xref: /external/mesa3d/src/mesa/main/teximage.c

/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2004  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */


/**
 * \file teximage.c
 * Texture images manipulation functions.
 *
 * \note Mesa's native texture data type is GLchan.  Native formats are
 * GL_ALPHA, GL_LUMINANCE, GL_LUMANCE_ALPHA, GL_INTENSITY, GL_RGB, GL_RGBA, and
 * GL_COLOR_INDEX.
 *
 * \note Device drivers are free to implement any internal format they want.
 */


#include "glheader.h"
#include "bufferobj.h"
#include "context.h"
#include "convolve.h"
#include "image.h"
#include "imports.h"
#include "macros.h"
#include "state.h"
#include "texcompress.h"
#include "texformat.h"
#include "teximage.h"
#include "texstate.h"
#include "texstore.h"
#include "mtypes.h"


/**
 * We allocate texture memory on 512-byte boundaries so we can use MMX/SSE
 * elsewhere.
 */
void *
_mesa_alloc_texmemory(GLsizei bytes)
{
   return _mesa_align_malloc(bytes, 512);
}


/**
 * Free texture memory allocated with _mesa_alloc_texmemory()
 */
void
_mesa_free_texmemory(void *m)
{
   _mesa_align_free(m);
}




#if 0
static void PrintTexture(GLcontext *ctx, const struct gl_texture_image *img)
{
#if CHAN_TYPE == GL_FLOAT
   _mesa_problem(NULL, "PrintTexture doesn't support float channels");
#else
   GLuint i, j, c;
   const GLchan *data = (const GLchan *) img->Data;

   if (!data) {
      _mesa_printf("No texture data\n");
      return;
   }

   switch (img->Format) {
      case GL_ALPHA:
      case GL_LUMINANCE:
      case GL_INTENSITY:
      case GL_COLOR_INDEX:
         c = 1;
         break;
      case GL_LUMINANCE_ALPHA:
         c = 2;
         break;
      case GL_RGB:
         c = 3;
         break;
      case GL_RGBA:
         c = 4;
         break;
      default:
         _mesa_problem(NULL, "error in PrintTexture\n");
         return;
   }

   for (i = 0; i < img->Height; i++) {
      for (j = 0; j < img->Width; j++) {
         if (c==1)
            _mesa_printf("%02x  ", data[0]);
         else if (c==2)
            _mesa_printf("%02x%02x  ", data[0], data[1]);
         else if (c==3)
            _mesa_printf("%02x%02x%02x  ", data[0], data[1], data[2]);
         else if (c==4)
            _mesa_printf("%02x%02x%02x%02x  ", data[0], data[1], data[2], data[3]);
         data += (img->RowStride - img->Width) * c;
      }
      _mesa_printf("\n");
   }
#endif
}
#endif


/*
 * Compute floor(log_base_2(n)).
 * If n < 0 return -1.
 */
static int
logbase2( int n )
{
   GLint i = 1;
   GLint log2 = 0;

   if (n < 0)
      return -1;

   if (n == 0)
      return 0;

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



/**
 * Return the simple base format for a given internal texture format.
 * For example, given GL_LUMINANCE12_ALPHA4, return GL_LUMINANCE_ALPHA.
 *
 * \param ctx GL context.
 * \param internalFormat the internal texture format token or 1, 2, 3, or 4.
 *
 * \return the corresponding \u base internal format (GL_ALPHA, GL_LUMINANCE,
 * GL_LUMANCE_ALPHA, GL_INTENSITY, GL_RGB, or GL_RGBA), or -1 if invalid enum.
 *
 * This is the format which is used during texture application (i.e. the
 * texture format and env mode determine the arithmetic used.
 */
GLint
_mesa_base_tex_format( GLcontext *ctx, GLint internalFormat )
{
   switch (internalFormat) {
      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:
         ; /* fallthrough */
   }

   if (ctx->Extensions.EXT_paletted_texture) {
      switch (internalFormat) {
         case GL_COLOR_INDEX:
         case GL_COLOR_INDEX1_EXT:
         case GL_COLOR_INDEX2_EXT:
         case GL_COLOR_INDEX4_EXT:
         case GL_COLOR_INDEX8_EXT:
         case GL_COLOR_INDEX12_EXT:
         case GL_COLOR_INDEX16_EXT:
            return GL_COLOR_INDEX;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.SGIX_depth_texture ||
       ctx->Extensions.ARB_depth_texture) {
      switch (internalFormat) {
         case GL_DEPTH_COMPONENT:
         case GL_DEPTH_COMPONENT16_SGIX:
         case GL_DEPTH_COMPONENT24_SGIX:
         case GL_DEPTH_COMPONENT32_SGIX:
            return GL_DEPTH_COMPONENT;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.ARB_texture_compression) {
      switch (internalFormat) {
         case GL_COMPRESSED_ALPHA:
            return GL_ALPHA;
         case GL_COMPRESSED_LUMINANCE:
            return GL_LUMINANCE;
         case GL_COMPRESSED_LUMINANCE_ALPHA:
            return GL_LUMINANCE_ALPHA;
         case GL_COMPRESSED_INTENSITY:
            return GL_INTENSITY;
         case GL_COMPRESSED_RGB:
            return GL_RGB;
         case GL_COMPRESSED_RGBA:
            return GL_RGBA;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.TDFX_texture_compression_FXT1) {
      switch (internalFormat) {
         case GL_COMPRESSED_RGB_FXT1_3DFX:
            return GL_RGB;
         case GL_COMPRESSED_RGBA_FXT1_3DFX:
            return GL_RGBA;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.EXT_texture_compression_s3tc) {
      switch (internalFormat) {
         case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
            return GL_RGB;
         case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
         case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
         case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
            return GL_RGBA;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.S3_s3tc) {
      switch (internalFormat) {
         case GL_RGB_S3TC:
         case GL_RGB4_S3TC:
            return GL_RGB;
         case GL_RGBA_S3TC:
         case GL_RGBA4_S3TC:
            return GL_RGBA;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.MESA_ycbcr_texture) {
      if (internalFormat == GL_YCBCR_MESA)
         return GL_YCBCR_MESA;
   }

   if (ctx->Extensions.ARB_texture_float) {
      switch (internalFormat) {
         case GL_ALPHA16F_ARB:
         case GL_ALPHA32F_ARB:
            return GL_ALPHA;
         case GL_RGBA16F_ARB:
         case GL_RGBA32F_ARB:
            return GL_RGBA;
         case GL_RGB16F_ARB:
         case GL_RGB32F_ARB:
            return GL_RGB;
         case GL_INTENSITY16F_ARB:
         case GL_INTENSITY32F_ARB:
            return GL_INTENSITY;
         case GL_LUMINANCE16F_ARB:
         case GL_LUMINANCE32F_ARB:
            return GL_LUMINANCE;
         case GL_LUMINANCE_ALPHA16F_ARB:
         case GL_LUMINANCE_ALPHA32F_ARB:
            return GL_LUMINANCE_ALPHA;
         default:
            ; /* fallthrough */
      }
   }

   if (ctx->Extensions.EXT_packed_depth_stencil) {
      switch (internalFormat) {
         case GL_DEPTH_STENCIL_EXT:
         case GL_DEPTH24_STENCIL8_EXT:
            return GL_DEPTH_STENCIL_EXT;
         default:
            ; /* fallthrough */
      }
   }

   return -1; /* error */
}


/**
 * Test if the given image format is a color/RGBA format (i.e., not color
 * index, depth, stencil, etc).
 * \param format  the image format value (may by an internal texture format)
 * \return GL_TRUE if its a color/RGBA format, GL_FALSE otherwise.
 */
static GLboolean
is_color_format(GLenum format)
{
   switch (format) {
      case GL_RED:
      case GL_GREEN:
      case GL_BLUE:
      case GL_ALPHA:
      case GL_ALPHA4:
      case GL_ALPHA8:
      case GL_ALPHA12:
      case GL_ALPHA16:
      case 1:
      case GL_LUMINANCE:
      case GL_LUMINANCE4:
      case GL_LUMINANCE8:
      case GL_LUMINANCE12:
      case GL_LUMINANCE16:
      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:
      case GL_INTENSITY:
      case GL_INTENSITY4:
      case GL_INTENSITY8:
      case GL_INTENSITY12:
      case GL_INTENSITY16:
      case 3:
      case GL_RGB:
      case GL_BGR:
      case GL_R3_G3_B2:
      case GL_RGB4:
      case GL_RGB5:
      case GL_RGB8:
      case GL_RGB10:
      case GL_RGB12:
      case GL_RGB16:
      case 4:
      case GL_ABGR_EXT:
      case GL_RGBA:
      case GL_BGRA:
      case GL_RGBA2:
      case GL_RGBA4:
      case GL_RGB5_A1:
      case GL_RGBA8:
      case GL_RGB10_A2:
      case GL_RGBA12:
      case GL_RGBA16:
      /* float texture formats */
      case GL_ALPHA16F_ARB:
      case GL_ALPHA32F_ARB:
      case GL_LUMINANCE16F_ARB:
      case GL_LUMINANCE32F_ARB:
      case GL_LUMINANCE_ALPHA16F_ARB:
      case GL_LUMINANCE_ALPHA32F_ARB:
      case GL_INTENSITY16F_ARB:
      case GL_INTENSITY32F_ARB:
      case GL_RGB16F_ARB:
      case GL_RGB32F_ARB:
      case GL_RGBA16F_ARB:
      case GL_RGBA32F_ARB:
      /* compressed formats */
      case GL_COMPRESSED_ALPHA:
      case GL_COMPRESSED_LUMINANCE:
      case GL_COMPRESSED_LUMINANCE_ALPHA:
      case GL_COMPRESSED_INTENSITY:
      case GL_COMPRESSED_RGB:
      case GL_COMPRESSED_RGBA:
      case GL_RGB_S3TC:
      case GL_RGB4_S3TC:
      case GL_RGBA_S3TC:
      case GL_RGBA4_S3TC:
      case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
      case GL_COMPRESSED_RGB_FXT1_3DFX:
      case GL_COMPRESSED_RGBA_FXT1_3DFX:
         return GL_TRUE;
      case GL_YCBCR_MESA:  /* not considered to be RGB */
      default:
         return GL_FALSE;
   }
}


/**
 * Test if the given image format is a color index format.
 */
static GLboolean
is_index_format(GLenum format)
{
   switch (format) {
      case GL_COLOR_INDEX:
      case GL_COLOR_INDEX1_EXT:
      case GL_COLOR_INDEX2_EXT:
      case GL_COLOR_INDEX4_EXT:
      case GL_COLOR_INDEX8_EXT:
      case GL_COLOR_INDEX12_EXT:
      case GL_COLOR_INDEX16_EXT:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/**
 * Test if the given image format is a depth component format.
 */
static GLboolean
is_depth_format(GLenum format)
{
   switch (format) {
      case GL_DEPTH_COMPONENT16_ARB:
      case GL_DEPTH_COMPONENT24_ARB:
      case GL_DEPTH_COMPONENT32_ARB:
      case GL_DEPTH_COMPONENT:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/**
 * Test if the given image format is a YCbCr format.
 */
static GLboolean
is_ycbcr_format(GLenum format)
{
   switch (format) {
      case GL_YCBCR_MESA:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/**
 * Test if the given image format is a Depth/Stencil format.
 */
static GLboolean
is_depthstencil_format(GLenum format)
{
   switch (format) {
      case GL_DEPTH24_STENCIL8_EXT:
      case GL_DEPTH_STENCIL_EXT:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}



/**
 * Test if it is a supported compressed format.
 *
 * \param internalFormat the internal format token provided by the user.
 *
 * \ret GL_TRUE if \p internalFormat is a supported compressed format, or
 * GL_FALSE otherwise.
 *
 * Currently only GL_COMPRESSED_RGB_FXT1_3DFX and GL_COMPRESSED_RGBA_FXT1_3DFX
 * are supported.
 */
static GLboolean
is_compressed_format(GLcontext *ctx, GLenum internalFormat)
{
   (void) ctx;
   switch (internalFormat) {
      case GL_COMPRESSED_RGB_FXT1_3DFX:
      case GL_COMPRESSED_RGBA_FXT1_3DFX:
      case GL_COMPRESSED_RGB_S3TC_DXT1_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT1_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT3_EXT:
      case GL_COMPRESSED_RGBA_S3TC_DXT5_EXT:
      case GL_RGB_S3TC:
      case GL_RGB4_S3TC:
      case GL_RGBA_S3TC:
      case GL_RGBA4_S3TC:
         return GL_TRUE;
      default:
         return GL_FALSE;
   }
}


