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1 /*
2  * Mesa 3-D graphics library
3  *
4  * Copyright (C) 1999-2006  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 software-based renderbuffers.
28  * Also, routines for reading/writing software-based renderbuffer data as
29  * ubytes, ushorts, uints, etc.
30  */
31 
32 
33 #include "main/glheader.h"
34 #include "main/imports.h"
35 #include "main/context.h"
36 #include "main/fbobject.h"
37 #include "main/formats.h"
38 #include "main/mtypes.h"
39 #include "main/renderbuffer.h"
40 #include "swrast/s_context.h"
41 #include "swrast/s_renderbuffer.h"
42 
43 
44 /**
45  * This is a software fallback for the gl_renderbuffer->AllocStorage
46  * function.
47  * Device drivers will typically override this function for the buffers
48  * which it manages (typically color buffers, Z and stencil).
49  * Other buffers (like software accumulation and aux buffers) which the driver
50  * doesn't manage can be handled with this function.
51  *
52  * This one multi-purpose function can allocate stencil, depth, accum, color
53  * or color-index buffers!
54  */
55 static GLboolean
soft_renderbuffer_storage(struct gl_context * ctx,struct gl_renderbuffer * rb,GLenum internalFormat,GLuint width,GLuint height)56 soft_renderbuffer_storage(struct gl_context *ctx, struct gl_renderbuffer *rb,
57                           GLenum internalFormat,
58                           GLuint width, GLuint height)
59 {
60    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
61    GLuint bpp;
62 
63    switch (internalFormat) {
64    case GL_RGB:
65    case GL_R3_G3_B2:
66    case GL_RGB4:
67    case GL_RGB5:
68    case GL_RGB8:
69    case GL_RGB10:
70    case GL_RGB12:
71    case GL_RGB16:
72       rb->Format = MESA_FORMAT_BGR_UNORM8;
73       break;
74    case GL_RGBA:
75    case GL_RGBA2:
76    case GL_RGBA4:
77    case GL_RGB5_A1:
78    case GL_RGBA8:
79 #if 1
80    case GL_RGB10_A2:
81    case GL_RGBA12:
82 #endif
83       if (_mesa_little_endian())
84          rb->Format = MESA_FORMAT_R8G8B8A8_UNORM;
85       else
86          rb->Format = MESA_FORMAT_A8B8G8R8_UNORM;
87       break;
88    case GL_RGBA16:
89    case GL_RGBA16_SNORM:
90       /* for accum buffer */
91       rb->Format = MESA_FORMAT_RGBA_SNORM16;
92       break;
93    case GL_STENCIL_INDEX:
94    case GL_STENCIL_INDEX1_EXT:
95    case GL_STENCIL_INDEX4_EXT:
96    case GL_STENCIL_INDEX8_EXT:
97    case GL_STENCIL_INDEX16_EXT:
98       rb->Format = MESA_FORMAT_S_UINT8;
99       break;
100    case GL_DEPTH_COMPONENT:
101    case GL_DEPTH_COMPONENT16:
102       rb->Format = MESA_FORMAT_Z_UNORM16;
103       break;
104    case GL_DEPTH_COMPONENT24:
105       rb->Format = MESA_FORMAT_Z24_UNORM_X8_UINT;
106       break;
107    case GL_DEPTH_COMPONENT32:
108       rb->Format = MESA_FORMAT_Z_UNORM32;
109       break;
110    case GL_DEPTH_STENCIL_EXT:
111    case GL_DEPTH24_STENCIL8_EXT:
112       rb->Format = MESA_FORMAT_S8_UINT_Z24_UNORM;
113       break;
114    default:
115       /* unsupported format */
116       return GL_FALSE;
117    }
118 
119    bpp = _mesa_get_format_bytes(rb->Format);
120 
121    /* free old buffer storage */
122    free(srb->Buffer);
123    srb->Buffer = NULL;
124 
125    srb->RowStride = width * bpp;
126 
127    if (width > 0 && height > 0) {
128       /* allocate new buffer storage */
129       srb->Buffer = malloc(srb->RowStride * height);
130 
131       if (srb->Buffer == NULL) {
132          rb->Width = 0;
133          rb->Height = 0;
134          _mesa_error(ctx, GL_OUT_OF_MEMORY,
135                      "software renderbuffer allocation (%d x %d x %d)",
136                      width, height, bpp);
137          return GL_FALSE;
138       }
139    }
140 
141    rb->Width = width;
142    rb->Height = height;
143    rb->_BaseFormat = _mesa_base_fbo_format(ctx, internalFormat);
144 
145    if (rb->Name == 0 &&
146        internalFormat == GL_RGBA16_SNORM &&
147        rb->_BaseFormat == 0) {
148       /* NOTE: This is a special case just for accumulation buffers.
