1 /**************************************************************************
2 *
3 * Copyright 2007 VMware, Inc.
4 * 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
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sub license, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
13 *
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
16 * of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
19 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
21 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
22 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25 *
26 **************************************************************************/
27
28 #include "main/bufferobj.h"
29 #include "main/image.h"
30 #include "main/pbo.h"
31 #include "main/imports.h"
32 #include "main/readpix.h"
33 #include "main/enums.h"
34 #include "main/framebuffer.h"
35 #include "util/u_inlines.h"
36 #include "util/u_format.h"
37 #include "cso_cache/cso_context.h"
38
39 #include "st_cb_fbo.h"
40 #include "st_atom.h"
41 #include "st_context.h"
42 #include "st_cb_bitmap.h"
43 #include "st_cb_readpixels.h"
44 #include "st_debug.h"
45 #include "state_tracker/st_cb_texture.h"
46 #include "state_tracker/st_format.h"
47 #include "state_tracker/st_pbo.h"
48 #include "state_tracker/st_texture.h"
49
50 /* The readpixels cache caches a blitted staging texture so that back-to-back
51 * calls to glReadPixels with user pointers require less CPU-GPU synchronization.
52 *
53 * Assumptions:
54 *
55 * (1) Blits have high synchronization overheads, and it is beneficial to
56 * use a single blit of the entire framebuffer instead of many smaller
57 * blits (because the smaller blits cannot be batched, and we have to wait
58 * for the GPU after each one).
59 *
60 * (2) transfer_map implicitly involves a blit as well (for de-tiling, copy
61 * from VRAM, etc.), so that it is beneficial to replace the
62 * _mesa_readpixels path as well when possible.
63 *
64 * Change this #define to true to fill and use the cache whenever possible
65 * (this is inefficient and only meant for testing / debugging).
66 */
67 #define ALWAYS_READPIXELS_CACHE false
68
69 static boolean
needs_integer_signed_unsigned_conversion(const struct gl_context * ctx,GLenum format,GLenum type)70 needs_integer_signed_unsigned_conversion(const struct gl_context *ctx,
71 GLenum format, GLenum type)
72 {
73 struct gl_renderbuffer *rb =
74 _mesa_get_read_renderbuffer_for_format(ctx, format);
75
76 assert(rb);
77
78 GLenum srcType = _mesa_get_format_datatype(rb->Format);
79
80 if ((srcType == GL_INT &&
81 (type == GL_UNSIGNED_INT ||
82 type == GL_UNSIGNED_SHORT ||
83 type == GL_UNSIGNED_BYTE)) ||
84 (srcType == GL_UNSIGNED_INT &&
85 (type == GL_INT ||
86 type == GL_SHORT ||
87 type == GL_BYTE))) {
88 return TRUE;
89 }
90
91 return FALSE;
92 }
93
94 static bool
try_pbo_readpixels(struct st_context * st,struct st_renderbuffer * strb,bool invert_y,GLint x,GLint y,GLsizei width,GLsizei height,enum pipe_format src_format,enum pipe_format dst_format,const struct gl_pixelstore_attrib * pack,void * pixels)95 try_pbo_readpixels(struct st_context *st, struct st_renderbuffer *strb,
96 bool invert_y,
97 GLint x, GLint y, GLsizei width, GLsizei height,
98 enum pipe_format src_format, enum pipe_format dst_format,
99 const struct gl_pixelstore_attrib *pack, void *pixels)
100 {
101 struct pipe_context *pipe = st->pipe;
102 struct pipe_screen *screen = pipe->screen;
103 struct cso_context *cso = st->cso_context;