/**
 * Store a gl_texture_image pointer in a gl_texture_object structure
 * according to the target and level parameters.
 *
 * \param tObj texture object.
 * \param target texture target.
 * \param level image level.
 * \param texImage texture image.
 *
 * This was basically prompted by the introduction of cube maps.
 */
void
_mesa_set_tex_image(struct gl_texture_object *tObj,
                    GLenum target, GLint level,
                    struct gl_texture_image *texImage)
{
   ASSERT(tObj);
   ASSERT(texImage);
   switch (target) {
      case GL_TEXTURE_1D:
      case GL_TEXTURE_2D:
      case GL_TEXTURE_3D:
         tObj->Image[0][level] = texImage;
         break;
      case GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB:
      case GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB:
      case GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB:
      case GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB:
      case GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB:
      case GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB:
         {
            GLuint face = ((GLuint) target -
                           (GLuint) GL_TEXTURE_CUBE_MAP_POSITIVE_X);
            tObj->Image[face][level] = texImage;
         }
         break;
      case GL_TEXTURE_RECTANGLE_NV:
         ASSERT(level == 0);
         tObj->Image[0][level] = texImage;
         break;
      default:
         _mesa_problem(NULL, "bad target in _mesa_set_tex_image()");
         return;
   }
   /* Set the 'back' pointer */
   texImage->TexObject = tObj;
}


/**
 * Allocate a texture image structure.
 *
 * Called via ctx->Driver.NewTextureImage() unless overriden by a device
 * driver.
 *
 * \return a pointer to gl_texture_image struct with all fields initialized to
 * zero.
 */
struct gl_texture_image *
_mesa_new_texture_image( GLcontext *ctx )
{
   (void) ctx;
   return CALLOC_STRUCT(gl_texture_image);
}


/**
 * Free texture image data.
 * This function is a fallback called via ctx->Driver.FreeTexImageData().
 *
 * \param teximage texture image.
 *
 * Free the texture image data if it's not marked as client data.
 */
void
_mesa_free_texture_image_data(GLcontext *ctx,
                              struct gl_texture_image *texImage)
{
   if (texImage->Data && !texImage->IsClientData) {
      /* free the old texture data */
      _mesa_free_texmemory(texImage->Data);
   }

   texImage->Data = NULL;
}


/**
 * Free texture image.
 *
 * \param teximage texture image.
 *
 * Free the texture image structure and the associated image data.
 */
void
_mesa_delete_texture_image( GLcontext *ctx, struct gl_texture_image *texImage )
{
   if (texImage->Data) {
      ctx->Driver.FreeTexImageData( ctx, texImage );
   }
   ASSERT(texImage->Data == NULL);
   FREE( texImage );
}


/**
 * Test if a target is a proxy target.
 *
 * \param target texture target.
 *
 * \return GL_TRUE if the target is a proxy target, GL_FALSE otherwise.
 */
static GLboolean
is_proxy_target(GLenum target)
{
   return (target == GL_PROXY_TEXTURE_1D ||
           target == GL_PROXY_TEXTURE_2D ||
           target == GL_PROXY_TEXTURE_3D ||
           target == GL_PROXY_TEXTURE_CUBE_MAP_ARB ||
           target == GL_PROXY_TEXTURE_RECTANGLE_NV);
}


/**
 * Get the texture object that corresponds to the target of the given texture unit.
 *
 * \param ctx GL context.
 * \param texUnit texture unit.
 * \param target texture target.
 *
 * \return pointer to the texture object on success, or NULL on failure.
 *
 * \sa gl_texture_unit.
 */
struct gl_texture_object *
_mesa_select_tex_object(GLcontext *ctx, const struct gl_texture_unit *texUnit,
                        GLenum target)
{
   switch (target) {
      case GL_TEXTURE_1D:
         return texUnit->Current1D;
      case GL_PROXY_TEXTURE_1D:
         return ctx->Texture.Proxy1D;
      case GL_TEXTURE_2D:
         return texUnit->Current2D;
      case GL_PROXY_TEXTURE_2D:
         return ctx->Texture.Proxy2D;
      case GL_TEXTURE_3D:
         return texUnit->Current3D;
      case GL_PROXY_TEXTURE_3D:
         return ctx->Texture.Proxy3D;
      case GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB:
      case GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB:
      case GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB:
      case GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB:
      case GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB:
      case GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB:
      case GL_TEXTURE_CUBE_MAP_ARB:
         return ctx->Extensions.ARB_texture_cube_map
                ? texUnit->CurrentCubeMap : NULL;
      case GL_PROXY_TEXTURE_CUBE_MAP_ARB:
         return ctx->Extensions.ARB_texture_cube_map
                ? ctx->Texture.ProxyCubeMap : NULL;
      case GL_TEXTURE_RECTANGLE_NV:
         return ctx->Extensions.NV_texture_rectangle
                ? texUnit->CurrentRect : NULL;
      case GL_PROXY_TEXTURE_RECTANGLE_NV:
         return ctx->Extensions.NV_texture_rectangle
                ? ctx->Texture.ProxyRect : NULL;
      default:
         _mesa_problem(NULL, "bad target in _mesa_select_tex_object()");
         return NULL;
   }
}


/**
 * Get the texture image struct which corresponds to target and level
 * of the given texture unit.
 *
 * \param ctx GL context.
 * \param texUnit texture unit.
 * \param target texture target.
 * \param level image level.
 *
 * \return pointer to the texture image structure on success, or NULL on failure.
 *
 * \sa gl_texture_unit.
 */
struct gl_texture_image *
_mesa_select_tex_image(GLcontext *ctx, const struct gl_texture_unit *texUnit,
                       GLenum target, GLint level)
{
   ASSERT(texUnit);
   ASSERT(level < MAX_TEXTURE_LEVELS);
   switch (target) {
      case GL_TEXTURE_1D:
         return texUnit->Current1D->Image[0][level];
      case GL_PROXY_TEXTURE_1D:
         return ctx->Texture.Proxy1D->Image[0][level];
      case GL_TEXTURE_2D:
         return texUnit->Current2D->Image[0][level];
      case GL_PROXY_TEXTURE_2D:
         return ctx->Texture.Proxy2D->Image[0][level];
      case GL_TEXTURE_3D:
         return texUnit->Current3D->Image[0][level];
      case GL_PROXY_TEXTURE_3D:
         return ctx->Texture.Proxy3D->Image[0][level];
      case GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB:
      case GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB:
      case GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB:
      case GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB:
      case GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB:
      case GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB:
         if (ctx->Extensions.ARB_texture_cube_map) {
	    GLuint face = ((GLuint) target -
			   (GLuint) GL_TEXTURE_CUBE_MAP_POSITIVE_X);
            return texUnit->CurrentCubeMap->Image[face][level];
	 }
         else
            return NULL;
      case GL_PROXY_TEXTURE_CUBE_MAP_ARB:
         if (ctx->Extensions.ARB_texture_cube_map)
            return ctx->Texture.ProxyCubeMap->Image[0][level];
         else
            return NULL;
      case GL_TEXTURE_RECTANGLE_NV:
         if (ctx->Extensions.NV_texture_rectangle) {
            ASSERT(level == 0);
            return texUnit->CurrentRect->Image[0][level];
         }
         else {
            return NULL;
         }
      case GL_PROXY_TEXTURE_RECTANGLE_NV:
         if (ctx->Extensions.NV_texture_rectangle) {
            ASSERT(level == 0);
            return ctx->Texture.ProxyRect->Image[0][level];
         }
         else {
            return NULL;
         }
      default:
         _mesa_problem(ctx, "bad target in _mesa_select_tex_image()");
         return NULL;
   }
}


/**
 * Like _mesa_select_tex_image() but if the image doesn't exist, allocate
 * it and install it.  Only return NULL if passed a bad parameter or run
 * out of memory.
 */
struct gl_texture_image *
_mesa_get_tex_image(GLcontext *ctx, const struct gl_texture_unit *texUnit,
                    GLenum target, GLint level)
{
   struct gl_texture_image *texImage;
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   if (!texImage) {
      struct gl_texture_object *texObj;
      texImage = ctx->Driver.NewTextureImage(ctx);
      if (!texImage) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "texture image allocation");
         return NULL;
      }
      texObj = _mesa_select_tex_object(ctx, texUnit, target);
      ASSERT(texObj);
      _mesa_set_tex_image(texObj, target, level, texImage);
   }
   return texImage;
}


/**
 * Return pointer to the specified proxy texture image.
 * Note that proxy textures are per-context, not per-texture unit.
 * \return pointer to texture image or NULL if invalid target, invalid
 *         level, or out of memory.
 */
struct gl_texture_image *
_mesa_get_proxy_tex_image(GLcontext *ctx, GLenum target, GLint level)
{
   struct gl_texture_image *texImage;

   if (level < 0 )
      return NULL;

   switch (target) {
   case GL_PROXY_TEXTURE_1D:
      if (level >= ctx->Const.MaxTextureLevels)
         return NULL;
      texImage = ctx->Texture.Proxy1D->Image[0][level];
      if (!texImage) {
         texImage = ctx->Driver.NewTextureImage(ctx);
         if (!texImage) {
            _mesa_error(ctx, GL_OUT_OF_MEMORY, "proxy texture allocation");
            return NULL;
         }
         ctx->Texture.Proxy1D->Image[0][level] = texImage;
         /* Set the 'back' pointer */
         texImage->TexObject = ctx->Texture.Proxy1D;
      }
      return texImage;
   case GL_PROXY_TEXTURE_2D:
      if (level >= ctx->Const.MaxTextureLevels)
         return NULL;
      texImage = ctx->Texture.Proxy2D->Image[0][level];
      if (!texImage) {
         texImage = ctx->Driver.NewTextureImage(ctx);
         if (!texImage) {
            _mesa_error(ctx, GL_OUT_OF_MEMORY, "proxy texture allocation");
            return NULL;
         }
         ctx->Texture.Proxy2D->Image[0][level] = texImage;
         /* Set the 'back' pointer */
         texImage->TexObject = ctx->Texture.Proxy2D;
      }
      return texImage;
   case GL_PROXY_TEXTURE_3D:
      if (level >= ctx->Const.Max3DTextureLevels)
         return NULL;
      texImage = ctx->Texture.Proxy3D->Image[0][level];
      if (!texImage) {
         texImage = ctx->Driver.NewTextureImage(ctx);
         if (!texImage) {
            _mesa_error(ctx, GL_OUT_OF_MEMORY, "proxy texture allocation");
            return NULL;
         }
         ctx->Texture.Proxy3D->Image[0][level] = texImage;
         /* Set the 'back' pointer */
         texImage->TexObject = ctx->Texture.Proxy3D;
      }
      return texImage;
   case GL_PROXY_TEXTURE_CUBE_MAP:
      if (level >= ctx->Const.MaxCubeTextureLevels)
         return NULL;
      texImage = ctx->Texture.ProxyCubeMap->Image[0][level];
      if (!texImage) {
         texImage = ctx->Driver.NewTextureImage(ctx);
         if (!texImage) {
            _mesa_error(ctx, GL_OUT_OF_MEMORY, "proxy texture allocation");
            return NULL;
         }
         ctx->Texture.ProxyCubeMap->Image[0][level] = texImage;
         /* Set the 'back' pointer */
         texImage->TexObject = ctx->Texture.ProxyCubeMap;
      }
      return texImage;
   case GL_PROXY_TEXTURE_RECTANGLE_NV:
      if (level > 0)
         return NULL;
      texImage = ctx->Texture.ProxyRect->Image[0][level];
      if (!texImage) {
         texImage = ctx->Driver.NewTextureImage(ctx);
         if (!texImage) {
            _mesa_error(ctx, GL_OUT_OF_MEMORY, "proxy texture allocation");
            return NULL;
         }
         ctx->Texture.ProxyRect->Image[0][level] = texImage;
         /* Set the 'back' pointer */
         texImage->TexObject = ctx->Texture.ProxyRect;
      }
      return texImage;
   default:
      return NULL;
   }
}


/**
 * Get the maximum number of allowed mipmap levels.
 *
 * \param ctx GL context.
 * \param target texture target.
 *
 * \return the maximum number of allowed mipmap levels for the given
 * texture target, or zero if passed a bad target.
 *
 * \sa gl_constants.
 */
GLint
_mesa_max_texture_levels(GLcontext *ctx, GLenum target)
{
   switch (target) {
   case GL_TEXTURE_1D:
   case GL_PROXY_TEXTURE_1D:
   case GL_TEXTURE_2D:
   case GL_PROXY_TEXTURE_2D:
      return ctx->Const.MaxTextureLevels;
   case GL_TEXTURE_3D:
   case GL_PROXY_TEXTURE_3D:
      return ctx->Const.Max3DTextureLevels;
   case GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB:
   case GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB:
   case GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB:
   case GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB:
   case GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB:
   case GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB:
   case GL_TEXTURE_CUBE_MAP_ARB:
   case GL_PROXY_TEXTURE_CUBE_MAP_ARB:
      return ctx->Const.MaxCubeTextureLevels;
   case GL_TEXTURE_RECTANGLE_NV:
   case GL_PROXY_TEXTURE_RECTANGLE_NV:
      return 1;
   default:
      return 0; /* bad target */
   }
}



#if 000 /* not used anymore */
/*
 * glTexImage[123]D can accept a NULL image pointer.  In this case we
 * create a texture image with unspecified image contents per the OpenGL
 * spec.
 */
static GLubyte *
make_null_texture(GLint width, GLint height, GLint depth, GLenum format)
{
   const GLint components = _mesa_components_in_format(format);
   const GLint numPixels = width * height * depth;
   GLubyte *data = (GLubyte *) MALLOC(numPixels * components * sizeof(GLubyte));

