1/*
2 * Copyright © 2013 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 */
23
24#ifndef BRW_MULTISAMPLE_STATE_H
25#define BRW_MULTISAMPLE_STATE_H
26
27#include <stdint.h>
28
29/**
30 * Note: There are no standard multisample positions defined in OpenGL
31 * specifications. Implementations have the freedom to pick the positions
32 * which give plausible results. But the Vulkan specification does define
33 * standard sample positions. So, we decided to pick the same pattern in
34 * OpenGL as in Vulkan to keep it uniform across drivers and also to avoid
35 * breaking applications which rely on this standard pattern.
36 */
37
38/**
39 * 1x MSAA has a single sample at the center: (0.5, 0.5) -> (0x8, 0x8).
40 *
41 * 2x MSAA sample positions are (0.75, 0.75) and (0.25, 0.25):
42 *   4 c
43 * 4 1
44 * c   0
45 */
46static const uint32_t
47brw_multisample_positions_1x_2x = 0x008844cc;
48
49/**
50 * Sample positions:
51 *   2 6 a e
52 * 2   0
53 * 6       1
54 * a 2
55 * e     3
56 */
57static const uint32_t
58brw_multisample_positions_4x = 0xae2ae662;
59
60/**
61 * Sample positions:
62 *
63 * From the Ivy Bridge PRM, Vol2 Part1 p304 (3DSTATE_MULTISAMPLE:
64 * Programming Notes):
65 *     "When programming the sample offsets (for NUMSAMPLES_4 or _8 and
66 *     MSRASTMODE_xxx_PATTERN), the order of the samples 0 to 3 (or 7
67 *     for 8X) must have monotonically increasing distance from the
68 *     pixel center. This is required to get the correct centroid
69 *     computation in the device."
70 *
71 * Sample positions:
72 *   1 3 5 7 9 b d f
73 * 1               7
74 * 3     3
75 * 5         0
76 * 7 5
77 * 9             2
78 * b       1
79 * d   4
80 * f           6
81 */
82static const uint32_t
83brw_multisample_positions_8x[] = { 0x53d97b95, 0xf1bf173d };
84
85/**
86 * Sample positions:
87 *
88 *    0 1 2 3 4 5 6 7 8 9 a b c d e f
89 * 0   15
90 * 1                  9
91 * 2         10
92 * 3                        7
93 * 4                               13
94 * 5                1
95 * 6        4
96 * 7                          3
97 * 8 12
98 * 9                    0
99 * a            2
100 * b                            6
101 * c     11
102 * d                      5
103 * e              8
104 * f                             14
105 */
106static const uint32_t
107brw_multisample_positions_16x[] = {
108   0xc75a7599, 0xb3dbad36, 0x2c42816e, 0x10eff408
109};
110
111#endif /* BRW_MULTISAMPLE_STATE_H */
112