyTexImage2D( GLcontext *ctx,
                        GLenum target, GLint level, GLenum internalformat,
                        GLint x, GLint y, GLsizei width, GLsizei height,
                        GLint border )
{
   GLint format;
   struct gl_image *teximage;

   if (INSIDE_BEGIN_END(ctx)) {
      gl_error( ctx, GL_INVALID_OPERATION, "glCopyTexImage2D" );
      return;
   }
   if (target!=GL_TEXTURE_2D) {
      gl_error( ctx, GL_INVALID_ENUM, "glCopyTexImage2D(target)" );
      return;
   }
   if (level<0 || level>=MAX_TEXTURE_LEVELS) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexImage2D(level)" );
      return;
   }
   if (border!=0 && border!=1) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexImage2D(border)" );
      return;
   }
   if (width<2*border || width>2+MAX_TEXTURE_SIZE || width<0) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexImage2D(width)" );
      return;
   }
   if (height<2*border || height>2+MAX_TEXTURE_SIZE || height<0) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexImage2D(height)" );
      return;
   }
   format = decode_internal_format( internalformat );
   if (format<0 || (internalformat>=1 && internalformat<=4)) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexImage2D(format)" );
      return;
   }

   teximage = gl_read_color_image( ctx, x, y, width, height, format );
   if (!teximage) {
      gl_error( ctx, GL_OUT_OF_MEMORY, "glCopyTexImage1D" );
      return;
   }

   gl_TexImage2D( ctx, target, level, internalformat, width, height,
                  border, GL_RGBA, GL_UNSIGNED_BYTE, teximage );

   gl_free_image( teximage );
}




/*
 * Do the work of glCopyTexSubImage[12]D.
 * TODO: apply pixel bias scale and mapping.
 */
static void copy_tex_sub_image( GLcontext *ctx, struct gl_texture_image *dest,
                                GLint width, GLint height,
                                GLint srcx, GLint srcy,
                                GLint dstx, GLint dsty )
{
   GLint i, j;
   GLint format, components;

   format = dest->Format;
   components = components_in_intformat( format );

   for (j=0;j<height;j++) {
      GLubyte red[MAX_WIDTH], green[MAX_WIDTH];
      GLubyte blue[MAX_WIDTH], alpha[MAX_WIDTH];
      GLubyte *texptr;

      gl_read_color_span( ctx, width, srcx, srcy+j, red, green, blue, alpha );

      if (!ctx->Visual->EightBitColor) {
         /* scale red, green, blue, alpha values to range [0,255] */
         GLfloat rscale = 255.0f * ctx->Visual->InvRedScale;
         GLfloat gscale = 255.0f * ctx->Visual->InvGreenScale;
         GLfloat bscale = 255.0f * ctx->Visual->InvBlueScale;
         GLfloat ascale = 255.0f * ctx->Visual->InvAlphaScale;
         for (i=0;i<width;i++) {
            red[i]   = (GLubyte) (GLint) (red[i]   * rscale);
            green[i] = (GLubyte) (GLint) (green[i] * gscale);
            blue[i]  = (GLubyte) (GLint) (blue[i]  * bscale);
            alpha[i] = (GLubyte) (GLint) (alpha[i] * ascale);
         }
      }

      texptr = dest->Data + ((dsty+j) * width + dstx) * components;

      switch (format) {
         case GL_ALPHA:
            for (i=0;i<width;i++) {
               *texptr++ = alpha[i];
            }
            break;
         case GL_LUMINANCE:
            for (i=0;i<width;i++) {
               *texptr++ = red[i];
            }
            break;
         case GL_LUMINANCE_ALPHA:
            for (i=0;i<width;i++) {
               *texptr++ = red[i];
               *texptr++ = alpha[i];
            }
            break;
         case GL_INTENSITY:
            for (i=0;i<width;i++) {
               *texptr++ = red[i];
            }
            break;
         case GL_RGB:
            for (i=0;i<width;i++) {
               *texptr++ = red[i];
               *texptr++ = green[i];
               *texptr++ = blue[i];
            }
            break;
         case GL_RGBA:
            for (i=0;i<width;i++) {
               *texptr++ = red[i];
               *texptr++ = green[i];
               *texptr++ = blue[i];
               *texptr++ = alpha[i];
            }
            break;
      } /*switch*/
   } /*for*/         
}




