1 /*
2  * Mesa 3-D graphics library
3  * Version:  7.1
4  *
5  * Copyright (C) 1999-2008  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 #include "glheader.h"
26 #include "imports.h"
27 #include "bufferobj.h"
28 #include "context.h"
29 #include "enums.h"
30 #include "readpix.h"
31 #include "framebuffer.h"
32 #include "formats.h"
33 #include "format_unpack.h"
34 #include "image.h"
35 #include "mtypes.h"
36 #include "pack.h"
37 #include "pbo.h"
38 #include "state.h"
39 #include "glformats.h"
40 #include "fbobject.h"
41 #include "teximage.h"
42 
43 /* Inexplicably, GL_HALF_FLOAT_OES has a different value than GL_HALF_FLOAT.
44  */
45 #ifndef GL_HALF_FLOAT_OES
46 #define GL_HALF_FLOAT_OES 0x8D61
47 #endif
48 
49 /**
50  * Tries to implement glReadPixels() of GL_DEPTH_COMPONENT using memcpy of the
51  * mapping.
52  */
53 static GLboolean
fast_read_depth_pixels(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum type,GLvoid * pixels,const struct gl_pixelstore_attrib * packing)54 fast_read_depth_pixels( struct gl_context *ctx,
55 			GLint x, GLint y,
56 			GLsizei width, GLsizei height,
57 			GLenum type, GLvoid *pixels,
58 			const struct gl_pixelstore_attrib *packing )
59 {
60    struct gl_framebuffer *fb = ctx->ReadBuffer;
61    struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
62    GLubyte *map, *dst;
63    int stride, dstStride, j;
64 
65    if (ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0)
66       return GL_FALSE;
67 
68    if (packing->SwapBytes)
69       return GL_FALSE;
70 
71    if (_mesa_get_format_datatype(rb->Format) != GL_UNSIGNED_NORMALIZED)
72       return GL_FALSE;
73 
74    if (!((type == GL_UNSIGNED_SHORT && rb->Format == MESA_FORMAT_Z16) ||
75 	 type == GL_UNSIGNED_INT))
76       return GL_FALSE;
77 
78    ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
79 			       &map, &stride);
80 
81    if (!map) {
82       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
83       return GL_TRUE;  /* don't bother trying the slow path */
84    }
85 
86    dstStride = _mesa_image_row_stride(packing, width, GL_DEPTH_COMPONENT, type);
87    dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
88 					   GL_DEPTH_COMPONENT, type, 0, 0);
89 
90    for (j = 0; j < height; j++) {
91       if (type == GL_UNSIGNED_INT) {
92 	 _mesa_unpack_uint_z_row(rb->Format, width, map, (GLuint *)dst);
93       } else {
94 	 ASSERT(type == GL_UNSIGNED_SHORT && rb->Format == MESA_FORMAT_Z16);
95 	 memcpy(dst, map, width * 2);
96       }
97 
98       map += stride;
99       dst += dstStride;
100    }
101    ctx->Driver.UnmapRenderbuffer(ctx, rb);
102 
103    return GL_TRUE;
104 }
105 
106 /**
107  * Read pixels for format=GL_DEPTH_COMPONENT.
