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[mesa.git] / src / mesa / swrast / s_depth.c
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 #include "main/glheader.h"
27 #include "main/context.h"
28 #include "main/formats.h"
29 #include "main/format_unpack.h"
30 #include "main/format_pack.h"
31 #include "main/macros.h"
32 #include "main/imports.h"
33
34 #include "s_context.h"
35 #include "s_depth.h"
36 #include "s_span.h"
37
38
39
40 #define Z_TEST(COMPARE) \
41 do { \
42 GLuint i; \
43 for (i = 0; i < n; i++) { \
44 if (mask[i]) { \
45 if (COMPARE) { \
46 /* pass */ \
47 if (write) { \
48 zbuffer[i] = zfrag[i]; \
49 } \
50 passed++; \
51 } \
52 else { \
53 /* fail */ \
54 mask[i] = 0; \
55 } \
56 } \
57 } \
58 } while (0)
59
60
61 /**
62 * Do depth test for an array of 16-bit Z values.
63 * @param zbuffer array of Z buffer values (16-bit)
64 * @param zfrag array of fragment Z values (use 16-bit in 32-bit uint)
65 * @param mask which fragments are alive, killed afterward
66 * @return number of fragments which pass the test.
67 */
68 static GLuint
69 depth_test_span16( struct gl_context *ctx, GLuint n,
70 GLushort zbuffer[], const GLuint zfrag[], GLubyte mask[] )
71 {
72 const GLboolean write = ctx->Depth.Mask;
73 GLuint passed = 0;
74
75 /* switch cases ordered from most frequent to less frequent */
76 switch (ctx->Depth.Func) {
77 case GL_LESS:
78 Z_TEST(zfrag[i] < zbuffer[i]);
79 break;
80 case GL_LEQUAL:
81 Z_TEST(zfrag[i] <= zbuffer[i]);
82 break;
83 case GL_GEQUAL:
84 Z_TEST(zfrag[i] >= zbuffer[i]);
85 break;
86 case GL_GREATER:
87 Z_TEST(zfrag[i] > zbuffer[i]);
88 break;
89 case GL_NOTEQUAL:
90 Z_TEST(zfrag[i] != zbuffer[i]);
91 break;
92 case GL_EQUAL:
93 Z_TEST(zfrag[i] == zbuffer[i]);
94 break;
95 case GL_ALWAYS:
96 Z_TEST(1);
97 break;
98 case GL_NEVER:
99 memset(mask, 0, n * sizeof(GLubyte));
100 break;
101 default:
102 _mesa_problem(ctx, "Bad depth func in depth_test_span16");
103 }
104
105 return passed;
106 }
107
108
109 /**
110 * Do depth test for an array of 32-bit Z values.
111 * @param zbuffer array of Z buffer values (32-bit)
112 * @param zfrag array of fragment Z values (use 32-bits in 32-bit uint)
113 * @param mask which fragments are alive, killed afterward
114 * @return number of fragments which pass the test.
115 */
116 static GLuint
117 depth_test_span32( struct gl_context *ctx, GLuint n,
118 GLuint zbuffer[], const GLuint zfrag[], GLubyte mask[])
119 {
120 const GLboolean write = ctx->Depth.Mask;
121 GLuint passed = 0;
122
123 /* switch cases ordered from most frequent to less frequent */
124 switch (ctx->Depth.Func) {
125 case GL_LESS:
126 Z_TEST(zfrag[i] < zbuffer[i]);
127 break;
128 case GL_LEQUAL:
129 Z_TEST(zfrag[i] <= zbuffer[i]);
130 break;
131 case GL_GEQUAL:
132 Z_TEST(zfrag[i] >= zbuffer[i]);
133 break;
134 case GL_GREATER:
135 Z_TEST(zfrag[i] > zbuffer[i]);
136 break;
137 case GL_NOTEQUAL:
138 Z_TEST(zfrag[i] != zbuffer[i]);
139 break;
140 case GL_EQUAL:
141 Z_TEST(zfrag[i] == zbuffer[i]);
142 break;
143 case GL_ALWAYS:
144 Z_TEST(1);
145 break;
146 case GL_NEVER:
147 memset(mask, 0, n * sizeof(GLubyte));
148 break;
149 default:
150 _mesa_problem(ctx, "Bad depth func in depth_test_span32");
151 }
152
153 return passed;
154 }
155
156
157 /**
158 * Clamp fragment Z values to the depth near/far range (glDepthRange()).
