- /* Section 4.2 (Whole Framebuffer Operations) of the OpenGL 3.0
- * specification says:
- *
- * "Each buffer listed in bufs must be BACK, NONE, or one of the values
- * from table 4.3 (NONE, COLOR_ATTACHMENTi)"
- */
- if (_mesa_is_gles3(ctx) && buffers[output] != GL_NONE &&
- buffers[output] != GL_BACK &&
- (buffers[output] < GL_COLOR_ATTACHMENT0 ||
- buffers[output] >= GL_COLOR_ATTACHMENT0 + ctx->Const.MaxColorAttachments)) {
- _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffers(buffer)");
- return;
+ if (!no_error) {
+ /* From the OpenGL 4.5 specification, page 493 (page 515 of the PDF)
+ * "An INVALID_ENUM error is generated if any value in bufs is FRONT,
+ * LEFT, RIGHT, or FRONT_AND_BACK . This restriction applies to both
+ * the default framebuffer and framebuffer objects, and exists because
+ * these constants may themselves refer to multiple buffers, as shown
+ * in table 17.4."
+ *
+ * From the OpenGL 4.5 specification, page 492 (page 514 of the PDF):
+ * "If the default framebuffer is affected, then each of the constants
+ * must be one of the values listed in table 17.6 or the special value
+ * BACK. When BACK is used, n must be 1 and color values are written
+ * into the left buffer for single-buffered contexts, or into the back
+ * left buffer for double-buffered contexts."
+ *
+ * Note "special value BACK". GL_BACK also refers to multiple buffers,
+ * but it is consider a special case here. This is a change on 4.5.
+ * For OpenGL 4.x we check that behaviour. For any previous version we
+ * keep considering it wrong (as INVALID_ENUM).
+ */
+ if (buffers[output] == GL_BACK &&
+ _mesa_is_winsys_fbo(fb) &&
+ _mesa_is_desktop_gl(ctx) &&
+ ctx->Version >= 40) {
+ if (n != 1) {
+ _mesa_error(ctx, GL_INVALID_OPERATION, "%s(with GL_BACK n must be 1)",
+ caller);
+ return;
+ }
+ } else if (buffers[output] == GL_FRONT ||
+ buffers[output] == GL_LEFT ||
+ buffers[output] == GL_RIGHT ||
+ buffers[output] == GL_FRONT_AND_BACK ||
+ (buffers[output] == GL_BACK &&
+ _mesa_is_desktop_gl(ctx))) {
+ _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)",
+ caller, _mesa_enum_to_string(buffers[output]));
+ return;
+ }
+ }
+
+ destMask[output] = draw_buffer_enum_to_bitmask(ctx, buffers[output]);
+
+ if (!no_error) {
+ /* From the OpenGL 3.0 specification, page 258:
+ * "Each buffer listed in bufs must be one of the values from tables
+ * 4.5 or 4.6. Otherwise, an INVALID_ENUM error is generated.
+ */
+ if (destMask[output] == BAD_MASK) {
+ _mesa_error(ctx, GL_INVALID_ENUM, "%s(invalid buffer %s)",
+ caller, _mesa_enum_to_string(buffers[output]));
+ return;
+ }
+
+ /* Section 4.2 (Whole Framebuffer Operations) of the OpenGL ES 3.0
+ * specification says:
+ *
+ * "If the GL is bound to a draw framebuffer object, the ith
+ * buffer listed in bufs must be COLOR_ATTACHMENTi or NONE .
+ * Specifying a buffer out of order, BACK , or COLOR_ATTACHMENTm
+ * where m is greater than or equal to the value of MAX_-
+ * COLOR_ATTACHMENTS , will generate the error INVALID_OPERATION .
+ */
+ if (_mesa_is_gles3(ctx) && _mesa_is_user_fbo(fb) &&
+ buffers[output] != GL_NONE &&
+ (buffers[output] < GL_COLOR_ATTACHMENT0 ||
+ buffers[output] >= GL_COLOR_ATTACHMENT0 + ctx->Const.MaxColorAttachments)) {
+ _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffers(buffer)");
+ return;
+ }