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