149        * This is a very limited use case- there's no snorm texturing or
150        * rendering going on.
151        */
152       rb->_BaseFormat = GL_RGBA;
153    }
154    else {
155       /* the internalFormat should have been error checked long ago */
156       assert(rb->_BaseFormat);
157    }
158 
159    return GL_TRUE;
160 }
161 
162 
163 /**
164  * Called via gl_renderbuffer::Delete()
165  */
166 static void
soft_renderbuffer_delete(struct gl_context * ctx,struct gl_renderbuffer * rb)167 soft_renderbuffer_delete(struct gl_context *ctx, struct gl_renderbuffer *rb)
168 {
169    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
170 
171    free(srb->Buffer);
172    srb->Buffer = NULL;
173    _mesa_delete_renderbuffer(ctx, rb);
174 }
175 
176 
177 void
_swrast_map_soft_renderbuffer(struct gl_context * ctx,struct gl_renderbuffer * rb,GLuint x,GLuint y,GLuint w,GLuint h,GLbitfield mode,GLubyte ** out_map,GLint * out_stride)178 _swrast_map_soft_renderbuffer(struct gl_context *ctx,
179                               struct gl_renderbuffer *rb,
180                               GLuint x, GLuint y, GLuint w, GLuint h,
181                               GLbitfield mode,
182                               GLubyte **out_map,
183                               GLint *out_stride)
184 {
185    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
186    GLubyte *map = srb->Buffer;
187    int cpp = _mesa_get_format_bytes(rb->Format);
188    int stride = rb->Width * cpp;
189 
190    if (!map) {
191       *out_map = NULL;
192       *out_stride = 0;
193    }
194 
195    map += y * stride;
196    map += x * cpp;
197 
198    *out_map = map;
199    *out_stride = stride;
200 }
201 
202 
203 void
_swrast_unmap_soft_renderbuffer(struct gl_context * ctx,struct gl_renderbuffer * rb)204 _swrast_unmap_soft_renderbuffer(struct gl_context *ctx,
205                                 struct gl_renderbuffer *rb)
206 {
207 }
208 
209 
210 
211 /**
212  * Allocate a software-based renderbuffer.  This is called via the
213  * ctx->Driver.NewRenderbuffer() function when the user creates a new
214  * renderbuffer.
215  * This would not be used for hardware-based renderbuffers.
216  */
217 struct gl_renderbuffer *
_swrast_new_soft_renderbuffer(struct gl_context * ctx,GLuint name)218 _swrast_new_soft_renderbuffer(struct gl_context *ctx, GLuint name)
219 {
220    struct swrast_renderbuffer *srb = CALLOC_STRUCT(swrast_renderbuffer);
221    if (srb) {
222       _mesa_init_renderbuffer(&srb->Base, name);
223       srb->Base.AllocStorage = soft_renderbuffer_storage;
224       srb->Base.Delete = soft_renderbuffer_delete;
225    }
226    return &srb->Base;
227 }
228 
229 
230 /**
231  * Add software-based color renderbuffers to the given framebuffer.
232  * This is a helper routine for device drivers when creating a
233  * window system framebuffer (not a user-created render/framebuffer).
234  * Once this function is called, you can basically forget about this
235  * renderbuffer; core Mesa will handle all the buffer management and
236  * rendering!