void gl_CopyTexSubImage1D( GLcontext *ctx,
                              GLenum target, GLint level,
                              GLint xoffset, GLint x, GLint y, GLsizei width )
{
   struct gl_texture_image *teximage;

   if (INSIDE_BEGIN_END(ctx)) {
      gl_error( ctx, GL_INVALID_OPERATION, "glCopyTexSubImage1D" );
      return;
   }
   if (target!=GL_TEXTURE_1D) {
      gl_error( ctx, GL_INVALID_ENUM, "glCopyTexSubImage1D(target)" );
      return;
   }
   if (level<0 || level>=MAX_TEXTURE_LEVELS) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexSubImage1D(level)" );
      return;
   }
   if (width<0) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexSubImage1D(width)" );
      return;
   }

   teximage = ctx->Texture.Current1D->Image[level];

   if (teximage) {
      if (xoffset < -teximage->Border) {
         gl_error( ctx, GL_INVALID_VALUE, "glCopyTexSubImage1D(xoffset)" );
         return;
      }
      /* NOTE: we're adding the border here, not subtracting! */
      if (xoffset+width > teximage->Width+teximage->Border) {
         gl_error( ctx, GL_INVALID_VALUE,
                   "glCopyTexSubImage1D(xoffset+width)" );
         return;
      }
      if (teximage->Data) {
         copy_tex_sub_image( ctx, teximage, width, 1, x, y, xoffset, 0 );
      }
   }
   else {
      gl_error( ctx, GL_INVALID_OPERATION, "glCopyTexSubImage1D" );
   }
}



void gl_CopyTexSubImage2D( GLcontext *ctx,
                              GLenum target, GLint level,
                              GLint xoffset, GLint yoffset,
                              GLint x, GLint y, GLsizei width, GLsizei height )
{
   struct gl_texture_image *teximage;

   if (INSIDE_BEGIN_END(ctx)) {
      gl_error( ctx, GL_INVALID_OPERATION, "glCopyTexSubImage2D" );
      return;
   }
   if (target!=GL_TEXTURE_2D) {
      gl_error( ctx, GL_INVALID_ENUM, "glCopyTexSubImage2D(target)" );
      return;
   }
   if (level<0 || level>=MAX_TEXTURE_LEVELS) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexSubImage2D(level)" );
      return;
   }
   if (width<0) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexSubImage2D(width)" );
      return;
   }
   if (height<0) {
      gl_error( ctx, GL_INVALID_VALUE, "glCopyTexSubImage2D(height)" );
      return;
   }

   teximage = ctx->Texture.Current2D->Image[level];

   if (teximage) {
      if (xoffset < -teximage->Border) {
         gl_error( ctx, GL_INVALID_VALUE, "glCopyTexSubImage2D(xoffset)" );
         return;
      }
      if (yoffset < -teximage->Border) {
         gl_error( ctx, GL_INVALID_VALUE, "glCopyTexSubImage2D(yoffset)" );
         return;
      }
      /* NOTE: we're adding the border here, not subtracting! */
      if (xoffset+width > teximage->Width+teximage->Border) {
         gl_error( ctx, GL_INVALID_VALUE,
                   "glCopyTexSubImage2D(xoffset+width)" );
         return;
      }
      if (yoffset+height > teximage->Height+teximage->Border) {
         gl_error( ctx, GL_INVALID_VALUE,
                   "glCopyTexSubImage2D(yoffset+height)" );
         return;
      }

      if (teximage->Data) {
         copy_tex_sub_image( ctx, teximage, width, height,
                             x, y, xoffset, yoffset );
      }
   }
   else {
      gl_error( ctx, GL_INVALID_OPERATION, "glCopyTexSubImage2D" );
   }
}