#ifdef DEBUG
   /*
    * Let's see if anyone finds this.  If glTexImage2D() is called with
    * a NULL image pointer then load the texture image with something
    * interesting instead of leaving it indeterminate.
    */
   if (data) {
      static const char message[8][32] = {
         "   X   X  XXXXX   XXX     X    ",
         "   XX XX  X      X   X   X X   ",
         "   X X X  X      X      X   X  ",
         "   X   X  XXXX    XXX   XXXXX  ",
         "   X   X  X          X  X   X  ",
         "   X   X  X      X   X  X   X  ",
         "   X   X  XXXXX   XXX   X   X  ",
         "                               "
      };

      GLubyte *imgPtr = data;
      GLint h, i, j, k;
      for (h = 0; h < depth; h++) {
         for (i = 0; i < height; i++) {
            GLint srcRow = 7 - (i % 8);
            for (j = 0; j < width; j++) {
               GLint srcCol = j % 32;
               GLubyte texel = (message[srcRow][srcCol]=='X') ? 255 : 70;
               for (k = 0; k < components; k++) {
                  *imgPtr++ = texel;
               }
            }
         }
      }
   }
#endif

   return data;
}
#endif



/**
 * Reset the fields of a gl_texture_image struct to zero.
 *
 * \param img texture image structure.
 *
 * This is called when a proxy texture test fails, we set all the
 * image members (except DriverData) to zero.
 * It's also used in glTexImage[123]D as a safeguard to be sure all
 * required fields get initialized properly by the Driver.TexImage[123]D
 * functions.
 */
static void
clear_teximage_fields(struct gl_texture_image *img)
{
   ASSERT(img);
   img->Format = 0;
   img->IntFormat = 0;
   img->Border = 0;
   img->Width = 0;
   img->Height = 0;
   img->Depth = 0;
   img->RowStride = 0;
   img->Width2 = 0;
   img->Height2 = 0;
   img->Depth2 = 0;
   img->WidthLog2 = 0;
   img->HeightLog2 = 0;
   img->DepthLog2 = 0;
   img->Data = NULL;
   img->TexFormat = &_mesa_null_texformat;
   img->FetchTexelc = NULL;
   img->FetchTexelf = NULL;
   img->IsCompressed = 0;
   img->CompressedSize = 0;
}


/**
 * Initialize basic fields of the gl_texture_image struct.
 *
 * \param ctx GL context.
 * \param target texture target.
 * \param img texture image structure to be initialized.
 * \param width image width.
 * \param height image height.
 * \param depth image depth.
 * \param border image border.
 * \param internalFormat internal format.
 *
 * Fills in the fields of \p img with the given information.
 * Note: width, height and depth include the border.
 */
void
_mesa_init_teximage_fields(GLcontext *ctx, GLenum target,
                           struct gl_texture_image *img,
                           GLsizei width, GLsizei height, GLsizei depth,
                           GLint border, GLenum internalFormat)
{
   ASSERT(img);
   img->Format = _mesa_base_tex_format( ctx, internalFormat );
   ASSERT(img->Format > 0);
   img->IntFormat = internalFormat;
   img->Border = border;
   img->Width = width;
   img->Height = height;
   img->Depth = depth;
   img->RowStride = width;
   img->WidthLog2 = logbase2(width - 2 * border);
   if (height == 1)  /* 1-D texture */
      img->HeightLog2 = 0;
   else
      img->HeightLog2 = logbase2(height - 2 * border);
   if (depth == 1)   /* 2-D texture */
      img->DepthLog2 = 0;
   else
      img->DepthLog2 = logbase2(depth - 2 * border);
   img->Width2 = width - 2 * border; /*1 << img->WidthLog2;*/
   img->Height2 = height - 2 * border; /*1 << img->HeightLog2;*/
   img->Depth2 = depth - 2 * border; /*1 << img->DepthLog2;*/
   img->MaxLog2 = MAX2(img->WidthLog2, img->HeightLog2);
   img->IsCompressed = is_compressed_format(ctx, internalFormat);
   if (img->IsCompressed)
      img->CompressedSize = ctx->Driver.CompressedTextureSize(ctx, width,
                                               height, depth, internalFormat);
   else
      img->CompressedSize = 0;

   if ((width == 1 || _mesa_bitcount(width - 2 * border) == 1) &&
       (height == 1 || _mesa_bitcount(height - 2 * border) == 1) &&
       (depth == 1 || _mesa_bitcount(depth - 2 * border) == 1))
      img->_IsPowerOfTwo = GL_TRUE;
   else
      img->_IsPowerOfTwo = GL_FALSE;

   /* Compute Width/Height/DepthScale for mipmap lod computation */
   if (target == GL_TEXTURE_RECTANGLE_NV) {
      /* scale = 1.0 since texture coords directly map to texels */
      img->WidthScale = 1.0;
      img->HeightScale = 1.0;
      img->DepthScale = 1.0;
   }
   else {
      img->WidthScale = (GLfloat) img->Width;
      img->HeightScale = (GLfloat) img->Height;
      img->DepthScale = (GLfloat) img->Depth;
   }
}


/**
 * This is the fallback for Driver.TestProxyTexImage().  Test the texture
 * level, width, height and depth against the ctx->Const limits for textures.
 *
 * A hardware driver might override this function if, for example, the
 * max 3D texture size is 512x512x64 (i.e. not a cube).
 *
 * \param target  one of GL_PROXY_TEXTURE_1D, GL_PROXY_TEXTURE_2D,
 *                GL_PROXY_TEXTURE_3D, GL_PROXY_TEXTURE_RECTANGLE_NV,
 *                GL_PROXY_TEXTURE_CUBE_MAP_ARB.
 * \param level  as passed to glTexImage
 * \param internalFormat  as passed to glTexImage
 * \param format  as passed to glTexImage
 * \param type  as passed to glTexImage
 * \param width  as passed to glTexImage
 * \param height  as passed to glTexImage
 * \param depth  as passed to glTexImage
 * \param border  as passed to glTexImage
 * \return GL_TRUE if the image is acceptable, GL_FALSE if not acceptable.
 */
GLboolean
_mesa_test_proxy_teximage(GLcontext *ctx, GLenum target, GLint level,
                          GLint internalFormat, GLenum format, GLenum type,
                          GLint width, GLint height, GLint depth, GLint border)
{
   GLint maxSize;

   (void) internalFormat;
   (void) format;
   (void) type;

   switch (target) {
   case GL_PROXY_TEXTURE_1D:
      maxSize = 1 << (ctx->Const.MaxTextureLevels - 1);
      if (width < 2 * border || width > 2 + maxSize ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(width - 2 * border) != 1) ||
          level >= ctx->Const.MaxTextureLevels) {
         /* bad width or level */
         return GL_FALSE;
      }
      return GL_TRUE;
   case GL_PROXY_TEXTURE_2D:
      maxSize = 1 << (ctx->Const.MaxTextureLevels - 1);
      if (width < 2 * border || width > 2 + maxSize ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(width - 2 * border) != 1) ||
          height < 2 * border || height > 2 + maxSize ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(height - 2 * border) != 1) ||
          level >= ctx->Const.MaxTextureLevels) {
         /* bad width or height or level */
         return GL_FALSE;
      }
      return GL_TRUE;
   case GL_PROXY_TEXTURE_3D:
      maxSize = 1 << (ctx->Const.Max3DTextureLevels - 1);
      if (width < 2 * border || width > 2 + maxSize ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(width - 2 * border) != 1) ||
          height < 2 * border || height > 2 + maxSize ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(height - 2 * border) != 1) ||
          depth < 2 * border || depth > 2 + maxSize ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(depth - 2 * border) != 1) ||
          level >= ctx->Const.Max3DTextureLevels) {
         /* bad width or height or depth or level */
         return GL_FALSE;
      }
      return GL_TRUE;
   case GL_PROXY_TEXTURE_RECTANGLE_NV:
      if (width < 1 || width > ctx->Const.MaxTextureRectSize ||
          height < 1 || height > ctx->Const.MaxTextureRectSize ||
          level != 0) {
         /* bad width or height or level */
         return GL_FALSE;
      }
      return GL_TRUE;
   case GL_PROXY_TEXTURE_CUBE_MAP_ARB:
      maxSize = 1 << (ctx->Const.MaxCubeTextureLevels - 1);
      if (width < 2 * border || width > 2 + maxSize ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(width - 2 * border) != 1) ||
          height < 2 * border || height > 2 + maxSize ||
          (!ctx->Extensions.ARB_texture_non_power_of_two &&
           _mesa_bitcount(height - 2 * border) != 1) ||
          level >= ctx->Const.MaxCubeTextureLevels) {
         /* bad width or height */
         return GL_FALSE;
      }
      return GL_TRUE;
   default:
      _mesa_problem(ctx, "Invalid target in _mesa_test_proxy_teximage");
      return GL_FALSE;
   }
}


/**
 * Test the glTexImage[123]D() parameters for errors.
 *
 * \param ctx GL context.
 * \param target texture target given by the user.
 * \param level image level given by the user.
 * \param internalFormat internal format given by the user.
 * \param format pixel data format given by the user.
 * \param type pixel data type given by the user.
 * \param dimensions texture image dimensions (must be 1, 2 or 3).
 * \param width image width given by the user.
 * \param height image height given by the user.
 * \param depth image depth given by the user.
 * \param border image border given by the user.
 *
 * \return GL_TRUE if an error was detected, or GL_FALSE if no errors.
 *
 * Verifies each of the parameters against the constants specified in
 * __GLcontextRec::Const and the supported extensions, and according to the
 * OpenGL specification.
 */
static GLboolean
texture_error_check( GLcontext *ctx, GLenum target,
                     GLint level, GLint internalFormat,
                     GLenum format, GLenum type,
                     GLuint dimensions,
                     GLint width, GLint height,
                     GLint depth, GLint border )
{
   const GLboolean isProxy = is_proxy_target(target);
   GLboolean sizeOK;
   GLboolean colorFormat, indexFormat;

   /* Basic level check (more checking in ctx->Driver.TestProxyTexImage) */
   if (level < 0 || level >= MAX_TEXTURE_LEVELS) {
      if (!isProxy) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glTexImage%dD(level=%d)", dimensions, level);
      }
      return GL_TRUE;
   }

   /* Check border */
   if (border < 0 || border > 1 ||
       ((target == GL_TEXTURE_RECTANGLE_NV ||
         target == GL_PROXY_TEXTURE_RECTANGLE_NV) && border != 0)) {
      if (!isProxy) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glTexImage%dD(border=%d)", dimensions, border);
      }
      return GL_TRUE;
   }

   if (width < 0 || height < 0 || depth < 0) {
      if (!isProxy) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glTexImage%dD(width, height or depth < 0)", dimensions);
      }
      return GL_TRUE;
   }

   /* Check target and call ctx->Driver.TestProxyTexImage() to check the
    * level, width, height and depth.
    */
   if (dimensions == 1) {
      if (target == GL_PROXY_TEXTURE_1D || target == GL_TEXTURE_1D) {
         sizeOK = ctx->Driver.TestProxyTexImage(ctx, GL_PROXY_TEXTURE_1D,
                                                level, internalFormat,
                                                format, type,
                                                width, 1, 1, border);
      }
      else {
         _mesa_error( ctx, GL_INVALID_ENUM, "glTexImage1D(target)" );
         return GL_TRUE;
      }
   }
   else if (dimensions == 2) {
      if (target == GL_PROXY_TEXTURE_2D || target == GL_TEXTURE_2D) {
         sizeOK = ctx->Driver.TestProxyTexImage(ctx, GL_PROXY_TEXTURE_2D,
                                                level, internalFormat,
                                                format, type,
                                                width, height, 1, border);
      }
      else if (target == GL_PROXY_TEXTURE_CUBE_MAP_ARB ||
               (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB &&
                target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB)) {
         if (!ctx->Extensions.ARB_texture_cube_map) {
            _mesa_error(ctx, GL_INVALID_ENUM, "glTexImage2D(target)");
            return GL_TRUE;
         }
         sizeOK = (width == height) &&
            ctx->Driver.TestProxyTexImage(ctx, GL_PROXY_TEXTURE_CUBE_MAP_ARB,
                                          level, internalFormat, format, type,
                                          width, height, 1, border);
      }
      else if (target == GL_PROXY_TEXTURE_RECTANGLE_NV ||
               target == GL_TEXTURE_RECTANGLE_NV) {
         if (!ctx->Extensions.NV_texture_rectangle) {
            _mesa_error(ctx, GL_INVALID_ENUM, "glTexImage2D(target)");
            return GL_TRUE;
         }
         sizeOK = ctx->Driver.TestProxyTexImage(ctx,
                                                GL_PROXY_TEXTURE_RECTANGLE_NV,
                                                level, internalFormat,
                                                format, type,
                                                width, height, 1, border);
      }
      else {
         _mesa_error(ctx, GL_INVALID_ENUM, "glTexImage2D(target)");
         return GL_TRUE;
      }
   }
   else if (dimensions == 3) {
      if (target == GL_PROXY_TEXTURE_3D || target == GL_TEXTURE_3D) {
         sizeOK = ctx->Driver.TestProxyTexImage(ctx, GL_PROXY_TEXTURE_3D,
                                                level, internalFormat,
                                                format, type,
                                                width, height, depth, border);
      }
      else {
         _mesa_error( ctx, GL_INVALID_ENUM, "glTexImage3D(target)" );
         return GL_TRUE;
      }
   }
   else {
      _mesa_problem( ctx, "bad dims in texture_error_check" );
      return GL_TRUE;
   }

   if (!sizeOK) {
      if (!isProxy) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glTexImage%dD(level=%d, width=%d, height=%d, depth=%d)",
                     dimensions, level, width, height, depth);
      }
      return GL_TRUE;
   }

