1 /*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
5 *
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:
12 *
13 * The above copyright notice and this permission notice shall be included
14 * in all copies or substantial portions of the Software.
15 *
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.
23 */
24
25
26 /**
27 * Functions for allocating/managing framebuffers and renderbuffers.
28 * Also, routines for reading/writing renderbuffer data as ubytes,
29 * ushorts, uints, etc.
30 */
31
32 #include <stdio.h>
33 #include "glheader.h"
34 #include "imports.h"
35 #include "blend.h"
36 #include "buffers.h"
37 #include "context.h"
38 #include "enums.h"
39 #include "formats.h"
40 #include "macros.h"
41 #include "mtypes.h"
42 #include "fbobject.h"
43 #include "framebuffer.h"
44 #include "renderbuffer.h"
45 #include "texobj.h"
46 #include "glformats.h"
47 #include "state.h"
48
49
50
51 /**
52 * Compute/set the _DepthMax field for the given framebuffer.
53 * This value depends on the Z buffer resolution.
54 */
55 static void
compute_depth_max(struct gl_framebuffer * fb)56 compute_depth_max(struct gl_framebuffer *fb)
57 {
58 if (fb->Visual.depthBits == 0) {
59 /* Special case. Even if we don't have a depth buffer we need
60 * good values for DepthMax for Z vertex transformation purposes
61 * and for per-fragment fog computation.
62 */
63 fb->_DepthMax = (1 << 16) - 1;
64 }
65 else if (fb->Visual.depthBits < 32) {
66 fb->_DepthMax = (1 << fb->Visual.depthBits) - 1;
67 }
68 else {
69 /* Special case since shift values greater than or equal to the
70 * number of bits in the left hand expression's type are undefined.
71 */
72 fb->_DepthMax = 0xffffffff;
73 }
74 fb->_DepthMaxF = (GLfloat) fb->_DepthMax;
75
76 /* Minimum resolvable depth value, for polygon offset */
77 fb->_MRD = (GLfloat)1.0 / fb->_DepthMaxF;
78 }
79
80 /**
81 * Create and initialize a gl_framebuffer object.
82 * This is intended for creating _window_system_ framebuffers, not generic
83 * framebuffer objects ala GL_EXT_framebuffer_object.
84 *
85 * \sa _mesa_new_framebuffer
86 */
87 struct gl_framebuffer *
_mesa_create_framebuffer(const struct gl_config * visual)88 _mesa_create_framebuffer(const struct gl_config *visual)
89 {
90 struct gl_framebuffer *fb = CALLOC_STRUCT(gl_framebuffer);
91 assert(visual);
92 if (fb) {
93 _mesa_initialize_window_framebuffer(fb, visual);
94 }
95 return fb;
96 }
97
98
99 /**
100 * Allocate a new gl_framebuffer object.
101 * This is the default function for ctx->Driver.NewFramebuffer().
102 * This is for allocating user-created framebuffers, not window-system
103 * framebuffers!
104 * \sa _mesa_create_framebuffer
105 */
106 struct gl_framebuffer *
_mesa_new_framebuffer(struct gl_context * ctx,GLuint name)107 _mesa_new_framebuffer(struct gl_context *ctx, GLuint name)
108 {
109 struct gl_framebuffer *fb;
110 (void) ctx;
111 assert(name != 0);
112 fb = CALLOC_STRUCT(gl_framebuffer);
113 if (fb) {
114 _mesa_initialize_user_framebuffer(fb, name);
115 }
116 return fb;
117 }
118
119
120 /**
121 * Initialize a gl_framebuffer object. Typically used to initialize
122 * window system-created framebuffers, not user-created framebuffers.
123 * \sa _mesa_initialize_user_framebuffer
124 */
125 void
_mesa_initialize_window_framebuffer(struct gl_framebuffer * fb,const struct gl_config * visual)126 _mesa_initialize_window_framebuffer(struct gl_framebuffer *fb,
127 const struct gl_config *visual)
128 {
129 assert(fb);
130 assert(visual);
131
132 memset(fb, 0, sizeof(struct gl_framebuffer));
133
134 simple_mtx_init(&fb->Mutex, mtx_plain);
135
136 fb->RefCount = 1;
137
138 /* save the visual */
139 fb->Visual = *visual;
140
141 /* Init read/draw renderbuffer state */
142 if (visual->doubleBufferMode) {
143 fb->_NumColorDrawBuffers = 1;
144 fb->ColorDrawBuffer[0] = GL_BACK;
145 fb->_ColorDrawBufferIndexes[0] = BUFFER_BACK_LEFT;
146 fb->ColorReadBuffer = GL_BACK;
147 fb->_ColorReadBufferIndex = BUFFER_BACK_LEFT;
148 }
149 else {
150 fb->_NumColorDrawBuffers = 1;
151 fb->ColorDrawBuffer[0] = GL_FRONT;
152 fb->_ColorDrawBufferIndexes[0] = BUFFER_FRONT_LEFT;
153 fb->ColorReadBuffer = GL_FRONT;
154 fb->_ColorReadBufferIndex = BUFFER_FRONT_LEFT;
155 }
156
157 fb->Delete = _mesa_destroy_framebuffer;
158 fb->_Status = GL_FRAMEBUFFER_COMPLETE_EXT;
159 fb->_AllColorBuffersFixedPoint = !visual->floatMode;
160 fb->_HasSNormOrFloatColorBuffer = visual->floatMode;
161 fb->_HasAttachments = true;
162
163 compute_depth_max(fb);
164 }
165
166
167 /**
168 * Initialize a user-created gl_framebuffer object.
