* return -1 for an invalid buffer.
*/
static gl_buffer_index
-read_buffer_enum_to_index(GLenum buffer)
+read_buffer_enum_to_index(const struct gl_context *ctx, GLenum buffer)
{
switch (buffer) {
case GL_FRONT:
return BUFFER_FRONT_LEFT;
case GL_BACK:
+ if (_mesa_is_gles(ctx)) {
+ /* In draw_buffer_enum_to_bitmask, when GLES contexts draw to
+ * GL_BACK with a single-buffered configuration, we actually end
+ * up drawing to the sole front buffer in our internal
+ * representation. For consistency, we must read from that
+ * front left buffer too.
+ */
+ if (!ctx->DrawBuffer->Visual.doubleBufferMode)
+ return BUFFER_FRONT_LEFT;
+ }
return BUFFER_BACK_LEFT;
case GL_RIGHT:
return BUFFER_FRONT_RIGHT;
return BUFFER_FRONT_LEFT;
case GL_AUX0:
return BUFFER_AUX0;
+ case GL_FRONT_AND_BACK:
+ return BUFFER_FRONT_LEFT;
case GL_AUX1:
case GL_AUX2:
case GL_AUX3:
if (buffer >= GL_COLOR_ATTACHMENT8 && buffer <= GL_COLOR_ATTACHMENT31)
return BUFFER_COUNT;
/* error */
- return -1;
+ return BUFFER_NONE;
}
}
* \param n number of outputs
* \param buffers array [n] of renderbuffer names. Unlike glDrawBuffer, the
* names cannot specify more than one buffer. For example,
- * GL_FRONT_AND_BACK is illegal.
+ * GL_FRONT_AND_BACK is illegal. The only exception is GL_BACK
+ * that is considered special and allowed as far as n is one
+ * since 4.5.
*/
static void
draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb,
/* complicated error checking... */
for (output = 0; output < n; output++) {
- /* Section 4.2 (Whole Framebuffer Operations) of the OpenGL 3.0
+ destMask[output] = draw_buffer_enum_to_bitmask(ctx, buffers[output]);
+
+ /* 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;
+ }
+
+ /* 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."
+ *
+ * And on 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 (_mesa_bitcount(destMask[output]) > 1) {
+ if (_mesa_is_winsys_fbo(fb) && ctx->Version >= 40 &&
+ buffers[output] == GL_BACK) {
+ if (n != 1) {
+ _mesa_error(ctx, GL_INVALID_OPERATION, "%s(with GL_BACK n must be 1)",
+ caller);
+ return;
+ }
+ } else {
+ _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:
*
- * "Each buffer listed in bufs must be BACK, NONE, or one of the values
- * from table 4.3 (NONE, COLOR_ATTACHMENTi)"
+ * "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) && buffers[output] != GL_NONE &&
- buffers[output] != GL_BACK &&
+ 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_ENUM, "glDrawBuffers(buffer)");
+ _mesa_error(ctx, GL_INVALID_OPERATION, "glDrawBuffers(buffer)");
return;
}
return;
}
- destMask[output] = draw_buffer_enum_to_bitmask(ctx, buffers[output]);
-
- /* 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;
- }
-
- /* 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_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_ENUM, "%s(invalid buffer %s)",
- caller, _mesa_enum_to_string(buffers[output]));
- return;
- }
-
/* From the OpenGL 3.0 specification, page 259:
* "If the GL is bound to the default framebuffer and DrawBuffers is
* supplied with a constant (other than NONE) that does not indicate
if (buffer == GL_NONE) {
/* This is legal--it means that no buffer should be bound for reading. */
- srcBuffer = -1;
+ srcBuffer = BUFFER_NONE;
}
else {
/* general case / window-system framebuffer */
if (_mesa_is_gles3(ctx) && !is_legal_es3_readbuffer_enum(buffer))
- srcBuffer = -1;
+ srcBuffer = BUFFER_NONE;
else
- srcBuffer = read_buffer_enum_to_index(buffer);
+ srcBuffer = read_buffer_enum_to_index(ctx, buffer);
- if (srcBuffer == -1) {
+ if (srcBuffer == BUFFER_NONE) {
_mesa_error(ctx, GL_INVALID_ENUM,
"%s(invalid buffer %s)", caller,
_mesa_enum_to_string(buffer));
projects / mesa.git / blobdiff