   /* Check internalFormat */
   if (_mesa_base_tex_format(ctx, internalFormat) < 0) {
      if (!isProxy) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glTexImage%dD(internalFormat=0x%x)",
                     dimensions, internalFormat);
      }
      return GL_TRUE;
   }

   /* Check incoming image format and type */
   if (!_mesa_is_legal_format_and_type(ctx, format, type)) {
      /* Yes, generate GL_INVALID_OPERATION, not GL_INVALID_ENUM, if there
       * is a type/format mismatch.  See 1.2 spec page 94, sec 3.6.4.
       */
      if (!isProxy) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glTexImage%dD(format or type)", dimensions);
      }
      return GL_TRUE;
   }

   /* make sure internal format and format basically agree */
   colorFormat = is_color_format(format);
   indexFormat = is_index_format(format);
   if ((is_color_format(internalFormat) && !colorFormat && !indexFormat) ||
       (is_index_format(internalFormat) && !indexFormat) ||
       (is_depth_format(internalFormat) != is_depth_format(format)) ||
       (is_ycbcr_format(internalFormat) != is_ycbcr_format(format)) ||
       (is_depthstencil_format(internalFormat) != is_depthstencil_format(format))) {
      if (!isProxy)
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glTexImage(internalFormat/format)");
      return GL_TRUE;
   }

   /* additional checks for ycbcr textures */
   if (internalFormat == GL_YCBCR_MESA) {
      ASSERT(ctx->Extensions.MESA_ycbcr_texture);
      if (type != GL_UNSIGNED_SHORT_8_8_MESA &&
          type != GL_UNSIGNED_SHORT_8_8_REV_MESA) {
         char message[100];
         _mesa_sprintf(message,
                 "glTexImage%d(format/type YCBCR mismatch", dimensions);
         _mesa_error(ctx, GL_INVALID_ENUM, message);
         return GL_TRUE; /* error */
      }
      if (target != GL_TEXTURE_2D &&
          target != GL_PROXY_TEXTURE_2D &&
          target != GL_TEXTURE_RECTANGLE_NV &&
          target != GL_PROXY_TEXTURE_RECTANGLE_NV) {
         if (!isProxy)
            _mesa_error(ctx, GL_INVALID_ENUM, "glTexImage(target)");
         return GL_TRUE;
      }
      if (border != 0) {
         if (!isProxy) {
            char message[100];
            _mesa_sprintf(message,
                    "glTexImage%d(format=GL_YCBCR_MESA and border=%d)",
                    dimensions, border);
            _mesa_error(ctx, GL_INVALID_VALUE, message);
         }
         return GL_TRUE;
      }
   }

   /* additional checks for depth textures */
   if (_mesa_base_tex_format(ctx, internalFormat) == GL_DEPTH_COMPONENT) {
      /* Only 1D and 2D textures supported */
      if (target != GL_TEXTURE_1D &&
          target != GL_PROXY_TEXTURE_1D &&
          target != GL_TEXTURE_2D &&
          target != GL_PROXY_TEXTURE_2D) {
         if (!isProxy)
            _mesa_error(ctx, GL_INVALID_ENUM,
                        "glTexImage(target/internalFormat)");
         return GL_TRUE;
      }
   }

   /* additional checks for compressed textures */
   if (is_compressed_format(ctx, internalFormat)) {
      if (target == GL_TEXTURE_2D || target == GL_PROXY_TEXTURE_2D) {
         /* OK */
      }
      else if (ctx->Extensions.ARB_texture_cube_map &&
               (target == GL_PROXY_TEXTURE_CUBE_MAP ||
                (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X &&
                 target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z))) {
         /* OK */
      }
      else {
         if (!isProxy) {
            _mesa_error(ctx, GL_INVALID_ENUM,
                        "glTexImage%d(target)", dimensions);
            return GL_TRUE;
         }
      }
      if (border != 0) {
         if (!isProxy) {
            _mesa_error(ctx, GL_INVALID_OPERATION,
                        "glTexImage%D(border!=0)", dimensions);
         }
         return GL_TRUE;
      }
   }

   /* if we get here, the parameters are OK */
   return GL_FALSE;
}


/**
 * Test glTexSubImage[123]D() parameters for errors.
 *
 * \param ctx GL context.
 * \param dimensions texture image dimensions (must be 1, 2 or 3).
 * \param target texture target given by the user.
 * \param level image level given by the user.
 * \param xoffset sub-image x offset given by the user.
 * \param yoffset sub-image y offset given by the user.
 * \param zoffset sub-image z offset given by the user.
 * \param format pixel data format given by the user.
 * \param type pixel data type given by the user.
 * \param width image width given by the user.
 * \param height image height given by the user.
 * \param depth image depth given by the user.
 *
 * \return GL_TRUE if an error was detected, or GL_FALSE if no errors.
 *
 * Verifies each of the parameters against the constants specified in
 * __GLcontextRec::Const and the supported extensions, and according to the
 * OpenGL specification.
 */
static GLboolean
subtexture_error_check( GLcontext *ctx, GLuint dimensions,
                        GLenum target, GLint level,
                        GLint xoffset, GLint yoffset, GLint zoffset,
                        GLint width, GLint height, GLint depth,
                        GLenum format, GLenum type )
{
   struct gl_texture_unit *texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   struct gl_texture_image *destTex;

   /* Check target */
   if (dimensions == 1) {
      if (target != GL_TEXTURE_1D) {
         _mesa_error( ctx, GL_INVALID_ENUM, "glTexSubImage1D(target)" );
         return GL_TRUE;
      }
   }
   else if (dimensions == 2) {
      if (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB &&
          target <=GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB) {
         if (!ctx->Extensions.ARB_texture_cube_map) {
            _mesa_error( ctx, GL_INVALID_ENUM, "glTexSubImage2D(target)" );
            return GL_TRUE;
         }
      }
      else if (ctx->Extensions.NV_texture_rectangle &&
               target == GL_TEXTURE_RECTANGLE_NV) {
         if (!ctx->Extensions.NV_texture_rectangle) {
            _mesa_error( ctx, GL_INVALID_ENUM, "glTexSubImage2D(target)" );
            return GL_TRUE;
         }
      }
      else if (target != GL_TEXTURE_2D) {
         _mesa_error( ctx, GL_INVALID_ENUM, "glTexSubImage2D(target)" );
         return GL_TRUE;
      }
   }
   else if (dimensions == 3) {
      if (target != GL_TEXTURE_3D) {
         _mesa_error( ctx, GL_INVALID_ENUM, "glTexSubImage3D(target)" );
         return GL_TRUE;
      }
   }
   else {
      _mesa_problem( ctx, "invalid dims in texture_error_check" );
      return GL_TRUE;
   }

   /* Basic level check */
   if (level < 0 || level >= MAX_TEXTURE_LEVELS) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glTexSubImage2D(level=%d)", level);
      return GL_TRUE;
   }

   if (width < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glTexSubImage%dD(width=%d)", dimensions, width);
      return GL_TRUE;
   }
   if (height < 0 && dimensions > 1) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glTexSubImage%dD(height=%d)", dimensions, height);
      return GL_TRUE;
   }
   if (depth < 0 && dimensions > 2) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glTexSubImage%dD(depth=%d)", dimensions, depth);
      return GL_TRUE;
   }

   destTex = _mesa_select_tex_image(ctx, texUnit, target, level);

   if (!destTex) {
      /* undefined image level */
      _mesa_error(ctx, GL_INVALID_OPERATION, "glTexSubImage%dD", dimensions);
      return GL_TRUE;
   }

   if (xoffset < -((GLint)destTex->Border)) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glTexSubImage%dD(xoffset)",
                  dimensions);
      return GL_TRUE;
   }
   if (xoffset + width > (GLint) (destTex->Width + destTex->Border)) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glTexSubImage%dD(xoffset+width)",
                  dimensions);
      return GL_TRUE;
   }
   if (dimensions > 1) {
      if (yoffset < -((GLint)destTex->Border)) {
         _mesa_error(ctx, GL_INVALID_VALUE, "glTexSubImage%dD(yoffset)",
                     dimensions);
         return GL_TRUE;
      }
      if (yoffset + height > (GLint) (destTex->Height + destTex->Border)) {
         _mesa_error(ctx, GL_INVALID_VALUE, "glTexSubImage%dD(yoffset+height)",
                     dimensions);
         return GL_TRUE;
      }
   }
   if (dimensions > 2) {
      if (zoffset < -((GLint)destTex->Border)) {
         _mesa_error(ctx, GL_INVALID_VALUE, "glTexSubImage3D(zoffset)");
         return GL_TRUE;
      }
      if (zoffset + depth  > (GLint) (destTex->Depth + destTex->Border)) {
         _mesa_error(ctx, GL_INVALID_VALUE, "glTexSubImage3D(zoffset+depth)");
         return GL_TRUE;
      }
   }

   if (!_mesa_is_legal_format_and_type(ctx, format, type)) {
      _mesa_error(ctx, GL_INVALID_ENUM,
                  "glTexSubImage%dD(format or type)", dimensions);
      return GL_TRUE;
   }

   if (destTex->IsCompressed) {
      const struct gl_texture_unit *texUnit;
      const struct gl_texture_image *texImage;
      texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
      texImage = _mesa_select_tex_image(ctx, texUnit, target, level);

      if (target == GL_TEXTURE_2D || target == GL_PROXY_TEXTURE_2D) {
         /* OK */
      }
      else if (ctx->Extensions.ARB_texture_cube_map &&
               (target == GL_PROXY_TEXTURE_CUBE_MAP ||
                (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X &&
                 target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z))) {
         /* OK */
      }
      else {
         _mesa_error(ctx, GL_INVALID_ENUM,
                     "glTexSubImage%D(target)", dimensions);
         return GL_TRUE;
      }
      /* offset must be multiple of 4 */
      if ((xoffset & 3) || (yoffset & 3)) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glTexSubImage%D(xoffset or yoffset)", dimensions);
         return GL_TRUE;
      }
      /* size must be multiple of 4 or equal to whole texture size */
      if ((width & 3) && (GLuint) width != texImage->Width) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glTexSubImage%D(width)", dimensions);
         return GL_TRUE;
      }
      if ((height & 3) && (GLuint) height != texImage->Height) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glTexSubImage%D(width)", dimensions);
         return GL_TRUE;
      }
   }

   return GL_FALSE;
}


/**
 * Test glCopyTexImage[12]D() parameters for errors.
 *
 * \param ctx GL context.
 * \param dimensions texture image dimensions (must be 1, 2 or 3).
 * \param target texture target given by the user.
 * \param level image level given by the user.
 * \param internalFormat internal format given by the user.
 * \param width image width given by the user.
 * \param height image height given by the user.
 * \param depth image depth given by the user.
 * \param border texture border.
 *
 * \return GL_TRUE if an error was detected, or GL_FALSE if no errors.
 *
 * Verifies each of the parameters against the constants specified in
 * __GLcontextRec::Const and the supported extensions, and according to the
 * OpenGL specification.
 */
static GLboolean
copytexture_error_check( GLcontext *ctx, GLuint dimensions,
                         GLenum target, GLint level, GLint internalFormat,
                         GLint width, GLint height, GLint border )
{
   GLenum type;
   GLboolean sizeOK;
   GLint format;

   /* Basic level check (more checking in ctx->Driver.TestProxyTexImage) */
   if (level < 0 || level >= MAX_TEXTURE_LEVELS) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyTexImage%dD(level=%d)", dimensions, level);
      return GL_TRUE;
   }

   /* Check border */
   if (border < 0 || border > 1 ||
       ((target == GL_TEXTURE_RECTANGLE_NV ||
         target == GL_PROXY_TEXTURE_RECTANGLE_NV) && border != 0)) {
      return GL_TRUE;
   }

   format = _mesa_base_tex_format(ctx, internalFormat);
   if (format < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyTexImage%dD(internalFormat)", dimensions);
      return GL_TRUE;
   }

   /* NOTE: the format and type aren't really significant for
    * TestProxyTexImage().  Only the internalformat really matters.
    */
   type = GL_FLOAT;

