2 * Mesa 3-D graphics library
4 * Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
17 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
28 * glReadBuffer, DrawBuffer functions.
39 #include "util/bitscan.h"
46 * Return bitmask of BUFFER_BIT_* flags indicating which color buffers are
47 * available to the rendering context (for drawing or reading).
48 * This depends on the type of framebuffer. For window system framebuffers
49 * we look at the framebuffer's visual. But for user-create framebuffers we
50 * look at the number of supported color attachments.
51 * \param fb the framebuffer to draw to, or read from
52 * \return bitmask of BUFFER_BIT_* flags
55 supported_buffer_bitmask(const struct gl_context
*ctx
,
56 const struct gl_framebuffer
*fb
)
58 GLbitfield mask
= 0x0;
60 if (_mesa_is_user_fbo(fb
)) {
61 /* A user-created renderbuffer */
62 mask
= ((1 << ctx
->Const
.MaxColorAttachments
) - 1) << BUFFER_COLOR0
;
65 /* A window system framebuffer */
67 mask
= BUFFER_BIT_FRONT_LEFT
; /* always have this */
68 if (fb
->Visual
.stereoMode
) {
69 mask
|= BUFFER_BIT_FRONT_RIGHT
;
70 if (fb
->Visual
.doubleBufferMode
) {
71 mask
|= BUFFER_BIT_BACK_LEFT
| BUFFER_BIT_BACK_RIGHT
;
74 else if (fb
->Visual
.doubleBufferMode
) {
75 mask
|= BUFFER_BIT_BACK_LEFT
;
78 for (i
= 0; i
< fb
->Visual
.numAuxBuffers
; i
++) {
79 mask
|= (BUFFER_BIT_AUX0
<< i
);
88 * Helper routine used by glDrawBuffer and glDrawBuffersARB.
89 * Given a GLenum naming one or more color buffers (such as
90 * GL_FRONT_AND_BACK), return the corresponding bitmask of BUFFER_BIT_* flags.
93 draw_buffer_enum_to_bitmask(const struct gl_context
*ctx
, GLenum buffer
)
99 return BUFFER_BIT_FRONT_LEFT
| BUFFER_BIT_FRONT_RIGHT
;
101 if (_mesa_is_gles(ctx
)) {
102 /* Page 181 (page 192 of the PDF) in section 4.2.1 of the OpenGL
103 * ES 3.0.1 specification says:
105 * "When draw buffer zero is BACK, color values are written
106 * into the sole buffer for single-buffered contexts, or into
107 * the back buffer for double-buffered contexts."
109 * Since there is no stereo rendering in ES 3.0, only return the
110 * LEFT bits. This also satisfies the "n must be 1" requirement.
112 * We also do this for GLES 1 and 2 because those APIs have no
113 * concept of selecting the front and back buffer anyway and it's
114 * convenient to be able to maintain the magic behaviour of
115 * GL_BACK in that case.
117 if (ctx
->DrawBuffer
->Visual
.doubleBufferMode
)
118 return BUFFER_BIT_BACK_LEFT
;
119 return BUFFER_BIT_FRONT_LEFT
;
121 return BUFFER_BIT_BACK_LEFT
| BUFFER_BIT_BACK_RIGHT
;
123 return BUFFER_BIT_FRONT_RIGHT
| BUFFER_BIT_BACK_RIGHT
;
125 return BUFFER_BIT_FRONT_RIGHT
;
127 return BUFFER_BIT_BACK_RIGHT
;
129 return BUFFER_BIT_BACK_LEFT
;
130 case GL_FRONT_AND_BACK
:
131 return BUFFER_BIT_FRONT_LEFT
| BUFFER_BIT_BACK_LEFT
132 | BUFFER_BIT_FRONT_RIGHT
| BUFFER_BIT_BACK_RIGHT
;
134 return BUFFER_BIT_FRONT_LEFT
| BUFFER_BIT_BACK_LEFT
;
136 return BUFFER_BIT_FRONT_LEFT
;
138 return BUFFER_BIT_AUX0
;
142 return 1 << BUFFER_COUNT
; /* invalid, but not BAD_MASK */
143 case GL_COLOR_ATTACHMENT0_EXT
:
144 return BUFFER_BIT_COLOR0
;
145 case GL_COLOR_ATTACHMENT1_EXT
:
146 return BUFFER_BIT_COLOR1
;
147 case GL_COLOR_ATTACHMENT2_EXT
:
148 return BUFFER_BIT_COLOR2
;
149 case GL_COLOR_ATTACHMENT3_EXT
:
150 return BUFFER_BIT_COLOR3
;
151 case GL_COLOR_ATTACHMENT4_EXT
:
152 return BUFFER_BIT_COLOR4
;
153 case GL_COLOR_ATTACHMENT5_EXT
:
154 return BUFFER_BIT_COLOR5
;
155 case GL_COLOR_ATTACHMENT6_EXT
:
156 return BUFFER_BIT_COLOR6
;
157 case GL_COLOR_ATTACHMENT7_EXT
:
158 return BUFFER_BIT_COLOR7
;
160 /* not an error, but also not supported */
161 if (buffer
>= GL_COLOR_ATTACHMENT8
&& buffer
<= GL_COLOR_ATTACHMENT31
)
162 return 1 << BUFFER_COUNT
;
170 * Helper routine used by glReadBuffer.