169 * \sa _mesa_initialize_window_framebuffer
170 */
171 void
_mesa_initialize_user_framebuffer(struct gl_framebuffer * fb,GLuint name)172 _mesa_initialize_user_framebuffer(struct gl_framebuffer *fb, GLuint name)
173 {
174 assert(fb);
175 assert(name);
176
177 memset(fb, 0, sizeof(struct gl_framebuffer));
178
179 fb->Name = name;
180 fb->RefCount = 1;
181 fb->_NumColorDrawBuffers = 1;
182 fb->ColorDrawBuffer[0] = GL_COLOR_ATTACHMENT0_EXT;
183 fb->_ColorDrawBufferIndexes[0] = BUFFER_COLOR0;
184 fb->ColorReadBuffer = GL_COLOR_ATTACHMENT0_EXT;
185 fb->_ColorReadBufferIndex = BUFFER_COLOR0;
186 fb->Delete = _mesa_destroy_framebuffer;
187 simple_mtx_init(&fb->Mutex, mtx_plain);
188 }
189
190
191 /**
192 * Deallocate buffer and everything attached to it.
193 * Typically called via the gl_framebuffer->Delete() method.
194 */
195 void
_mesa_destroy_framebuffer(struct gl_framebuffer * fb)196 _mesa_destroy_framebuffer(struct gl_framebuffer *fb)
197 {
198 if (fb) {
199 _mesa_free_framebuffer_data(fb);
200 free(fb->Label);
201 free(fb);
202 }
203 }
204
205
206 /**
207 * Free all the data hanging off the given gl_framebuffer, but don't free
208 * the gl_framebuffer object itself.
209 */
210 void
_mesa_free_framebuffer_data(struct gl_framebuffer * fb)211 _mesa_free_framebuffer_data(struct gl_framebuffer *fb)
212 {
213 GLuint i;
214
215 assert(fb);
216 assert(fb->RefCount == 0);
217
218 simple_mtx_destroy(&fb->Mutex);
219
220 for (i = 0; i < BUFFER_COUNT; i++) {
221 struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
222 if (att->Renderbuffer) {
223 _mesa_reference_renderbuffer(&att->Renderbuffer, NULL);
224 }
225 if (att->Texture) {
226 _mesa_reference_texobj(&att->Texture, NULL);
227 }
228 assert(!att->Renderbuffer);
229 assert(!att->Texture);
230 att->Type = GL_NONE;
231 }
232 }
233
234
235 /**
236 * Set *ptr to point to fb, with refcounting and locking.
237 * This is normally only called from the _mesa_reference_framebuffer() macro
238 * when there's a real pointer change.
239 */
240 void
_mesa_reference_framebuffer_(struct gl_framebuffer ** ptr,struct gl_framebuffer * fb)241 _mesa_reference_framebuffer_(struct gl_framebuffer **ptr,
242 struct gl_framebuffer *fb)
243 {
244 if (*ptr) {
245 /* unreference old renderbuffer */
246 GLboolean deleteFlag = GL_FALSE;
247 struct gl_framebuffer *oldFb = *ptr;
248
249 simple_mtx_lock(&oldFb->Mutex);
250 assert(oldFb->RefCount > 0);
251 oldFb->RefCount--;
252 deleteFlag = (oldFb->RefCount == 0);
253 simple_mtx_unlock(&oldFb->Mutex);
254
255 if (deleteFlag)
256 oldFb->Delete(oldFb);
257
258 *ptr = NULL;
259 }
260
261 if (fb) {
262 simple_mtx_lock(&fb->Mutex);
263 fb->RefCount++;
264 simple_mtx_unlock(&fb->Mutex);
265 *ptr = fb;
266 }
267 }
268
269
270 /**
271 * Resize the given framebuffer's renderbuffers to the new width and height.
272 * This should only be used for window-system framebuffers, not
273 * user-created renderbuffers (i.e. made with GL_EXT_framebuffer_object).
274 * This will typically be called directly from a device driver.
275 *
276 * \note it's possible for ctx to be null since a window can be resized
277 * without a currently bound rendering context.
278 */
279 void
_mesa_resize_framebuffer(struct gl_context * ctx,struct gl_framebuffer * fb,GLuint width,GLuint height)280 _mesa_resize_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
281 GLuint width, GLuint height)
282 {
283 GLuint i;
284
285 /* XXX I think we could check if the size is not changing
286 * and return early.