   /* Check target and call ctx->Driver.TestProxyTexImage() to check the
    * level, width, height and depth.
    */
   if (dimensions == 1) {
      if (target == GL_TEXTURE_1D) {
         sizeOK = ctx->Driver.TestProxyTexImage(ctx, GL_PROXY_TEXTURE_1D,
                                                level, internalFormat,
                                                format, type,
                                                width, 1, 1, border);
      }
      else {
         _mesa_error( ctx, GL_INVALID_ENUM, "glCopyTexImage1D(target)" );
         return GL_TRUE;
      }
   }
   else if (dimensions == 2) {
      if (target == GL_TEXTURE_2D) {
         sizeOK = ctx->Driver.TestProxyTexImage(ctx, GL_PROXY_TEXTURE_2D,
                                                level, internalFormat,
                                                format, type,
                                                width, height, 1, border);
      }
      else if (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB &&
               target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB) {
         if (!ctx->Extensions.ARB_texture_cube_map) {
            _mesa_error( ctx, GL_INVALID_ENUM, "glCopyTexImage2D(target)" );
            return GL_TRUE;
         }
         sizeOK = (width == height) &&
            ctx->Driver.TestProxyTexImage(ctx, GL_PROXY_TEXTURE_CUBE_MAP_ARB,
                                          level, internalFormat, format, type,
                                          width, height, 1, border);
      }
      else if (target == GL_TEXTURE_RECTANGLE_NV) {
         if (!ctx->Extensions.NV_texture_rectangle) {
            _mesa_error( ctx, GL_INVALID_ENUM, "glCopyTexImage2D(target)" );
            return GL_TRUE;
         }
         sizeOK = ctx->Driver.TestProxyTexImage(ctx,
                                                GL_PROXY_TEXTURE_RECTANGLE_NV,
                                                level, internalFormat,
                                                format, type,
                                                width, height, 1, border);
      }
      else {
         _mesa_error( ctx, GL_INVALID_ENUM, "glCopyTexImage2D(target)" );
         return GL_TRUE;
      }
   }
   else {
      _mesa_problem(ctx, "invalid dimensions in copytexture_error_check");
      return GL_TRUE;
   }

   if (!sizeOK) {
      if (dimensions == 1) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glCopyTexImage1D(width=%d)", width);
      }
      else {
         ASSERT(dimensions == 2);
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glCopyTexImage2D(width=%d, height=%d)", width, height);
      }
      return GL_TRUE;
   }

   if (is_compressed_format(ctx, internalFormat)) {
      if (target != GL_TEXTURE_2D) {
         _mesa_error(ctx, GL_INVALID_ENUM,
                     "glCopyTexImage%d(target)", dimensions);
         return GL_TRUE;
      }
      if (border != 0) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glCopyTexImage%D(border!=0)", dimensions);
         return GL_TRUE;
      }
   }
   else if (is_depth_format(internalFormat)) {
      /* make sure we have depth/stencil buffers */
      if (!ctx->ReadBuffer->Attachment[BUFFER_DEPTH].Renderbuffer) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glCopyTexImage%D(no depth)", dimensions);
         return GL_TRUE;
      }
   }
   else if (is_depthstencil_format(internalFormat)) {
      /* make sure we have depth/stencil buffers */
      if (!ctx->ReadBuffer->Attachment[BUFFER_DEPTH].Renderbuffer ||
          !ctx->ReadBuffer->Attachment[BUFFER_STENCIL].Renderbuffer) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glCopyTexImage%D(no depth/stencil buffer)", dimensions);
         return GL_TRUE;
      }
   }

   /* if we get here, the parameters are OK */
   return GL_FALSE;
}


/**
 * Test glCopyTexImage[12]D() parameters for errors.
 *
 * \param ctx GL context.
 * \param dimensions texture image dimensions (must be 1, 2 or 3).
 * \param target texture target given by the user.
 * \param level image level given by the user.
 * \param xoffset sub-image x offset given by the user.
 * \param yoffset sub-image y offset given by the user.
 * \param zoffset sub-image z offset given by the user.
 * \param width image width given by the user.
 * \param height image height given by the user.
 *
 * \return GL_TRUE if an error was detected, or GL_FALSE if no errors.
 *
 * Verifies each of the parameters against the constants specified in
 * __GLcontextRec::Const and the supported extensions, and according to the
 * OpenGL specification.
 */
static GLboolean
copytexsubimage_error_check( GLcontext *ctx, GLuint dimensions,
                             GLenum target, GLint level,
                             GLint xoffset, GLint yoffset, GLint zoffset,
                             GLsizei width, GLsizei height )
{
   struct gl_texture_unit *texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   struct gl_texture_image *teximage;

   /* Check target */
   if (dimensions == 1) {
      if (target != GL_TEXTURE_1D) {
         _mesa_error( ctx, GL_INVALID_ENUM, "glCopyTexSubImage1D(target)" );
         return GL_TRUE;
      }
   }
   else if (dimensions == 2) {
      if (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB &&
          target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB) {
         if (!ctx->Extensions.ARB_texture_cube_map) {
            _mesa_error( ctx, GL_INVALID_ENUM, "glCopyTexSubImage2D(target)" );
            return GL_TRUE;
         }
      }
      else if (target == GL_TEXTURE_RECTANGLE_NV) {
         if (!ctx->Extensions.NV_texture_rectangle) {
            _mesa_error( ctx, GL_INVALID_ENUM, "glCopyTexSubImage2D(target)" );
            return GL_TRUE;
         }
      }
      else if (target != GL_TEXTURE_2D) {
         _mesa_error( ctx, GL_INVALID_ENUM, "glCopyTexSubImage2D(target)" );
         return GL_TRUE;
      }
   }
   else if (dimensions == 3) {
      if (target != GL_TEXTURE_3D) {
         _mesa_error( ctx, GL_INVALID_ENUM, "glCopyTexSubImage3D(target)" );
         return GL_TRUE;
      }
   }

   /* Check level */
   if (level < 0 || level >= MAX_TEXTURE_LEVELS) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyTexSubImage%dD(level=%d)", dimensions, level);
      return GL_TRUE;
   }

   /* Check size */
   if (width < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyTexSubImage%dD(width=%d)", dimensions, width);
      return GL_TRUE;
   }
   if (dimensions > 1 && height < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyTexSubImage%dD(height=%d)", dimensions, height);
      return GL_TRUE;
   }

   teximage = _mesa_select_tex_image(ctx, texUnit, target, level);
   if (!teximage) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glCopyTexSubImage%dD(undefined texture level: %d)",
                  dimensions, level);
      return GL_TRUE;
   }

   if (xoffset < -((GLint)teximage->Border)) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyTexSubImage%dD(xoffset=%d)", dimensions, xoffset);
      return GL_TRUE;
   }
   if (xoffset + width > (GLint) (teximage->Width + teximage->Border)) {
      _mesa_error(ctx, GL_INVALID_VALUE,
                  "glCopyTexSubImage%dD(xoffset+width)", dimensions);
      return GL_TRUE;
   }
   if (dimensions > 1) {
      if (yoffset < -((GLint)teximage->Border)) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glCopyTexSubImage%dD(yoffset=%d)", dimensions, yoffset);
         return GL_TRUE;
      }
      /* NOTE: we're adding the border here, not subtracting! */
      if (yoffset + height > (GLint) (teximage->Height + teximage->Border)) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glCopyTexSubImage%dD(yoffset+height)", dimensions);
         return GL_TRUE;
      }
   }

   if (dimensions > 2) {
      if (zoffset < -((GLint)teximage->Border)) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glCopyTexSubImage%dD(zoffset)", dimensions);
         return GL_TRUE;
      }
      if (zoffset > (GLint) (teximage->Depth + teximage->Border)) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glCopyTexSubImage%dD(zoffset+depth)", dimensions);
         return GL_TRUE;
      }
   }

   if (teximage->IsCompressed) {
      if (target != GL_TEXTURE_2D) {
         _mesa_error(ctx, GL_INVALID_ENUM,
                     "glCopyTexSubImage%d(target)", dimensions);
         return GL_TRUE;
      }
      /* offset must be multiple of 4 */
      if ((xoffset & 3) || (yoffset & 3)) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glCopyTexSubImage%D(xoffset or yoffset)", dimensions);
         return GL_TRUE;
      }
      /* size must be multiple of 4 */
      if ((width & 3) != 0 && (GLuint) width != teximage->Width) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glCopyTexSubImage%D(width)", dimensions);
         return GL_TRUE;
      }
      if ((height & 3) != 0 && (GLuint) height != teximage->Height) {
         _mesa_error(ctx, GL_INVALID_VALUE,
                     "glCopyTexSubImage%D(height)", dimensions);
         return GL_TRUE;
      }
   }

   if (teximage->IntFormat == GL_YCBCR_MESA) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glCopyTexSubImage2D");
      return GL_TRUE;
   }

   if (teximage->Format == GL_DEPTH_COMPONENT) {
      if (!ctx->ReadBuffer->Attachment[BUFFER_DEPTH].Renderbuffer) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glCopyTexSubImage%D(no depth buffer)",
                     dimensions);
         return GL_TRUE;
      }
   }
   else if (teximage->Format == GL_DEPTH_STENCIL_EXT) {
      if (!ctx->ReadBuffer->Attachment[BUFFER_DEPTH].Renderbuffer ||
          !ctx->ReadBuffer->Attachment[BUFFER_STENCIL].Renderbuffer) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glCopyTexSubImage%D(no depth/stencil buffer)",
                     dimensions);
         return GL_TRUE;
      }
   }

   /* if we get here, the parameters are OK */
   return GL_FALSE;
}


/**
 * Get texture image.  Called by glGetTexImage.
 *
 * \param target texture target.
 * \param level image level.
 * \param format pixel data format for returned image.
 * \param type pixel data type for returned image.
 * \param pixels returned pixel data.
 */
void GLAPIENTRY
_mesa_GetTexImage( GLenum target, GLint level, GLenum format,
                   GLenum type, GLvoid *pixels )
{
   const struct gl_texture_unit *texUnit;
   const struct gl_texture_object *texObj;
   const struct gl_texture_image *texImage;
   GLint maxLevels = 0;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   texUnit = &(ctx->Texture.Unit[ctx->Texture.CurrentUnit]);
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   if (!texObj || is_proxy_target(target)) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glGetTexImage(target)");
      return;
   }

   maxLevels = _mesa_max_texture_levels(ctx, target);
   ASSERT(maxLevels > 0);  /* 0 indicates bad target, caught above */

   if (level < 0 || level >= maxLevels) {
      _mesa_error( ctx, GL_INVALID_VALUE, "glGetTexImage(level)" );
      return;
   }

   if (_mesa_sizeof_packed_type(type) <= 0) {
      _mesa_error( ctx, GL_INVALID_ENUM, "glGetTexImage(type)" );
      return;
   }

   if (_mesa_components_in_format(format) <= 0 ||
       format == GL_STENCIL_INDEX) {
      _mesa_error( ctx, GL_INVALID_ENUM, "glGetTexImage(format)" );
      return;
   }

   if (!ctx->Extensions.EXT_paletted_texture && is_index_format(format)) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glGetTexImage(format)");
   }

   if (!ctx->Extensions.SGIX_depth_texture &&
       !ctx->Extensions.ARB_depth_texture && is_depth_format(format)) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glGetTexImage(format)");
   }

   if (!ctx->Extensions.MESA_ycbcr_texture && is_ycbcr_format(format)) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glGetTexImage(format)");
   }

   if (!ctx->Extensions.EXT_packed_depth_stencil
       && is_depthstencil_format(format)) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glGetTexImage(format)");
   }

   if (!pixels)
      return;

   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   if (!texImage) {
      /* invalid mipmap level, not an error */
      return;
   }

   /* Make sure the requested image format is compatible with the
    * texture's format.  Note that a color index texture can be converted
    * to RGBA so that combo is allowed.
    */
   if (is_color_format(format)
       && !is_color_format(texImage->TexFormat->BaseFormat)
       && !is_index_format(texImage->TexFormat->BaseFormat)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetTexImage(format mismatch)");
      return;
   }
   else if (is_index_format(format)
       && !is_index_format(texImage->TexFormat->BaseFormat)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetTexImage(format mismatch)");
      return;
   }
   else if (is_depth_format(format)
       && !is_depth_format(texImage->TexFormat->BaseFormat)
       && !is_depthstencil_format(texImage->TexFormat->BaseFormat)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetTexImage(format mismatch)");
      return;
   }
   else if (is_ycbcr_format(format)
       && !is_ycbcr_format(texImage->TexFormat->BaseFormat)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetTexImage(format mismatch)");
      return;
   }
   else if (is_depthstencil_format(format)
       && !is_depthstencil_format(texImage->TexFormat->BaseFormat)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetTexImage(format mismatch)");
      return;
   }

   /* typically, this will call _mesa_get_teximage() */
   ctx->Driver.GetTexImage(ctx, target, level, format, type, pixels,
                           texObj, texImage);
}