171 * Given a GLenum naming a color buffer, return the index of the corresponding
172 * renderbuffer (a BUFFER_* value).
173 * return BUFFER_NONE for an invalid buffer.
175 static gl_buffer_index
176 read_buffer_enum_to_index(const struct gl_context
*ctx
, GLenum buffer
)
180 return BUFFER_FRONT_LEFT
;
182 if (_mesa_is_gles(ctx
)) {
183 /* In draw_buffer_enum_to_bitmask, when GLES contexts draw to
184 * GL_BACK with a single-buffered configuration, we actually end
185 * up drawing to the sole front buffer in our internal
186 * representation. For consistency, we must read from that
187 * front left buffer too.
189 if (!ctx
->DrawBuffer
->Visual
.doubleBufferMode
)
190 return BUFFER_FRONT_LEFT
;
192 return BUFFER_BACK_LEFT
;
194 return BUFFER_FRONT_RIGHT
;
196 return BUFFER_FRONT_RIGHT
;
198 return BUFFER_BACK_RIGHT
;
200 return BUFFER_BACK_LEFT
;
202 return BUFFER_FRONT_LEFT
;
204 return BUFFER_FRONT_LEFT
;
207 case GL_FRONT_AND_BACK
:
208 return BUFFER_FRONT_LEFT
;
212 return BUFFER_COUNT
; /* invalid, but not -1 */
213 case GL_COLOR_ATTACHMENT0_EXT
:
214 return BUFFER_COLOR0
;
215 case GL_COLOR_ATTACHMENT1_EXT
:
216 return BUFFER_COLOR1
;
217 case GL_COLOR_ATTACHMENT2_EXT
:
218 return BUFFER_COLOR2
;
219 case GL_COLOR_ATTACHMENT3_EXT
:
220 return BUFFER_COLOR3
;
221 case GL_COLOR_ATTACHMENT4_EXT
:
222 return BUFFER_COLOR4
;
223 case GL_COLOR_ATTACHMENT5_EXT
:
224 return BUFFER_COLOR5
;
225 case GL_COLOR_ATTACHMENT6_EXT
:
226 return BUFFER_COLOR6
;
227 case GL_COLOR_ATTACHMENT7_EXT
:
228 return BUFFER_COLOR7
;
230 /* not an error, but also not supported */
231 if (buffer
>= GL_COLOR_ATTACHMENT8
&& buffer
<= GL_COLOR_ATTACHMENT31
)
239 is_legal_es3_readbuffer_enum(GLenum buf
)
241 return buf
== GL_BACK
|| buf
== GL_NONE
||
242 (buf
>= GL_COLOR_ATTACHMENT0
&& buf
<= GL_COLOR_ATTACHMENT31
);
246 * Called by glDrawBuffer() and glNamedFramebufferDrawBuffer().
247 * Specify which renderbuffer(s) to draw into for the first color output.
248 * <buffer> can name zero, one, two or four renderbuffers!
249 * \sa _mesa_DrawBuffers
251 * \param buffer buffer token such as GL_LEFT or GL_FRONT_AND_BACK, etc.
253 * Note that the behaviour of this function depends on whether the
254 * current ctx->DrawBuffer is a window-system framebuffer or a user-created
255 * framebuffer object.
256 * In the former case, we update the per-context ctx->Color.DrawBuffer
257 * state var _and_ the FB's ColorDrawBuffer state.