287 */
288
289 /* Can only resize win-sys framebuffer objects */
290 assert(_mesa_is_winsys_fbo(fb));
291
292 for (i = 0; i < BUFFER_COUNT; i++) {
293 struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
294 if (att->Type == GL_RENDERBUFFER_EXT && att->Renderbuffer) {
295 struct gl_renderbuffer *rb = att->Renderbuffer;
296 /* only resize if size is changing */
297 if (rb->Width != width || rb->Height != height) {
298 if (rb->AllocStorage(ctx, rb, rb->InternalFormat, width, height)) {
299 assert(rb->Width == width);
300 assert(rb->Height == height);
301 }
302 else {
303 _mesa_error(ctx, GL_OUT_OF_MEMORY, "Resizing framebuffer");
304 /* no return */
305 }
306 }
307 }
308 }
309
310 fb->Width = width;
311 fb->Height = height;
312
313 if (ctx) {
314 /* update scissor / window bounds */
315 _mesa_update_draw_buffer_bounds(ctx, ctx->DrawBuffer);
316 /* Signal new buffer state so that swrast will update its clipping
317 * info (the CLIP_BIT flag).
318 */
319 ctx->NewState |= _NEW_BUFFERS;
320 }
321 }
322
323 /**
324 * Given a bounding box, intersect the bounding box with the scissor of
325 * a specified vieport.
326 *
327 * \param ctx GL context.
328 * \param idx Index of the desired viewport
329 * \param bbox Bounding box for the scissored viewport. Stored as xmin,
330 * xmax, ymin, ymax.
331 */
332 void
_mesa_intersect_scissor_bounding_box(const struct gl_context * ctx,unsigned idx,int * bbox)333 _mesa_intersect_scissor_bounding_box(const struct gl_context *ctx,
334 unsigned idx, int *bbox)
335 {
336 if (ctx->Scissor.EnableFlags & (1u << idx)) {
337 if (ctx->Scissor.ScissorArray[idx].X > bbox[0]) {
338 bbox[0] = ctx->Scissor.ScissorArray[idx].X;
339 }
340 if (ctx->Scissor.ScissorArray[idx].Y > bbox[2]) {
341 bbox[2] = ctx->Scissor.ScissorArray[idx].Y;
342 }
343 if (ctx->Scissor.ScissorArray[idx].X + ctx->Scissor.ScissorArray[idx].Width < bbox[1]) {
344 bbox[1] = ctx->Scissor.ScissorArray[idx].X + ctx->Scissor.ScissorArray[idx].Width;
345 }
346 if (ctx->Scissor.ScissorArray[idx].Y + ctx->Scissor.ScissorArray[idx].Height < bbox[3]) {
347 bbox[3] = ctx->Scissor.ScissorArray[idx].Y + ctx->Scissor.ScissorArray[idx].Height;
348 }
349 /* finally, check for empty region */
350 if (bbox[0] > bbox[1]) {
351 bbox[0] = bbox[1];
352 }
353 if (bbox[2] > bbox[3]) {
354 bbox[2] = bbox[3];
355 }
356 }
357 }
358
359 /**
360 * Calculate the inclusive bounding box for the scissor of a specific viewport
361 *
362 * \param ctx GL context.
363 * \param buffer Framebuffer to be checked against
364 * \param idx Index of the desired viewport
365 * \param bbox Bounding box for the scissored viewport. Stored as xmin,
366 * xmax, ymin, ymax.
367 *
368 * \warning This function assumes that the framebuffer dimensions are up to
369 * date.
370 *
371 * \sa _mesa_clip_to_region
372 */
373 static void
scissor_bounding_box(const struct gl_context * ctx,const struct gl_framebuffer * buffer,unsigned idx,int * bbox)374 scissor_bounding_box(const struct gl_context *ctx,
375 const struct gl_framebuffer *buffer,
376 unsigned idx, int *bbox)
377 {
378 bbox[0] = 0;
379 bbox[2] = 0;
380 bbox[1] = buffer->Width;
381 bbox[3] = buffer->Height;
382
383 _mesa_intersect_scissor_bounding_box(ctx, idx, bbox);
384
385 assert(bbox[0] <= bbox[1]);
386 assert(bbox[2] <= bbox[3]);
387 }
388
389 /**
390 * Update the context's current drawing buffer's Xmin, Xmax, Ymin, Ymax fields.
391 * These values are computed from the buffer's width and height and
392 * the scissor box, if it's enabled.
393 * \param ctx the GL context.
394 */
395 void
_mesa_update_draw_buffer_bounds(struct gl_context * ctx,struct gl_framebuffer * buffer)396 _mesa_update_draw_buffer_bounds(struct gl_context *ctx,
397 struct gl_framebuffer *buffer)
398 {
399 int bbox[4];
400
401 if (!buffer)
402 return;
403
404 /* Default to the first scissor as that's always valid */
405 scissor_bounding_box(ctx, buffer, 0, bbox);
406 buffer->_Xmin = bbox[0];
407 buffer->_Ymin = bbox[2];
408 buffer->_Xmax = bbox[1];
409 buffer->_Ymax = bbox[3];
410 }
411
412
413 /**
414 * The glGet queries of the framebuffer red/green/blue size, stencil size,
415 * etc. are satisfied by the fields of ctx->DrawBuffer->Visual. These can
416 * change depending on the renderbuffer bindings. This function updates
417 * the given framebuffer's Visual from the current renderbuffer bindings.
418 *
419 * This may apply to user-created framebuffers or window system framebuffers.
420 *
421 * Also note: ctx->DrawBuffer->Visual.depthBits might not equal
422 * ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer.DepthBits.