108  */
109 static void
read_depth_pixels(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum type,GLvoid * pixels,const struct gl_pixelstore_attrib * packing)110 read_depth_pixels( struct gl_context *ctx,
111                    GLint x, GLint y,
112                    GLsizei width, GLsizei height,
113                    GLenum type, GLvoid *pixels,
114                    const struct gl_pixelstore_attrib *packing )
115 {
116    struct gl_framebuffer *fb = ctx->ReadBuffer;
117    struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
118    GLint j;
119    GLubyte *dst, *map;
120    int dstStride, stride;
121    GLfloat *depthValues;
122 
123    if (!rb)
124       return;
125 
126    /* clipping should have been done already */
127    ASSERT(x >= 0);
128    ASSERT(y >= 0);
129    ASSERT(x + width <= (GLint) rb->Width);
130    ASSERT(y + height <= (GLint) rb->Height);
131 
132    if (fast_read_depth_pixels(ctx, x, y, width, height, type, pixels, packing))
133       return;
134 
135    dstStride = _mesa_image_row_stride(packing, width, GL_DEPTH_COMPONENT, type);
136    dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
137 					   GL_DEPTH_COMPONENT, type, 0, 0);
138 
139    ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
140 			       &map, &stride);
141    if (!map) {
142       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
143       return;
144    }
145 
146    depthValues = (GLfloat *) malloc(width * sizeof(GLfloat));
147 
148    if (depthValues) {
149       /* General case (slower) */
150       for (j = 0; j < height; j++, y++) {
151          _mesa_unpack_float_z_row(rb->Format, width, map, depthValues);
152          _mesa_pack_depth_span(ctx, width, dst, type, depthValues, packing);
153 
154          dst += dstStride;
155          map += stride;
156       }
157    }
158    else {
159       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
160    }
161 
162    free(depthValues);
163 
164    ctx->Driver.UnmapRenderbuffer(ctx, rb);
165 }
166 
167 
168 /**
169  * Read pixels for format=GL_STENCIL_INDEX.
170  */
171 static void
read_stencil_pixels(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum type,GLvoid * pixels,const struct gl_pixelstore_attrib * packing)172 read_stencil_pixels( struct gl_context *ctx,
173                      GLint x, GLint y,
174                      GLsizei width, GLsizei height,
175                      GLenum type, GLvoid *pixels,
176                      const struct gl_pixelstore_attrib *packing )
177 {
178    struct gl_framebuffer *fb = ctx->ReadBuffer;
179    struct gl_renderbuffer *rb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
180    GLint j;
181    GLubyte *map, *stencil;
182    GLint stride;
183 
184    if (!rb)
185       return;
186 
187    ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
188 			       &map, &stride);
189    if (!map) {
190       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
191       return;
192    }
193 
194    stencil = (GLubyte *) malloc(width * sizeof(GLubyte));
195 
196    if (stencil) {
197       /* process image row by row */
198       for (j = 0; j < height; j++) {
199          GLvoid *dest;
200 
201          _mesa_unpack_ubyte_stencil_row(rb->Format, width, map, stencil);
202          dest = _mesa_image_address2d(packing, pixels, width, height,
203                                       GL_STENCIL_INDEX, type, j, 0);
204 
205          _mesa_pack_stencil_span(ctx, width, type, dest, stencil, packing);
206 
207          map += stride;
208       }
209    }
210    else {
211       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
212    }
213 
214    free(stencil);
215 
216    ctx->Driver.UnmapRenderbuffer(ctx, rb);
217 }
218 
219 
220 /**
221  * Try to do glReadPixels of RGBA data using a simple memcpy or swizzle.
222  * \return GL_TRUE if successful, GL_FALSE otherwise (use the slow path)
223  */
224 static GLboolean
fast_read_rgba_pixels_memcpy(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum format,GLenum type,GLvoid * pixels,const struct gl_pixelstore_attrib * packing,GLbitfield transferOps)225 fast_read_rgba_pixels_memcpy( struct gl_context *ctx,
226 			      GLint x, GLint y,
227 			      GLsizei width, GLsizei height,
228 			      GLenum format, GLenum type,
229 			      GLvoid *pixels,
230 			      const struct gl_pixelstore_attrib *packing,
231 			      GLbitfield transferOps )
232 {
233    struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
234    GLubyte *dst, *map;
235    int dstStride, stride, j, texelBytes;
236    GLboolean swizzle_rb = GL_FALSE, copy_xrgb = GL_FALSE;
237 
238    /* XXX we could check for other swizzle/special cases here as needed */
239    if (rb->Format == MESA_FORMAT_RGBA8888_REV &&
240        format == GL_BGRA &&
241        type == GL_UNSIGNED_INT_8_8_8_8_REV &&
242        !ctx->Pack.SwapBytes) {
243       swizzle_rb = GL_TRUE;
244    }
245    else if (rb->Format == MESA_FORMAT_XRGB8888 &&
246        format == GL_BGRA &&
247        type == GL_UNSIGNED_INT_8_8_8_8_REV &&
248        !ctx->Pack.SwapBytes) {
249       copy_xrgb = GL_TRUE;
250    }
251    else if (!_mesa_format_matches_format_and_type(rb->Format, format, type,
252                                                   ctx->Pack.SwapBytes))
253       return GL_FALSE;
254 
255    /* If the format is unsigned normalized then we can ignore clamping
256     * because the values are already in the range [0,1] so it won't
257     * have any effect anyway.