159 * This is used when GL_ARB_depth_clamp/GL_DEPTH_CLAMP is turned on.
160 * In that case, vertexes are not clipped against the near/far planes
161 * so rasterization will produce fragment Z values outside the usual
162 * [0,1] range.
163 */
164 void
165 _swrast_depth_clamp_span( struct gl_context *ctx, SWspan *span )
166 {
167 struct gl_framebuffer *fb = ctx->DrawBuffer;
168 const GLuint count = span->end;
169 GLint *zValues = (GLint *) span->array->z; /* sign change */
170 GLint min, max;
171 GLfloat min_f, max_f;
172 GLuint i;
173
174 if (ctx->ViewportArray[0].Near < ctx->ViewportArray[0].Far) {
175 min_f = ctx->ViewportArray[0].Near;
176 max_f = ctx->ViewportArray[0].Far;
177 } else {
178 min_f = ctx->ViewportArray[0].Far;
179 max_f = ctx->ViewportArray[0].Near;
180 }
181
182 /* Convert floating point values in [0,1] to device Z coordinates in
183 * [0, DepthMax].
184 * ex: If the Z buffer has 24 bits, DepthMax = 0xffffff.
185 *
186 * XXX this all falls apart if we have 31 or more bits of Z because
187 * the triangle rasterization code produces unsigned Z values. Negative
188 * vertex Z values come out as large fragment Z uints.
189 */
190 min = (GLint) (min_f * fb->_DepthMaxF);
191 max = (GLint) (max_f * fb->_DepthMaxF);
192 if (max < 0)
193 max = 0x7fffffff; /* catch over flow for 30-bit z */
194
195 /* Note that we do the comparisons here using signed integers.
196 */
197 for (i = 0; i < count; i++) {
198 if (zValues[i] < min)
199 zValues[i] = min;
200 if (zValues[i] > max)
201 zValues[i] = max;
202 }
203 }
204
205
206 /**
207 * Get array of 32-bit z values from the depth buffer. With clipping.
208 * Note: the returned values are always in the range [0, 2^32-1].
209 */
210 static void
211 get_z32_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
212 GLuint count, const GLint x[], const GLint y[],
213 GLuint zbuffer[])
214 {
215 struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
216 const GLint w = rb->Width, h = rb->Height;
217 const GLubyte *map = _swrast_pixel_address(rb, 0, 0);
218 GLuint i;
219
220 if (rb->Format == MESA_FORMAT_Z_UNORM32) {
221 const GLint rowStride = srb->RowStride;
222 for (i = 0; i < count; i++) {
223 if (x[i] >= 0 && y[i] >= 0 && x[i] < w && y[i] < h) {
224 zbuffer[i] = *((GLuint *) (map + y[i] * rowStride + x[i] * 4));
225 }
226 }
227 }
228 else {
229 const GLint bpp = _mesa_get_format_bytes(rb->Format);
230 const GLint rowStride = srb->RowStride;
231 for (i = 0; i < count; i++) {
232 if (x[i] >= 0 && y[i] >= 0 && x[i] < w && y[i] < h) {
233 const GLubyte *src = map + y[i] * rowStride+ x[i] * bpp;
234 _mesa_unpack_uint_z_row(rb->Format, 1, src, &zbuffer[i]);
235 }
236 }
237 }
238 }
239
240
241 /**
242 * Put an array of 32-bit z values into the depth buffer.
