teximage.c

mesa-6.5-minigui源码

      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->_BaseFormat = 0;
   img->InternalFormat = 0;
   img->Border = 0;
   img->Width = 0;
   img->Height = 0;
   img->Depth = 0;
   img->RowStride = 0;
   img->ImageStride = 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->_BaseFormat = _mesa_base_tex_format( ctx, internalFormat );
   ASSERT(img->_BaseFormat > 0);
   img->InternalFormat = internalFormat;
   img->Border = border;
   img->Width = width;
   img->Height = height;
   img->Depth = depth;
   img->RowStride = width;
   img->ImageStride = width * height;
   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->WidthLog2 = logbase2(img->Width2);
   if (height == 1)  /* 1-D texture */
      img->HeightLog2 = 0;
   else
      img->HeightLog2 = logbase2(img->Height2);
   if (depth == 1)   /* 2-D texture */
      img->DepthLog2 = 0;
   else
      img->DepthLog2 = logbase2(img->Depth2);
   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(img->Width2) == 1) &&
       (height == 1 || _mesa_bitcount(img->Height2) == 1) &&
       (depth == 1 || _mesa_bitcount(img->Depth2) == 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;
   }
}