237  */
238 static GLboolean
add_color_renderbuffers(struct gl_context * ctx,struct gl_framebuffer * fb,GLuint rgbBits,GLuint alphaBits,GLboolean frontLeft,GLboolean backLeft,GLboolean frontRight,GLboolean backRight)239 add_color_renderbuffers(struct gl_context *ctx, struct gl_framebuffer *fb,
240                         GLuint rgbBits, GLuint alphaBits,
241                         GLboolean frontLeft, GLboolean backLeft,
242                         GLboolean frontRight, GLboolean backRight)
243 {
244    gl_buffer_index b;
245 
246    if (rgbBits > 16 || alphaBits > 16) {
247       _mesa_problem(ctx,
248                     "Unsupported bit depth in add_color_renderbuffers");
249       return GL_FALSE;
250    }
251 
252    assert(MAX_COLOR_ATTACHMENTS >= 4);
253 
254    for (b = BUFFER_FRONT_LEFT; b <= BUFFER_BACK_RIGHT; b++) {
255       struct gl_renderbuffer *rb;
256 
257       if (b == BUFFER_FRONT_LEFT && !frontLeft)
258          continue;
259       else if (b == BUFFER_BACK_LEFT && !backLeft)
260          continue;
261       else if (b == BUFFER_FRONT_RIGHT && !frontRight)
262          continue;
263       else if (b == BUFFER_BACK_RIGHT && !backRight)
264          continue;
265 
266       assert(fb->Attachment[b].Renderbuffer == NULL);
267 
268       rb = ctx->Driver.NewRenderbuffer(ctx, 0);
269       if (!rb) {
270          _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating color buffer");
271          return GL_FALSE;
272       }
273 
274       rb->InternalFormat = GL_RGBA;
275 
276       rb->AllocStorage = soft_renderbuffer_storage;
277       _mesa_attach_and_own_rb(fb, b, rb);
278    }
279 
280    return GL_TRUE;
281 }
282 
283 
284 /**
285  * Add a software-based depth renderbuffer to the given framebuffer.
286  * This is a helper routine for device drivers when creating a
287  * window system framebuffer (not a user-created render/framebuffer).
288  * Once this function is called, you can basically forget about this
289  * renderbuffer; core Mesa will handle all the buffer management and
290  * rendering!
291  */
292 static GLboolean
add_depth_renderbuffer(struct gl_context * ctx,struct gl_framebuffer * fb,GLuint depthBits)293 add_depth_renderbuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
294                        GLuint depthBits)
295 {
296    struct gl_renderbuffer *rb;
297 
298    if (depthBits > 32) {
299       _mesa_problem(ctx,
300                     "Unsupported depthBits in add_depth_renderbuffer");
301       return GL_FALSE;
302    }
303 
304    assert(fb->Attachment[BUFFER_DEPTH].Renderbuffer == NULL);
305 
306    rb = _swrast_new_soft_renderbuffer(ctx, 0);
307    if (!rb) {
308       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating depth buffer");
309       return GL_FALSE;
310    }
311 
312    if (depthBits <= 16) {
313       rb->InternalFormat = GL_DEPTH_COMPONENT16;
314    }
315    else if (depthBits <= 24) {
316       rb->InternalFormat = GL_DEPTH_COMPONENT24;
317    }
318    else {
319       rb->InternalFormat = GL_DEPTH_COMPONENT32;
320    }
321 
322    rb->AllocStorage = soft_renderbuffer_storage;
323    _mesa_attach_and_own_rb(fb, BUFFER_DEPTH, rb);
324 
325    return GL_TRUE;
326 }
327 
328 
329 /**
330  * Add a software-based stencil renderbuffer to the given framebuffer.
331  * This is a helper routine for device drivers when creating a
332  * window system framebuffer (not a user-created render/framebuffer).
333  * Once this function is called, you can basically forget about this
334  * renderbuffer; core Mesa will handle all the buffer management and
335  * rendering!
336  */
337 static GLboolean
add_stencil_renderbuffer(struct gl_context * ctx,struct gl_framebuffer * fb,GLuint stencilBits)338 add_stencil_renderbuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
339                          GLuint stencilBits)
340 {
341    struct gl_renderbuffer *rb;
342 
343    if (stencilBits > 16) {
344       _mesa_problem(ctx,
345                   "Unsupported stencilBits in add_stencil_renderbuffer");
346       return GL_FALSE;
347    }
348 
349    assert(fb->Attachment[BUFFER_STENCIL].Renderbuffer == NULL);
350 
351    rb = _swrast_new_soft_renderbuffer(ctx, 0);
352    if (!rb) {
353       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating stencil buffer");
354       return GL_FALSE;
355    }
356 
357    assert(stencilBits <= 8);
358    rb->InternalFormat = GL_STENCIL_INDEX8;
359 
360    rb->AllocStorage = soft_renderbuffer_storage;
361    _mesa_attach_and_own_rb(fb, BUFFER_STENCIL, rb);
362 
363    return GL_TRUE;
364 }
365 
366 
367 static GLboolean
add_depth_stencil_renderbuffer(struct gl_context * ctx,struct gl_framebuffer * fb)368 add_depth_stencil_renderbuffer(struct gl_context *ctx,
369                                struct gl_framebuffer *fb)
370 {
371    struct gl_renderbuffer *rb;
372 
373    assert(fb->Attachment[BUFFER_DEPTH].Renderbuffer == NULL);
374    assert(fb->Attachment[BUFFER_STENCIL].Renderbuffer == NULL);
375 
376    rb = _swrast_new_soft_renderbuffer(ctx, 0);
377    if (!rb) {
378       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating depth+stencil buffer");
379       return GL_FALSE;
380    }
381 
382    rb->InternalFormat = GL_DEPTH_STENCIL;
383 
384    rb->AllocStorage = soft_renderbuffer_storage;
385    _mesa_attach_and_own_rb(fb, BUFFER_DEPTH, rb);
386    _mesa_attach_and_reference_rb(fb, BUFFER_STENCIL, rb);
387 
388    return GL_TRUE;
389 }
390 
391 
392 /**
393  * Add a software-based accumulation renderbuffer to the given framebuffer.
