case GL_FRONT:
return BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_FRONT_RIGHT;
case GL_BACK:
- if (_mesa_is_gles3(ctx)) {
+ if (_mesa_is_gles(ctx)) {
/* Page 181 (page 192 of the PDF) in section 4.2.1 of the OpenGL
* ES 3.0.1 specification says:
*
*
* Since there is no stereo rendering in ES 3.0, only return the
* LEFT bits. This also satisfies the "n must be 1" requirement.
+ *
+ * We also do this for GLES 1 and 2 because those APIs have no
+ * concept of selecting the front and back buffer anyway and it's
+ * convenient to be able to maintain the magic behaviour of
+ * GL_BACK in that case.
*/
if (ctx->DrawBuffer->Visual.doubleBufferMode)
return BUFFER_BIT_BACK_LEFT;
return;
}
- /* From the OpenGL 3.0 specification, page 259:
+ /* From the OpenGL 4.0 specification, page 256:
* "For both the default framebuffer and framebuffer objects, the
* constants FRONT, BACK, LEFT, RIGHT, and FRONT_AND_BACK are not
* valid in the bufs array passed to DrawBuffers, and will result in
- * the error INVALID_OPERATION. This restriction is because these
+ * the error INVALID_ENUM. This restriction is because these
* constants may themselves refer to multiple buffers, as shown in
* table 4.4."
+ * Previous versions of the OpenGL specification say INVALID_OPERATION,
+ * but the Khronos conformance tests expect INVALID_ENUM.
*/
if (_mesa_bitcount(destMask[output]) > 1) {
- _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffersARB(buffer)");
+ _mesa_error(ctx, GL_INVALID_ENUM, "glDrawBuffersARB(buffer)");
return;
}