258 * In the later case, we update the FB's ColorDrawBuffer state only.
260 * Furthermore, upon a MakeCurrent() or BindFramebuffer() call, if the
261 * new FB is a window system FB, we need to re-update the FB's
262 * ColorDrawBuffer state to match the context. This is handled in
263 * _mesa_update_framebuffer().
265 * See the GL_EXT_framebuffer_object spec for more info.
267 static ALWAYS_INLINE
void
268 draw_buffer(struct gl_context
*ctx
, struct gl_framebuffer
*fb
,
269 GLenum buffer
, const char *caller
, bool no_error
)
273 FLUSH_VERTICES(ctx
, 0);
275 if (MESA_VERBOSE
& VERBOSE_API
) {
276 _mesa_debug(ctx
, "%s %s\n", caller
, _mesa_enum_to_string(buffer
));
279 if (buffer
== GL_NONE
) {
283 const GLbitfield supportedMask
284 = supported_buffer_bitmask(ctx
, fb
);
285 destMask
= draw_buffer_enum_to_bitmask(ctx
, buffer
);
286 if (!no_error
&& destMask
== BAD_MASK
) {
287 /* totally bogus buffer */
288 _mesa_error(ctx
, GL_INVALID_ENUM
, "%s(invalid buffer %s)", caller
,
289 _mesa_enum_to_string(buffer
));
292 destMask
&= supportedMask
;
293 if (!no_error
&& destMask
== 0x0) {
294 /* none of the named color buffers exist! */
295 _mesa_error(ctx
, GL_INVALID_OPERATION
, "%s(invalid buffer %s)",
296 caller
, _mesa_enum_to_string(buffer
));
301 /* if we get here, there's no error so set new state */
302 const GLenum16 buffer16
= buffer
;
303 _mesa_drawbuffers(ctx
, fb
, 1, &buffer16
, &destMask
);
305 /* Call device driver function only if fb is the bound draw buffer */
306 if (fb
== ctx
->DrawBuffer
) {
307 if (ctx
->Driver
.DrawBuffer
)
308 ctx
->Driver
.DrawBuffer(ctx
, buffer
);
309 if (ctx
->Driver
.DrawBufferAllocate
)
310 ctx
->Driver
.DrawBufferAllocate(ctx
);
316 draw_buffer_error(struct gl_context
*ctx
, struct gl_framebuffer
*fb
,
317 GLenum buffer
, const char *caller
)
319 draw_buffer(ctx
, fb
, buffer
, caller
, false);
324 draw_buffer_no_error(struct gl_context
*ctx
, struct gl_framebuffer
*fb
,
325 GLenum buffer
, const char *caller
)
327 draw_buffer(ctx
, fb
, buffer
, caller
, true);
332 _mesa_DrawBuffer_no_error(GLenum buffer
)
334 GET_CURRENT_CONTEXT(ctx
);
335 draw_buffer_no_error(ctx
, ctx
->DrawBuffer
, buffer
, "glDrawBuffer");
340 _mesa_DrawBuffer(GLenum buffer
)
342 GET_CURRENT_CONTEXT(ctx
);
343 draw_buffer_error(ctx
, ctx
->DrawBuffer
, buffer
, "glDrawBuffer");
348 _mesa_NamedFramebufferDrawBuffer_no_error(GLuint framebuffer
, GLenum buf
)
350 GET_CURRENT_CONTEXT(ctx
);
351 struct gl_framebuffer
*fb
;
354 fb
= _mesa_lookup_framebuffer(ctx
, framebuffer
);
356 fb
= ctx
->WinSysDrawBuffer
;
359 draw_buffer_no_error(ctx
, fb
, buf
, "glNamedFramebufferDrawBuffer");
364 _mesa_NamedFramebufferDrawBuffer(GLuint framebuffer
, GLenum buf
)
366 GET_CURRENT_CONTEXT(ctx
);
367 struct gl_framebuffer
*fb
;
370 fb
= _mesa_lookup_framebuffer_err(ctx
, framebuffer
,
371 "glNamedFramebufferDrawBuffer");
376 fb
= ctx
->WinSysDrawBuffer
;
378 draw_buffer_error(ctx
, fb
, buf
, "glNamedFramebufferDrawBuffer");
383 * Called by glDrawBuffersARB() and glNamedFramebufferDrawBuffers() to specify
384 * the destination color renderbuffers for N fragment program color outputs.
