teximage.c

winNT技术操作系统,国外开放的原代码和LIUX一样

      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 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;