394  * This is a helper routine for device drivers when creating a
395  * window system framebuffer (not a user-created render/framebuffer).
396  * Once this function is called, you can basically forget about this
397  * renderbuffer; core Mesa will handle all the buffer management and
398  * rendering!
399  */
400 static GLboolean
add_accum_renderbuffer(struct gl_context * ctx,struct gl_framebuffer * fb,GLuint redBits,GLuint greenBits,GLuint blueBits,GLuint alphaBits)401 add_accum_renderbuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
402                        GLuint redBits, GLuint greenBits,
403                        GLuint blueBits, GLuint alphaBits)
404 {
405    struct gl_renderbuffer *rb;
406 
407    if (redBits > 16 || greenBits > 16 || blueBits > 16 || alphaBits > 16) {
408       _mesa_problem(ctx,
409                     "Unsupported accumBits in add_accum_renderbuffer");
410       return GL_FALSE;
411    }
412 
413    assert(fb->Attachment[BUFFER_ACCUM].Renderbuffer == NULL);
414 
415    rb = _swrast_new_soft_renderbuffer(ctx, 0);
416    if (!rb) {
417       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating accum buffer");
418       return GL_FALSE;
419    }
420 
421    rb->InternalFormat = GL_RGBA16_SNORM;
422    rb->AllocStorage = soft_renderbuffer_storage;
423    _mesa_attach_and_own_rb(fb, BUFFER_ACCUM, rb);
424 
425    return GL_TRUE;
426 }
427 
428 
429 
430 /**
431  * Add a software-based aux renderbuffer to the given framebuffer.
432  * This is a helper routine for device drivers when creating a
433  * window system framebuffer (not a user-created render/framebuffer).
434  * Once this function is called, you can basically forget about this
435  * renderbuffer; core Mesa will handle all the buffer management and
436  * rendering!
437  *
438  * NOTE: color-index aux buffers not supported.
439  */
440 static GLboolean
add_aux_renderbuffers(struct gl_context * ctx,struct gl_framebuffer * fb,GLuint colorBits,GLuint numBuffers)441 add_aux_renderbuffers(struct gl_context *ctx, struct gl_framebuffer *fb,
442                       GLuint colorBits, GLuint numBuffers)
443 {
444    GLuint i;
445 
446    if (colorBits > 16) {
447       _mesa_problem(ctx,
448                     "Unsupported colorBits in add_aux_renderbuffers");
449       return GL_FALSE;
450    }
451 
452    assert(numBuffers <= MAX_AUX_BUFFERS);
453 
454    for (i = 0; i < numBuffers; i++) {
455       struct gl_renderbuffer *rb = _swrast_new_soft_renderbuffer(ctx, 0);
456 
457       assert(fb->Attachment[BUFFER_AUX0 + i].Renderbuffer == NULL);
458 
459       if (!rb) {
460          _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating aux buffer");
461          return GL_FALSE;
462       }
463 
464       assert (colorBits <= 8);
465       rb->InternalFormat = GL_RGBA;
466 
467       rb->AllocStorage = soft_renderbuffer_storage;
468       _mesa_attach_and_own_rb(fb, BUFFER_AUX0 + i, rb);
469    }
470    return GL_TRUE;
471 }
472 
473 
474 /**
475  * Create/attach software-based renderbuffers to the given framebuffer.