258     */
259    if (_mesa_get_format_datatype(rb->Format) == GL_UNSIGNED_NORMALIZED)
260       transferOps &= ~IMAGE_CLAMP_BIT;
261 
262    if (transferOps)
263       return GL_FALSE;
264 
265    dstStride = _mesa_image_row_stride(packing, width, format, type);
266    dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
267 					   format, type, 0, 0);
268 
269    ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
270 			       &map, &stride);
271    if (!map) {
272       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
273       return GL_TRUE;  /* don't bother trying the slow path */
274    }
275 
276    texelBytes = _mesa_get_format_bytes(rb->Format);
277 
278    if (swizzle_rb) {
279       /* swap R/B */
280       for (j = 0; j < height; j++) {
281          int i;
282          for (i = 0; i < width; i++) {
283             GLuint *dst4 = (GLuint *) dst, *map4 = (GLuint *) map;
284             GLuint pixel = map4[i];
285             dst4[i] = (pixel & 0xff00ff00)
286                    | ((pixel & 0x00ff0000) >> 16)
287                    | ((pixel & 0x000000ff) << 16);
288          }
289          dst += dstStride;
290          map += stride;
291       }
292    } else if (copy_xrgb) {
293       /* convert xrgb -> argb */
294       for (j = 0; j < height; j++) {
295          GLuint *dst4 = (GLuint *) dst, *map4 = (GLuint *) map;
296          int i;
297          for (i = 0; i < width; i++) {
298             dst4[i] = map4[i] | 0xff000000;  /* set A=0xff */
299          }
300          dst += dstStride;
301          map += stride;
302       }
303    } else {
304       /* just memcpy */
305       for (j = 0; j < height; j++) {
306          memcpy(dst, map, width * texelBytes);
307          dst += dstStride;
308          map += stride;
309       }
310    }
311 
312    ctx->Driver.UnmapRenderbuffer(ctx, rb);
313 
314    return GL_TRUE;
315 }
316 
317 static void
slow_read_rgba_pixels(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum format,GLenum type,GLvoid * pixels,const struct gl_pixelstore_attrib * packing,GLbitfield transferOps)318 slow_read_rgba_pixels( struct gl_context *ctx,
319 		       GLint x, GLint y,
320 		       GLsizei width, GLsizei height,
321 		       GLenum format, GLenum type,
322 		       GLvoid *pixels,
323 		       const struct gl_pixelstore_attrib *packing,
324 		       GLbitfield transferOps )
325 {
326    struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
327    const gl_format rbFormat = _mesa_get_srgb_format_linear(rb->Format);
328    void *rgba;
329    GLubyte *dst, *map;
330    int dstStride, stride, j;
331    GLboolean dst_is_integer = _mesa_is_enum_format_integer(format);
332    GLboolean dst_is_uint = _mesa_is_format_unsigned(rbFormat);
333 
334    dstStride = _mesa_image_row_stride(packing, width, format, type);
335    dst = (GLubyte *) _mesa_image_address2d(packing, pixels, width, height,
336 					   format, type, 0, 0);
337 
338    ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
339 			       &map, &stride);
340    if (!map) {
341       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
342       return;
343    }
344 
345    rgba = malloc(width * MAX_PIXEL_BYTES);
346    if (!rgba)
347       goto done;
348 
349    for (j = 0; j < height; j++) {
350       if (dst_is_integer) {
351 	 _mesa_unpack_uint_rgba_row(rbFormat, width, map, (GLuint (*)[4]) rgba);
352          _mesa_rebase_rgba_uint(width, (GLuint (*)[4]) rgba,
353                                 rb->_BaseFormat);
354          if (dst_is_uint) {
355             _mesa_pack_rgba_span_from_uints(ctx, width, (GLuint (*)[4]) rgba, format,
356                                             type, dst);
357          } else {
