2 * Copyright © 2012 Intel Corporation
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:
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
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
24 #include "intel_batchbuffer.h"
26 #include "brw_context.h"
27 #include "brw_defines.h"
28 #include "brw_multisample_state.h"
29 #include "main/framebuffer.h"
32 gen6_get_sample_position(struct gl_context
*ctx
,
33 struct gl_framebuffer
*fb
,
34 GLuint index
, GLfloat
*result
)
38 switch (_mesa_geometric_samples(fb
)) {
40 result
[0] = result
[1] = 0.5f
;
43 bits
= brw_multisample_positions_1x_2x
>> (8 * index
);
46 bits
= brw_multisample_positions_4x
>> (8 * index
);
49 bits
= brw_multisample_positions_8x
[index
>> 2] >> (8 * (index
& 3));
52 bits
= brw_multisample_positions_16x
[index
>> 2] >> (8 * (index
& 3));
55 unreachable("Not implemented");
58 /* Convert from U0.4 back to a floating point coordinate. */
59 result
[0] = ((bits
>> 4) & 0xf) / 16.0f
;
60 result
[1] = (bits
& 0xf) / 16.0f
;
64 * Sample index layout shows the numbering of slots in a rectangular
65 * grid of samples with in a pixel. Sample number layout shows the
66 * rectangular grid of samples roughly corresponding to the real sample
67 * locations with in a pixel. Sample number layout matches the sample
68 * index layout in case of 2X and 4x MSAA, but they are different in
71 * 2X MSAA sample index / number layout
76 * 4X MSAA sample index / number layout
83 * 8X MSAA sample index layout 8x MSAA sample number layout
94 * 16X MSAA sample index layout 16x MSAA sample number layout
95 * ----------------- -----------------
96 * | 0 | 1 | 2 | 3 | |15 |10 | 9 | 7 |
97 * ----------------- -----------------
98 * | 4 | 5 | 6 | 7 | | 4 | 1 | 3 |13 |
99 * ----------------- -----------------
100 * | 8 | 9 |10 |11 | |12 | 2 | 0 | 6 |
101 * ----------------- -----------------
102 * |12 |13 |14 |15 | |11 | 8 | 5 |14 |
103 * ----------------- -----------------
105 * A sample map is used to map sample indices to sample numbers.
108 gen6_set_sample_maps(struct gl_context
*ctx
)
110 uint8_t map_2x
[2] = {0, 1};
111 uint8_t map_4x
[4] = {0, 1, 2, 3};
112 uint8_t map_8x
[8] = {3, 7, 5, 0, 1, 2, 4, 6};
113 uint8_t map_16x
[16] = { 15, 10, 9, 7, 4, 1, 3, 13,
114 12, 2, 0, 6, 11, 8, 5, 14 };
116 memcpy(ctx
->Const
.SampleMap2x
, map_2x
, sizeof(map_2x
));
117 memcpy(ctx
->Const
.SampleMap4x
, map_4x
, sizeof(map_4x
));
118 memcpy(ctx
->Const
.SampleMap8x
, map_8x
, sizeof(map_8x
));
119 memcpy(ctx
->Const
.SampleMap16x
, map_16x
, sizeof(map_16x
));