+ err = _mesa_error_check_format_and_type(ctx, format, type);
+ if (err != GL_NO_ERROR) {
+ _mesa_error(ctx, err, "glDrawPixels(invalid format %s and/or type %s)",
+ _mesa_enum_to_string(format),
+ _mesa_enum_to_string(type));
+ goto end;
+ }
+
+ /* do special format-related checks */
+ switch (format) {
+ case GL_STENCIL_INDEX:
+ case GL_DEPTH_COMPONENT:
+ case GL_DEPTH_STENCIL_EXT:
+ /* these buffers must exist */
+ if (!_mesa_dest_buffer_exists(ctx, format)) {
+ _mesa_error(ctx, GL_INVALID_OPERATION,
+ "glDrawPixels(missing dest buffer)");
+ goto end;
+ }
+ break;
+ case GL_COLOR_INDEX:
+ if (ctx->PixelMaps.ItoR.Size == 0 ||
+ ctx->PixelMaps.ItoG.Size == 0 ||
+ ctx->PixelMaps.ItoB.Size == 0) {
+ _mesa_error(ctx, GL_INVALID_OPERATION,
+ "glDrawPixels(drawing color index pixels into RGB buffer)");
+ goto end;
+ }
+ break;
+ default:
+ /* for color formats it's not an error if the destination color
+ * buffer doesn't exist.
+ */
+ break;
+ }
+
+ if (ctx->RasterDiscard) {