476  * This is a helper routine for device drivers.  Drivers can just as well
477  * call the individual _mesa_add_*_renderbuffer() routines directly.
478  */
479 void
_swrast_add_soft_renderbuffers(struct gl_framebuffer * fb,GLboolean color,GLboolean depth,GLboolean stencil,GLboolean accum,GLboolean alpha,GLboolean aux)480 _swrast_add_soft_renderbuffers(struct gl_framebuffer *fb,
481                                GLboolean color,
482                                GLboolean depth,
483                                GLboolean stencil,
484                                GLboolean accum,
485                                GLboolean alpha,
486                                GLboolean aux)
487 {
488    GLboolean frontLeft = GL_TRUE;
489    GLboolean backLeft = fb->Visual.doubleBufferMode;
490    GLboolean frontRight = fb->Visual.stereoMode;
491    GLboolean backRight = fb->Visual.stereoMode && fb->Visual.doubleBufferMode;
492 
493    if (color) {
494       assert(fb->Visual.redBits == fb->Visual.greenBits);
495       assert(fb->Visual.redBits == fb->Visual.blueBits);
496       add_color_renderbuffers(NULL, fb,
497                               fb->Visual.redBits,
498                               fb->Visual.alphaBits,
499                               frontLeft, backLeft,
500                               frontRight, backRight);
501    }
502 
503 #if 0
504    /* This is pretty much for debugging purposes only since there's a perf
505     * hit for using combined depth/stencil in swrast.
506     */
507    if (depth && fb->Visual.depthBits == 24 &&
508        stencil && fb->Visual.stencilBits == 8) {
509       /* use combined depth/stencil buffer */
510       add_depth_stencil_renderbuffer(NULL, fb);
511    }
512    else
513 #else
514    (void) add_depth_stencil_renderbuffer;
515 #endif
516    {
517       if (depth) {
518          assert(fb->Visual.depthBits > 0);
519          add_depth_renderbuffer(NULL, fb, fb->Visual.depthBits);
520       }
521 
522       if (stencil) {
523          assert(fb->Visual.stencilBits > 0);
524          add_stencil_renderbuffer(NULL, fb, fb->Visual.stencilBits);
525       }
526    }
527 
528    if (accum) {
529       assert(fb->Visual.accumRedBits > 0);
530       assert(fb->Visual.accumGreenBits > 0);
531       assert(fb->Visual.accumBlueBits > 0);
532       add_accum_renderbuffer(NULL, fb,
533                              fb->Visual.accumRedBits,
534                              fb->Visual.accumGreenBits,
535                              fb->Visual.accumBlueBits,
536                              fb->Visual.accumAlphaBits);
537    }
538 
539    if (aux) {
540       assert(fb->Visual.numAuxBuffers > 0);
541       add_aux_renderbuffers(NULL, fb, fb->Visual.redBits,
542                             fb->Visual.numAuxBuffers);
543    }
544 
545 #if 0
546    if (multisample) {
547       /* maybe someday */
548    }
549 #endif
550 }
551 
552 
553 
554 static void
map_attachment(struct gl_context * ctx,struct gl_framebuffer * fb,gl_buffer_index buffer)555 map_attachment(struct gl_context *ctx,
556                  struct gl_framebuffer *fb,
557                  gl_buffer_index buffer)
558 {
559    struct gl_texture_object *texObj = fb->Attachment[buffer].Texture;
560    struct gl_renderbuffer *rb = fb->Attachment[buffer].Renderbuffer;
561    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
562 
563    if (texObj) {
564       /* map texture image (render to texture) */
565       const GLuint level = fb->Attachment[buffer].TextureLevel;
566       const GLuint face = fb->Attachment[buffer].CubeMapFace;
567       const GLuint slice = fb->Attachment[buffer].Zoffset;
568       struct gl_texture_image *texImage = texObj->Image[face][level];
569       if (texImage) {
570          ctx->Driver.MapTextureImage(ctx, texImage, slice,
571                                      0, 0, texImage->Width, texImage->Height,
572                                      GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
573                                      &srb->Map, &srb->RowStride);
574       }
575    }
576    else if (rb) {
577       /* Map ordinary renderbuffer */
578       ctx->Driver.MapRenderbuffer(ctx, rb,
