1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
|
/*
* Copyright © 2012 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "intel_batchbuffer.h"
#include "brw_context.h"
#include "brw_defines.h"
/* Sample positions:
* 2 6 a e
* 2 0
* 6 1
* a 2
* e 3
*/
static uint32_t
sample_positions_4x[] = { 0xae2ae662 };
/* Sample positions are based on a solution to the "8 queens" puzzle.
* Rationale: in a solution to the 8 queens puzzle, no two queens share
* a row, column, or diagonal. This is a desirable property for samples
* in a multisampling pattern, because it ensures that the samples are
* relatively uniformly distributed through the pixel.
*
* There are several solutions to the 8 queens puzzle (see
* http://en.wikipedia.org/wiki/Eight_queens_puzzle). This solution was
* chosen because it has a queen close to the center; this should
* improve the accuracy of centroid interpolation, since the hardware
* implements centroid interpolation by choosing the centermost sample
* that overlaps with the primitive being drawn.
*
* Note: from the Ivy Bridge PRM, Vol2 Part1 p304 (3DSTATE_MULTISAMPLE:
* Programming Notes):
*
* "When programming the sample offsets (for NUMSAMPLES_4 or _8 and
* MSRASTMODE_xxx_PATTERN), the order of the samples 0 to 3 (or 7
* for 8X) must have monotonically increasing distance from the
* pixel center. This is required to get the correct centroid
* computation in the device."
*
* Sample positions:
* 1 3 5 7 9 b d f
* 1 5
* 3 2
* 5 6
* 7 4
* 9 0
* b 3
* d 1
* f 7
*/
static uint32_t
sample_positions_8x[] = { 0xdbb39d79, 0x3ff55117 };
void
gen6_get_sample_position(struct gl_context *ctx,
struct gl_framebuffer *fb,
GLuint index, GLfloat *result)
{
switch (fb->Visual.samples) {
case 1:
result[0] = result[1] = 0.5f;
break;
case 4: {
uint8_t val = (uint8_t)(sample_positions_4x[0] >> (8*index));
result[0] = ((val >> 4) & 0xf) / 16.0f;
result[1] = (val & 0xf) / 16.0f;
break;
}
case 8: {
uint8_t val = (uint8_t)(sample_positions_8x[index>>2] >> (8*(index & 3)));
result[0] = ((val >> 4) & 0xf) / 16.0f;
result[1] = (val & 0xf) / 16.0f;
break;
}
default:
assert(!"Not implemented");
}
}
/**
* 3DSTATE_MULTISAMPLE
*/
void
gen6_emit_3dstate_multisample(struct brw_context *brw,
unsigned num_samples)
{
uint32_t number_of_multisamples = 0;
uint32_t sample_positions_3210 = 0;
uint32_t sample_positions_7654 = 0;
switch (num_samples) {
case 0:
case 1:
number_of_multisamples = MS_NUMSAMPLES_1;
break;
case 4:
number_of_multisamples = MS_NUMSAMPLES_4;
sample_positions_3210 = sample_positions_4x[0];
break;
case 8:
number_of_multisamples = MS_NUMSAMPLES_8;
sample_positions_3210 = sample_positions_8x[0];
sample_positions_7654 = sample_positions_8x[1];
break;
default:
assert(!"Unrecognized num_samples in gen6_emit_3dstate_multisample");
break;
}
int len = brw->gen >= 7 ? 4 : 3;
BEGIN_BATCH(len);
OUT_BATCH(_3DSTATE_MULTISAMPLE << 16 | (len - 2));
OUT_BATCH(MS_PIXEL_LOCATION_CENTER | number_of_multisamples);
OUT_BATCH(sample_positions_3210);
if (brw->gen >= 7)
OUT_BATCH(sample_positions_7654);
ADVANCE_BATCH();
}
/**
* 3DSTATE_SAMPLE_MASK
*/
void
gen6_emit_3dstate_sample_mask(struct brw_context *brw,
unsigned num_samples, float coverage,
bool coverage_invert, unsigned sample_mask)
{
BEGIN_BATCH(2);
OUT_BATCH(_3DSTATE_SAMPLE_MASK << 16 | (2 - 2));
if (num_samples > 1) {
int coverage_int = (int) (num_samples * coverage + 0.5);
uint32_t coverage_bits = (1 << coverage_int) - 1;
if (coverage_invert)
coverage_bits ^= (1 << num_samples) - 1;
OUT_BATCH(coverage_bits & sample_mask);
} else {
OUT_BATCH(1);
}
ADVANCE_BATCH();
}
static void upload_multisample_state(struct brw_context *brw)
{
struct gl_context *ctx = &brw->ctx;
float coverage = 1.0;
float coverage_invert = false;
unsigned sample_mask = ~0u;
/* _NEW_BUFFERS */
unsigned num_samples = ctx->DrawBuffer->Visual.samples;
/* _NEW_MULTISAMPLE */
if (ctx->Multisample._Enabled) {
if (ctx->Multisample.SampleCoverage) {
coverage = ctx->Multisample.SampleCoverageValue;
coverage_invert = ctx->Multisample.SampleCoverageInvert;
}
if (ctx->Multisample.SampleMask) {
sample_mask = ctx->Multisample.SampleMaskValue;
}
}
/* 3DSTATE_MULTISAMPLE is nonpipelined. */
intel_emit_post_sync_nonzero_flush(brw);
gen6_emit_3dstate_multisample(brw, num_samples);
gen6_emit_3dstate_sample_mask(brw, num_samples, coverage,
coverage_invert, sample_mask);
}
const struct brw_tracked_state gen6_multisample_state = {
.dirty = {
.mesa = _NEW_BUFFERS |
_NEW_MULTISAMPLE,
.brw = BRW_NEW_CONTEXT,
.cache = 0
},
.emit = upload_multisample_state
};
|
