1/*
2 * Copyright © 2015 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#include "brw_context.h"
25#include "brw_state.h"
26#include "main/context.h"
27#include "main/formatquery.h"
28#include "main/glformats.h"
29
30static size_t
31brw_query_samples_for_format(struct gl_context *ctx, GLenum target,
32                             GLenum internalFormat, int samples[16])
33{
34   struct brw_context *brw = brw_context(ctx);
35   const struct gen_device_info *devinfo = &brw->screen->devinfo;
36
37   (void) target;
38   (void) internalFormat;
39
40   switch (devinfo->gen) {
41   case 11:
42   case 10:
43   case 9:
44      samples[0] = 16;
45      samples[1] = 8;
46      samples[2] = 4;
47      samples[3] = 2;
48      return 4;
49
50   case 8:
51      samples[0] = 8;
52      samples[1] = 4;
53      samples[2] = 2;
54      return 3;
55
56   case 7:
57      if (internalFormat == GL_RGBA32F && _mesa_is_gles(ctx)) {
58         /* For GLES, we are allowed to return a smaller number of samples for
59          * GL_RGBA32F. See OpenGLES 3.2 spec, section 20.3.1 Internal Format
60          * Query Parameters, under SAMPLES:
61          *
62          * "A value less than or equal to the value of MAX_SAMPLES, if
63          *  internalformat is RGBA16F, R32F, RG32F, or RGBA32F."
64          *
65          * In brw_render_target_supported, we prevent formats with a size
66          * greater than 8 bytes from using 8x MSAA on gen7.
67          */
68         samples[0] = 4;
69         return 1;
70      } else {
71         samples[0] = 8;
72         samples[1] = 4;
73         return 2;
74      }
75
76   case 6:
77      samples[0] = 4;
78      return 1;
79
80   default:
81      assert(devinfo->gen < 6);
82      samples[0] = 1;
83      return 1;
84   }
85}
86
87void
88brw_query_internal_format(struct gl_context *ctx, GLenum target,
89                          GLenum internalFormat, GLenum pname, GLint *params)
90{
91   /* The Mesa layer gives us a temporary params buffer that is guaranteed
92    * to be non-NULL, and have at least 16 elements.
93    */
94   assert(params != NULL);
95
96   switch (pname) {
97   case GL_SAMPLES:
98      brw_query_samples_for_format(ctx, target, internalFormat, params);
99      break;
100
101   case GL_NUM_SAMPLE_COUNTS: {
102      size_t num_samples;
103      GLint dummy_buffer[16];
104
105      num_samples = brw_query_samples_for_format(ctx, target, internalFormat,
106                                                 dummy_buffer);
107      params[0] = (GLint) num_samples;
108      break;
109   }
110
111   default:
112      /* By default, we call the driver hook's fallback function from the frontend,
113       * which has generic implementation for all pnames.
114       */
115      _mesa_query_internal_format_default(ctx, target, internalFormat, pname,
116                                          params);
117      break;
118   }
119}
120