579                                   0, 0, rb->Width, rb->Height,
580                                   GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
581                                   &srb->Map, &srb->RowStride);
582    }
583 
584    assert(srb->Map);
585 }
586 
587 
588 static void
unmap_attachment(struct gl_context * ctx,struct gl_framebuffer * fb,gl_buffer_index buffer)589 unmap_attachment(struct gl_context *ctx,
590                    struct gl_framebuffer *fb,
591                    gl_buffer_index buffer)
592 {
593    struct gl_texture_object *texObj = fb->Attachment[buffer].Texture;
594    struct gl_renderbuffer *rb = fb->Attachment[buffer].Renderbuffer;
595    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
596 
597    if (texObj) {
598       /* unmap texture image (render to texture) */
599       const GLuint level = fb->Attachment[buffer].TextureLevel;
600       const GLuint face = fb->Attachment[buffer].CubeMapFace;
601       const GLuint slice = fb->Attachment[buffer].Zoffset;
602       struct gl_texture_image *texImage = texObj->Image[face][level];
603       if (texImage) {
604          ctx->Driver.UnmapTextureImage(ctx, texImage, slice);
605       }
606    }
607    else if (rb) {
608       /* unmap ordinary renderbuffer */
609       ctx->Driver.UnmapRenderbuffer(ctx, rb);
610    }
611 
612    srb->Map = NULL;
613 }
614 
615 
616 /**
617  * Determine what type to use (ubyte vs. float) for span colors for the
618  * given renderbuffer.
619  * See also _swrast_write_rgba_span().
620  */
621 static void
find_renderbuffer_colortype(struct gl_renderbuffer * rb)622 find_renderbuffer_colortype(struct gl_renderbuffer *rb)
623 {
624    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
625    GLuint rbMaxBits = _mesa_get_format_max_bits(rb->Format);
626    GLenum rbDatatype = _mesa_get_format_datatype(rb->Format);
627 
628    if (rbDatatype == GL_UNSIGNED_NORMALIZED && rbMaxBits <= 8) {
629       /* the buffer's values fit in GLubyte values */
630       srb->ColorType = GL_UNSIGNED_BYTE;
631    }
632    else {
633       /* use floats otherwise */
634       srb->ColorType = GL_FLOAT;
635    }
636 }
637 
638 
639 /**
640  * Map the renderbuffers we'll use for tri/line/point rendering.
641  */
642 void
_swrast_map_renderbuffers(struct gl_context * ctx)643 _swrast_map_renderbuffers(struct gl_context *ctx)
644 {
645    struct gl_framebuffer *fb = ctx->DrawBuffer;
646    struct gl_renderbuffer *depthRb, *stencilRb;
647    GLuint buf;
648 
649    depthRb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
650    if (depthRb) {
651       /* map depth buffer */
652       map_attachment(ctx, fb, BUFFER_DEPTH);
653    }
654 
655    stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
656    if (stencilRb && stencilRb != depthRb) {
657       /* map stencil buffer */
658       map_attachment(ctx, fb, BUFFER_STENCIL);
659    }
660 
661    for (buf = 0; buf < fb->_NumColorDrawBuffers; buf++) {
662       if (fb->_ColorDrawBufferIndexes[buf] != BUFFER_NONE) {
663          map_attachment(ctx, fb, fb->_ColorDrawBufferIndexes[buf]);
664          find_renderbuffer_colortype(fb->_ColorDrawBuffers[buf]);
665       }
666    }
667 }
668 
669 
670 /**
671  * Unmap renderbuffers after rendering.
672  */
673 void
_swrast_unmap_renderbuffers(struct gl_context * ctx)674 _swrast_unmap_renderbuffers(struct gl_context *ctx)
675 {
676    struct gl_framebuffer *fb = ctx->DrawBuffer;
677    struct gl_renderbuffer *depthRb, *stencilRb;
678    GLuint buf;
679 
680    depthRb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
681    if (depthRb) {
682       /* map depth buffer */
683       unmap_attachment(ctx, fb, BUFFER_DEPTH);
684    }
685 
686    stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
687    if (stencilRb && stencilRb != depthRb) {
688       /* map stencil buffer */
689       unmap_attachment(ctx, fb, BUFFER_STENCIL);
690    }
691 
692    for (buf = 0; buf < fb->_NumColorDrawBuffers; buf++) {
693       if (fb->_ColorDrawBufferIndexes[buf] != BUFFER_NONE) {
694          unmap_attachment(ctx, fb, fb->_ColorDrawBufferIndexes[buf]);
695       }
696    }
697 }
698