1 /**************************************************************************
2 *
3 * Copyright 2010 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
29 #include "u_format.h"
30 #include "u_sampler.h"
31
32
33 /**
34 * Initialize a pipe_sampler_view. 'view' is considered to have
35 * uninitialized contents.
36 */
37 static void
default_template(struct pipe_sampler_view * view,const struct pipe_resource * texture,enum pipe_format format,unsigned expand_green_blue)38 default_template(struct pipe_sampler_view *view,
39 const struct pipe_resource *texture,
40 enum pipe_format format,
41 unsigned expand_green_blue)
42 {
43 memset(view, 0, sizeof(*view));
44
45 /* XXX: Check if format is compatible with texture->format.
46 */
47
48 view->format = format;
49 view->u.tex.first_level = 0;
50 view->u.tex.last_level = texture->last_level;
51 view->u.tex.first_layer = 0;
52 view->u.tex.last_layer = texture->target == PIPE_TEXTURE_3D ?
53 texture->depth0 - 1 : texture->array_size - 1;
54 view->swizzle_r = PIPE_SWIZZLE_RED;
55 view->swizzle_g = PIPE_SWIZZLE_GREEN;
56 view->swizzle_b = PIPE_SWIZZLE_BLUE;
57 view->swizzle_a = PIPE_SWIZZLE_ALPHA;
58
59 /* Override default green and blue component expansion to the requested
60 * one.
61 *
62 * Gallium expands nonexistent components to (0,0,0,1), DX9 expands
63 * to (1,1,1,1). Since alpha is always expanded to 1, and red is
64 * always present, we only really care about green and blue
65 * components.
66 *
67 * To make it look less hackish, one would have to add
68 * UTIL_FORMAT_SWIZZLE_EXPAND to indicate components for expansion
69 * and then override without exceptions or favoring one component
70 * over another.
71 */
72 if (format != PIPE_FORMAT_A8_UNORM) {
73 const struct util_format_description *desc = util_format_description(format);
74
75 assert(desc);
76 if (desc) {
77 if (desc->swizzle[1] == UTIL_FORMAT_SWIZZLE_0) {
78 view->swizzle_g = expand_green_blue;
79 }
80 if (desc->swizzle[2] == UTIL_FORMAT_SWIZZLE_0) {
81 view->swizzle_b = expand_green_blue;
82 }
83 }
84 }
85 }
86
87 void
u_sampler_view_default_template(struct pipe_sampler_view * view,const struct pipe_resource * texture,enum pipe_format format)88 u_sampler_view_default_template(struct pipe_sampler_view *view,
89 const struct pipe_resource *texture,
90 enum pipe_format format)
91 {
92 /* Expand to (0, 0, 0, 1) */
93 default_template(view,
94 texture,
95 format,
96 PIPE_SWIZZLE_ZERO);
97 }
98
99 void
u_sampler_view_default_dx9_template(struct pipe_sampler_view * view,const struct pipe_resource * texture,enum pipe_format format)100 u_sampler_view_default_dx9_template(struct pipe_sampler_view *view,
101 const struct pipe_resource *texture,
102 enum pipe_format format)
103 {
104 /* Expand to (1, 1, 1, 1) */
105 default_template(view,
106 texture,
107 format,
108 PIPE_SWIZZLE_ONE);
109 }
110