243 * Note: the z values are always in the range [0, 2^32-1].
244 */
245 static void
246 put_z32_values(struct gl_context *ctx, struct gl_renderbuffer *rb,
247 GLuint count, const GLint x[], const GLint y[],
248 const GLuint zvalues[], const GLubyte mask[])
249 {
250 struct swrast_renderbuffer *srb = swrast_renderbuffer(rb);
251 const GLint w = rb->Width, h = rb->Height;
252 GLubyte *map = _swrast_pixel_address(rb, 0, 0);
253 GLuint i;
254
255 if (rb->Format == MESA_FORMAT_Z_UNORM32) {
256 const GLint rowStride = srb->RowStride;
257 for (i = 0; i < count; i++) {
258 if (mask[i] && x[i] >= 0 && y[i] >= 0 && x[i] < w && y[i] < h) {
259 GLuint *dst = (GLuint *) (map + y[i] * rowStride + x[i] * 4);
260 *dst = zvalues[i];
261 }
262 }
263 }
264 else {
265 mesa_pack_uint_z_func packZ = _mesa_get_pack_uint_z_func(rb->Format);
266 const GLint bpp = _mesa_get_format_bytes(rb->Format);
267 const GLint rowStride = srb->RowStride;
268 for (i = 0; i < count; i++) {
269 if (mask[i] && x[i] >= 0 && y[i] >= 0 && x[i] < w && y[i] < h) {
270 void *dst = map + y[i] * rowStride + x[i] * bpp;
271 packZ(zvalues + i, dst);
272 }
273 }
274 }
275 }
276
277
278 /**
279 * Apply depth (Z) buffer testing to the span.
280 * \return approx number of pixels that passed (only zero is reliable)
281 */
282 GLuint
283 _swrast_depth_test_span(struct gl_context *ctx, SWspan *span)
284 {
285 struct gl_framebuffer *fb = ctx->DrawBuffer;
286 struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
287 const GLint bpp = _mesa_get_format_bytes(rb->Format);
288 void *zStart;
289 const GLuint count = span->end;
290 const GLuint *fragZ = span->array->z;
291 GLubyte *mask = span->array->mask;
292 void *zBufferVals;
293 GLuint *zBufferTemp = NULL;
294 GLuint passed;
295 GLuint zBits = _mesa_get_format_bits(rb->Format, GL_DEPTH_BITS);
296 GLboolean ztest16 = GL_FALSE;
297
298 if (span->arrayMask & SPAN_XY)
299 zStart = NULL;
300 else
301 zStart = _swrast_pixel_address(rb, span->x, span->y);
302
303 if (rb->Format == MESA_FORMAT_Z_UNORM16 && !(span->arrayMask & SPAN_XY)) {
304 /* directly read/write row of 16-bit Z values */
305 zBufferVals = zStart;
306 ztest16 = GL_TRUE;
307 }
308 else if (rb->Format == MESA_FORMAT_Z_UNORM32 && !(span->arrayMask & SPAN_XY)) {
309 /* directly read/write row of 32-bit Z values */
310 zBufferVals = zStart;
311 }
312 else {
313 /* copy Z buffer values into temp buffer (32-bit Z values) */
314 zBufferTemp = malloc(count * sizeof(GLuint));
315 if (!zBufferTemp)
316 return 0;
317
318 if (span->arrayMask & SPAN_XY) {
319 get_z32_values(ctx, rb, count,
320 span->array->x, span->array->y, zBufferTemp);
321 }
322 else {
323 _mesa_unpack_uint_z_row(rb->Format, count, zStart, zBufferTemp);
324 }
325
326 if (zBits == 24) {
327 GLuint i;
328 /* Convert depth buffer values from 32 to 24 bits to match the
329 * fragment Z values generated by rasterization.