423 * The former one is used to convert floating point depth values into
424 * integer Z values.
425 */
426 void
_mesa_update_framebuffer_visual(struct gl_context * ctx,struct gl_framebuffer * fb)427 _mesa_update_framebuffer_visual(struct gl_context *ctx,
428 struct gl_framebuffer *fb)
429 {
430 GLuint i;
431
432 memset(&fb->Visual, 0, sizeof(fb->Visual));
433 fb->Visual.rgbMode = GL_TRUE; /* assume this */
434
435 /* find first RGB renderbuffer */
436 for (i = 0; i < BUFFER_COUNT; i++) {
437 if (fb->Attachment[i].Renderbuffer) {
438 const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
439 const GLenum baseFormat = _mesa_get_format_base_format(rb->Format);
440 const mesa_format fmt = rb->Format;
441
442 /* Grab samples and sampleBuffers from any attachment point (assuming
443 * the framebuffer is complete, we'll get the same answer from all
444 * attachments).
445 */
446 fb->Visual.samples = rb->NumSamples;
447 fb->Visual.sampleBuffers = rb->NumSamples > 0 ? 1 : 0;
448
449 if (_mesa_is_legal_color_format(ctx, baseFormat)) {
450 fb->Visual.redBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
451 fb->Visual.greenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
452 fb->Visual.blueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
453 fb->Visual.alphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
454 fb->Visual.rgbBits = fb->Visual.redBits
455 + fb->Visual.greenBits + fb->Visual.blueBits;
456 if (_mesa_get_format_color_encoding(fmt) == GL_SRGB)
457 fb->Visual.sRGBCapable = ctx->Extensions.EXT_framebuffer_sRGB;
458 break;
459 }
460 }
461 }
462
463 fb->Visual.floatMode = GL_FALSE;
464 for (i = 0; i < BUFFER_COUNT; i++) {
465 if (fb->Attachment[i].Renderbuffer) {
466 const struct gl_renderbuffer *rb = fb->Attachment[i].Renderbuffer;
467 const mesa_format fmt = rb->Format;
468
469 if (_mesa_get_format_datatype(fmt) == GL_FLOAT) {
470 fb->Visual.floatMode = GL_TRUE;
471 break;
472 }
473 }
474 }
475
476 if (fb->Attachment[BUFFER_DEPTH].Renderbuffer) {
477 const struct gl_renderbuffer *rb =
478 fb->Attachment[BUFFER_DEPTH].Renderbuffer;
479 const mesa_format fmt = rb->Format;
480 fb->Visual.haveDepthBuffer = GL_TRUE;
481 fb->Visual.depthBits = _mesa_get_format_bits(fmt, GL_DEPTH_BITS);
482 }
483
484 if (fb->Attachment[BUFFER_STENCIL].Renderbuffer) {
485 const struct gl_renderbuffer *rb =
486 fb->Attachment[BUFFER_STENCIL].Renderbuffer;
487 const mesa_format fmt = rb->Format;
488 fb->Visual.haveStencilBuffer = GL_TRUE;
489 fb->Visual.stencilBits = _mesa_get_format_bits(fmt, GL_STENCIL_BITS);
490 }
491
492 if (fb->Attachment[BUFFER_ACCUM].Renderbuffer) {
493 const struct gl_renderbuffer *rb =
494 fb->Attachment[BUFFER_ACCUM].Renderbuffer;
495 const mesa_format fmt = rb->Format;
496 fb->Visual.haveAccumBuffer = GL_TRUE;
497 fb->Visual.accumRedBits = _mesa_get_format_bits(fmt, GL_RED_BITS);
498 fb->Visual.accumGreenBits = _mesa_get_format_bits(fmt, GL_GREEN_BITS);
499 fb->Visual.accumBlueBits = _mesa_get_format_bits(fmt, GL_BLUE_BITS);
500 fb->Visual.accumAlphaBits = _mesa_get_format_bits(fmt, GL_ALPHA_BITS);
501 }
502
503 compute_depth_max(fb);
504 }
505
506
507 /*
508 * Example DrawBuffers scenarios:
509 *
510 * 1. glDrawBuffer(GL_FRONT_AND_BACK), fixed-func or shader writes to
511 * "gl_FragColor" or program writes to the "result.color" register:
512 *
513 * fragment color output renderbuffer
514 * --------------------- ---------------
515 * color[0] Front, Back
516 *
517 *
518 * 2. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]), shader writes to
519 * gl_FragData[i] or program writes to result.color[i] registers:
520 *
521 * fragment color output renderbuffer
522 * --------------------- ---------------
523 * color[0] Front
524 * color[1] Aux0
525 * color[3] Aux1
526 *
527 *
528 * 3. glDrawBuffers(3, [GL_FRONT, GL_AUX0, GL_AUX1]) and shader writes to
529 * gl_FragColor, or fixed function:
530 *
531 * fragment color output renderbuffer
532 * --------------------- ---------------
533 * color[0] Front, Aux0, Aux1
534 *
535 *
536 * In either case, the list of renderbuffers is stored in the
537 * framebuffer->_ColorDrawBuffers[] array and
538 * framebuffer->_NumColorDrawBuffers indicates the number of buffers.