358             _mesa_pack_rgba_span_from_ints(ctx, width, (GLint (*)[4]) rgba, format,
359                                            type, dst);
360          }
361       } else {
362 	 _mesa_unpack_rgba_row(rbFormat, width, map, (GLfloat (*)[4]) rgba);
363          _mesa_rebase_rgba_float(width, (GLfloat (*)[4]) rgba,
364                                  rb->_BaseFormat);
365 	 _mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) rgba, format,
366                                     type, dst, packing, transferOps);
367       }
368       dst += dstStride;
369       map += stride;
370    }
371 
372    free(rgba);
373 
374 done:
375    ctx->Driver.UnmapRenderbuffer(ctx, rb);
376 }
377 
378 /*
379  * Read R, G, B, A, RGB, L, or LA pixels.
380  */
381 static void
read_rgba_pixels(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum format,GLenum type,GLvoid * pixels,const struct gl_pixelstore_attrib * packing)382 read_rgba_pixels( struct gl_context *ctx,
383                   GLint x, GLint y,
384                   GLsizei width, GLsizei height,
385                   GLenum format, GLenum type, GLvoid *pixels,
386                   const struct gl_pixelstore_attrib *packing )
387 {
388    GLbitfield transferOps = ctx->_ImageTransferState;
389    struct gl_framebuffer *fb = ctx->ReadBuffer;
390    struct gl_renderbuffer *rb = fb->_ColorReadBuffer;
391 
392    if (!rb)
393       return;
394 
395    if ((ctx->Color._ClampReadColor == GL_TRUE || type != GL_FLOAT) &&
396        !_mesa_is_enum_format_integer(format)) {
397       transferOps |= IMAGE_CLAMP_BIT;
398    }
399 
400    /* Try the optimized paths first. */
401    if (fast_read_rgba_pixels_memcpy(ctx, x, y, width, height,
402                                     format, type, pixels, packing,
403                                     transferOps)) {
404       return;
405    }
406 
407    slow_read_rgba_pixels(ctx, x, y, width, height,
408 			 format, type, pixels, packing, transferOps);
409 }
410 
411 /**
412  * For a packed depth/stencil buffer being read as depth/stencil, just memcpy the
413  * data (possibly swapping 8/24 vs 24/8 as we go).
414  */
415 static GLboolean
fast_read_depth_stencil_pixels(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLubyte * dst,int dstStride)416 fast_read_depth_stencil_pixels(struct gl_context *ctx,
417 			       GLint x, GLint y,
418 			       GLsizei width, GLsizei height,
419 			       GLubyte *dst, int dstStride)
420 {
421    struct gl_framebuffer *fb = ctx->ReadBuffer;
422    struct gl_renderbuffer *rb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
423    struct gl_renderbuffer *stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
424    GLubyte *map;
425    int stride, i;
426 
427    if (rb != stencilRb)
428       return GL_FALSE;
429 
430    if (rb->Format != MESA_FORMAT_Z24_S8 &&
431        rb->Format != MESA_FORMAT_S8_Z24)
432       return GL_FALSE;
433 
434    ctx->Driver.MapRenderbuffer(ctx, rb, x, y, width, height, GL_MAP_READ_BIT,
435 			       &map, &stride);
436    if (!map) {
437       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
438       return GL_TRUE;  /* don't bother trying the slow path */
439    }
440 
441    for (i = 0; i < height; i++) {
442       _mesa_unpack_uint_24_8_depth_stencil_row(rb->Format, width,
443 					       map, (GLuint *)dst);
444       map += stride;
445       dst += dstStride;
446    }
447 
448    ctx->Driver.UnmapRenderbuffer(ctx, rb);
449 
450    return GL_TRUE;
451 }
452 
453 
454 /**
455  * For non-float-depth and stencil buffers being read as 24/8 depth/stencil,
456  * copy the integer data directly instead of converting depth to float and
457  * re-packing.