330 */
331 for (i = 0; i < count; i++) {
332 zBufferTemp[i] >>= 8;
333 }
334 }
335 else if (zBits == 16) {
336 GLuint i;
337 /* Convert depth buffer values from 32 to 16 bits */
338 for (i = 0; i < count; i++) {
339 zBufferTemp[i] >>= 16;
340 }
341 }
342 else {
343 assert(zBits == 32);
344 }
345
346 zBufferVals = zBufferTemp;
347 }
348
349 /* do the depth test either with 16 or 32-bit values */
350 if (ztest16)
351 passed = depth_test_span16(ctx, count, zBufferVals, fragZ, mask);
352 else
353 passed = depth_test_span32(ctx, count, zBufferVals, fragZ, mask);
354
355 if (zBufferTemp) {
356 /* need to write temp Z values back into the buffer */
357
358 /* Convert depth buffer values back to 32-bit values. The least
359 * significant bits don't matter since they'll get dropped when
360 * they're packed back into the depth buffer.
361 */
362 if (zBits == 24) {
363 GLuint i;
364 for (i = 0; i < count; i++) {
365 zBufferTemp[i] = (zBufferTemp[i] << 8);
366 }
367 }
368 else if (zBits == 16) {
369 GLuint i;
370 for (i = 0; i < count; i++) {
371 zBufferTemp[i] = zBufferTemp[i] << 16;
372 }
373 }
374
375 if (span->arrayMask & SPAN_XY) {
376 /* random locations */
377 put_z32_values(ctx, rb, count, span->array->x, span->array->y,
378 zBufferTemp, mask);
379 }
380 else {
381 /* horizontal row */
382 mesa_pack_uint_z_func packZ = _mesa_get_pack_uint_z_func(rb->Format);
383 GLubyte *dst = zStart;
384 GLuint i;
385 for (i = 0; i < count; i++) {
386 if (mask[i]) {
387 packZ(&zBufferTemp[i], dst);
388 }
389 dst += bpp;
390 }
391 }
392
393 free(zBufferTemp);
394 }
395
396 if (passed < count) {
397 span->writeAll = GL_FALSE;
398 }
399 return passed;
400 }
401
402
403 /**
404 * GL_EXT_depth_bounds_test extension.
405 * Discard fragments depending on whether the corresponding Z-buffer
406 * values are outside the depth bounds test range.
407 * Note: we test the Z buffer values, not the fragment Z values!
408 * \return GL_TRUE if any fragments pass, GL_FALSE if no fragments pass
409 */
410 GLboolean
411 _swrast_depth_bounds_test( struct gl_context *ctx, SWspan *span )
412 {
413 struct gl_framebuffer *fb = ctx->DrawBuffer;
414 struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
415 GLubyte *zStart;
416 GLuint zMin = (GLuint)((double)ctx->Depth.BoundsMin * 0xffffffff);
417 GLuint zMax = (GLuint)((double)ctx->Depth.BoundsMax * 0xffffffff);
418 GLubyte *mask = span->array->mask;
419 const GLuint count = span->end;
420 GLuint i;
421 GLboolean anyPass = GL_FALSE;
422 GLuint *zBufferTemp;
423 const GLuint *zBufferVals;
424
425 zBufferTemp = malloc(count * sizeof(GLuint));
426 if (!zBufferTemp) {
427 /* don't generate a stream of OUT_OF_MEMORY errors here */
428 return GL_FALSE;
429 }
430
431 if (span->arrayMask & SPAN_XY)