539 * The renderer (like swrast) has to look at the current fragment shader
540 * to see if it writes to gl_FragColor vs. gl_FragData[i] to determine
541 * how to map color outputs to renderbuffers.
542 *
543 * Note that these two calls are equivalent (for fixed function fragment
544 * shading anyway):
545 * a) glDrawBuffer(GL_FRONT_AND_BACK); (assuming non-stereo framebuffer)
546 * b) glDrawBuffers(2, [GL_FRONT_LEFT, GL_BACK_LEFT]);
547 */
548
549
550
551
552 /**
553 * Update the (derived) list of color drawing renderbuffer pointers.
554 * Later, when we're rendering we'll loop from 0 to _NumColorDrawBuffers
555 * writing colors.
556 */
557 static void
update_color_draw_buffers(struct gl_context * ctx,struct gl_framebuffer * fb)558 update_color_draw_buffers(struct gl_context *ctx, struct gl_framebuffer *fb)
559 {
560 GLuint output;
561
562 /* set 0th buffer to NULL now in case _NumColorDrawBuffers is zero */
563 fb->_ColorDrawBuffers[0] = NULL;
564
565 for (output = 0; output < fb->_NumColorDrawBuffers; output++) {
566 gl_buffer_index buf = fb->_ColorDrawBufferIndexes[output];
567 if (buf != BUFFER_NONE) {
568 fb->_ColorDrawBuffers[output] = fb->Attachment[buf].Renderbuffer;
569 }
570 else {
571 fb->_ColorDrawBuffers[output] = NULL;
572 }
573 }
574 }
575
576
577 /**
578 * Update the (derived) color read renderbuffer pointer.
579 * Unlike the DrawBuffer, we can only read from one (or zero) color buffers.
580 */
581 static void
update_color_read_buffer(struct gl_context * ctx,struct gl_framebuffer * fb)582 update_color_read_buffer(struct gl_context *ctx, struct gl_framebuffer *fb)
583 {
584 (void) ctx;
585 if (fb->_ColorReadBufferIndex == BUFFER_NONE ||
586 fb->DeletePending ||
587 fb->Width == 0 ||
588 fb->Height == 0) {
589 fb->_ColorReadBuffer = NULL; /* legal! */
590 }
591 else {
592 assert(fb->_ColorReadBufferIndex >= 0);
593 assert(fb->_ColorReadBufferIndex < BUFFER_COUNT);
594 fb->_ColorReadBuffer
595 = fb->Attachment[fb->_ColorReadBufferIndex].Renderbuffer;
596 }
597 }
598
599
600 /**
601 * Update a gl_framebuffer's derived state.
602 *
603 * Specifically, update these framebuffer fields:
604 * _ColorDrawBuffers
605 * _NumColorDrawBuffers
606 * _ColorReadBuffer
607 *
608 * If the framebuffer is user-created, make sure it's complete.
609 *
610 * The following functions (at least) can effect framebuffer state:
611 * glReadBuffer, glDrawBuffer, glDrawBuffersARB, glFramebufferRenderbufferEXT,
612 * glRenderbufferStorageEXT.
613 */
614 static void
update_framebuffer(struct gl_context * ctx,struct gl_framebuffer * fb)615 update_framebuffer(struct gl_context *ctx, struct gl_framebuffer *fb)
616 {
617 if (_mesa_is_winsys_fbo(fb)) {
618 /* This is a window-system framebuffer */
619 /* Need to update the FB's GL_DRAW_BUFFER state to match the
620 * context state (GL_READ_BUFFER too).
621 */
622 if (fb->ColorDrawBuffer[0] != ctx->Color.DrawBuffer[0]) {
623 _mesa_drawbuffers(ctx, fb, ctx->Const.MaxDrawBuffers,
624 ctx->Color.DrawBuffer, NULL);
625 }
626 }
627 else {
628 /* This is a user-created framebuffer.
629 * Completeness only matters for user-created framebuffers.
630 */
631 if (fb->_Status != GL_FRAMEBUFFER_COMPLETE) {
632 _mesa_test_framebuffer_completeness(ctx, fb);
633 }
634 }
635
636 /* Strictly speaking, we don't need to update the draw-state
637 * if this FB is bound as ctx->ReadBuffer (and conversely, the
638 * read-state if this FB is bound as ctx->DrawBuffer), but no
639 * harm.
640 */
641 update_color_draw_buffers(ctx, fb);
642 update_color_read_buffer(ctx, fb);
643
644 compute_depth_max(fb);
645 }
646
647
648 /**
649 * Update state related to the draw/read framebuffers.
650 */
651 void
_mesa_update_framebuffer(struct gl_context * ctx,struct gl_framebuffer * readFb,struct gl_framebuffer * drawFb)652 _mesa_update_framebuffer(struct gl_context *ctx,
653 struct gl_framebuffer *readFb,
654 struct gl_framebuffer *drawFb)
655 {
656 assert(ctx);
657
658 update_framebuffer(ctx, drawFb);
659 if (readFb != drawFb)
660 update_framebuffer(ctx, readFb);
661
662 _mesa_update_clamp_vertex_color(ctx, drawFb);
663 _mesa_update_clamp_fragment_color(ctx, drawFb);
664 }
665
666
667 /**
668 * Check if the renderbuffer for a read/draw operation exists.
