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 "util/format/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->target = texture->target;
49 view->is_tex2d_from_buf = false;
50 view->format = format;
51 view->u.tex.first_level = 0;
52 view->u.tex.last_level = texture->last_level;
53 view->u.tex.first_layer = 0;
54 view->u.tex.last_layer = texture->target == PIPE_TEXTURE_3D ?
55 texture->depth0 - 1 : texture->array_size - 1;
56 view->swizzle_r = PIPE_SWIZZLE_X;
57 view->swizzle_g = PIPE_SWIZZLE_Y;
58 view->swizzle_b = PIPE_SWIZZLE_Z;
59 view->swizzle_a = PIPE_SWIZZLE_W;
60
61 /* Override default green and blue component expansion to the requested
62 * one.
63 *
64 * Gallium expands nonexistent components to (0,0,0,1), DX9 expands
65 * to (1,1,1,1). Since alpha is always expanded to 1, and red is
66 * always present, we only really care about green and blue
67 * components.
68 *
69 * To make it look less hackish, one would have to add
70 * PIPE_SWIZZLE_EXPAND to indicate components for expansion
71 * and then override without exceptions or favoring one component
72 * over another.
73 */
74 if (format != PIPE_FORMAT_A8_UNORM) {
75 const struct util_format_description *desc = util_format_description(format);
76
77 if (desc->swizzle[1] == PIPE_SWIZZLE_0) {
78 view->swizzle_g = expand_green_blue;
79 }
80 if (desc->swizzle[2] == PIPE_SWIZZLE_0) {
81 view->swizzle_b = expand_green_blue;
82 }
83 }
84 }
85
86 void
u_sampler_view_default_template(struct pipe_sampler_view * view,const struct pipe_resource * texture,enum pipe_format format)87 u_sampler_view_default_template(struct pipe_sampler_view *view,
88 const struct pipe_resource *texture,
89 enum pipe_format format)
90 {
91 /* Expand to (0, 0, 0, 1) */
92 default_template(view,
93 texture,
94 format,
95 PIPE_SWIZZLE_0);
96 }
97