1 /*
2  * Mesa 3-D graphics library
3  * Version:  6.5
4  *
5  * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
6  *
7  * Permission is hereby granted, free of charge, to any person obtaining a
8  * copy of this software and associated documentation files (the "Software"),
9  * to deal in the Software without restriction, including without limitation
10  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11  * and/or sell copies of the Software, and to permit persons to whom the
12  * Software is furnished to do so, subject to the following conditions:
13  *
14  * The above copyright notice and this permission notice shall be included
15  * in all copies or substantial portions of the Software.
16  *
17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
21  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
22  * CONNECTION WITH THE SOFTWARE OR THE USE OR 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_RGB888;
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_RGBA8888_REV;
85       else
86          rb->Format = MESA_FORMAT_RGBA8888;
87       break;
88    case GL_RGBA16:
89    case GL_RGBA16_SNORM:
90       /* for accum buffer */
91       rb->Format = MESA_FORMAT_SIGNED_RGBA_16;
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_S8;
99       break;
100    case GL_DEPTH_COMPONENT:
101    case GL_DEPTH_COMPONENT16:
102       rb->Format = MESA_FORMAT_Z16;
103       break;
104    case GL_DEPTH_COMPONENT24:
105       rb->Format = MESA_FORMAT_X8_Z24;
106       break;
107    case GL_DEPTH_COMPONENT32:
108       rb->Format = MESA_FORMAT_Z32;
109       break;
110    case GL_DEPTH_STENCIL_EXT:
111    case GL_DEPTH24_STENCIL8_EXT:
112       rb->Format = MESA_FORMAT_Z24_S8;
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    if (srb->Buffer) {
123       free(srb->Buffer);
124       srb->Buffer = NULL;
125    }
126 
127    srb->RowStride = width * bpp;
128 
129    if (width > 0 && height > 0) {
130       /* allocate new buffer storage */
131       srb->Buffer = malloc(srb->RowStride * height);
132 
133       if (srb->Buffer == NULL) {
134          rb->Width = 0;
135          rb->Height = 0;
136          _mesa_error(ctx, GL_OUT_OF_MEMORY,
137                      "software renderbuffer allocation (%d x %d x %d)",
138                      width, height, bpp);
139          return GL_FALSE;
140       }
141    }
142 
143    rb->Width = width;
144    rb->Height = height;
145    rb->_BaseFormat = _mesa_base_fbo_format(ctx, internalFormat);
146 
147    if (rb->Name == 0 &&
148        internalFormat == GL_RGBA16_SNORM &&
149        rb->_BaseFormat == 0) {
150       /* NOTE: This is a special case just for accumulation buffers.
151        * This is a very limited use case- there's no snorm texturing or
152        * rendering going on.
153        */
154       rb->_BaseFormat = GL_RGBA;
155    }
156    else {
157       /* the internalFormat should have been error checked long ago */
158       ASSERT(rb->_BaseFormat);
159    }
160 
161    return GL_TRUE;
162 }
163 
164 
165 /**
166  * Called via gl_renderbuffer::Delete()
167  */
168 static void
soft_renderbuffer_delete(struct gl_context * ctx,struct gl_renderbuffer * rb)169 soft_renderbuffer_delete(struct gl_context *ctx, struct gl_renderbuffer *rb)
170 {
171    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
172 
173    free(srb->Buffer);
174    srb->Buffer = NULL;
175    _mesa_delete_renderbuffer(ctx, rb);
176 }
177 
178 
179 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)180 _swrast_map_soft_renderbuffer(struct gl_context *ctx,
181                               struct gl_renderbuffer *rb,
182                               GLuint x, GLuint y, GLuint w, GLuint h,
183                               GLbitfield mode,
184                               GLubyte **out_map,
185                               GLint *out_stride)
186 {
187    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
188    GLubyte *map = srb->Buffer;
189    int cpp = _mesa_get_format_bytes(rb->Format);
190    int stride = rb->Width * cpp;
191 
192    if (!map) {
193       *out_map = NULL;
194       *out_stride = 0;
195    }
196 
197    map += y * stride;
198    map += x * cpp;
199 
200    *out_map = map;
201    *out_stride = stride;
202 }
203 
204 
205 void
_swrast_unmap_soft_renderbuffer(struct gl_context * ctx,struct gl_renderbuffer * rb)206 _swrast_unmap_soft_renderbuffer(struct gl_context *ctx,
207                                 struct gl_renderbuffer *rb)
208 {
209 }
210 
211 
212 
213 /**
214  * Allocate a software-based renderbuffer.  This is called via the
215  * ctx->Driver.NewRenderbuffer() function when the user creates a new
216  * renderbuffer.
