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 THE AUTHORS 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 "st_context.h"
30#include "pipe/p_screen.h"
31#include "pipe/p_context.h"
32#include "st_atom.h"
33#include "st_program.h"
34#include "st_util.h"
35
36#include "cso_cache/cso_context.h"
37#include "util/u_framebuffer.h"
38#include "main/framebuffer.h"
39
40
41/**
42 * Update the sample locations
43 */
44static void
45update_sample_locations(struct st_context *st)
46{
47   struct gl_framebuffer *fb = st->ctx->DrawBuffer;
48
49   if (!st->ctx->Extensions.ARB_sample_locations)
50      return;
51
52   if (fb->ProgrammableSampleLocations) {
53      unsigned grid_width, grid_height, size, pixel, sample_index;
54      unsigned samples = st->state.fb_num_samples;
55      bool sample_location_pixel_grid = fb->SampleLocationPixelGrid;
56      uint8_t locations[
57         PIPE_MAX_SAMPLE_LOCATION_GRID_SIZE *
58         PIPE_MAX_SAMPLE_LOCATION_GRID_SIZE * 32];
59
60      st->screen->get_sample_pixel_grid(st->screen, samples,
61                                        &grid_width, &grid_height);
62      size = grid_width * grid_height * samples;
63
64      /**
65       * when a dimension is greater than MAX_SAMPLE_LOCATION_GRID_SIZE,
66       * st->ctx->Driver.GetSamplePixelGrid() returns 1 for both dimensions.
67       */
68      if (grid_width > MAX_SAMPLE_LOCATION_GRID_SIZE ||
69          grid_height > MAX_SAMPLE_LOCATION_GRID_SIZE)
70         sample_location_pixel_grid = false;
71
72      for (pixel = 0; pixel < grid_width * grid_height; pixel++) {
73         for (sample_index = 0; sample_index < samples; sample_index++) {
74            int table_index = sample_index;
75            float x = 0.5f, y = 0.5f;
76            uint8_t loc;
77            if (sample_location_pixel_grid)
78               table_index = pixel * samples + sample_index;
79            if (fb->SampleLocationTable) {
80               x = fb->SampleLocationTable[table_index*2];
81               y = fb->SampleLocationTable[table_index*2+1];
82            }
83            if (st->state.fb_orientation == Y_0_BOTTOM)
84               y = 1.0 - y;
85
86            loc = roundf(CLAMP(x * 16.0f, 0.0f, 15.0f));
87            loc |= (int)roundf(CLAMP(y * 16.0f, 0.0f, 15.0f)) << 4;
88            locations[pixel * samples + sample_index] = loc;
89         }
90      }
91
92      util_sample_locations_flip_y(
93         st->screen, st->state.fb_height, samples, locations);
94
95      if (!st->state.enable_sample_locations ||
96          st->state.sample_locations_samples != samples ||
97          memcmp(locations, st->state.sample_locations, size) != 0) {
98         st->pipe->set_sample_locations( st->pipe, size, locations);
99
100         st->state.sample_locations_samples = samples;
101         memcpy(st->state.sample_locations, locations, size);
102      }
103   } else if (st->state.enable_sample_locations) {
104      st->pipe->set_sample_locations(st->pipe, 0, NULL);
105   }
106
107   st->state.enable_sample_locations = fb->ProgrammableSampleLocations;
108}
109
110
111/* Update the sample mask and locations for MSAA.
112 */
113void
114st_update_sample_state(struct st_context *st)
115{
116   unsigned sample_mask = 0xffffffff;
117   unsigned sample_count = st->state.fb_num_samples;
118
119   if (_mesa_is_multisample_enabled(st->ctx) && sample_count > 1) {
120      /* unlike in gallium/d3d10 the mask is only active if msaa is enabled */
121      if (st->ctx->Multisample.SampleCoverage) {
122         unsigned nr_bits = (unsigned)
123            (st->ctx->Multisample.SampleCoverageValue * (float) sample_count);
124         /* there's lot of ways how to do this. We just use first few bits,
125          * since we have no knowledge of sample positions here. When
126          * app-supplied mask though is used too might need to be smarter.
127          * Also, there's an interface restriction here in theory it is
128          * encouraged this mask not be the same at each pixel.
129          */
130         sample_mask = (1 << nr_bits) - 1;
131         if (st->ctx->Multisample.SampleCoverageInvert)
132            sample_mask = ~sample_mask;
133      }
134      if (st->ctx->Multisample.SampleMask)
135         sample_mask &= st->ctx->Multisample.SampleMaskValue;
136   }
137
138   cso_set_sample_mask(st->cso_context, sample_mask);
139
140   update_sample_locations(st);
141}
142
143
144void
145st_update_sample_shading(struct st_context *st)
146{
147   if (!st->fp)
148      return;
149
150   if (!st->ctx->Extensions.ARB_sample_shading)
151      return;
152
153   cso_set_min_samples(st->cso_context,
154                       _mesa_get_min_invocations_per_fragment(st->ctx, st->fp));
155}
156