458  */
459 static GLboolean
fast_read_depth_stencil_pixels_separate(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,uint32_t * dst,int dstStride)460 fast_read_depth_stencil_pixels_separate(struct gl_context *ctx,
461 					GLint x, GLint y,
462 					GLsizei width, GLsizei height,
463 					uint32_t *dst, int dstStride)
464 {
465    struct gl_framebuffer *fb = ctx->ReadBuffer;
466    struct gl_renderbuffer *depthRb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
467    struct gl_renderbuffer *stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
468    GLubyte *depthMap, *stencilMap, *stencilVals;
469    int depthStride, stencilStride, i, j;
470 
471    if (_mesa_get_format_datatype(depthRb->Format) != GL_UNSIGNED_NORMALIZED)
472       return GL_FALSE;
473 
474    ctx->Driver.MapRenderbuffer(ctx, depthRb, x, y, width, height,
475 			       GL_MAP_READ_BIT, &depthMap, &depthStride);
476    if (!depthMap) {
477       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
478       return GL_TRUE;  /* don't bother trying the slow path */
479    }
480 
481    ctx->Driver.MapRenderbuffer(ctx, stencilRb, x, y, width, height,
482 			       GL_MAP_READ_BIT, &stencilMap, &stencilStride);
483    if (!stencilMap) {
484       ctx->Driver.UnmapRenderbuffer(ctx, depthRb);
485       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
486       return GL_TRUE;  /* don't bother trying the slow path */
487    }
488 
489    stencilVals = (GLubyte *) malloc(width * sizeof(GLubyte));
490 
491    if (stencilVals) {
492       for (j = 0; j < height; j++) {
493          _mesa_unpack_uint_z_row(depthRb->Format, width, depthMap, dst);
494          _mesa_unpack_ubyte_stencil_row(stencilRb->Format, width,
495                                         stencilMap, stencilVals);
496 
497          for (i = 0; i < width; i++) {
498             dst[i] = (dst[i] & 0xffffff00) | stencilVals[i];
499          }
500 
501          depthMap += depthStride;
502          stencilMap += stencilStride;
503          dst += dstStride / 4;
504       }
505    }
506    else {
507       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
508    }
509 
510    free(stencilVals);
511 
512    ctx->Driver.UnmapRenderbuffer(ctx, depthRb);
513    ctx->Driver.UnmapRenderbuffer(ctx, stencilRb);
514 
515    return GL_TRUE;
516 }
517 
518 static void
slow_read_depth_stencil_pixels_separate(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum type,const struct gl_pixelstore_attrib * packing,GLubyte * dst,int dstStride)519 slow_read_depth_stencil_pixels_separate(struct gl_context *ctx,
520 					GLint x, GLint y,
521 					GLsizei width, GLsizei height,
522 					GLenum type,
523 					const struct gl_pixelstore_attrib *packing,
524 					GLubyte *dst, int dstStride)
525 {
526    struct gl_framebuffer *fb = ctx->ReadBuffer;
527    struct gl_renderbuffer *depthRb = fb->Attachment[BUFFER_DEPTH].Renderbuffer;
528    struct gl_renderbuffer *stencilRb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
529    GLubyte *depthMap, *stencilMap;
530    int depthStride, stencilStride, j;
531    GLubyte *stencilVals;
532    GLfloat *depthVals;
533 
534 
535    /* The depth and stencil buffers might be separate, or a single buffer.