217  * This would not be used for hardware-based renderbuffers.
218  */
219 struct gl_renderbuffer *
_swrast_new_soft_renderbuffer(struct gl_context * ctx,GLuint name)220 _swrast_new_soft_renderbuffer(struct gl_context *ctx, GLuint name)
221 {
222    struct swrast_renderbuffer *srb = CALLOC_STRUCT(swrast_renderbuffer);
223    if (srb) {
224       _mesa_init_renderbuffer(&srb->Base, name);
225       srb->Base.AllocStorage = soft_renderbuffer_storage;
226       srb->Base.Delete = soft_renderbuffer_delete;
227    }
228    return &srb->Base;
229 }
230 
231 
232 /**
233  * Add software-based color renderbuffers to the given framebuffer.
234  * This is a helper routine for device drivers when creating a
235  * window system framebuffer (not a user-created render/framebuffer).
236  * Once this function is called, you can basically forget about this
237  * renderbuffer; core Mesa will handle all the buffer management and
238  * rendering!
239  */
240 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)241 add_color_renderbuffers(struct gl_context *ctx, struct gl_framebuffer *fb,
242                         GLuint rgbBits, GLuint alphaBits,
243                         GLboolean frontLeft, GLboolean backLeft,
244                         GLboolean frontRight, GLboolean backRight)
245 {
246    gl_buffer_index b;
247 
248    if (rgbBits > 16 || alphaBits > 16) {
249       _mesa_problem(ctx,
250                     "Unsupported bit depth in add_color_renderbuffers");
251       return GL_FALSE;
252    }
253 
254    assert(MAX_COLOR_ATTACHMENTS >= 4);
255 
256    for (b = BUFFER_FRONT_LEFT; b <= BUFFER_BACK_RIGHT; b++) {
257       struct gl_renderbuffer *rb;
258 
259       if (b == BUFFER_FRONT_LEFT && !frontLeft)
260          continue;
261       else if (b == BUFFER_BACK_LEFT && !backLeft)
262          continue;
263       else if (b == BUFFER_FRONT_RIGHT && !frontRight)
264          continue;
265       else if (b == BUFFER_BACK_RIGHT && !backRight)
266          continue;
267 
268       assert(fb->Attachment[b].Renderbuffer == NULL);
269 
270       rb = ctx->Driver.NewRenderbuffer(ctx, 0);
271       if (!rb) {
272          _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating color buffer");
273          return GL_FALSE;
274       }
275 
276       rb->InternalFormat = GL_RGBA;
277 
278       rb->AllocStorage = soft_renderbuffer_storage;
279       _mesa_add_renderbuffer(fb, b, rb);
280    }
281 
282    return GL_TRUE;
283 }
284 
285 
286 /**
287  * Add a software-based depth renderbuffer to the given framebuffer.
288  * This is a helper routine for device drivers when creating a
289  * window system framebuffer (not a user-created render/framebuffer).
290  * Once this function is called, you can basically forget about this
291  * renderbuffer; core Mesa will handle all the buffer management and
292  * rendering!
293  */
294 static GLboolean
add_depth_renderbuffer(struct gl_context * ctx,struct gl_framebuffer * fb,GLuint depthBits)295 add_depth_renderbuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
296                        GLuint depthBits)
297 {
298    struct gl_renderbuffer *rb;
299 
300    if (depthBits > 32) {
301       _mesa_problem(ctx,
302                     "Unsupported depthBits in add_depth_renderbuffer");
303       return GL_FALSE;
304    }
305 
306    assert(fb->Attachment[BUFFER_DEPTH].Renderbuffer == NULL);
307 
308    rb = _swrast_new_soft_renderbuffer(ctx, 0);
309    if (!rb) {
310       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating depth buffer");
311       return GL_FALSE;
312    }
313 
314    if (depthBits <= 16) {
315       rb->InternalFormat = GL_DEPTH_COMPONENT16;
316    }
317    else if (depthBits <= 24) {
318       rb->InternalFormat = GL_DEPTH_COMPONENT24;
319    }
320    else {
321       rb->InternalFormat = GL_DEPTH_COMPONENT32;
322    }
323 
324    rb->AllocStorage = soft_renderbuffer_storage;
325    _mesa_add_renderbuffer(fb, BUFFER_DEPTH, rb);
326 
327    return GL_TRUE;
328 }
329 
330 
331 /**
332  * Add a software-based stencil renderbuffer to the given framebuffer.