432 zStart = NULL;
433 else
434 zStart = _swrast_pixel_address(rb, span->x, span->y);
435
436 if (rb->Format == MESA_FORMAT_Z_UNORM32 && !(span->arrayMask & SPAN_XY)) {
437 /* directly access 32-bit values in the depth buffer */
438 zBufferVals = (const GLuint *) zStart;
439 }
440 else {
441 /* Round the bounds to the precision of the zbuffer. */
442 if (rb->Format == MESA_FORMAT_Z_UNORM16) {
443 zMin = (zMin & 0xffff0000) | (zMin >> 16);
444 zMax = (zMax & 0xffff0000) | (zMax >> 16);
445 } else {
446 /* 24 bits */
447 zMin = (zMin & 0xffffff00) | (zMin >> 24);
448 zMax = (zMax & 0xffffff00) | (zMax >> 24);
449 }
450
451 /* unpack Z values into a temporary array */
452 if (span->arrayMask & SPAN_XY) {
453 get_z32_values(ctx, rb, count, span->array->x, span->array->y,
454 zBufferTemp);
455 }
456 else {
457 _mesa_unpack_uint_z_row(rb->Format, count, zStart, zBufferTemp);
458 }
459 zBufferVals = zBufferTemp;
460 }
461
462 /* Now do the tests */
463 for (i = 0; i < count; i++) {
464 if (mask[i]) {
465 if (zBufferVals[i] < zMin || zBufferVals[i] > zMax)
466 mask[i] = GL_FALSE;
467 else
468 anyPass = GL_TRUE;
469 }
470 }
471
472 free(zBufferTemp);
473
474 return anyPass;
475 }
476
477
478
479 /**********************************************************************/
480 /***** Read Depth Buffer *****/
481 /**********************************************************************/
482
483
484 /**
485 * Read a span of depth values from the given depth renderbuffer, returning
486 * the values as GLfloats.
487 * This function does clipping to prevent reading outside the depth buffer's
488 * bounds.
489 */
490 void
491 _swrast_read_depth_span_float(struct gl_context *ctx,
492 struct gl_renderbuffer *rb,
493 GLint n, GLint x, GLint y, GLfloat depth[])
494 {
495 if (!rb) {
496 /* really only doing this to prevent FP exceptions later */
497 memset(depth, 0, n * sizeof(GLfloat));
498 return;
499 }
500
501 if (y < 0 || y >= (GLint) rb->Height ||
502 x + n <= 0 || x >= (GLint) rb->Width) {
503 /* span is completely outside framebuffer */
504 memset(depth, 0, n * sizeof(GLfloat));
505 return;
506 }
507
508 if (x < 0) {
509 GLint dx = -x;
510 GLint i;
511 for (i = 0; i < dx; i++)
512 depth[i] = 0.0;
513 x = 0;
514 n -= dx;
515 depth += dx;
516 }
517 if (x + n > (GLint) rb->Width) {
518 GLint dx = x + n - (GLint) rb->Width;
519 GLint i;
520 for (i = 0; i < dx; i++)
521 depth[n - i - 1] = 0.0;
522 n -= dx;
523 }
524 if (n <= 0) {
525 return;
526 }
527
528 _mesa_unpack_float_z_row(rb->Format, n, _swrast_pixel_address(rb, x, y),
529 depth);
530 }
531
532
533 /**
534 * Clear the given z/depth renderbuffer. If the buffer is a combined
535 * depth+stencil buffer, only the Z bits will be touched.