385 * \sa _mesa_DrawBuffer
386 * \param n number of outputs
387 * \param buffers array [n] of renderbuffer names. Unlike glDrawBuffer, the
388 * names cannot specify more than one buffer. For example,
389 * GL_FRONT_AND_BACK is illegal. The only exception is GL_BACK
390 * that is considered special and allowed as far as n is one
393 static ALWAYS_INLINE
void
394 draw_buffers(struct gl_context
*ctx
, struct gl_framebuffer
*fb
, GLsizei n
,
395 const GLenum
*buffers
, const char *caller
, bool no_error
)
398 GLbitfield usedBufferMask
, supportedMask
;
399 GLbitfield destMask
[MAX_DRAW_BUFFERS
];
401 FLUSH_VERTICES(ctx
, 0);
404 /* Turns out n==0 is a valid input that should not produce an error.
405 * The remaining code below correctly handles the n==0 case.
407 * From the OpenGL 3.0 specification, page 258:
408 * "An INVALID_VALUE error is generated if n is greater than
412 _mesa_error(ctx
, GL_INVALID_VALUE
, "%s(n < 0)", caller
);
416 if (n
> (GLsizei
) ctx
->Const
.MaxDrawBuffers
) {
417 _mesa_error(ctx
, GL_INVALID_VALUE
,
418 "%s(n > maximum number of draw buffers)", caller
);
422 /* From the ES 3.0 specification, page 180:
423 * "If the GL is bound to the default framebuffer, then n must be 1
424 * and the constant must be BACK or NONE."
425 * (same restriction applies with GL_EXT_draw_buffers specification)
427 if (ctx
->API
== API_OPENGLES2
&& _mesa_is_winsys_fbo(fb
) &&
428 (n
!= 1 || (buffers
[0] != GL_NONE
&& buffers
[0] != GL_BACK
))) {
429 _mesa_error(ctx
, GL_INVALID_OPERATION
, "%s(invalid buffers)", caller
);
434 supportedMask
= supported_buffer_bitmask(ctx
, fb
);
435 usedBufferMask
= 0x0;
437 /* complicated error checking... */
438 for (output
= 0; output
< n
; output
++) {
439 destMask
[output
] = draw_buffer_enum_to_bitmask(ctx
, buffers
[output
]);
442 /* From the OpenGL 3.0 specification, page 258:
443 * "Each buffer listed in bufs must be one of the values from tables
444 * 4.5 or 4.6. Otherwise, an INVALID_ENUM error is generated.
446 if (destMask
[output
] == BAD_MASK
) {
447 _mesa_error(ctx
, GL_INVALID_ENUM
, "%s(invalid buffer %s)",
448 caller
, _mesa_enum_to_string(buffers
[output
]));
452 /* From the OpenGL 4.5 specification, page 493 (page 515 of the PDF)
453 * "An INVALID_ENUM error is generated if any value in bufs is FRONT,
454 * LEFT, RIGHT, or FRONT_AND_BACK . This restriction applies to both
455 * the default framebuffer and framebuffer objects, and exists because
456 * these constants may themselves refer to multiple buffers, as shown
459 * And on page 492 (page 514 of the PDF):
460 * "If the default framebuffer is affected, then each of the constants
461 * must be one of the values listed in table 17.6 or the special value
462 * BACK. When BACK is used, n must be 1 and color values are written
463 * into the left buffer for single-buffered contexts, or into the back
464 * left buffer for double-buffered contexts."
466 * Note "special value BACK". GL_BACK also refers to multiple buffers,
467 * but it is consider a special case here. This is a change on 4.5.
468 * For OpenGL 4.x we check that behaviour. For any previous version we
469 * keep considering it wrong (as INVALID_ENUM).
471 if (_mesa_bitcount(destMask
[output
]) > 1) {
472 if (_mesa_is_winsys_fbo(fb
) && ctx
->Version
>= 40 &&
473 buffers
[output
] == GL_BACK
) {
475 _mesa_error(ctx
, GL_INVALID_OPERATION
, "%s(with GL_BACK n must be 1)",
480 _mesa_error(ctx
, GL_INVALID_ENUM
, "%s(invalid buffer %s)",
481 caller
, _mesa_enum_to_string(buffers
[output
]));
486 /* Section 4.2 (Whole Framebuffer Operations) of the OpenGL ES 3.0
487 * specification says:
489 * "If the GL is bound to a draw framebuffer object, the ith
490 * buffer listed in bufs must be COLOR_ATTACHMENTi or NONE .