/*
 * Called from the API.  Note that width includes the border.
 */
void GLAPIENTRY
_mesa_TexImage1D( GLenum target, GLint level, GLint internalFormat,
                  GLsizei width, GLint border, GLenum format,
                  GLenum type, const GLvoid *pixels )
{
   GLsizei postConvWidth = width;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (is_color_format(internalFormat)) {
      _mesa_adjust_image_for_convolution(ctx, 1, &postConvWidth, NULL);
   }

   if (target == GL_TEXTURE_1D) {
      /* non-proxy target */
      struct gl_texture_unit *texUnit;
      struct gl_texture_object *texObj;
      struct gl_texture_image *texImage;

      if (texture_error_check(ctx, target, level, internalFormat,
                              format, type, 1, postConvWidth, 1, 1, border)) {
         return;   /* error was recorded */
      }

      texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
      texObj = _mesa_select_tex_object(ctx, texUnit, target);
      texImage = _mesa_get_tex_image(ctx, texUnit, target, level);

      if (!texImage) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glTexImage1D");
         return;
      }
      else if (texImage->Data) {
	 ctx->Driver.FreeTexImageData( ctx, texImage );
      }
      ASSERT(texImage->Data == NULL);
      clear_teximage_fields(texImage); /* not really needed, but helpful */
      _mesa_init_teximage_fields(ctx, target, texImage,
                                 postConvWidth, 1, 1,
                                 border, internalFormat);

      if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
         _mesa_update_state(ctx);

      ASSERT(ctx->Driver.TexImage1D);

      /* Give the texture to the driver!  <pixels> may be null! */
      (*ctx->Driver.TexImage1D)(ctx, target, level, internalFormat,
                                width, border, format, type, pixels,
                                &ctx->Unpack, texObj, texImage);

      ASSERT(texImage->TexFormat);

      /* state update */
      texObj->Complete = GL_FALSE;
      ctx->NewState |= _NEW_TEXTURE;
   }
   else if (target == GL_PROXY_TEXTURE_1D) {
      /* Proxy texture: check for errors and update proxy state */
      struct gl_texture_image *texImage;
      texImage = _mesa_get_proxy_tex_image(ctx, target, level);
      if (texture_error_check(ctx, target, level, internalFormat,
                              format, type, 1, postConvWidth, 1, 1, border)) {
         /* when error, clear all proxy texture image parameters */
         if (texImage)
            clear_teximage_fields(texImage);
      }
      else {
         /* no error, set the tex image parameters */
         ASSERT(texImage);
         _mesa_init_teximage_fields(ctx, target, texImage,
                                    postConvWidth, 1, 1,
                                    border, internalFormat);
         texImage->TexFormat = (*ctx->Driver.ChooseTextureFormat)(ctx,
                                          internalFormat, format, type);
      }
   }
   else {
      _mesa_error( ctx, GL_INVALID_ENUM, "glTexImage1D(target)" );
      return;
   }
}


void GLAPIENTRY
_mesa_TexImage2D( GLenum target, GLint level, GLint internalFormat,
                  GLsizei width, GLsizei height, GLint border,
                  GLenum format, GLenum type,
                  const GLvoid *pixels )
{
   GLsizei postConvWidth = width, postConvHeight = height;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (is_color_format(internalFormat)) {
      _mesa_adjust_image_for_convolution(ctx, 2, &postConvWidth,
					 &postConvHeight);
   }

   if (target == GL_TEXTURE_2D ||
       (ctx->Extensions.ARB_texture_cube_map &&
        target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB &&
        target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB) ||
       (ctx->Extensions.NV_texture_rectangle &&
        target == GL_TEXTURE_RECTANGLE_NV)) {
      /* non-proxy target */
      struct gl_texture_unit *texUnit;
      struct gl_texture_object *texObj;
      struct gl_texture_image *texImage;

      if (texture_error_check(ctx, target, level, internalFormat,
                              format, type, 2, postConvWidth, postConvHeight,
                              1, border)) {
         return;   /* error was recorded */
      }

      texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
      texObj = _mesa_select_tex_object(ctx, texUnit, target);
      texImage = _mesa_get_tex_image(ctx, texUnit, target, level);
      if (!texImage) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glTexImage2D");
         return;
      }
      else if (texImage->Data) {
	 ctx->Driver.FreeTexImageData( ctx, texImage );
      }
      ASSERT(texImage->Data == NULL);
      clear_teximage_fields(texImage); /* not really needed, but helpful */
      _mesa_init_teximage_fields(ctx, target, texImage,
                                 postConvWidth, postConvHeight, 1,
                                 border, internalFormat);

      if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
         _mesa_update_state(ctx);

      ASSERT(ctx->Driver.TexImage2D);

      /* Give the texture to the driver!  <pixels> may be null! */
      (*ctx->Driver.TexImage2D)(ctx, target, level, internalFormat,
                                width, height, border, format, type, pixels,
                                &ctx->Unpack, texObj, texImage);

      ASSERT(texImage->TexFormat);

      /* state update */
      texObj->Complete = GL_FALSE;
      ctx->NewState |= _NEW_TEXTURE;
   }
   else if (target == GL_PROXY_TEXTURE_2D ||
            (target == GL_PROXY_TEXTURE_CUBE_MAP_ARB &&
             ctx->Extensions.ARB_texture_cube_map) ||
            (target == GL_PROXY_TEXTURE_RECTANGLE_NV &&
             ctx->Extensions.NV_texture_rectangle)) {
      /* Proxy texture: check for errors and update proxy state */
      struct gl_texture_image *texImage;
      texImage = _mesa_get_proxy_tex_image(ctx, target, level);
      if (texture_error_check(ctx, target, level, internalFormat,
                              format, type, 2, postConvWidth, postConvHeight,
                              1, border)) {
         /* when error, clear all proxy texture image parameters */
         if (texImage)
            clear_teximage_fields(ctx->Texture.Proxy2D->Image[0][level]);
      }
      else {
         /* no error, set the tex image parameters */
         _mesa_init_teximage_fields(ctx, target, texImage,
                                    postConvWidth, postConvHeight, 1,
                                    border, internalFormat);
         texImage->TexFormat = (*ctx->Driver.ChooseTextureFormat)(ctx,
                                          internalFormat, format, type);
      }
   }
   else {
      _mesa_error( ctx, GL_INVALID_ENUM, "glTexImage2D(target)" );
      return;
   }
}


/*
 * Called by the API or display list executor.
 * Note that width and height include the border.
 */
void GLAPIENTRY
_mesa_TexImage3D( GLenum target, GLint level, GLint internalFormat,
                  GLsizei width, GLsizei height, GLsizei depth,
                  GLint border, GLenum format, GLenum type,
                  const GLvoid *pixels )
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (target == GL_TEXTURE_3D) {
      struct gl_texture_unit *texUnit;
      struct gl_texture_object *texObj;
      struct gl_texture_image *texImage;
      /* non-proxy target */

      if (texture_error_check(ctx, target, level, (GLint) internalFormat,
                              format, type, 3, width, height, depth, border)) {
         return;   /* error was recorded */
      }

      texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
      texObj = _mesa_select_tex_object(ctx, texUnit, target);
      texImage = _mesa_get_tex_image(ctx, texUnit, target, level);
      if (!texImage) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glTexImage3D");
         return;
      }
      else if (texImage->Data) {
	 ctx->Driver.FreeTexImageData( ctx, texImage );
      }
      ASSERT(texImage->Data == NULL);
      clear_teximage_fields(texImage); /* not really needed, but helpful */
      _mesa_init_teximage_fields(ctx, target, texImage,
                                 width, height, depth,
                                 border, internalFormat);

      if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
         _mesa_update_state(ctx);

      ASSERT(ctx->Driver.TexImage3D);

      /* Give the texture to the driver!  <pixels> may be null! */
      (*ctx->Driver.TexImage3D)(ctx, target, level, internalFormat,
                                width, height, depth, border, format, type,
                                pixels, &ctx->Unpack, texObj, texImage);

      ASSERT(texImage->TexFormat);

      /* state update */
      texObj->Complete = GL_FALSE;
      ctx->NewState |= _NEW_TEXTURE;
   }
   else if (target == GL_PROXY_TEXTURE_3D) {
      /* Proxy texture: check for errors and update proxy state */
      struct gl_texture_image *texImage;
      texImage = _mesa_get_proxy_tex_image(ctx, target, level);
      if (texture_error_check(ctx, target, level, internalFormat,
                              format, type, 3, width, height, depth, border)) {
         /* when error, clear all proxy texture image parameters */
         if (texImage)
            clear_teximage_fields(texImage);
      }
      else {
         /* no error, set the tex image parameters */
         _mesa_init_teximage_fields(ctx, target, texImage, width, height, 1,
                                    border, internalFormat);
         texImage->TexFormat = (*ctx->Driver.ChooseTextureFormat)(ctx,
                                          internalFormat, format, type);
      }
   }
   else {
      _mesa_error( ctx, GL_INVALID_ENUM, "glTexImage3D(target)" );
      return;
   }
}


void GLAPIENTRY
_mesa_TexImage3DEXT( GLenum target, GLint level, GLenum internalFormat,
                     GLsizei width, GLsizei height, GLsizei depth,
                     GLint border, GLenum format, GLenum type,
                     const GLvoid *pixels )
{
   _mesa_TexImage3D(target, level, (GLint) internalFormat, width, height,
                    depth, border, format, type, pixels);
}



void GLAPIENTRY
_mesa_TexSubImage1D( GLenum target, GLint level,
                     GLint xoffset, GLsizei width,
                     GLenum format, GLenum type,
                     const GLvoid *pixels )
{
   GLsizei postConvWidth = width;
   struct gl_texture_unit *texUnit;
   struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
      _mesa_update_state(ctx);

   /* XXX should test internal format */
   if (is_color_format(format)) {
      _mesa_adjust_image_for_convolution(ctx, 1, &postConvWidth, NULL);
   }

   if (subtexture_error_check(ctx, 1, target, level, xoffset, 0, 0,
                              postConvWidth, 1, 1, format, type)) {
      return;   /* error was detected */
   }

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   assert(texImage);

   if (width == 0)
      return;  /* no-op, not an error */

   /* If we have a border, xoffset=-1 is legal.  Bias by border width */
   xoffset += texImage->Border;

   ASSERT(ctx->Driver.TexSubImage1D);
   (*ctx->Driver.TexSubImage1D)(ctx, target, level, xoffset, width,
                                format, type, pixels, &ctx->Unpack,
                                texObj, texImage);
   ctx->NewState |= _NEW_TEXTURE;
}


void GLAPIENTRY
_mesa_TexSubImage2D( GLenum target, GLint level,
                     GLint xoffset, GLint yoffset,
                     GLsizei width, GLsizei height,
                     GLenum format, GLenum type,
                     const GLvoid *pixels )
{
   GLsizei postConvWidth = width, postConvHeight = height;
   struct gl_texture_unit *texUnit;
   struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
      _mesa_update_state(ctx);

   /* XXX should test internal format */
   if (is_color_format(format)) {
      _mesa_adjust_image_for_convolution(ctx, 2, &postConvWidth,
                                         &postConvHeight);
   }

   if (subtexture_error_check(ctx, 2, target, level, xoffset, yoffset, 0,
                             postConvWidth, postConvHeight, 1, format, type)) {
      return;   /* error was detected */
   }

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   assert(texImage);

   if (width == 0 || height == 0)
      return;  /* no-op, not an error */

   /* If we have a border, xoffset=-1 is legal.  Bias by border width */
   xoffset += texImage->Border;
   yoffset += texImage->Border;

   ASSERT(ctx->Driver.TexSubImage2D);
   (*ctx->Driver.TexSubImage2D)(ctx, target, level, xoffset, yoffset,
                                width, height, format, type, pixels,
                                &ctx->Unpack, texObj, texImage);
   ctx->NewState |= _NEW_TEXTURE;
}



void GLAPIENTRY
_mesa_TexSubImage3D( GLenum target, GLint level,
                     GLint xoffset, GLint yoffset, GLint zoffset,
                     GLsizei width, GLsizei height, GLsizei depth,
                     GLenum format, GLenum type,
                     const GLvoid *pixels )
{
   struct gl_texture_unit *texUnit;
   struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
      _mesa_update_state(ctx);

   if (subtexture_error_check(ctx, 3, target, level, xoffset, yoffset, zoffset,
                              width, height, depth, format, type)) {
      return;   /* error was detected */
   }

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   assert(texImage);

   if (width == 0 || height == 0 || height == 0)
      return;  /* no-op, not an error */

   /* If we have a border, xoffset=-1 is legal.  Bias by border width */
   xoffset += texImage->Border;
   yoffset += texImage->Border;
   zoffset += texImage->Border;

   ASSERT(ctx->Driver.TexSubImage3D);
   (*ctx->Driver.TexSubImage3D)(ctx, target, level,
                                xoffset, yoffset, zoffset,
                                width, height, depth,
                                format, type, pixels,
                                &ctx->Unpack, texObj, texImage );
   ctx->NewState |= _NEW_TEXTURE;
}



void GLAPIENTRY
_mesa_CopyTexImage1D( GLenum target, GLint level,
                      GLenum internalFormat,
                      GLint x, GLint y,
                      GLsizei width, GLint border )
{
   struct gl_texture_unit *texUnit;
   struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;
   GLsizei postConvWidth = width;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
      _mesa_update_state(ctx);

   if (is_color_format(internalFormat)) {
      _mesa_adjust_image_for_convolution(ctx, 1, &postConvWidth, NULL);
   }

   if (copytexture_error_check(ctx, 1, target, level, internalFormat,
                               postConvWidth, 1, border))
      return;