333  * This is a helper routine for device drivers when creating a
334  * window system framebuffer (not a user-created render/framebuffer).
335  * Once this function is called, you can basically forget about this
336  * renderbuffer; core Mesa will handle all the buffer management and
337  * rendering!
338  */
339 static GLboolean
add_stencil_renderbuffer(struct gl_context * ctx,struct gl_framebuffer * fb,GLuint stencilBits)340 add_stencil_renderbuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
341                          GLuint stencilBits)
342 {
343    struct gl_renderbuffer *rb;
344 
345    if (stencilBits > 16) {
346       _mesa_problem(ctx,
347                   "Unsupported stencilBits in add_stencil_renderbuffer");
348       return GL_FALSE;
349    }
350 
351    assert(fb->Attachment[BUFFER_STENCIL].Renderbuffer == NULL);
352 
353    rb = _swrast_new_soft_renderbuffer(ctx, 0);
354    if (!rb) {
355       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating stencil buffer");
356       return GL_FALSE;
357    }
358 
359    assert(stencilBits <= 8);
360    rb->InternalFormat = GL_STENCIL_INDEX8;
361 
362    rb->AllocStorage = soft_renderbuffer_storage;
363    _mesa_add_renderbuffer(fb, BUFFER_STENCIL, rb);
364 
365    return GL_TRUE;
366 }
367 
368 
369 static GLboolean
add_depth_stencil_renderbuffer(struct gl_context * ctx,struct gl_framebuffer * fb)370 add_depth_stencil_renderbuffer(struct gl_context *ctx,
371                                struct gl_framebuffer *fb)
372 {
373    struct gl_renderbuffer *rb;
374 
375    assert(fb->Attachment[BUFFER_DEPTH].Renderbuffer == NULL);
376    assert(fb->Attachment[BUFFER_STENCIL].Renderbuffer == NULL);
377 
378    rb = _swrast_new_soft_renderbuffer(ctx, 0);
379    if (!rb) {
380       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating depth+stencil buffer");
381       return GL_FALSE;
382    }
383 
384    rb->InternalFormat = GL_DEPTH_STENCIL;
385 
386    rb->AllocStorage = soft_renderbuffer_storage;
387    _mesa_add_renderbuffer(fb, BUFFER_DEPTH, rb);
388    _mesa_add_renderbuffer(fb, BUFFER_STENCIL, rb);
389 
390    return GL_TRUE;
391 }
392 
393 
394 /**
395  * Add a software-based accumulation renderbuffer to the given framebuffer.
396  * This is a helper routine for device drivers when creating a
397  * window system framebuffer (not a user-created render/framebuffer).
398  * Once this function is called, you can basically forget about this
399  * renderbuffer; core Mesa will handle all the buffer management and
400  * rendering!
401  */
402 static GLboolean
add_accum_renderbuffer(struct gl_context * ctx,struct gl_framebuffer * fb,GLuint redBits,GLuint greenBits,GLuint blueBits,GLuint alphaBits)403 add_accum_renderbuffer(struct gl_context *ctx, struct gl_framebuffer *fb,
404                        GLuint redBits, GLuint greenBits,
405                        GLuint blueBits, GLuint alphaBits)
406 {
407    struct gl_renderbuffer *rb;
408 
409    if (redBits > 16 || greenBits > 16 || blueBits > 16 || alphaBits > 16) {
410       _mesa_problem(ctx,
411                     "Unsupported accumBits in add_accum_renderbuffer");
412       return GL_FALSE;
413    }
414 
415    assert(fb->Attachment[BUFFER_ACCUM].Renderbuffer == NULL);
416 
417    rb = _swrast_new_soft_renderbuffer(ctx, 0);
418    if (!rb) {
419       _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating accum buffer");
420       return GL_FALSE;
421    }
422 
423    rb->InternalFormat = GL_RGBA16_SNORM;
424    rb->AllocStorage = soft_renderbuffer_storage;
425    _mesa_add_renderbuffer(fb, BUFFER_ACCUM, rb);
426 
427    return GL_TRUE;
428 }
429 
430 
431 
432 /**
433  * Add a software-based aux renderbuffer to the given framebuffer.
434  * This is a helper routine for device drivers when creating a
435  * window system framebuffer (not a user-created render/framebuffer).
436  * Once this function is called, you can basically forget about this
437  * renderbuffer; core Mesa will handle all the buffer management and
438  * rendering!
439  *
440  * NOTE: color-index aux buffers not supported.