669 * \param format a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
670 * GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
671 * \param reading if TRUE, we're going to read from the buffer,
672 if FALSE, we're going to write to the buffer.
673 * \return GL_TRUE if buffer exists, GL_FALSE otherwise
674 */
675 static GLboolean
renderbuffer_exists(struct gl_context * ctx,struct gl_framebuffer * fb,GLenum format,GLboolean reading)676 renderbuffer_exists(struct gl_context *ctx,
677 struct gl_framebuffer *fb,
678 GLenum format,
679 GLboolean reading)
680 {
681 const struct gl_renderbuffer_attachment *att = fb->Attachment;
682
683 /* If we don't know the framebuffer status, update it now */
684 if (fb->_Status == 0) {
685 _mesa_test_framebuffer_completeness(ctx, fb);
686 }
687
688 if (fb->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
689 return GL_FALSE;
690 }
691
692 switch (format) {
693 case GL_COLOR:
694 case GL_RED:
695 case GL_GREEN:
696 case GL_BLUE:
697 case GL_ALPHA:
698 case GL_LUMINANCE:
699 case GL_LUMINANCE_ALPHA:
700 case GL_INTENSITY:
701 case GL_RG:
702 case GL_RGB:
703 case GL_BGR:
704 case GL_RGBA:
705 case GL_BGRA:
706 case GL_ABGR_EXT:
707 case GL_RED_INTEGER_EXT:
708 case GL_RG_INTEGER:
709 case GL_GREEN_INTEGER_EXT:
710 case GL_BLUE_INTEGER_EXT:
711 case GL_ALPHA_INTEGER_EXT:
712 case GL_RGB_INTEGER_EXT:
713 case GL_RGBA_INTEGER_EXT:
714 case GL_BGR_INTEGER_EXT:
715 case GL_BGRA_INTEGER_EXT:
716 case GL_LUMINANCE_INTEGER_EXT:
717 case GL_LUMINANCE_ALPHA_INTEGER_EXT:
718 if (reading) {
719 /* about to read from a color buffer */
720 const struct gl_renderbuffer *readBuf = fb->_ColorReadBuffer;
721 if (!readBuf) {
722 return GL_FALSE;
723 }
724 assert(_mesa_get_format_bits(readBuf->Format, GL_RED_BITS) > 0 ||
725 _mesa_get_format_bits(readBuf->Format, GL_ALPHA_BITS) > 0 ||
726 _mesa_get_format_bits(readBuf->Format, GL_TEXTURE_LUMINANCE_SIZE) > 0 ||
727 _mesa_get_format_bits(readBuf->Format, GL_TEXTURE_INTENSITY_SIZE) > 0 ||
728 _mesa_get_format_bits(readBuf->Format, GL_INDEX_BITS) > 0);
729 }
730 else {
731 /* about to draw to zero or more color buffers (none is OK) */
732 return GL_TRUE;
733 }
734 break;
735 case GL_DEPTH:
736 case GL_DEPTH_COMPONENT:
737 if (att[BUFFER_DEPTH].Type == GL_NONE) {
738 return GL_FALSE;
739 }
740 break;
741 case GL_STENCIL:
742 case GL_STENCIL_INDEX:
743 if (att[BUFFER_STENCIL].Type == GL_NONE) {
744 return GL_FALSE;
745 }
746 break;
747 case GL_DEPTH_STENCIL_EXT:
748 if (att[BUFFER_DEPTH].Type == GL_NONE ||
749 att[BUFFER_STENCIL].Type == GL_NONE) {
750 return GL_FALSE;
751 }
752 break;
753 default:
754 _mesa_problem(ctx,
755 "Unexpected format 0x%x in renderbuffer_exists",
756 format);
757 return GL_FALSE;
758 }
759
760 /* OK */
761 return GL_TRUE;
762 }
763
764
765 /**
766 * Check if the renderbuffer for a read operation (glReadPixels, glCopyPixels,
767 * glCopyTex[Sub]Image, etc) exists.
768 * \param format a basic image format such as GL_RGB, GL_RGBA, GL_ALPHA,
769 * GL_DEPTH_COMPONENT, etc. or GL_COLOR, GL_DEPTH, GL_STENCIL.
770 * \return GL_TRUE if buffer exists, GL_FALSE otherwise
771 */
772 GLboolean
_mesa_source_buffer_exists(struct gl_context * ctx,GLenum format)773 _mesa_source_buffer_exists(struct gl_context *ctx, GLenum format)
774 {
775 return renderbuffer_exists(ctx, ctx->ReadBuffer, format, GL_TRUE);
776 }
777
778
779 /**
780 * As above, but for drawing operations.
781 */
782 GLboolean
_mesa_dest_buffer_exists(struct gl_context * ctx,GLenum format)783 _mesa_dest_buffer_exists(struct gl_context *ctx, GLenum format)
784 {
785 return renderbuffer_exists(ctx, ctx->DrawBuffer, format, GL_FALSE);
786 }
787
788
789 /**
790 * Used to answer the GL_IMPLEMENTATION_COLOR_READ_FORMAT_OES queries (using
791 * GetIntegerv, GetFramebufferParameteriv, etc)
792 *
793 * If @fb is NULL, the method returns the value for the current bound
794 * framebuffer.