104 struct pipe_surface *surface = strb->surface;
105 struct pipe_resource *texture = strb->texture;
106 const struct util_format_description *desc;
107 struct st_pbo_addresses addr;
108 struct pipe_framebuffer_state fb;
109 enum pipe_texture_target view_target;
110 bool success = false;
111
112 if (texture->nr_samples > 1)
113 return false;
114
115 if (!screen->is_format_supported(screen, dst_format, PIPE_BUFFER, 0,
116 PIPE_BIND_SHADER_IMAGE))
117 return false;
118
119 desc = util_format_description(dst_format);
120
121 /* Compute PBO addresses */
122 addr.bytes_per_pixel = desc->block.bits / 8;
123 addr.xoffset = x;
124 addr.yoffset = y;
125 addr.width = width;
126 addr.height = height;
127 addr.depth = 1;
128 if (!st_pbo_addresses_pixelstore(st, GL_TEXTURE_2D, false, pack, pixels, &addr))
129 return false;
130
131 cso_save_state(cso, (CSO_BIT_FRAGMENT_SAMPLER_VIEWS |
132 CSO_BIT_FRAGMENT_SAMPLERS |
133 CSO_BIT_FRAGMENT_IMAGE0 |
134 CSO_BIT_BLEND |
135 CSO_BIT_VERTEX_ELEMENTS |
136 CSO_BIT_AUX_VERTEX_BUFFER_SLOT |
137 CSO_BIT_FRAMEBUFFER |
138 CSO_BIT_VIEWPORT |
139 CSO_BIT_RASTERIZER |
140 CSO_BIT_DEPTH_STENCIL_ALPHA |
141 CSO_BIT_STREAM_OUTPUTS |
142 CSO_BIT_PAUSE_QUERIES |
143 CSO_BIT_SAMPLE_MASK |
144 CSO_BIT_MIN_SAMPLES |
145 CSO_BIT_RENDER_CONDITION |
146 CSO_BITS_ALL_SHADERS));
147 cso_save_constant_buffer_slot0(cso, PIPE_SHADER_FRAGMENT);
148
149 cso_set_sample_mask(cso, ~0);
150 cso_set_min_samples(cso, 1);
151 cso_set_render_condition(cso, NULL, FALSE, 0);
152
153 /* Set up the sampler_view */
154 {
155 struct pipe_sampler_view templ;
156 struct pipe_sampler_view *sampler_view;
157 struct pipe_sampler_state sampler = {0};
158 const struct pipe_sampler_state *samplers[1] = {&sampler};
159
160 u_sampler_view_default_template(&templ, texture, src_format);
161
162 switch (texture->target) {
163 case PIPE_TEXTURE_CUBE:
164 case PIPE_TEXTURE_CUBE_ARRAY:
165 view_target = PIPE_TEXTURE_2D_ARRAY;
166 break;
167 default:
168 view_target = texture->target;
169 break;
170 }
171
172 templ.target = view_target;
173 templ.u.tex.first_level = surface->u.tex.level;
174 templ.u.tex.last_level = templ.u.tex.first_level;
175
176 if (view_target != PIPE_TEXTURE_3D) {
177 templ.u.tex.first_layer = surface->u.tex.first_layer;
178 templ.u.tex.last_layer = templ.u.tex.first_layer;
179 } else {
180 addr.constants.layer_offset = surface->u.tex.first_layer;
181 }
182
183 sampler_view = pipe->create_sampler_view(pipe, texture, &templ);
184 if (sampler_view == NULL)
185 goto fail;
186
187 cso_set_sampler_views(cso, PIPE_SHADER_FRAGMENT, 1, &sampler_view);
188
189 pipe_sampler_view_reference(&sampler_view, NULL);
190
191 cso_set_samplers(cso, PIPE_SHADER_FRAGMENT, 1, samplers);
192 }
193
194 /* Set up destination image */
195 {
196 struct pipe_image_view image;
197
198 memset(&image, 0, sizeof(image));
199 image.resource = addr.buffer;
200 image.format = dst_format;
201 image.access = PIPE_IMAGE_ACCESS_WRITE;
202 image.u.buf.offset = addr.first_element * addr.bytes_per_pixel;
203 image.u.buf.size = (addr.last_element - addr.first_element + 1) *
204 addr.bytes_per_pixel;
205
206 cso_set_shader_images(cso, PIPE_SHADER_FRAGMENT, 0, 1, &image);
207 }
208
209 /* Set up no-attachment framebuffer */
210 memset(&fb, 0, sizeof(fb));
211 fb.width = surface->width;
212 fb.height = surface->height;
213 fb.samples = 1;
214 fb.layers = 1;
215 cso_set_framebuffer(cso, &fb);
216
217 /* Any blend state would do. Set this just to prevent drivers having
218 * blend == NULL.