491 * Specifying a buffer out of order, BACK , or COLOR_ATTACHMENTm
492 * where m is greater than or equal to the value of MAX_-
493 * COLOR_ATTACHMENTS , will generate the error INVALID_OPERATION .
495 if (_mesa_is_gles3(ctx
) && _mesa_is_user_fbo(fb
) &&
496 buffers
[output
] != GL_NONE
&&
497 (buffers
[output
] < GL_COLOR_ATTACHMENT0
||
498 buffers
[output
] >= GL_COLOR_ATTACHMENT0
+ ctx
->Const
.MaxColorAttachments
)) {
499 _mesa_error(ctx
, GL_INVALID_OPERATION
, "glDrawBuffers(buffer)");
504 if (buffers
[output
] == GL_NONE
) {
505 destMask
[output
] = 0x0;
508 /* Page 259 (page 275 of the PDF) in section 4.2.1 of the OpenGL 3.0
509 * spec (20080923) says:
511 * "If the GL is bound to a framebuffer object and DrawBuffers is
512 * supplied with [...] COLOR_ATTACHMENTm where m is greater than
513 * or equal to the value of MAX_COLOR_ATTACHMENTS, then the error
514 * INVALID_OPERATION results."
516 if (!no_error
&& _mesa_is_user_fbo(fb
) && buffers
[output
] >=
517 GL_COLOR_ATTACHMENT0
+ ctx
->Const
.MaxDrawBuffers
) {
518 _mesa_error(ctx
, GL_INVALID_OPERATION
,
519 "%s(buffers[%d] >= maximum number of draw buffers)",
524 /* From the OpenGL 3.0 specification, page 259:
525 * "If the GL is bound to the default framebuffer and DrawBuffers is
526 * supplied with a constant (other than NONE) that does not indicate
527 * any of the color buffers allocated to the GL context by the window
528 * system, the error INVALID_OPERATION will be generated.
530 * If the GL is bound to a framebuffer object and DrawBuffers is
531 * supplied with a constant from table 4.6 [...] then the error
532 * INVALID_OPERATION results."
534 destMask
[output
] &= supportedMask
;
536 if (destMask
[output
] == 0) {
537 _mesa_error(ctx
, GL_INVALID_OPERATION
,
538 "%s(unsupported buffer %s)",
539 caller
, _mesa_enum_to_string(buffers
[output
]));
543 /* ES 3.0 is even more restrictive. From the ES 3.0 spec, page 180:
544 * "If the GL is bound to a framebuffer object, the ith buffer
545 * listed in bufs must be COLOR_ATTACHMENTi or NONE. [...]
546 * INVALID_OPERATION." (same restriction applies with
547 * GL_EXT_draw_buffers specification)
549 if (ctx
->API
== API_OPENGLES2
&& _mesa_is_user_fbo(fb
) &&
550 buffers
[output
] != GL_NONE
&&
551 buffers
[output
] != GL_COLOR_ATTACHMENT0
+ output
) {
552 _mesa_error(ctx
, GL_INVALID_OPERATION
,
553 "%s(unsupported buffer %s)",
554 caller
, _mesa_enum_to_string(buffers
[output
]));
558 /* From the OpenGL 3.0 specification, page 258:
559 * "Except for NONE, a buffer may not appear more than once in the
560 * array pointed to by bufs. Specifying a buffer more then once
561 * will result in the error INVALID_OPERATION."
563 if (destMask
[output
] & usedBufferMask
) {
564 _mesa_error(ctx
, GL_INVALID_OPERATION
,
565 "%s(duplicated buffer %s)",
566 caller
, _mesa_enum_to_string(buffers
[output
]));
572 usedBufferMask
|= destMask
[output
];
576 /* OK, if we get here, there were no errors so set the new state */
577 GLenum16 buffers16
[MAX_DRAW_BUFFERS
];
578 for (int i
= 0; i
< n
; i
++)
579 buffers16
[i
] = buffers
[i
];
581 _mesa_drawbuffers(ctx
, fb
, n
, buffers16
, destMask
);
584 * Call device driver function if fb is the bound draw buffer.
