summaryrefslogtreecommitdiffstats
path: root/src/mesa/state_tracker/st_cb_readpixels.c
blob: 3f7bbd9738cb33310a29fa08e139472d24ab1567 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
/**************************************************************************
 * 
 * Copyright 2007 VMware, Inc.
 * All Rights Reserved.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
 * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 * 
 **************************************************************************/

#include "main/image.h"
#include "main/pbo.h"
#include "main/imports.h"
#include "main/readpix.h"
#include "main/enums.h"
#include "main/framebuffer.h"
#include "util/u_inlines.h"
#include "util/u_format.h"

#include "st_cb_fbo.h"
#include "st_atom.h"
#include "st_context.h"
#include "st_cb_bitmap.h"
#include "st_cb_readpixels.h"
#include "state_tracker/st_cb_texture.h"
#include "state_tracker/st_format.h"
#include "state_tracker/st_texture.h"


/**
 * This uses a blit to copy the read buffer to a texture format which matches
 * the format and type combo and then a fast read-back is done using memcpy.
 * We can do arbitrary X/Y/Z/W/0/1 swizzling here as long as there is
 * a format which matches the swizzling.
 *
 * If such a format isn't available, we fall back to _mesa_readpixels.
 *
 * NOTE: Some drivers use a blit to convert between tiled and linear
 *       texture layouts during texture uploads/downloads, so the blit
 *       we do here should be free in such cases.
 */
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,
              GLvoid *pixels)
{
   struct st_context *st = st_context(ctx);
   struct gl_renderbuffer *rb =
         _mesa_get_read_renderbuffer_for_format(ctx, format);
   struct st_renderbuffer *strb = st_renderbuffer(rb);
   struct pipe_context *pipe = st->pipe;
   struct pipe_screen *screen = pipe->screen;
   struct pipe_resource *src;
   struct pipe_resource *dst = NULL;
   struct pipe_resource dst_templ;
   enum pipe_format dst_format, src_format;
   struct pipe_blit_info blit;
   unsigned bind = PIPE_BIND_TRANSFER_READ;
   struct pipe_transfer *tex_xfer;
   ubyte *map = NULL;

   /* Validate state (to be sure we have up-to-date framebuffer surfaces)
    * and flush the bitmap cache prior to reading. */
   st_validate_state(st);
   st_flush_bitmap_cache(st);

   if (!st->prefer_blit_based_texture_transfer) {
      goto fallback;
   }

   /* This must be done after state validation. */
   src = strb->texture;

   /* XXX Fallback for depth-stencil formats due to an incomplete
    * stencil blit implementation in some drivers. */
   if (format == GL_DEPTH_STENCIL) {
      goto fallback;
   }

   /* We are creating a texture of the size of the region being read back.
    * Need to check for NPOT texture support. */
   if (!screen->get_param(screen, PIPE_CAP_NPOT_TEXTURES) &&
       (!util_is_power_of_two(width) ||
        !util_is_power_of_two(height))) {
      goto fallback;
   }

   /* If the base internal format and the texture format don't match, we have
    * to use the slow path. */
   if (rb->_BaseFormat !=
       _mesa_get_format_base_format(rb->Format)) {
      goto fallback;
   }

   /* See if the texture format already matches the format and type,
    * in which case the memcpy-based fast path will likely be used and
    * we don't have to blit. */
   if (_mesa_format_matches_format_and_type(rb->Format, format,
                                            type, pack->SwapBytes)) {
      goto fallback;
   }

   if (_mesa_readpixels_needs_slow_path(ctx, format, type, GL_TRUE)) {
      goto fallback;
   }

   /* Convert the source format to what is expected by ReadPixels
    * and see if it's supported. */
   src_format = util_format_linear(src->format);
   src_format = util_format_luminance_to_red(src_format);
   src_format = util_format_intensity_to_red(src_format);

   if (!src_format ||
       !screen->is_format_supported(screen, src_format, src->target,
                                    src->nr_samples,
                                    PIPE_BIND_SAMPLER_VIEW)) {
      goto fallback;
   }

   if (format == GL_DEPTH_COMPONENT || format == GL_DEPTH_STENCIL)
      bind |= PIPE_BIND_DEPTH_STENCIL;
   else
      bind |= PIPE_BIND_RENDER_TARGET;

   /* Choose the destination format by finding the best match
    * for the format+type combo. */
   dst_format = st_choose_matching_format(screen, bind, format, type,
                                          pack->SwapBytes);
   if (dst_format == PIPE_FORMAT_NONE) {
      goto fallback;
   }

   /* create the destination texture */
   memset(&dst_templ, 0, sizeof(dst_templ));
   dst_templ.target = PIPE_TEXTURE_2D;
   dst_templ.format = dst_format;
   dst_templ.bind = bind;
   dst_templ.usage = PIPE_USAGE_STAGING;

   st_gl_texture_dims_to_pipe_dims(GL_TEXTURE_2D, width, height, 1,
                                   &dst_templ.width0, &dst_templ.height0,
                                   &dst_templ.depth0, &dst_templ.array_size);

   dst = screen->resource_create(screen, &dst_templ);
   if (!dst) {
      goto fallback;
   }

   memset(&blit, 0, sizeof(blit));
   blit.src.resource = src;
   blit.src.level = strb->surface->u.tex.level;
   blit.src.format = src_format;
   blit.dst.resource = dst;
   blit.dst.level = 0;
   blit.dst.format = dst->format;
   blit.src.box.x = x;
   blit.dst.box.x = 0;
   blit.src.box.y = y;
   blit.dst.box.y = 0;
   blit.src.box.z = strb->surface->u.tex.first_layer;
   blit.dst.box.z = 0;
   blit.src.box.width = blit.dst.box.width = width;
   blit.src.box.height = blit.dst.box.height = height;
   blit.src.box.depth = blit.dst.box.depth = 1;
   blit.mask = st_get_blit_mask(rb->_BaseFormat, format);
   blit.filter = PIPE_TEX_FILTER_NEAREST;
   blit.scissor_enable = FALSE;

   if (st_fb_orientation(ctx->ReadBuffer) == Y_0_TOP) {
      blit.src.box.y = rb->Height - blit.src.box.y;
      blit.src.box.height = -blit.src.box.height;
   }

   /* blit */
   st->pipe->blit(st->pipe, &blit);

   /* map resources */
   pixels = _mesa_map_pbo_dest(ctx, pack, pixels);

   map = pipe_transfer_map_3d(pipe, dst, 0, PIPE_TRANSFER_READ,
                              0, 0, 0, width, height, 1, &tex_xfer);
   if (!map) {
      _mesa_unmap_pbo_dest(ctx, pack);
      pipe_resource_reference(&dst, NULL);
      goto fallback;
   }

   /* memcpy data into a user buffer */
   {
      const uint bytesPerRow = width * util_format_get_blocksize(dst_format);
      GLuint row;

      for (row = 0; row < (unsigned) height; row++) {
         GLvoid *dest = _mesa_image_address3d(pack, pixels,
                                              width, height, format,
                                              type, 0, row, 0);
         memcpy(dest, map, bytesPerRow);
         map += tex_xfer->stride;
      }
   }

   pipe_transfer_unmap(pipe, tex_xfer);
   _mesa_unmap_pbo_dest(ctx, pack);
   pipe_resource_reference(&dst, NULL);
   return;

fallback:
   _mesa_readpixels(ctx, x, y, width, height, format, type, pack, pixels);
}

void st_init_readpixels_functions(struct dd_function_table *functions)
{
   functions->ReadPixels = st_readpixels;
}