219 */
220 cso_set_blend(cso, &st->pbo.upload_blend);
221
222 cso_set_viewport_dims(cso, fb.width, fb.height, invert_y);
223
224 if (invert_y)
225 st_pbo_addresses_invert_y(&addr, fb.height);
226
227 {
228 struct pipe_depth_stencil_alpha_state dsa;
229 memset(&dsa, 0, sizeof(dsa));
230 cso_set_depth_stencil_alpha(cso, &dsa);
231 }
232
233 /* Set up the fragment shader */
234 {
235 void *fs = st_pbo_get_download_fs(st, view_target, src_format, dst_format);
236 if (!fs)
237 goto fail;
238
239 cso_set_fragment_shader_handle(cso, fs);
240 }
241
242 success = st_pbo_draw(st, &addr, fb.width, fb.height);
243
244 /* Buffer written via shader images needs explicit synchronization. */
245 pipe->memory_barrier(pipe, PIPE_BARRIER_ALL);
246
247 fail:
248 cso_restore_state(cso);
249 cso_restore_constant_buffer_slot0(cso, PIPE_SHADER_FRAGMENT);
250
251 return success;
252 }
253
254 /**
255 * Create a staging texture and blit the requested region to it.
256 */
257 static struct pipe_resource *
blit_to_staging(struct st_context * st,struct st_renderbuffer * strb,bool invert_y,GLint x,GLint y,GLsizei width,GLsizei height,GLenum format,enum pipe_format src_format,enum pipe_format dst_format)258 blit_to_staging(struct st_context *st, struct st_renderbuffer *strb,
259 bool invert_y,
260 GLint x, GLint y, GLsizei width, GLsizei height,
261 GLenum format,
262 enum pipe_format src_format, enum pipe_format dst_format)
263 {
264 struct pipe_context *pipe = st->pipe;
265 struct pipe_screen *screen = pipe->screen;
266 struct pipe_resource dst_templ;
267 struct pipe_resource *dst;
268 struct pipe_blit_info blit;
269
270 /* We are creating a texture of the size of the region being read back.
271 * Need to check for NPOT texture support. */
272 if (!screen->get_param(screen, PIPE_CAP_NPOT_TEXTURES) &&
273 (!util_is_power_of_two(width) ||
274 !util_is_power_of_two(height)))
275 return NULL;
276
277 /* create the destination texture */
278 memset(&dst_templ, 0, sizeof(dst_templ));
279 dst_templ.target = PIPE_TEXTURE_2D;
280 dst_templ.format = dst_format;
281 if (util_format_is_depth_or_stencil(dst_format))
282 dst_templ.bind |= PIPE_BIND_DEPTH_STENCIL;
283 else
284 dst_templ.bind |= PIPE_BIND_RENDER_TARGET;
285 dst_templ.usage = PIPE_USAGE_STAGING;
286
287 st_gl_texture_dims_to_pipe_dims(GL_TEXTURE_2D, width, height, 1,
288 &dst_templ.width0, &dst_templ.height0,
289 &dst_templ.depth0, &dst_templ.array_size);
290
291 dst = screen->resource_create(screen, &dst_templ);
292 if (!dst)
293 return NULL;
294
295 memset(&blit, 0, sizeof(blit));
296 blit.src.resource = strb->texture;
297 blit.src.level = strb->surface->u.tex.level;
298 blit.src.format = src_format;
299 blit.dst.resource = dst;
300 blit.dst.level = 0;
301 blit.dst.format = dst->format;
302 blit.src.box.x = x;
303 blit.dst.box.x = 0;
304 blit.src.box.y = y;
305 blit.dst.box.y = 0;
306 blit.src.box.z = strb->surface->u.tex.first_layer;
307 blit.dst.box.z = 0;
308 blit.src.box.width = blit.dst.box.width = width;
309 blit.src.box.height = blit.dst.box.height = height;
310 blit.src.box.depth = blit.dst.box.depth = 1;
311 blit.mask = st_get_blit_mask(strb->Base._BaseFormat, format);
312 blit.filter = PIPE_TEX_FILTER_NEAREST;
313 blit.scissor_enable = FALSE;
314
315 if (invert_y) {
316 blit.src.box.y = strb->Base.Height - blit.src.box.y;
317 blit.src.box.height = -blit.src.box.height;
318 }
319
320 /* blit */
321 st->pipe->blit(st->pipe, &blit);
322
323 return dst;
324 }
325
326 static struct pipe_resource *
try_cached_readpixels(struct st_context * st,struct st_renderbuffer * strb,bool invert_y,GLsizei width,GLsizei height,GLenum format,enum pipe_format src_format,enum pipe_format dst_format)327 try_cached_readpixels(struct st_context *st, struct st_renderbuffer *strb,
328 bool invert_y,