585 * Note that n can be equal to 0,
586 * in which case we don't want to reference buffers[0], which
589 if (fb
== ctx
->DrawBuffer
) {
590 if (ctx
->Driver
.DrawBuffer
)
591 ctx
->Driver
.DrawBuffer(ctx
, n
> 0 ? buffers
[0] : GL_NONE
);
592 if (ctx
->Driver
.DrawBufferAllocate
)
593 ctx
->Driver
.DrawBufferAllocate(ctx
);
599 draw_buffers_error(struct gl_context
*ctx
, struct gl_framebuffer
*fb
, GLsizei n
,
600 const GLenum
*buffers
, const char *caller
)
602 draw_buffers(ctx
, fb
, n
, buffers
, caller
, false);
607 draw_buffers_no_error(struct gl_context
*ctx
, struct gl_framebuffer
*fb
,
608 GLsizei n
, const GLenum
*buffers
, const char *caller
)
610 draw_buffers(ctx
, fb
, n
, buffers
, caller
, true);
615 _mesa_DrawBuffers_no_error(GLsizei n
, const GLenum
*buffers
)
617 GET_CURRENT_CONTEXT(ctx
);
618 draw_buffers_no_error(ctx
, ctx
->DrawBuffer
, n
, buffers
, "glDrawBuffers");
623 _mesa_DrawBuffers(GLsizei n
, const GLenum
*buffers
)
625 GET_CURRENT_CONTEXT(ctx
);
626 draw_buffers_error(ctx
, ctx
->DrawBuffer
, n
, buffers
, "glDrawBuffers");
631 _mesa_NamedFramebufferDrawBuffers_no_error(GLuint framebuffer
, GLsizei n
,
634 GET_CURRENT_CONTEXT(ctx
);
635 struct gl_framebuffer
*fb
;
638 fb
= _mesa_lookup_framebuffer(ctx
, framebuffer
);
640 fb
= ctx
->WinSysDrawBuffer
;
643 draw_buffers_no_error(ctx
, fb
, n
, bufs
, "glNamedFramebufferDrawBuffers");
648 _mesa_NamedFramebufferDrawBuffers(GLuint framebuffer
, GLsizei n
,
651 GET_CURRENT_CONTEXT(ctx
);
652 struct gl_framebuffer
*fb
;
655 fb
= _mesa_lookup_framebuffer_err(ctx
, framebuffer
,
656 "glNamedFramebufferDrawBuffers");
661 fb
= ctx
->WinSysDrawBuffer
;
663 draw_buffers_error(ctx
, fb
, n
, bufs
, "glNamedFramebufferDrawBuffers");
668 * Performs necessary state updates when _mesa_drawbuffers makes an
672 updated_drawbuffers(struct gl_context
*ctx
, struct gl_framebuffer
*fb
)
674 FLUSH_VERTICES(ctx
, _NEW_BUFFERS
);
676 if (ctx
->API
== API_OPENGL_COMPAT
&& !ctx
->Extensions
.ARB_ES2_compatibility
) {
677 /* Flag the FBO as requiring validation. */
678 if (_mesa_is_user_fbo(fb
)) {
686 * Helper function to set the GL_DRAW_BUFFER state for the given context and
687 * FBO. Called via glDrawBuffer(), glDrawBuffersARB()
689 * All error checking will have been done prior to calling this function
690 * so nothing should go wrong at this point.
692 * \param ctx current context
693 * \param fb the desired draw buffer
694 * \param n number of color outputs to set
695 * \param buffers array[n] of colorbuffer names, like GL_LEFT.
696 * \param destMask array[n] of BUFFER_BIT_* bitmasks which correspond to the
697 * colorbuffer names. (i.e. GL_FRONT_AND_BACK =>
698 * BUFFER_BIT_FRONT_LEFT | BUFFER_BIT_BACK_LEFT).
701 _mesa_drawbuffers(struct gl_context
*ctx
, struct gl_framebuffer
*fb
,
702 GLuint n
, const GLenum16
*buffers
,
703 const GLbitfield
*destMask
)
705 GLbitfield mask
[MAX_DRAW_BUFFERS
];
709 /* compute destMask values now */
710 const GLbitfield supportedMask
= supported_buffer_bitmask(ctx
, fb
);
712 for (output
= 0; output
< n
; output
++) {
713 mask
[output
] = draw_buffer_enum_to_bitmask(ctx
, buffers
[output
]);
714 assert(mask
[output
] != BAD_MASK
);
715 mask
[output
] &= supportedMask
;
721 * destMask[0] may have up to four bits set
722 * (ex: glDrawBuffer(GL_FRONT_AND_BACK)).