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   texImage = _mesa_get_tex_image(ctx, texUnit, target, level);
   if (!texImage) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCopyTexImage1D");
      return;
   }
   else if (texImage->Data) {
      ctx->Driver.FreeTexImageData( ctx, texImage );
   }
   ASSERT(texImage->Data == NULL);

   clear_teximage_fields(texImage); /* not really needed, but helpful */
   _mesa_init_teximage_fields(ctx, target, texImage, postConvWidth, 1, 1,
                              border, internalFormat);


   ASSERT(ctx->Driver.CopyTexImage1D);
   (*ctx->Driver.CopyTexImage1D)(ctx, target, level, internalFormat,
                                 x, y, width, border);

   ASSERT(texImage->TexFormat);

   /* state update */
   texObj->Complete = GL_FALSE;
   ctx->NewState |= _NEW_TEXTURE;
}



void GLAPIENTRY
_mesa_CopyTexImage2D( GLenum target, GLint level, GLenum internalFormat,
                      GLint x, GLint y, GLsizei width, GLsizei height,
                      GLint border )
{
   struct gl_texture_unit *texUnit;
   struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;
   GLsizei postConvWidth = width, postConvHeight = height;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
      _mesa_update_state(ctx);

   if (is_color_format(internalFormat)) {
      _mesa_adjust_image_for_convolution(ctx, 2, &postConvWidth,
                                         &postConvHeight);
   }

   if (copytexture_error_check(ctx, 2, target, level, internalFormat,
                               postConvWidth, postConvHeight, border))
      return;

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   texImage = _mesa_get_tex_image(ctx, texUnit, target, level);
   if (!texImage) {
      _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCopyTexImage2D");
      return;
   }
   else if (texImage->Data) {
      ctx->Driver.FreeTexImageData( ctx, texImage );
   }
   ASSERT(texImage->Data == NULL);

   clear_teximage_fields(texImage); /* not really needed, but helpful */
   _mesa_init_teximage_fields(ctx, target, texImage,
                              postConvWidth, postConvHeight, 1,
                              border, internalFormat);

   ASSERT(ctx->Driver.CopyTexImage2D);
   (*ctx->Driver.CopyTexImage2D)(ctx, target, level, internalFormat,
                                 x, y, width, height, border);

   ASSERT(texImage->TexFormat);

   /* state update */
   texObj->Complete = GL_FALSE;
   ctx->NewState |= _NEW_TEXTURE;
}



void GLAPIENTRY
_mesa_CopyTexSubImage1D( GLenum target, GLint level,
                         GLint xoffset, GLint x, GLint y, GLsizei width )
{
   struct gl_texture_unit *texUnit;
   struct gl_texture_image *texImage;
   GLsizei postConvWidth = width;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
      _mesa_update_state(ctx);

   /* XXX should test internal format */
   _mesa_adjust_image_for_convolution(ctx, 1, &postConvWidth, NULL);

   if (copytexsubimage_error_check(ctx, 1, target, level,
                                   xoffset, 0, 0, postConvWidth, 1))
      return;

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   ASSERT(texImage);

   /* If we have a border, xoffset=-1 is legal.  Bias by border width */
   xoffset += texImage->Border;

   ASSERT(ctx->Driver.CopyTexSubImage1D);
   (*ctx->Driver.CopyTexSubImage1D)(ctx, target, level, xoffset, x, y, width);
   ctx->NewState |= _NEW_TEXTURE;
}



void GLAPIENTRY
_mesa_CopyTexSubImage2D( GLenum target, GLint level,
                         GLint xoffset, GLint yoffset,
                         GLint x, GLint y, GLsizei width, GLsizei height )
{
   struct gl_texture_unit *texUnit;
   struct gl_texture_image *texImage;
   GLsizei postConvWidth = width, postConvHeight = height;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
      _mesa_update_state(ctx);

   /* XXX should test internal format */
   _mesa_adjust_image_for_convolution(ctx, 2, &postConvWidth, &postConvHeight);

   if (copytexsubimage_error_check(ctx, 2, target, level, xoffset, yoffset, 0,
                                   postConvWidth, postConvHeight))
      return;

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   ASSERT(texImage);

   /* If we have a border, xoffset=-1 is legal.  Bias by border width */
   xoffset += texImage->Border;
   yoffset += texImage->Border;

   ASSERT(ctx->Driver.CopyTexSubImage2D);
   (*ctx->Driver.CopyTexSubImage2D)(ctx, target, level,
                                    xoffset, yoffset, x, y, width, height);
   ctx->NewState |= _NEW_TEXTURE;
}



void GLAPIENTRY
_mesa_CopyTexSubImage3D( GLenum target, GLint level,
                         GLint xoffset, GLint yoffset, GLint zoffset,
                         GLint x, GLint y, GLsizei width, GLsizei height )
{
   struct gl_texture_unit *texUnit;
   struct gl_texture_image *texImage;
   GLsizei postConvWidth = width, postConvHeight = height;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (ctx->NewState & _IMAGE_NEW_TRANSFER_STATE)
      _mesa_update_state(ctx);

   /* XXX should test internal format */
   _mesa_adjust_image_for_convolution(ctx, 2, &postConvWidth, &postConvHeight);

   if (copytexsubimage_error_check(ctx, 3, target, level, xoffset, yoffset,
                                   zoffset, postConvWidth, postConvHeight))
      return;

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   ASSERT(texImage);

   /* If we have a border, xoffset=-1 is legal.  Bias by border width */
   xoffset += texImage->Border;
   yoffset += texImage->Border;
   zoffset += texImage->Border;

   ASSERT(ctx->Driver.CopyTexSubImage3D);
   (*ctx->Driver.CopyTexSubImage3D)(ctx, target, level,
                                    xoffset, yoffset, zoffset,
                                    x, y, width, height);
   ctx->NewState |= _NEW_TEXTURE;
}




/**********************************************************************/
/******                   Compressed Textures                    ******/
/**********************************************************************/


/**
 * Error checking for glCompressedTexImage[123]D().
 * \return error code or GL_NO_ERROR.
 */
static GLenum
compressed_texture_error_check(GLcontext *ctx, GLint dimensions,
                               GLenum target, GLint level,
                               GLenum internalFormat, GLsizei width,
                               GLsizei height, GLsizei depth, GLint border,
                               GLsizei imageSize)
{
   GLint expectedSize, maxLevels = 0, maxTextureSize;

   if (dimensions == 1) {
      /* 1D compressed textures not allowed */
      return GL_INVALID_ENUM;
   }
   else if (dimensions == 2) {
      if (target == GL_PROXY_TEXTURE_2D) {
         maxLevels = ctx->Const.MaxTextureLevels;
      }
      else if (target == GL_TEXTURE_2D) {
         maxLevels = ctx->Const.MaxTextureLevels;
      }
      else if (target == GL_PROXY_TEXTURE_CUBE_MAP_ARB) {
         if (!ctx->Extensions.ARB_texture_cube_map)
            return GL_INVALID_ENUM; /*target*/
         maxLevels = ctx->Const.MaxCubeTextureLevels;
      }
      else if (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB &&
               target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB) {
         if (!ctx->Extensions.ARB_texture_cube_map)
            return GL_INVALID_ENUM; /*target*/
         maxLevels = ctx->Const.MaxCubeTextureLevels;
      }
      else {
         return GL_INVALID_ENUM; /*target*/
      }
   }
   else if (dimensions == 3) {
      /* 3D compressed textures not allowed */
      return GL_INVALID_ENUM;
   }

   maxTextureSize = 1 << (maxLevels - 1);

   if (!is_compressed_format(ctx, internalFormat))
      return GL_INVALID_ENUM;

   if (_mesa_base_tex_format(ctx, internalFormat) < 0)
      return GL_INVALID_ENUM;

   if (border != 0)
      return GL_INVALID_VALUE;

   /*
    * XXX We should probably use the proxy texture error check function here.
    */
   if (width < 1 || width > maxTextureSize ||
       (!ctx->Extensions.ARB_texture_non_power_of_two && _mesa_bitcount(width) != 1))
      return GL_INVALID_VALUE;

   if ((height < 1 || height > maxTextureSize ||
       (!ctx->Extensions.ARB_texture_non_power_of_two && _mesa_bitcount(height) != 1))
       && dimensions > 1)
      return GL_INVALID_VALUE;

   if ((depth < 1 || depth > maxTextureSize ||
       (!ctx->Extensions.ARB_texture_non_power_of_two && _mesa_bitcount(depth) != 1))
       && dimensions > 2)
      return GL_INVALID_VALUE;

   /* For cube map, width must equal height */
   if (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB &&
       target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB && width != height)
      return GL_INVALID_VALUE;

   if (level < 0 || level >= maxLevels)
      return GL_INVALID_VALUE;

   expectedSize = ctx->Driver.CompressedTextureSize(ctx, width, height, depth,
                                                    internalFormat);
   if (expectedSize != imageSize)
      return GL_INVALID_VALUE;

   return GL_NO_ERROR;
}


/**
 * Error checking for glCompressedTexSubImage[123]D().
 * \warning  There are some bad assumptions here about the size of compressed
 *           texture tiles (multiple of 4) used to test the validity of the
 *           offset and size parameters.
 * \return error code or GL_NO_ERROR.
 */
static GLenum
compressed_subtexture_error_check(GLcontext *ctx, GLint dimensions,
                                  GLenum target, GLint level,
                                  GLint xoffset, GLint yoffset, GLint zoffset,
                                  GLsizei width, GLsizei height, GLsizei depth,
                                  GLenum format, GLsizei imageSize)
{
   GLint expectedSize, maxLevels = 0, maxTextureSize;
   (void) zoffset;

   if (dimensions == 1) {
      /* 1D compressed textures not allowed */
      return GL_INVALID_ENUM;
   }
   else if (dimensions == 2) {
      if (target == GL_PROXY_TEXTURE_2D) {
         maxLevels = ctx->Const.MaxTextureLevels;
      }
      else if (target == GL_TEXTURE_2D) {
         maxLevels = ctx->Const.MaxTextureLevels;
      }
      else if (target == GL_PROXY_TEXTURE_CUBE_MAP_ARB) {
         if (!ctx->Extensions.ARB_texture_cube_map)
            return GL_INVALID_ENUM; /*target*/
         maxLevels = ctx->Const.MaxCubeTextureLevels;
      }
      else if (target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB &&
               target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB) {
         if (!ctx->Extensions.ARB_texture_cube_map)
            return GL_INVALID_ENUM; /*target*/
         maxLevels = ctx->Const.MaxCubeTextureLevels;
      }
      else {
         return GL_INVALID_ENUM; /*target*/
      }
   }
   else if (dimensions == 3) {
      /* 3D compressed textures not allowed */
      return GL_INVALID_ENUM;
   }

   maxTextureSize = 1 << (maxLevels - 1);

   if (!is_compressed_format(ctx, format))
      return GL_INVALID_ENUM;

   if (width < 1 || width > maxTextureSize)
      return GL_INVALID_VALUE;

   if ((height < 1 || height > maxTextureSize)
       && dimensions > 1)
      return GL_INVALID_VALUE;

   if (level < 0 || level >= maxLevels)
      return GL_INVALID_VALUE;

   /* XXX these tests are specific to the compressed format.
    * this code should be generalized in some way.
    */
   if ((xoffset & 3) != 0 || (yoffset & 3) != 0)
      return GL_INVALID_VALUE;

   if ((width & 3) != 0 && width != 2 && width != 1)
      return GL_INVALID_VALUE;

   if ((height & 3) != 0 && height != 2 && height != 1)
      return GL_INVALID_VALUE;

   expectedSize = ctx->Driver.CompressedTextureSize(ctx, width, height, depth,
                                                    format);
   if (expectedSize != imageSize)
      return GL_INVALID_VALUE;

   return GL_NO_ERROR;
}



void GLAPIENTRY
_mesa_CompressedTexImage1DARB(GLenum target, GLint level,
                              GLenum internalFormat, GLsizei width,
                              GLint border, GLsizei imageSize,
                              const GLvoid *data)
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (target == GL_TEXTURE_1D) {
      /* non-proxy target */
      struct gl_texture_unit *texUnit;
      struct gl_texture_object *texObj;
      struct gl_texture_image *texImage;
      GLenum error = compressed_texture_error_check(ctx, 1, target, level,
                               internalFormat, width, 1, 1, border, imageSize);
      if (error) {
         _mesa_error(ctx, error, "glCompressedTexImage1D");
         return;
      }

      texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
      texObj = _mesa_select_tex_object(ctx, texUnit, target);
      texImage = _mesa_get_tex_image(ctx, texUnit, target, level);
      if (!texImage) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCompressedTexImage1D");
         return;
      }
      else if (texImage->Data) {
	 ctx->Driver.FreeTexImageData( ctx, texImage );
      }
      ASSERT(texImage->Data == NULL);