536 */
537 void
538 _swrast_clear_depth_buffer(struct gl_context *ctx)
539 {
540 struct gl_renderbuffer *rb =
541 ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
542 GLint x, y, width, height;
543 GLubyte *map;
544 GLint rowStride, i, j;
545 GLbitfield mapMode;
546
547 if (!rb || !ctx->Depth.Mask) {
548 /* no depth buffer, or writing to it is disabled */
549 return;
550 }
551
552 /* compute region to clear */
553 x = ctx->DrawBuffer->_Xmin;
554 y = ctx->DrawBuffer->_Ymin;
555 width = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
556 height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
557
558 mapMode = GL_MAP_WRITE_BIT;
559 if (rb->Format == MESA_FORMAT_Z24_UNORM_S8_UINT ||
560 rb->Format == MESA_FORMAT_Z24_UNORM_X8_UINT ||
561 rb->Format == MESA_FORMAT_S8_UINT_Z24_UNORM ||
562 rb->Format == MESA_FORMAT_X8_UINT_Z24_UNORM) {
563 mapMode |= GL_MAP_READ_BIT;
564 }
565
566 ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height,
567 mapMode, &map, &rowStride,
568 ctx->DrawBuffer->FlipY);
569 if (!map) {
570 _mesa_error(ctx, GL_OUT_OF_MEMORY, "glClear(depth)");
571 return;
572 }
573
574 switch (rb->Format) {
575 case MESA_FORMAT_Z_UNORM16:
576 {
577 GLfloat clear = (GLfloat) ctx->Depth.Clear;
578 GLushort clearVal = 0;
579 _mesa_pack_float_z_row(rb->Format, 1, &clear, &clearVal);
580 if (clearVal == 0xffff && width * 2 == rowStride) {
581 /* common case */
582 memset(map, 0xff, width * height * 2);
583 }
584 else {
585 for (i = 0; i < height; i++) {
586 GLushort *row = (GLushort *) map;
587 for (j = 0; j < width; j++) {
588 row[j] = clearVal;
589 }
590 map += rowStride;
591 }
592 }
593 }
594 break;
595 case MESA_FORMAT_Z_UNORM32:
596 case MESA_FORMAT_Z_FLOAT32:
597 {
598 GLfloat clear = (GLfloat) ctx->Depth.Clear;
599 GLuint clearVal = 0;
600 _mesa_pack_float_z_row(rb->Format, 1, &clear, &clearVal);
601 for (i = 0; i < height; i++) {
602 GLuint *row = (GLuint *) map;
603 for (j = 0; j < width; j++) {
604 row[j] = clearVal;
605 }
606 map += rowStride;
607 }
608 }
609 break;
610 case MESA_FORMAT_Z24_UNORM_S8_UINT:
611 case MESA_FORMAT_Z24_UNORM_X8_UINT:
612 case MESA_FORMAT_S8_UINT_Z24_UNORM:
613 case MESA_FORMAT_X8_UINT_Z24_UNORM:
614 {
615 GLfloat clear = (GLfloat) ctx->Depth.Clear;
616 GLuint clearVal = 0;
617 GLuint mask;
618
619 if (rb->Format == MESA_FORMAT_Z24_UNORM_S8_UINT ||
620 rb->Format == MESA_FORMAT_Z24_UNORM_X8_UINT)
621 mask = 0xff000000;
622 else
623 mask = 0xff;
624
625 _mesa_pack_float_z_row(rb->Format, 1, &clear, &clearVal);
626 for (i = 0; i < height; i++) {
627 GLuint *row = (GLuint *) map;
628 for (j = 0; j < width; j++) {
629 row[j] = (row[j] & mask) | clearVal;
630 }
631 map += rowStride;
632 }
633
634 }
635 break;
636 case MESA_FORMAT_Z32_FLOAT_S8X24_UINT:
637 /* XXX untested */
638 {
639 GLfloat clearVal = (GLfloat) ctx->Depth.Clear;
640 for (i = 0; i < height; i++) {
641 GLfloat *row = (GLfloat *) map;
642 for (j = 0; j < width; j++) {
643 row[j * 2] = clearVal;
644 }
645 map += rowStride;
646 }
647 }
648 break;
649 default:
650 _mesa_problem(ctx, "Unexpected depth buffer format %s"
651 " in _swrast_clear_depth_buffer()",
652 _mesa_get_format_name(rb->Format));
653 }
654
655 ctx->Driver.UnmapRenderbuffer(ctx, rb);
656 }
657
658
659
660
661 /**
662 * Clear both depth and stencil values in a combined depth+stencil buffer.