723 * Otherwise, destMask[x] can only have one bit set.
725 if (n
> 0 && _mesa_bitcount(destMask
[0]) > 1) {
726 GLuint count
= 0, destMask0
= destMask
[0];
728 const gl_buffer_index bufIndex
= u_bit_scan(&destMask0
);
729 if (fb
->_ColorDrawBufferIndexes
[count
] != bufIndex
) {
730 updated_drawbuffers(ctx
, fb
);
731 fb
->_ColorDrawBufferIndexes
[count
] = bufIndex
;
735 fb
->ColorDrawBuffer
[0] = buffers
[0];
736 fb
->_NumColorDrawBuffers
= count
;
740 for (buf
= 0; buf
< n
; buf
++ ) {
742 gl_buffer_index bufIndex
= ffs(destMask
[buf
]) - 1;
743 /* only one bit should be set in the destMask[buf] field */
744 assert(_mesa_bitcount(destMask
[buf
]) == 1);
745 if (fb
->_ColorDrawBufferIndexes
[buf
] != bufIndex
) {
746 updated_drawbuffers(ctx
, fb
);
747 fb
->_ColorDrawBufferIndexes
[buf
] = bufIndex
;
752 if (fb
->_ColorDrawBufferIndexes
[buf
] != BUFFER_NONE
) {
753 updated_drawbuffers(ctx
, fb
);
754 fb
->_ColorDrawBufferIndexes
[buf
] = BUFFER_NONE
;
757 fb
->ColorDrawBuffer
[buf
] = buffers
[buf
];
759 fb
->_NumColorDrawBuffers
= count
;
762 /* set remaining outputs to BUFFER_NONE */
763 for (buf
= fb
->_NumColorDrawBuffers
; buf
< ctx
->Const
.MaxDrawBuffers
; buf
++) {
764 if (fb
->_ColorDrawBufferIndexes
[buf
] != BUFFER_NONE
) {
765 updated_drawbuffers(ctx
, fb
);
766 fb
->_ColorDrawBufferIndexes
[buf
] = BUFFER_NONE
;
769 for (buf
= n
; buf
< ctx
->Const
.MaxDrawBuffers
; buf
++) {
770 fb
->ColorDrawBuffer
[buf
] = GL_NONE
;
773 if (_mesa_is_winsys_fbo(fb
)) {
774 /* also set context drawbuffer state */
775 for (buf
= 0; buf
< ctx
->Const
.MaxDrawBuffers
; buf
++) {
776 if (ctx
->Color
.DrawBuffer
[buf
] != fb
->ColorDrawBuffer
[buf
]) {
777 updated_drawbuffers(ctx
, fb
);
778 ctx
->Color
.DrawBuffer
[buf
] = fb
->ColorDrawBuffer
[buf
];
786 * Update the current drawbuffer's _ColorDrawBufferIndex[] list, etc.
787 * from the context's Color.DrawBuffer[] state.
788 * Use when changing contexts.
791 _mesa_update_draw_buffers(struct gl_context
*ctx
)
793 /* should be a window system FBO */
794 assert(_mesa_is_winsys_fbo(ctx
->DrawBuffer
));
796 _mesa_drawbuffers(ctx
, ctx
->DrawBuffer
, ctx
->Const
.MaxDrawBuffers
,
797 ctx
->Color
.DrawBuffer
, NULL
);
802 * Like \sa _mesa_drawbuffers(), this is a helper function for setting
803 * GL_READ_BUFFER state for the given context and FBO.
804 * Note that all error checking should have been done before calling
806 * \param ctx the rendering context
807 * \param fb the framebuffer object to update
808 * \param buffer GL_FRONT, GL_BACK, GL_COLOR_ATTACHMENT0, etc.
809 * \param bufferIndex the numerical index corresponding to 'buffer'
812 _mesa_readbuffer(struct gl_context
*ctx
, struct gl_framebuffer
*fb
,
813 GLenum buffer
, gl_buffer_index bufferIndex
)
815 if ((fb
== ctx
->ReadBuffer
) && _mesa_is_winsys_fbo(fb
)) {
816 /* Only update the per-context READ_BUFFER state if we're bound to
817 * a window-system framebuffer.