329 GLsizei width, GLsizei height,
330 GLenum format,
331 enum pipe_format src_format, enum pipe_format dst_format)
332 {
333 struct pipe_resource *src = strb->texture;
334 struct pipe_resource *dst = NULL;
335
336 if (ST_DEBUG & DEBUG_NOREADPIXCACHE)
337 return NULL;
338
339 /* Reset cache after invalidation or switch of parameters. */
340 if (st->readpix_cache.src != src ||
341 st->readpix_cache.dst_format != dst_format ||
342 st->readpix_cache.level != strb->surface->u.tex.level ||
343 st->readpix_cache.layer != strb->surface->u.tex.first_layer) {
344 pipe_resource_reference(&st->readpix_cache.src, src);
345 pipe_resource_reference(&st->readpix_cache.cache, NULL);
346 st->readpix_cache.dst_format = dst_format;
347 st->readpix_cache.level = strb->surface->u.tex.level;
348 st->readpix_cache.layer = strb->surface->u.tex.first_layer;
349 st->readpix_cache.hits = 0;
350 }
351
352 /* Decide whether to trigger the cache. */
353 if (!st->readpix_cache.cache) {
354 if (!strb->use_readpix_cache && !ALWAYS_READPIXELS_CACHE) {
355 /* Heuristic: If previous successive calls read at least a fraction
356 * of the surface _and_ we read again, trigger the cache.
357 */
358 unsigned threshold = MAX2(1, strb->Base.Width * strb->Base.Height / 8);
359
360 if (st->readpix_cache.hits < threshold) {
361 st->readpix_cache.hits += width * height;
362 return NULL;
363 }
364
365 strb->use_readpix_cache = true;
366 }
367
368 /* Fill the cache */
369 st->readpix_cache.cache = blit_to_staging(st, strb, invert_y,
370 0, 0,
371 strb->Base.Width,
372 strb->Base.Height, format,
373 src_format, dst_format);
374 }
375
376 /* Return an owning reference to stay consistent with the non-cached path */
377 pipe_resource_reference(&dst, st->readpix_cache.cache);
378
379 return dst;
380 }
381
382 /**
383 * This uses a blit to copy the read buffer to a texture format which matches
384 * the format and type combo and then a fast read-back is done using memcpy.
385 * We can do arbitrary X/Y/Z/W/0/1 swizzling here as long as there is
386 * a format which matches the swizzling.
387 *
388 * If such a format isn't available, we fall back to _mesa_readpixels.
389 *
390 * NOTE: Some drivers use a blit to convert between tiled and linear
391 * texture layouts during texture uploads/downloads, so the blit
392 * we do here should be free in such cases.
393 */
394 static void
st_ReadPixels(struct gl_context * ctx,GLint x,GLint y,GLsizei width,GLsizei height,GLenum format,GLenum type,const struct gl_pixelstore_attrib * pack,void * pixels)395 st_ReadPixels(struct gl_context *ctx, GLint x, GLint y,
396 GLsizei width, GLsizei height,
397 GLenum format, GLenum type,
398 const struct gl_pixelstore_attrib *pack,
399 void *pixels)
400 {
401 struct st_context *st = st_context(ctx);
402 struct gl_renderbuffer *rb =
403 _mesa_get_read_renderbuffer_for_format(ctx, format);
404 struct st_renderbuffer *strb = st_renderbuffer(rb);
405 struct pipe_context *pipe = st->pipe;
406 struct pipe_screen *screen = pipe->screen;
407 struct pipe_resource *src;
408 struct pipe_resource *dst = NULL;
409 enum pipe_format dst_format, src_format;
410 unsigned bind;
411 struct pipe_transfer *tex_xfer;
412 ubyte *map = NULL;
413 int dst_x, dst_y;
414
415 /* Validate state (to be sure we have up-to-date framebuffer surfaces)
416 * and flush the bitmap cache prior to reading. */
417 st_validate_state(st, ST_PIPELINE_UPDATE_FRAMEBUFFER);
418 st_flush_bitmap_cache(st);
419
420 if (!st->prefer_blit_based_texture_transfer) {
421 goto fallback;
422 }
423
424 /* This must be done after state validation. */
425 src = strb->texture;
426
427 /* XXX Fallback for depth-stencil formats due to an incomplete
428 * stencil blit implementation in some drivers. */
429 if (format == GL_DEPTH_STENCIL) {
430 goto fallback;