441  */
442 static GLboolean
add_aux_renderbuffers(struct gl_context * ctx,struct gl_framebuffer * fb,GLuint colorBits,GLuint numBuffers)443 add_aux_renderbuffers(struct gl_context *ctx, struct gl_framebuffer *fb,
444                       GLuint colorBits, GLuint numBuffers)
445 {
446    GLuint i;
447 
448    if (colorBits > 16) {
449       _mesa_problem(ctx,
450                     "Unsupported colorBits in add_aux_renderbuffers");
451       return GL_FALSE;
452    }
453 
454    assert(numBuffers <= MAX_AUX_BUFFERS);
455 
456    for (i = 0; i < numBuffers; i++) {
457       struct gl_renderbuffer *rb = _swrast_new_soft_renderbuffer(ctx, 0);
458 
459       assert(fb->Attachment[BUFFER_AUX0 + i].Renderbuffer == NULL);
460 
461       if (!rb) {
462          _mesa_error(ctx, GL_OUT_OF_MEMORY, "Allocating aux buffer");
463          return GL_FALSE;
464       }
465 
466       assert (colorBits <= 8);
467       rb->InternalFormat = GL_RGBA;
468 
469       rb->AllocStorage = soft_renderbuffer_storage;
470       _mesa_add_renderbuffer(fb, BUFFER_AUX0 + i, rb);
471    }
472    return GL_TRUE;
473 }
474 
475 
476 /**
477  * Create/attach software-based renderbuffers to the given framebuffer.
478  * This is a helper routine for device drivers.  Drivers can just as well
479  * call the individual _mesa_add_*_renderbuffer() routines directly.
480  */
481 void
_swrast_add_soft_renderbuffers(struct gl_framebuffer * fb,GLboolean color,GLboolean depth,GLboolean stencil,GLboolean accum,GLboolean alpha,GLboolean aux)482 _swrast_add_soft_renderbuffers(struct gl_framebuffer *fb,
483                                GLboolean color,
484                                GLboolean depth,
485                                GLboolean stencil,
486                                GLboolean accum,
487                                GLboolean alpha,
488                                GLboolean aux)
489 {
490    GLboolean frontLeft = GL_TRUE;
491    GLboolean backLeft = fb->Visual.doubleBufferMode;
492    GLboolean frontRight = fb->Visual.stereoMode;
493    GLboolean backRight = fb->Visual.stereoMode && fb->Visual.doubleBufferMode;
494 
495    if (color) {
496       assert(fb->Visual.redBits == fb->Visual.greenBits);
497       assert(fb->Visual.redBits == fb->Visual.blueBits);
498       add_color_renderbuffers(NULL, fb,
499                               fb->Visual.redBits,
500                               fb->Visual.alphaBits,
501                               frontLeft, backLeft,
502                               frontRight, backRight);
503    }
504 
505 #if 0
506    /* This is pretty much for debugging purposes only since there's a perf
507     * hit for using combined depth/stencil in swrast.
508     */
509    if (depth && fb->Visual.depthBits == 24 &&
510        stencil && fb->Visual.stencilBits == 8) {
511       /* use combined depth/stencil buffer */
512       add_depth_stencil_renderbuffer(NULL, fb);
513    }
514    else
515 #else
516    (void) add_depth_stencil_renderbuffer;
517 #endif
518    {
519       if (depth) {
520          assert(fb->Visual.depthBits > 0);
521          add_depth_renderbuffer(NULL, fb, fb->Visual.depthBits);
522       }
523 
524       if (stencil) {
525          assert(fb->Visual.stencilBits > 0);
526          add_stencil_renderbuffer(NULL, fb, fb->Visual.stencilBits);
527       }
528    }
529 
530    if (accum) {
531       assert(fb->Visual.accumRedBits > 0);
532       assert(fb->Visual.accumGreenBits > 0);
533       assert(fb->Visual.accumBlueBits > 0);
534       add_accum_renderbuffer(NULL, fb,
535                              fb->Visual.accumRedBits,
536                              fb->Visual.accumGreenBits,
537                              fb->Visual.accumBlueBits,
538                              fb->Visual.accumAlphaBits);
539    }
540 
541    if (aux) {
542       assert(fb->Visual.numAuxBuffers > 0);
543       add_aux_renderbuffers(NULL, fb, fb->Visual.redBits,
544                             fb->Visual.numAuxBuffers);
545    }
546 
547 #if 0
548    if (multisample) {
549       /* maybe someday */
550    }
551 #endif
552 }
553 
554 
555 
556 static void
map_attachment(struct gl_context * ctx,struct gl_framebuffer * fb,gl_buffer_index buffer)557 map_attachment(struct gl_context *ctx,
558                  struct gl_framebuffer *fb,
