1 /**************************************************************************
3 * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
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:
14 * The above copyright notice and this permission notice (including the
15 * next paragraph) shall be included in all copies or substantial portions
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 TUNGSTEN GRAPHICS 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.
26 **************************************************************************/
28 #include "main/image.h"
30 #include "main/imports.h"
31 #include "main/readpix.h"
32 #include "main/enums.h"
33 #include "main/framebuffer.h"
34 #include "util/u_inlines.h"
35 #include "util/u_format.h"
37 #include "st_cb_fbo.h"
39 #include "st_context.h"
40 #include "st_cb_bitmap.h"
41 #include "st_cb_readpixels.h"
42 #include "state_tracker/st_cb_texture.h"
43 #include "state_tracker/st_format.h"
44 #include "state_tracker/st_texture.h"
48 * This uses a blit to copy the read buffer to a texture format which matches
49 * the format and type combo and then a fast read-back is done using memcpy.
50 * We can do arbitrary X/Y/Z/W/0/1 swizzling here as long as there is
51 * a format which matches the swizzling.
53 * If such a format isn't available, we fall back to _mesa_readpixels.
55 * NOTE: Some drivers use a blit to convert between tiled and linear
56 * texture layouts during texture uploads/downloads, so the blit
57 * we do here should be free in such cases.
60 st_readpixels(struct gl_context
*ctx
, GLint x
, GLint y
,
61 GLsizei width
, GLsizei height
,
62 GLenum format
, GLenum type
,
63 const struct gl_pixelstore_attrib
*pack
,
66 struct st_context
*st
= st_context(ctx
);
67 struct gl_renderbuffer
*rb
=
68 _mesa_get_read_renderbuffer_for_format(ctx
, format
);
69 struct st_renderbuffer
*strb
= st_renderbuffer(rb
);
70 struct pipe_context
*pipe
= st
->pipe
;
71 struct pipe_screen
*screen
= pipe
->screen
;
72 struct pipe_resource
*src
;
73 struct pipe_resource
*dst
= NULL
;
74 struct pipe_resource dst_templ
;
75 enum pipe_format dst_format
, src_format
;
76 struct pipe_blit_info blit
;
77 unsigned bind
= PIPE_BIND_TRANSFER_READ
;
78 struct pipe_transfer
*tex_xfer
;
81 /* Validate state (to be sure we have up-to-date framebuffer surfaces)
82 * and flush the bitmap cache prior to reading. */
83 st_validate_state(st
);
84 st_flush_bitmap_cache(st
);
86 if (!st
->prefer_blit_based_texture_transfer
) {
90 /* This must be done after state validation. */
93 /* XXX Fallback for depth-stencil formats due to an incomplete
94 * stencil blit implementation in some drivers. */
95 if (format
== GL_DEPTH_STENCIL
) {
99 /* We are creating a texture of the size of the region being read back.
100 * Need to check for NPOT texture support. */
101 if (!screen
->get_param(screen
, PIPE_CAP_NPOT_TEXTURES
) &&
102 (!util_is_power_of_two(width
) ||
103 !util_is_power_of_two(height
))) {
107 /* If the base internal format and the texture format don't match, we have
108 * to use the slow path. */
109 if (rb
->_BaseFormat
!=
110 _mesa_get_format_base_format(rb
->Format
)) {
114 /* See if the texture format already matches the format and type,
115 * in which case the memcpy-based fast path will likely be used and
116 * we don't have to blit. */
117 if (_mesa_format_matches_format_and_type(rb
->Format
, format
,
118 type
, pack
->SwapBytes
)) {
122 if (_mesa_readpixels_needs_slow_path(ctx
, format
, type
, GL_TRUE
)) {
126 /* Convert the source format to what is expected by ReadPixels
127 * and see if it's supported. */
128 src_format
= util_format_linear(src
->format
);
129 src_format
= util_format_luminance_to_red(src_format
);
130 src_format
= util_format_intensity_to_red(src_format
);
133 !screen
->is_format_supported(screen
, src_format
, src
->target
,
135 PIPE_BIND_SAMPLER_VIEW
)) {
139 if (format
== GL_DEPTH_COMPONENT
|| format
== GL_DEPTH_STENCIL
)
140 bind
|= PIPE_BIND_DEPTH_STENCIL
;
142 bind
|= PIPE_BIND_RENDER_TARGET
;
144 /* Choose the destination format by finding the best match
145 * for the format+type combo. */
146 dst_format
= st_choose_matching_format(screen
, bind
, format
, type
,
148 if (dst_format
== PIPE_FORMAT_NONE
) {
152 /* create the destination texture */
153 memset(&dst_templ
, 0, sizeof(dst_templ
));
154 dst_templ
.target
= PIPE_TEXTURE_2D
;
155 dst_templ
.format
= dst_format
;
156 dst_templ
.bind
= bind
;
157 dst_templ
.usage
= PIPE_USAGE_STAGING
;
159 st_gl_texture_dims_to_pipe_dims(GL_TEXTURE_2D
, width
, height
, 1,
160 &dst_templ
.width0
, &dst_templ
.height0
,
161 &dst_templ
.depth0
, &dst_templ
.array_size
);
163 dst
= screen
->resource_create(screen
, &dst_templ
);
168 blit
.src
.resource
= src
;
169 blit
.src
.level
= strb
->rtt_level
;
170 blit
.src
.format
= src_format
;
171 blit
.dst
.resource
= dst
;
173 blit
.dst
.format
= dst
->format
;
178 blit
.src
.box
.z
= strb
->rtt_face
+ strb
->rtt_slice
;
180 blit
.src
.box
.width
= blit
.dst
.box
.width
= width
;
181 blit
.src
.box
.height
= blit
.dst
.box
.height
= height
;
182 blit
.src
.box
.depth
= blit
.dst
.box
.depth
= 1;
183 blit
.mask
= st_get_blit_mask(rb
->_BaseFormat
, format
);
184 blit
.filter
= PIPE_TEX_FILTER_NEAREST
;
185 blit
.scissor_enable
= FALSE
;
187 if (st_fb_orientation(ctx
->ReadBuffer
) == Y_0_TOP
) {
188 blit
.src
.box
.y
= rb
->Height
- blit
.src
.box
.y
;
189 blit
.src
.box
.height
= -blit
.src
.box
.height
;
193 st
->pipe
->blit(st
->pipe
, &blit
);
196 pixels
= _mesa_map_pbo_dest(ctx
, pack
, pixels
);
198 map
= pipe_transfer_map_3d(pipe
, dst
, 0, PIPE_TRANSFER_READ
,
199 0, 0, 0, width
, height
, 1, &tex_xfer
);
201 _mesa_unmap_pbo_dest(ctx
, pack
);
202 pipe_resource_reference(&dst
, NULL
);
206 /* memcpy data into a user buffer */
208 const uint bytesPerRow
= width
* util_format_get_blocksize(dst_format
);
211 for (row
= 0; row
< height
; row
++) {
212 GLvoid
*dest
= _mesa_image_address3d(pack
, pixels
,
213 width
, height
, format
,
215 memcpy(dest
, map
, bytesPerRow
);
216 map
+= tex_xfer
->stride
;
220 pipe_transfer_unmap(pipe
, tex_xfer
);
221 _mesa_unmap_pbo_dest(ctx
, pack
);
222 pipe_resource_reference(&dst
, NULL
);
226 _mesa_readpixels(ctx
, x
, y
, width
, height
, format
, type
, pack
, pixels
);
229 void st_init_readpixels_functions(struct dd_function_table
*functions
)
231 functions
->ReadPixels
= st_readpixels
;