431 }
432
433 /* If the base internal format and the texture format don't match, we have
434 * to use the slow path. */
435 if (rb->_BaseFormat !=
436 _mesa_get_format_base_format(rb->Format)) {
437 goto fallback;
438 }
439
440 if (_mesa_readpixels_needs_slow_path(ctx, format, type, GL_TRUE)) {
441 goto fallback;
442 }
443
444 /* Convert the source format to what is expected by ReadPixels
445 * and see if it's supported. */
446 src_format = util_format_linear(src->format);
447 src_format = util_format_luminance_to_red(src_format);
448 src_format = util_format_intensity_to_red(src_format);
449
450 if (!src_format ||
451 !screen->is_format_supported(screen, src_format, src->target,
452 src->nr_samples,
453 PIPE_BIND_SAMPLER_VIEW)) {
454 goto fallback;
455 }
456
457 if (format == GL_DEPTH_COMPONENT || format == GL_DEPTH_STENCIL)
458 bind = PIPE_BIND_DEPTH_STENCIL;
459 else
460 bind = PIPE_BIND_RENDER_TARGET;
461
462 /* Choose the destination format by finding the best match
463 * for the format+type combo. */
464 dst_format = st_choose_matching_format(st, bind, format, type,
465 pack->SwapBytes);
466 if (dst_format == PIPE_FORMAT_NONE) {
467 goto fallback;
468 }
469
470 if (st->pbo.download_enabled && _mesa_is_bufferobj(pack->BufferObj)) {
471 if (try_pbo_readpixels(st, strb,
472 st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP,
473 x, y, width, height,
474 src_format, dst_format,
475 pack, pixels))
476 return;
477 }
478
479 if (needs_integer_signed_unsigned_conversion(ctx, format, type)) {
480 goto fallback;
481 }
482
483 /* Cache a staging texture for back-to-back ReadPixels, to avoid CPU-GPU
484 * synchronization overhead.
485 */
486 dst = try_cached_readpixels(st, strb,
487 st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP,
488 width, height, format, src_format, dst_format);
489 if (dst) {
490 dst_x = x;
491 dst_y = y;
492 } else {
493 /* See if the texture format already matches the format and type,
494 * in which case the memcpy-based fast path will likely be used and
495 * we don't have to blit. */
496 if (_mesa_format_matches_format_and_type(rb->Format, format,
497 type, pack->SwapBytes, NULL)) {
498 goto fallback;
499 }
500
501 dst = blit_to_staging(st, strb,
502 st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP,
503 x, y, width, height, format,
504 src_format, dst_format);
505 if (!dst)
506 goto fallback;
507
508 dst_x = 0;
509 dst_y = 0;
510 }
511
512 /* map resources */
513 pixels = _mesa_map_pbo_dest(ctx, pack, pixels);
514
515 map = pipe_transfer_map_3d(pipe, dst, 0, PIPE_TRANSFER_READ,
516 dst_x, dst_y, 0, width, height, 1, &tex_xfer);
517 if (!map) {
518 _mesa_unmap_pbo_dest(ctx, pack);
519 pipe_resource_reference(&dst, NULL);
520 goto fallback;
521 }
522
523 /* memcpy data into a user buffer */
524 {
525 const uint bytesPerRow = width * util_format_get_blocksize(dst_format);
526 const int destStride = _mesa_image_row_stride(pack, width, format, type);
527 char *dest = _mesa_image_address2d(pack, pixels,
528 width, height, format,
529 type, 0, 0);
530
531 if (tex_xfer->stride == bytesPerRow && destStride == bytesPerRow) {
532 memcpy(dest, map, bytesPerRow * height);
533 } else {
534 GLuint row;
535
536 for (row = 0; row < (unsigned) height; row++) {
537 memcpy(dest, map, bytesPerRow);
538 map += tex_xfer->stride;
539 dest += destStride;
540 }
541 }
542 }
543
544 pipe_transfer_unmap(pipe, tex_xfer);
545 _mesa_unmap_pbo_dest(ctx, pack);
546 pipe_resource_reference(&dst, NULL);
547 return;
548
549 fallback:
550 _mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels);
551 }
552
st_init_readpixels_functions(struct dd_function_table * functions)553 void st_init_readpixels_functions(struct dd_function_table *functions)
554 {
555 functions->ReadPixels = st_ReadPixels;
556 }
557