795 */
796 GLenum
_mesa_get_color_read_format(struct gl_context * ctx,struct gl_framebuffer * fb,const char * caller)797 _mesa_get_color_read_format(struct gl_context *ctx,
798 struct gl_framebuffer *fb,
799 const char *caller)
800 {
801 if (ctx->NewState)
802 _mesa_update_state(ctx);
803
804 if (fb == NULL)
805 fb = ctx->ReadBuffer;
806
807 if (!fb || !fb->_ColorReadBuffer) {
808 /*
809 * From OpenGL 4.5 spec, section 18.2.2 "ReadPixels":
810 *
811 * "An INVALID_OPERATION error is generated by GetIntegerv if pname
812 * is IMPLEMENTATION_COLOR_READ_FORMAT or IMPLEMENTATION_COLOR_-
813 * READ_TYPE and any of:
814 * * the read framebuffer is not framebuffer complete.
815 * * the read framebuffer is a framebuffer object, and the selected
816 * read buffer (see section 18.2.1) has no image attached.
817 * * the selected read buffer is NONE."
818 *
819 * There is not equivalent quote for GetFramebufferParameteriv or
820 * GetNamedFramebufferParameteriv, but from section 9.2.3 "Framebuffer
821 * Object Queries":
822 *
823 * "Values of framebuffer-dependent state are identical to those that
824 * would be obtained were the framebuffer object bound and queried
825 * using the simple state queries in that table."
826 *
827 * Where "using the simple state queries" refer to use GetIntegerv. So
828 * we will assume that on that situation the same error should be
829 * triggered too.
830 */
831 _mesa_error(ctx, GL_INVALID_OPERATION,
832 "%s(GL_IMPLEMENTATION_COLOR_READ_FORMAT: no GL_READ_BUFFER)",
833 caller);
834 return GL_NONE;
835 }
836 else {
837 const mesa_format format = fb->_ColorReadBuffer->Format;
838 const GLenum data_type = _mesa_get_format_datatype(format);
839
840 if (format == MESA_FORMAT_B8G8R8A8_UNORM)
841 return GL_BGRA;
842 else if (format == MESA_FORMAT_B5G6R5_UNORM)
843 return GL_RGB;
844 else if (format == MESA_FORMAT_R_UNORM8)
845 return GL_RED;
846
847 switch (data_type) {
848 case GL_UNSIGNED_INT:
849 case GL_INT:
850 return GL_RGBA_INTEGER;
851 default:
852 return GL_RGBA;
853 }
854 }
855 }
856
857
858 /**
859 * Used to answer the GL_IMPLEMENTATION_COLOR_READ_TYPE_OES queries (using
860 * GetIntegerv, GetFramebufferParameteriv, etc)
861 *
862 * If @fb is NULL, the method returns the value for the current bound
863 * framebuffer.
864 */
865 GLenum
_mesa_get_color_read_type(struct gl_context * ctx,struct gl_framebuffer * fb,const char * caller)866 _mesa_get_color_read_type(struct gl_context *ctx,
867 struct gl_framebuffer *fb,
868 const char *caller)
869 {
870 if (ctx->NewState)
871 _mesa_update_state(ctx);
872
873 if (fb == NULL)
874 fb = ctx->ReadBuffer;
875
876 if (!fb || !fb->_ColorReadBuffer) {
877 /*
878 * See comment on _mesa_get_color_read_format
879 */
880 _mesa_error(ctx, GL_INVALID_OPERATION,
881 "%s(GL_IMPLEMENTATION_COLOR_READ_TYPE: no GL_READ_BUFFER)",
882 caller);
883 return GL_NONE;
884 }
885 else {
886 const GLenum format = fb->_ColorReadBuffer->Format;
887 const GLenum data_type = _mesa_get_format_datatype(format);
888
889 if (format == MESA_FORMAT_B5G6R5_UNORM)
890 return GL_UNSIGNED_SHORT_5_6_5;
891
892 if (format == MESA_FORMAT_B10G10R10A2_UNORM ||
893 format == MESA_FORMAT_B10G10R10X2_UNORM)
894 return GL_UNSIGNED_INT_2_10_10_10_REV;
895
896 switch (data_type) {
897 case GL_SIGNED_NORMALIZED:
898 return GL_BYTE;
899 case GL_UNSIGNED_INT:
900 case GL_INT:
901 case GL_FLOAT:
902 return data_type;
903 case GL_UNSIGNED_NORMALIZED:
904 default:
905 return GL_UNSIGNED_BYTE;
906 }
907 }
908 }
909
910
911 /**
912 * Returns the read renderbuffer for the specified format.