559                  gl_buffer_index buffer)
560 {
561    struct gl_texture_object *texObj = fb->Attachment[buffer].Texture;
562    struct gl_renderbuffer *rb = fb->Attachment[buffer].Renderbuffer;
563    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
564 
565    if (texObj) {
566       /* map texture image (render to texture) */
567       const GLuint level = fb->Attachment[buffer].TextureLevel;
568       const GLuint face = fb->Attachment[buffer].CubeMapFace;
569       const GLuint slice = fb->Attachment[buffer].Zoffset;
570       struct gl_texture_image *texImage = texObj->Image[face][level];
571       if (texImage) {
572          ctx->Driver.MapTextureImage(ctx, texImage, slice,
573                                      0, 0, texImage->Width, texImage->Height,
574                                      GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
575                                      &srb->Map, &srb->RowStride);
576       }
577    }
578    else if (rb) {
579       /* Map ordinary renderbuffer */
580       ctx->Driver.MapRenderbuffer(ctx, rb,
581                                   0, 0, rb->Width, rb->Height,
582                                   GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
583                                   &srb->Map, &srb->RowStride);
584    }
585 
586    assert(srb->Map);
587 }
588 
589 
590 static void
unmap_attachment(struct gl_context * ctx,struct gl_framebuffer * fb,gl_buffer_index buffer)591 unmap_attachment(struct gl_context *ctx,
592                    struct gl_framebuffer *fb,
593                    gl_buffer_index buffer)
594 {
595    struct gl_texture_object *texObj = fb->Attachment[buffer].Texture;
596    struct gl_renderbuffer *rb = fb->Attachment[buffer].Renderbuffer;
597    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
598 
599    if (texObj) {
600       /* unmap texture image (render to texture) */
601       const GLuint level = fb->Attachment[buffer].TextureLevel;
602       const GLuint face = fb->Attachment[buffer].CubeMapFace;
603       const GLuint slice = fb->Attachment[buffer].Zoffset;
604       struct gl_texture_image *texImage = texObj->Image[face][level];
605       if (texImage) {
606          ctx->Driver.UnmapTextureImage(ctx, texImage, slice);
607       }
608    }
609    else if (rb) {
610       /* unmap ordinary renderbuffer */
611       ctx->Driver.UnmapRenderbuffer(ctx, rb);
612    }
613 
614    srb->Map = NULL;
615 }
616 
617 
618 /**
619  * Determine what type to use (ubyte vs. float) for span colors for the
620  * given renderbuffer.
621  * See also _swrast_write_rgba_span().
622  */
623 static void
find_renderbuffer_colortype(struct gl_renderbuffer * rb)624 find_renderbuffer_colortype(struct gl_renderbuffer *rb)
625 {
626    struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
627    GLuint rbMaxBits = _mesa_get_format_max_bits(rb->Format);
628    GLenum rbDatatype = _mesa_get_format_datatype(rb->Format);
629 
630    if (rbDatatype == GL_UNSIGNED_NORMALIZED && rbMaxBits <= 8) {
631       /* the buffer's values fit in GLubyte values */
632       srb->ColorType = GL_UNSIGNED_BYTE;
633    }
634    else {
635       /* use floats otherwise */
636       srb->ColorType = GL_FLOAT;
637    }
638 }
639 
640 
641 /**
642  * Map the renderbuffers we'll use for tri/line/point rendering.
643  */
644 void
_swrast_map_renderbuffers(struct gl_context * ctx)645 _swrast_map_renderbuffers(struct gl_context *ctx)
646 {
647    struct gl_framebuffer *fb = ctx->DrawBuffer;
648    struct gl_renderbuffer *depthRb, *stencilRb;
649    GLuint buf;
650 
651    depthRb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
652    if (depthRb) {
653       /* map depth buffer */
654       map_attachment(ctx, fb, BUFFER_DEPTH);
655    }
656 
657    stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
658    if (stencilRb && stencilRb != depthRb) {
659       /* map stencil buffer */
660       map_attachment(ctx, fb, BUFFER_STENCIL);
661    }
662 
663    for (buf = 0; buf < fb->_NumColorDrawBuffers; buf++) {
664       map_attachment(ctx, fb, fb->_ColorDrawBufferIndexes[buf]);
665       find_renderbuffer_colortype(fb->_ColorDrawBuffers[buf]);
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       unmap_attachment(ctx, fb, fb->_ColorDrawBufferIndexes[buf]);
694    }
695 }
696