536     * If one buffer, only map it once.
537     */
538    ctx->Driver.MapRenderbuffer(ctx, depthRb, x, y, width, height,
539 			       GL_MAP_READ_BIT, &depthMap, &depthStride);
540    if (!depthMap) {
541       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
542       return;
543    }
544 
545    if (stencilRb != depthRb) {
546       ctx->Driver.MapRenderbuffer(ctx, stencilRb, x, y, width, height,
547                                   GL_MAP_READ_BIT, &stencilMap,
548                                   &stencilStride);
549       if (!stencilMap) {
550          ctx->Driver.UnmapRenderbuffer(ctx, depthRb);
551          _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
552          return;
553       }
554    }
555    else {
556       stencilMap = depthMap;
557       stencilStride = depthStride;
558    }
559 
560    stencilVals = (GLubyte *) malloc(width * sizeof(GLubyte));
561    depthVals = (GLfloat *) malloc(width * sizeof(GLfloat));
562 
563    if (stencilVals && depthVals) {
564       for (j = 0; j < height; j++) {
565          _mesa_unpack_float_z_row(depthRb->Format, width, depthMap, depthVals);
566          _mesa_unpack_ubyte_stencil_row(stencilRb->Format, width,
567                                         stencilMap, stencilVals);
568 
569          _mesa_pack_depth_stencil_span(ctx, width, type, (GLuint *)dst,
570                                        depthVals, stencilVals, packing);
571 
572          depthMap += depthStride;
573          stencilMap += stencilStride;
574          dst += dstStride;
575       }
576    }
577    else {
578       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glReadPixels");
579    }
580 
581    free(stencilVals);
582    free(depthVals);
583 
584    ctx->Driver.UnmapRenderbuffer(ctx, depthRb);
585    if (stencilRb != depthRb) {
586       ctx->Driver.UnmapRenderbuffer(ctx, stencilRb);
587    }
588 }
589 
590 
591 /**
592  * Read combined depth/stencil values.
593  * We'll have already done error checking to be sure the expected
594  * depth and stencil buffers really exist.
595  */
596 static void
read_depth_stencil_pixels(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum type,GLvoid * pixels,const struct gl_pixelstore_attrib * packing)597 read_depth_stencil_pixels(struct gl_context *ctx,
598                           GLint x, GLint y,
599                           GLsizei width, GLsizei height,
600                           GLenum type, GLvoid *pixels,
601                           const struct gl_pixelstore_attrib *packing )
602 {
603    const GLboolean scaleOrBias
604       = ctx->Pixel.DepthScale != 1.0 || ctx->Pixel.DepthBias != 0.0;
605    const GLboolean stencilTransfer = ctx->Pixel.IndexShift
606       || ctx->Pixel.IndexOffset || ctx->Pixel.MapStencilFlag;
607    GLubyte *dst;
608    int dstStride;
609 
610    dst = (GLubyte *) _mesa_image_address2d(packing, pixels,
611 					   width, height,
612 					   GL_DEPTH_STENCIL_EXT,
613 					   type, 0, 0);
614    dstStride = _mesa_image_row_stride(packing, width,
615 				      GL_DEPTH_STENCIL_EXT, type);
616 
617    /* Fast 24/8 reads. */
618    if (type == GL_UNSIGNED_INT_24_8 &&
619        !scaleOrBias && !stencilTransfer && !packing->SwapBytes) {
620       if (fast_read_depth_stencil_pixels(ctx, x, y, width, height,
621 					 dst, dstStride))
622 	 return;
623 
624       if (fast_read_depth_stencil_pixels_separate(ctx, x, y, width, height,
625 						  (uint32_t *)dst, dstStride))
626 	 return;
627    }
628 
629    slow_read_depth_stencil_pixels_separate(ctx, x, y, width, height,
630 					   type, packing,
631 					   dst, dstStride);
632 }
633 
634 
635 
636 /**
637  * Software fallback routine for ctx->Driver.ReadPixels().