913 */
914 struct gl_renderbuffer *
_mesa_get_read_renderbuffer_for_format(const struct gl_context * ctx,GLenum format)915 _mesa_get_read_renderbuffer_for_format(const struct gl_context *ctx,
916 GLenum format)
917 {
918 const struct gl_framebuffer *rfb = ctx->ReadBuffer;
919
920 if (_mesa_is_color_format(format)) {
921 return rfb->Attachment[rfb->_ColorReadBufferIndex].Renderbuffer;
922 } else if (_mesa_is_depth_format(format) ||
923 _mesa_is_depthstencil_format(format)) {
924 return rfb->Attachment[BUFFER_DEPTH].Renderbuffer;
925 } else {
926 return rfb->Attachment[BUFFER_STENCIL].Renderbuffer;
927 }
928 }
929
930
931 /**
932 * Print framebuffer info to stderr, for debugging.
933 */
934 void
_mesa_print_framebuffer(const struct gl_framebuffer * fb)935 _mesa_print_framebuffer(const struct gl_framebuffer *fb)
936 {
937 GLuint i;
938
939 fprintf(stderr, "Mesa Framebuffer %u at %p\n", fb->Name, (void *) fb);
940 fprintf(stderr, " Size: %u x %u Status: %s\n", fb->Width, fb->Height,
941 _mesa_enum_to_string(fb->_Status));
942 fprintf(stderr, " Attachments:\n");
943
944 for (i = 0; i < BUFFER_COUNT; i++) {
945 const struct gl_renderbuffer_attachment *att = &fb->Attachment[i];
946 if (att->Type == GL_TEXTURE) {
947 const struct gl_texture_image *texImage = att->Renderbuffer->TexImage;
948 fprintf(stderr,
949 " %2d: Texture %u, level %u, face %u, slice %u, complete %d\n",
950 i, att->Texture->Name, att->TextureLevel, att->CubeMapFace,
951 att->Zoffset, att->Complete);
952 fprintf(stderr, " Size: %u x %u x %u Format %s\n",
953 texImage->Width, texImage->Height, texImage->Depth,
954 _mesa_get_format_name(texImage->TexFormat));
955 }
956 else if (att->Type == GL_RENDERBUFFER) {
957 fprintf(stderr, " %2d: Renderbuffer %u, complete %d\n",
958 i, att->Renderbuffer->Name, att->Complete);
959 fprintf(stderr, " Size: %u x %u Format %s\n",
960 att->Renderbuffer->Width, att->Renderbuffer->Height,
961 _mesa_get_format_name(att->Renderbuffer->Format));
962 }
963 else {
964 fprintf(stderr, " %2d: none\n", i);
965 }
966 }
967 }
968
969 bool
_mesa_is_front_buffer_reading(const struct gl_framebuffer * fb)970 _mesa_is_front_buffer_reading(const struct gl_framebuffer *fb)
971 {
972 if (!fb || _mesa_is_user_fbo(fb))
973 return false;
974
975 return fb->_ColorReadBufferIndex == BUFFER_FRONT_LEFT;
976 }
977
978 bool
_mesa_is_front_buffer_drawing(const struct gl_framebuffer * fb)979 _mesa_is_front_buffer_drawing(const struct gl_framebuffer *fb)
980 {
981 if (!fb || _mesa_is_user_fbo(fb))
982 return false;
983
984 return (fb->_NumColorDrawBuffers >= 1 &&
985 fb->_ColorDrawBufferIndexes[0] == BUFFER_FRONT_LEFT);
986 }
987
988 static inline GLuint
_mesa_geometric_nonvalidated_samples(const struct gl_framebuffer * buffer)989 _mesa_geometric_nonvalidated_samples(const struct gl_framebuffer *buffer)
990 {
991 return buffer->_HasAttachments ?
992 buffer->Visual.samples :
993 buffer->DefaultGeometry.NumSamples;
994 }
995
996 bool
_mesa_is_multisample_enabled(const struct gl_context * ctx)997 _mesa_is_multisample_enabled(const struct gl_context *ctx)
998 {
999 /* The sample count may not be validated by the driver, but when it is set,
1000 * we know that is in a valid range and no driver should ever validate a
1001 * multisampled framebuffer to non-multisampled and vice-versa.
1002 */
1003 return ctx->Multisample.Enabled &&
1004 ctx->DrawBuffer &&
1005 _mesa_geometric_nonvalidated_samples(ctx->DrawBuffer) >= 1;
1006 }
1007
1008 /**
1009 * Is alpha testing enabled and applicable to the currently bound
1010 * framebuffer?
1011 */
1012 bool
_mesa_is_alpha_test_enabled(const struct gl_context * ctx)1013 _mesa_is_alpha_test_enabled(const struct gl_context *ctx)
1014 {
1015 bool buffer0_is_integer = ctx->DrawBuffer->_IntegerBuffers & 0x1;
1016 return (ctx->Color.AlphaEnabled && !buffer0_is_integer);
1017 }
1018
1019 /**
1020 * Is alpha to coverage enabled and applicable to the currently bound
1021 * framebuffer?
1022 */
1023 bool
_mesa_is_alpha_to_coverage_enabled(const struct gl_context * ctx)1024 _mesa_is_alpha_to_coverage_enabled(const struct gl_context *ctx)
1025 {
1026 bool buffer0_is_integer = ctx->DrawBuffer->_IntegerBuffers & 0x1;
1027 return (ctx->Multisample.SampleAlphaToCoverage &&
1028 _mesa_is_multisample_enabled(ctx) &&
1029 !buffer0_is_integer);
1030 }
1031