1 /*
2 * Copyright (C) 2019 Collabora, Ltd.
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 FROM,
20 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 * SOFTWARE.
22 */
23
24 #include "pan_device.h"
25 #include "pan_bo.h"
26
27 /* Sample positions are specified partially in hardware, partially in software
28 * on Mali. On Midgard, sample positions are completely fixed but need to be
29 * software accessible to implement gl_SamplePosition. On Bifrost, sample
30 * positions are part fixed, part programmable, and again need to be accessible
31 * for gl_SamplePosition. The mali_sample_position data structure is
32 * hardware-defined on Bifrost as a packed 8:8 fixed point format. The
33 * mali_sample_positions array is part-hardware, part-software-defined: it must
34 * give the sample position when indexed by the sample index, as well as
35 * reading back the origin when indexed by 32.
36 *
37 * The upshot is all of this is known at compile-time, so we can just hardcode
38 * the LUT, upload it to GPU memory on device initialization, and forget about
39 * it.
40 */
41
42 struct mali_sample_position {
43 uint16_t x, y;
44 } __attribute__((packed));
45
46 struct mali_sample_positions {
47 struct mali_sample_position positions[32];
48 struct mali_sample_position origin;
49 struct mali_sample_position padding[64 - (32 + 1)];
50 } __attribute__((packed));
51
52 /* SAMPLE16 constructs a single sample in terms of 1/16's of the grid, centered
53 * at the origin. SAMPLE4/8 swap the units for legibility. */
54
55 #define SAMPLE16(x, y) { \
56 (((x) + 8) * (256 / 16)), \
57 (((y) + 8) * (256 / 16)) \
58 }
59
60 #define SAMPLE8(x, y) SAMPLE16((x) * 2, (y) * 2)
61 #define SAMPLE4(x, y) SAMPLE16((x) * 4, (y) * 4)
62
63 const struct mali_sample_positions sample_position_lut[] = {
64 [MALI_SAMPLE_PATTERN_SINGLE_SAMPLED] = {
65 .positions = {
66 SAMPLE4(0, 0)
67 },
68 .origin = SAMPLE4(0, 0)
69 },
70
71 [MALI_SAMPLE_PATTERN_ORDERED_4X_GRID] = {
72 .positions = {
73 SAMPLE4(-1, -1),
74 SAMPLE4( 1, -1),
75 SAMPLE4(-1, 1),
76 SAMPLE4( 1, 1),
77 },
78 .origin = SAMPLE4(0, 0)
79 },
80
81 [MALI_SAMPLE_PATTERN_ROTATED_4X_GRID] = {
82 .positions = {
83 SAMPLE8(-1, -3),
84 SAMPLE8( 3, -1),
85 SAMPLE8(-3, 1),
86 SAMPLE8( 1, 3),
87 },
88 .origin = SAMPLE8(0, 0)
89 },
90
91 [MALI_SAMPLE_PATTERN_D3D_8X_GRID] = {
92 .positions = {
93 SAMPLE16( 1, -3),
94 SAMPLE16(-1, 3),
95 SAMPLE16( 5, 1),
96 SAMPLE16(-3, -5),
97 SAMPLE16(-5, 5),
98 SAMPLE16(-7, -1),
99 SAMPLE16( 3, 7),
100 SAMPLE16( 7, -7),
101 },
102 .origin = SAMPLE16(0, 0)
103 },
104
105 [MALI_SAMPLE_PATTERN_D3D_16X_GRID] = {
106 .positions = {
107 SAMPLE16( 1, 1),
108 SAMPLE16(-1, -3),
109 SAMPLE16(-3, 2),
110 SAMPLE16( 4, -1),
111 SAMPLE16(-5, -2),
112 SAMPLE16( 2, 5),
113 SAMPLE16( 5, 3),
114 SAMPLE16( 3, -5),
115 SAMPLE16(-2, 6),
116 SAMPLE16( 0, 7),
117 SAMPLE16(-4, -6),
118 SAMPLE16(-6, 4),
119 SAMPLE16(-8, 0),
120 SAMPLE16( 7, -4),
121 SAMPLE16( 6, 7),
122 SAMPLE16(-7, -8),
123
124 },
125 .origin = SAMPLE16(0, 0)
126 }
127 };
128
129 mali_ptr
panfrost_sample_positions(const struct panfrost_device * dev,enum mali_sample_pattern pattern)130 panfrost_sample_positions(const struct panfrost_device *dev,
131 enum mali_sample_pattern pattern)
132 {
133 assert(pattern < ARRAY_SIZE(sample_position_lut));
134 unsigned offset = (pattern * sizeof(sample_position_lut[0]));
135 return dev->sample_positions->ptr.gpu + offset;
136 }
137
138 void
panfrost_upload_sample_positions(struct panfrost_device * dev)139 panfrost_upload_sample_positions(struct panfrost_device *dev)
140 {
141 STATIC_ASSERT(sizeof(sample_position_lut) < 4096);
142 dev->sample_positions = panfrost_bo_create(dev, 4096, 0, "Sample positions");
143
144 memcpy(dev->sample_positions->ptr.cpu, sample_position_lut,
145 sizeof(sample_position_lut));
146 }
147
148 /* CPU side LUT query, to implement glGetMultisamplefv */
149
150 void
panfrost_query_sample_position(enum mali_sample_pattern pattern,unsigned sample_idx,float * out)151 panfrost_query_sample_position(
152 enum mali_sample_pattern pattern,
153 unsigned sample_idx,
154 float *out)
155 {
156 struct mali_sample_position pos =
157 sample_position_lut[pattern].positions[sample_idx];
158
159 out[0] = DECODE_FIXED_16(pos.x);
160 out[1] = DECODE_FIXED_16(pos.y);
161 }
162