      _mesa_init_teximage_fields(ctx, target, texImage, width, 1, 1,
                                 border, internalFormat);

      ASSERT(ctx->Driver.CompressedTexImage1D);
      (*ctx->Driver.CompressedTexImage1D)(ctx, target, level,
                                          internalFormat, width, border,
                                          imageSize, data,
                                          texObj, texImage);

      /* state update */
      texObj->Complete = GL_FALSE;
      ctx->NewState |= _NEW_TEXTURE;
   }
   else if (target == GL_PROXY_TEXTURE_1D) {
      /* Proxy texture: check for errors and update proxy state */
      GLenum error = compressed_texture_error_check(ctx, 1, target, level,
                               internalFormat, width, 1, 1, border, imageSize);
      if (!error) {
         ASSERT(ctx->Driver.TestProxyTexImage);
         error = !(*ctx->Driver.TestProxyTexImage)(ctx, target, level,
                                             internalFormat, GL_NONE, GL_NONE,
                                             width, 1, 1, border);
      }
      if (error) {
         /* if error, clear all proxy texture image parameters */
         struct gl_texture_image *texImage;
         texImage = _mesa_get_proxy_tex_image(ctx, target, level);
         if (texImage)
            clear_teximage_fields(texImage);
      }
      else {
         /* store the teximage parameters */
         struct gl_texture_unit *texUnit;
         struct gl_texture_image *texImage;
         texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
         texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
         _mesa_init_teximage_fields(ctx, target, texImage, width, 1, 1,
                                    border, internalFormat);
      }
   }
   else {
      _mesa_error(ctx, GL_INVALID_ENUM, "glCompressedTexImage1D(target)");
      return;
   }
}


void GLAPIENTRY
_mesa_CompressedTexImage2DARB(GLenum target, GLint level,
                              GLenum internalFormat, GLsizei width,
                              GLsizei height, GLint border, GLsizei imageSize,
                              const GLvoid *data)
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (target == GL_TEXTURE_2D ||
       (ctx->Extensions.ARB_texture_cube_map &&
        target >= GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB &&
        target <= GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB)) {
      /* non-proxy target */
      struct gl_texture_unit *texUnit;
      struct gl_texture_object *texObj;
      struct gl_texture_image *texImage;
      GLenum error = compressed_texture_error_check(ctx, 2, target, level,
                          internalFormat, width, height, 1, border, imageSize);
      if (error) {
         _mesa_error(ctx, error, "glCompressedTexImage2D");
         return;
      }

      texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
      texObj = _mesa_select_tex_object(ctx, texUnit, target);
      texImage = _mesa_get_tex_image(ctx, texUnit, target, level);
      if (!texImage) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCompressedTexImage2D");
         return;
      }
      else if (texImage->Data) {
	 ctx->Driver.FreeTexImageData( ctx, texImage );
      }
      ASSERT(texImage->Data == NULL);

      _mesa_init_teximage_fields(ctx, target, texImage, width, height, 1,
                                 border, internalFormat);

      ASSERT(ctx->Driver.CompressedTexImage2D);
      (*ctx->Driver.CompressedTexImage2D)(ctx, target, level,
                                          internalFormat, width, height,
                                          border, imageSize, data,
                                          texObj, texImage);

      /* state update */
      texObj->Complete = GL_FALSE;
      ctx->NewState |= _NEW_TEXTURE;
   }
   else if (target == GL_PROXY_TEXTURE_2D ||
            (target == GL_PROXY_TEXTURE_CUBE_MAP_ARB &&
             ctx->Extensions.ARB_texture_cube_map)) {
      /* Proxy texture: check for errors and update proxy state */
      GLenum error = compressed_texture_error_check(ctx, 2, target, level,
                          internalFormat, width, height, 1, border, imageSize);
      if (!error) {
         ASSERT(ctx->Driver.TestProxyTexImage);
         error = !(*ctx->Driver.TestProxyTexImage)(ctx, target, level,
                                              internalFormat, GL_NONE, GL_NONE,
                                              width, height, 1, border);
      }
      if (error) {
         /* if error, clear all proxy texture image parameters */
         struct gl_texture_image *texImage;
         texImage = _mesa_get_proxy_tex_image(ctx, target, level);
         if (texImage)
            clear_teximage_fields(texImage);
      }
      else {
         /* store the teximage parameters */
         struct gl_texture_unit *texUnit;
         struct gl_texture_image *texImage;
         texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
         texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
         _mesa_init_teximage_fields(ctx, target, texImage, width, height, 1,
                                    border, internalFormat);
      }
   }
   else {
      _mesa_error(ctx, GL_INVALID_ENUM, "glCompressedTexImage2D(target)");
      return;
   }
}


void GLAPIENTRY
_mesa_CompressedTexImage3DARB(GLenum target, GLint level,
                              GLenum internalFormat, GLsizei width,
                              GLsizei height, GLsizei depth, GLint border,
                              GLsizei imageSize, const GLvoid *data)
{
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   if (target == GL_TEXTURE_3D) {
      /* non-proxy target */
      struct gl_texture_unit *texUnit;
      struct gl_texture_object *texObj;
      struct gl_texture_image *texImage;
      GLenum error = compressed_texture_error_check(ctx, 3, target, level,
                      internalFormat, width, height, depth, border, imageSize);
      if (error) {
         _mesa_error(ctx, error, "glCompressedTexImage3D");
         return;
      }

      texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
      texObj = _mesa_select_tex_object(ctx, texUnit, target);
      texImage = _mesa_get_tex_image(ctx, texUnit, target, level);
      if (!texImage) {
         _mesa_error(ctx, GL_OUT_OF_MEMORY, "glCompressedTexImage3D");
         return;
      }
      else if (texImage->Data) {
	 ctx->Driver.FreeTexImageData( ctx, texImage );
      }
      ASSERT(texImage->Data == NULL);

      _mesa_init_teximage_fields(ctx, target, texImage, width, height, depth,
                                 border, internalFormat);

      ASSERT(ctx->Driver.CompressedTexImage3D);
      (*ctx->Driver.CompressedTexImage3D)(ctx, target, level,
                                          internalFormat,
                                          width, height, depth,
                                          border, imageSize, data,
                                          texObj, texImage);

      /* state update */
      texObj->Complete = GL_FALSE;
      ctx->NewState |= _NEW_TEXTURE;
   }
   else if (target == GL_PROXY_TEXTURE_3D) {
      /* Proxy texture: check for errors and update proxy state */
      GLenum error = compressed_texture_error_check(ctx, 3, target, level,
                      internalFormat, width, height, depth, border, imageSize);
      if (!error) {
         ASSERT(ctx->Driver.TestProxyTexImage);
         error = !(*ctx->Driver.TestProxyTexImage)(ctx, target, level,
                                             internalFormat, GL_NONE, GL_NONE,
                                             width, height, depth, border);
      }
      if (error) {
         /* if error, clear all proxy texture image parameters */
         struct gl_texture_image *texImage;
         texImage = _mesa_get_proxy_tex_image(ctx, target, level);
         if (texImage)
            clear_teximage_fields(texImage);
      }
      else {
         /* store the teximage parameters */
         struct gl_texture_unit *texUnit;
         struct gl_texture_image *texImage;
         texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
         texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
         _mesa_init_teximage_fields(ctx, target, texImage, width, height,
                                    depth, border, internalFormat);
      }
   }
   else {
      _mesa_error(ctx, GL_INVALID_ENUM, "glCompressedTexImage3D(target)");
      return;
   }
}


void GLAPIENTRY
_mesa_CompressedTexSubImage1DARB(GLenum target, GLint level, GLint xoffset,
                                 GLsizei width, GLenum format,
                                 GLsizei imageSize, const GLvoid *data)
{
   struct gl_texture_unit *texUnit;
   struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;
   GLenum error;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   error = compressed_subtexture_error_check(ctx, 1, target, level,
                                xoffset, 0, 0, width, 1, 1, format, imageSize);
   if (error) {
      _mesa_error(ctx, error, "glCompressedTexSubImage1D");
      return;
   }

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   assert(texImage);

   if ((GLint) format != texImage->IntFormat) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glCompressedTexSubImage1D(format)");
      return;
   }

   if ((width == 1 || width == 2) && (GLuint) width != texImage->Width) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glCompressedTexSubImage1D(width)");
      return;
   }

   if (width == 0)
      return;  /* no-op, not an error */

   if (ctx->Driver.CompressedTexSubImage1D) {
      (*ctx->Driver.CompressedTexSubImage1D)(ctx, target, level,
                                             xoffset, width,
                                             format, imageSize, data,
                                             texObj, texImage);
   }
   ctx->NewState |= _NEW_TEXTURE;
}


void GLAPIENTRY
_mesa_CompressedTexSubImage2DARB(GLenum target, GLint level, GLint xoffset,
                                 GLint yoffset, GLsizei width, GLsizei height,
                                 GLenum format, GLsizei imageSize,
                                 const GLvoid *data)
{
   struct gl_texture_unit *texUnit;
   struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;
   GLenum error;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   error = compressed_subtexture_error_check(ctx, 2, target, level,
                     xoffset, yoffset, 0, width, height, 1, format, imageSize);
   if (error) {
      /* XXX proxy target? */
      _mesa_error(ctx, error, "glCompressedTexSubImage2D");
      return;
   }

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   assert(texImage);

   if ((GLint) format != texImage->IntFormat) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glCompressedTexSubImage2D(format)");
      return;
   }

   if (((width == 1 || width == 2) && (GLuint) width != texImage->Width) ||
       ((height == 1 || height == 2) && (GLuint) height != texImage->Height)) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glCompressedTexSubImage2D(size)");
      return;
   }

   if (width == 0 || height == 0)
      return;  /* no-op, not an error */

   if (ctx->Driver.CompressedTexSubImage2D) {
      (*ctx->Driver.CompressedTexSubImage2D)(ctx, target, level,
                                             xoffset, yoffset, width, height,
                                             format, imageSize, data,
                                             texObj, texImage);
   }
   ctx->NewState |= _NEW_TEXTURE;
}


void GLAPIENTRY
_mesa_CompressedTexSubImage3DARB(GLenum target, GLint level, GLint xoffset,
                                 GLint yoffset, GLint zoffset, GLsizei width,
                                 GLsizei height, GLsizei depth, GLenum format,
                                 GLsizei imageSize, const GLvoid *data)
{
   struct gl_texture_unit *texUnit;
   struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;
   GLenum error;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   error = compressed_subtexture_error_check(ctx, 3, target, level,
           xoffset, yoffset, zoffset, width, height, depth, format, imageSize);
   if (error) {
      _mesa_error(ctx, error, "glCompressedTexSubImage2D");
      return;
   }

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   assert(texImage);

   if ((GLint) format != texImage->IntFormat) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glCompressedTexSubImage3D(format)");
      return;
   }

   if (((width == 1 || width == 2) && (GLuint) width != texImage->Width) ||
       ((height == 1 || height == 2) && (GLuint) height != texImage->Height) ||
       ((depth == 1 || depth == 2) && (GLuint) depth != texImage->Depth)) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glCompressedTexSubImage3D(size)");
      return;
   }

   if (width == 0 || height == 0 || depth == 0)
      return;  /* no-op, not an error */

   if (ctx->Driver.CompressedTexSubImage3D) {
      (*ctx->Driver.CompressedTexSubImage3D)(ctx, target, level,
                                             xoffset, yoffset, zoffset,
                                             width, height, depth,
                                             format, imageSize, data,
                                             texObj, texImage);
   }
   ctx->NewState |= _NEW_TEXTURE;
}


void GLAPIENTRY
_mesa_GetCompressedTexImageARB(GLenum target, GLint level, GLvoid *img)
{
   const struct gl_texture_unit *texUnit;
   const struct gl_texture_object *texObj;
   struct gl_texture_image *texImage;
   GLint maxLevels;
   GET_CURRENT_CONTEXT(ctx);
   ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);

   texUnit = &ctx->Texture.Unit[ctx->Texture.CurrentUnit];
   texObj = _mesa_select_tex_object(ctx, texUnit, target);
   if (!texObj) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glGetCompressedTexImageARB");
      return;
   }

   maxLevels = _mesa_max_texture_levels(ctx, target);
   ASSERT(maxLevels > 0); /* 0 indicates bad target, caught above */

   if (level < 0 || level >= maxLevels) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glGetCompressedTexImageARB(level)");
      return;
   }

   if (is_proxy_target(target)) {
      _mesa_error(ctx, GL_INVALID_ENUM, "glGetCompressedTexImageARB(target)");
      return;
   }

   texImage = _mesa_select_tex_image(ctx, texUnit, target, level);
   if (!texImage) {
      /* probably invalid mipmap level */
      _mesa_error(ctx, GL_INVALID_VALUE, "glGetCompressedTexImageARB(level)");
      return;
   }

   if (!texImage->IsCompressed) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetCompressedTexImageARB");
      return;
   }

   /* this typically calls _mesa_get_compressed_teximage() */
   ctx->Driver.GetCompressedTexImage(ctx, target, level, img, texObj,texImage);
}