663 */
664 void
665 _swrast_clear_depth_stencil_buffer(struct gl_context *ctx)
666 {
667 const GLubyte stencilBits = ctx->DrawBuffer->Visual.stencilBits;
668 const GLuint writeMask = ctx->Stencil.WriteMask[0];
669 const GLuint stencilMax = (1 << stencilBits) - 1;
670 struct gl_renderbuffer *rb =
671 ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
672 GLint x, y, width, height;
673 GLbitfield mapMode;
674 GLubyte *map;
675 GLint rowStride, i, j;
676
677 /* check that we really have a combined depth+stencil buffer */
678 assert(rb == ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer);
679
680 /* compute region to clear */
681 x = ctx->DrawBuffer->_Xmin;
682 y = ctx->DrawBuffer->_Ymin;
683 width = ctx->DrawBuffer->_Xmax - ctx->DrawBuffer->_Xmin;
684 height = ctx->DrawBuffer->_Ymax - ctx->DrawBuffer->_Ymin;
685
686 mapMode = GL_MAP_WRITE_BIT;
687 if ((writeMask & stencilMax) != stencilMax) {
688 /* need to mask stencil values */
689 mapMode |= GL_MAP_READ_BIT;
690 }
691
692 ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height,
693 mapMode, &map, &rowStride,
694 ctx->DrawBuffer->FlipY);
695 if (!map) {
696 _mesa_error(ctx, GL_OUT_OF_MEMORY, "glClear(depth+stencil)");
697 return;
698 }
699
700 switch (rb->Format) {
701 case MESA_FORMAT_Z24_UNORM_S8_UINT:
702 case MESA_FORMAT_S8_UINT_Z24_UNORM:
703 {
704 GLfloat zClear = (GLfloat) ctx->Depth.Clear;
705 GLuint clear = 0, mask;
706
707 _mesa_pack_float_z_row(rb->Format, 1, &zClear, &clear);
708
709 if (rb->Format == MESA_FORMAT_Z24_UNORM_S8_UINT) {
710 mask = ((~writeMask) & 0xff) << 24;
711 clear |= (ctx->Stencil.Clear & writeMask & 0xff) << 24;
712 }
713 else {
714 mask = ((~writeMask) & 0xff);
715 clear |= (ctx->Stencil.Clear & writeMask & 0xff);
716 }
717
718 for (i = 0; i < height; i++) {
719 GLuint *row = (GLuint *) map;
720 if (mask != 0x0) {
721 for (j = 0; j < width; j++) {
722 row[j] = (row[j] & mask) | clear;
723 }
724 }
725 else {
726 for (j = 0; j < width; j++) {
727 row[j] = clear;
728 }
729 }
730 map += rowStride;
731 }
732 }
733 break;
734 case MESA_FORMAT_Z32_FLOAT_S8X24_UINT:
735 /* XXX untested */
736 {
737 const GLfloat zClear = (GLfloat) ctx->Depth.Clear;
738 const GLuint sClear = ctx->Stencil.Clear & writeMask;
739 const GLuint sMask = (~writeMask) & 0xff;
740 for (i = 0; i < height; i++) {
741 GLfloat *zRow = (GLfloat *) map;
742 GLuint *sRow = (GLuint *) map;
743 for (j = 0; j < width; j++) {
744 zRow[j * 2 + 0] = zClear;
745 }
746 if (sMask != 0) {
747 for (j = 0; j < width; j++) {
748 sRow[j * 2 + 1] = (sRow[j * 2 + 1] & sMask) | sClear;
749 }
750 }
751 else {
752 for (j = 0; j < width; j++) {
753 sRow[j * 2 + 1] = sClear;
754 }
755 }
756 map += rowStride;
757 }
758 }
759 break;
760 default:
761 _mesa_problem(ctx, "Unexpected depth buffer format %s"
762 " in _swrast_clear_depth_buffer()",
763 _mesa_get_format_name(rb->Format));
764 }
765
766 ctx->Driver.UnmapRenderbuffer(ctx, rb);
767
768 }