638  * By time we get here, all error checking will have been done.
639  */
640 void
_mesa_readpixels(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum format,GLenum type,const struct gl_pixelstore_attrib * packing,GLvoid * pixels)641 _mesa_readpixels(struct gl_context *ctx,
642                  GLint x, GLint y, GLsizei width, GLsizei height,
643                  GLenum format, GLenum type,
644                  const struct gl_pixelstore_attrib *packing,
645                  GLvoid *pixels)
646 {
647    struct gl_pixelstore_attrib clippedPacking = *packing;
648 
649    if (ctx->NewState)
650       _mesa_update_state(ctx);
651 
652    /* Do all needed clipping here, so that we can forget about it later */
653    if (_mesa_clip_readpixels(ctx, &x, &y, &width, &height, &clippedPacking)) {
654 
655       pixels = _mesa_map_pbo_dest(ctx, &clippedPacking, pixels);
656 
657       if (pixels) {
658          switch (format) {
659          case GL_STENCIL_INDEX:
660             read_stencil_pixels(ctx, x, y, width, height, type, pixels,
661                                 &clippedPacking);
662             break;
663          case GL_DEPTH_COMPONENT:
664             read_depth_pixels(ctx, x, y, width, height, type, pixels,
665                               &clippedPacking);
666             break;
667          case GL_DEPTH_STENCIL_EXT:
668             read_depth_stencil_pixels(ctx, x, y, width, height, type, pixels,
669                                       &clippedPacking);
670             break;
671          default:
672             /* all other formats should be color formats */
673             read_rgba_pixels(ctx, x, y, width, height, format, type, pixels,
674                              &clippedPacking);
675          }
676 
677          _mesa_unmap_pbo_dest(ctx, &clippedPacking);
678       }
679    }
680 }
681 
682 
683 void GLAPIENTRY
_mesa_ReadnPixelsARB(GLint x,GLint y,GLsizei width,GLsizei height,GLenum format,GLenum type,GLsizei bufSize,GLvoid * pixels)684 _mesa_ReadnPixelsARB( GLint x, GLint y, GLsizei width, GLsizei height,
685 		      GLenum format, GLenum type, GLsizei bufSize,
686                       GLvoid *pixels )
687 {
688    GLenum err;
689 
690    GET_CURRENT_CONTEXT(ctx);
691    ASSERT_OUTSIDE_BEGIN_END_AND_FLUSH(ctx);
692 
693    FLUSH_CURRENT(ctx, 0);
694 
695    if (MESA_VERBOSE & VERBOSE_API)
696       _mesa_debug(ctx, "glReadPixels(%d, %d, %s, %s, %p)\n",
697                   width, height,
698                   _mesa_lookup_enum_by_nr(format),
699                   _mesa_lookup_enum_by_nr(type),
700                   pixels);
701 
702    if (width < 0 || height < 0) {
703       _mesa_error( ctx, GL_INVALID_VALUE,
704                    "glReadPixels(width=%d height=%d)", width, height );
705       return;
706    }
707 
708    /* OpenGL ES 1.x and OpenGL ES 2.0 impose additional restrictions on the
709     * combinations of format and type that can be used.
710     *
711     * Technically, only two combinations are actually allowed:
712     * GL_RGBA/GL_UNSIGNED_BYTE, and some implementation-specific internal
713     * preferred combination.  This code doesn't know what that preferred
714     * combination is, and Mesa can handle anything valid.  Just work instead.