819 ctx
->Pixel
.ReadBuffer
= buffer
;
822 fb
->ColorReadBuffer
= buffer
;
823 fb
->_ColorReadBufferIndex
= bufferIndex
;
825 ctx
->NewState
|= _NEW_BUFFERS
;
831 * Called by glReadBuffer and glNamedFramebufferReadBuffer to set the source
832 * renderbuffer for reading pixels.
833 * \param mode color buffer such as GL_FRONT, GL_BACK, etc.
835 static ALWAYS_INLINE
void
836 read_buffer(struct gl_context
*ctx
, struct gl_framebuffer
*fb
,
837 GLenum buffer
, const char *caller
, bool no_error
)
839 gl_buffer_index srcBuffer
;
841 FLUSH_VERTICES(ctx
, 0);
843 if (MESA_VERBOSE
& VERBOSE_API
)
844 _mesa_debug(ctx
, "%s %s\n", caller
, _mesa_enum_to_string(buffer
));
846 if (buffer
== GL_NONE
) {
847 /* This is legal--it means that no buffer should be bound for reading. */
848 srcBuffer
= BUFFER_NONE
;
851 /* general case / window-system framebuffer */
852 if (!no_error
&&_mesa_is_gles3(ctx
) &&
853 !is_legal_es3_readbuffer_enum(buffer
))
854 srcBuffer
= BUFFER_NONE
;
856 srcBuffer
= read_buffer_enum_to_index(ctx
, buffer
);
859 GLbitfield supportedMask
;
861 if (srcBuffer
== BUFFER_NONE
) {
862 _mesa_error(ctx
, GL_INVALID_ENUM
,
863 "%s(invalid buffer %s)", caller
,
864 _mesa_enum_to_string(buffer
));
868 supportedMask
= supported_buffer_bitmask(ctx
, fb
);
869 if (((1 << srcBuffer
) & supportedMask
) == 0) {
870 _mesa_error(ctx
, GL_INVALID_OPERATION
,
871 "%s(invalid buffer %s)", caller
,
872 _mesa_enum_to_string(buffer
));
878 /* OK, all error checking has been completed now */
880 _mesa_readbuffer(ctx
, fb
, buffer
, srcBuffer
);
882 /* Call the device driver function only if fb is the bound read buffer */
883 if (fb
== ctx
->ReadBuffer
) {
884 if (ctx
->Driver
.ReadBuffer
)
885 ctx
->Driver
.ReadBuffer(ctx
, buffer
);
891 read_buffer_err(struct gl_context
*ctx
, struct gl_framebuffer
*fb
,
892 GLenum buffer
, const char *caller
)
894 read_buffer(ctx
, fb
, buffer
, caller
, false);
899 read_buffer_no_error(struct gl_context
*ctx
, struct gl_framebuffer
*fb
,
900 GLenum buffer
, const char *caller
)
902 read_buffer(ctx
, fb
, buffer
, caller
, true);
907 _mesa_ReadBuffer_no_error(GLenum buffer
)
909 GET_CURRENT_CONTEXT(ctx
);
910 read_buffer_no_error(ctx
, ctx
->ReadBuffer
, buffer
, "glReadBuffer");
915 _mesa_ReadBuffer(GLenum buffer
)
917 GET_CURRENT_CONTEXT(ctx
);
918 read_buffer_err(ctx
, ctx
->ReadBuffer
, buffer
, "glReadBuffer");
923 _mesa_NamedFramebufferReadBuffer_no_error(GLuint framebuffer
, GLenum src
)
925 GET_CURRENT_CONTEXT(ctx
);
927 struct gl_framebuffer
*fb
;
930 fb
= _mesa_lookup_framebuffer(ctx
, framebuffer
);
932 fb
= ctx
->WinSysReadBuffer
;
935 read_buffer_no_error(ctx
, fb
, src
, "glNamedFramebufferReadBuffer");
940 _mesa_NamedFramebufferReadBuffer(GLuint framebuffer
, GLenum src
)
942 GET_CURRENT_CONTEXT(ctx
);
943 struct gl_framebuffer
*fb
;
946 fb
= _mesa_lookup_framebuffer_err(ctx
, framebuffer
,
947 "glNamedFramebufferReadBuffer");
952 fb
= ctx
->WinSysReadBuffer
;
954 read_buffer_err(ctx
, fb
, src
, "glNamedFramebufferReadBuffer");