715     */
716    if (_mesa_is_gles(ctx) && ctx->Version < 30) {
717       err = _mesa_es_error_check_format_and_type(format, type, 2);
718       if (err == GL_NO_ERROR) {
719          if (type == GL_FLOAT || type == GL_HALF_FLOAT_OES) {
720             err = GL_INVALID_OPERATION;
721          } else if (format == GL_DEPTH_COMPONENT
722                     || format == GL_DEPTH_STENCIL) {
723             err = GL_INVALID_ENUM;
724          }
725       }
726 
727       if (err != GL_NO_ERROR) {
728          _mesa_error(ctx, err, "glReadPixels(invalid format %s and/or type %s)",
729                      _mesa_lookup_enum_by_nr(format),
730                      _mesa_lookup_enum_by_nr(type));
731          return;
732       }
733    }
734 
735    if (ctx->NewState)
736       _mesa_update_state(ctx);
737 
738    err = _mesa_error_check_format_and_type(ctx, format, type);
739    if (err != GL_NO_ERROR) {
740       _mesa_error(ctx, err, "glReadPixels(invalid format %s and/or type %s)",
741                   _mesa_lookup_enum_by_nr(format),
742                   _mesa_lookup_enum_by_nr(type));
743       return;
744    }
745 
746    if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
747       _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
748                   "glReadPixels(incomplete framebuffer)" );
749       return;
750    }
751 
752    if (_mesa_is_user_fbo(ctx->ReadBuffer) &&
753        ctx->ReadBuffer->Visual.samples > 0) {
754       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(multisample FBO)");
755       return;
756    }
757 
758    if (!_mesa_source_buffer_exists(ctx, format)) {
759       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(no readbuffer)");
760       return;
761    }
762 
763    /* Check that the destination format and source buffer are both
764     * integer-valued or both non-integer-valued.
765     */
766    if (ctx->Extensions.EXT_texture_integer && _mesa_is_color_format(format)) {
767       const struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
768       const GLboolean srcInteger = _mesa_is_format_integer_color(rb->Format);
769       const GLboolean dstInteger = _mesa_is_enum_format_integer(format);
770       if (dstInteger != srcInteger) {
771          _mesa_error(ctx, GL_INVALID_OPERATION,
772                      "glReadPixels(integer / non-integer format mismatch");
773          return;
774       }
775    }
776 
777    if (width == 0 || height == 0)
778       return; /* nothing to do */
779 
780    if (!_mesa_validate_pbo_access(2, &ctx->Pack, width, height, 1,
781                                   format, type, bufSize, pixels)) {
782       if (_mesa_is_bufferobj(ctx->Pack.BufferObj)) {
783          _mesa_error(ctx, GL_INVALID_OPERATION,
784                      "glReadPixels(out of bounds PBO access)");
785       } else {
786          _mesa_error(ctx, GL_INVALID_OPERATION,
787                      "glReadnPixelsARB(out of bounds access:"
788                      " bufSize (%d) is too small)", bufSize);
789       }
790       return;
791    }
792 
793    if (_mesa_is_bufferobj(ctx->Pack.BufferObj) &&
794        _mesa_bufferobj_mapped(ctx->Pack.BufferObj)) {
795       /* buffer is mapped - that's an error */
796       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(PBO is mapped)");
797       return;
798    }
799 
800    ctx->Driver.ReadPixels(ctx, x, y, width, height,
801 			  format, type, &ctx->Pack, pixels);
802 }
803 
804 void GLAPIENTRY
_mesa_ReadPixels(GLint x,GLint y,GLsizei width,GLsizei height,GLenum format,GLenum type,GLvoid * pixels)805 _mesa_ReadPixels( GLint x, GLint y, GLsizei width, GLsizei height,
806 		  GLenum format, GLenum type, GLvoid *pixels )
807 {
808    _mesa_ReadnPixelsARB(x, y, width, height, format, type, INT_MAX, pixels);
809 }
810