tests/spec/ext_framebuffer_multisample/renderbuffer-samples.c

   1 /*
   2  * Copyright © 2011 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 "piglit-util-gl.h"
  25
  26 /**
  27  * @file renderbuffer-samples.c
  28  *
  29  * Tests that asking for samples gives the correct number of
  30  * GL_RENDERBUFFER_SAMPLES.
  31  *
  32  * From the EXT_framebuffer_multisample spec:
  33  *
  34  *     "If <samples> is zero, then RENDERBUFFER_SAMPLES_EXT is set to
  35  *      zero.  Otherwise <samples> represents a request for a desired
  36  *      minimum number of samples. Since different implementations may
  37  *      support different sample counts for multisampled rendering,
  38  *      the actual number of samples allocated for the renderbuffer
  39  *      image is implementation dependent.  However, the resulting
  40  *      value for RENDERBUFFER_SAMPLES_EXT is guaranteed to be greater
  41  *      than or equal to <samples> and no more than the next larger
  42  *      sample count supported by the implementation.
  43  *
  44  * Note also this issue:
  45  *
  46  * "    (2)  What happens when <samples> is zero or one?
  47  *
  48  *           RESOLVED, 0 = single sample, 1 = minimum multisample
  49  *
  50  *           Resolved by consensus, May 9, 2005
  51  *
  52  *           Zero means single sample, as if RenderbufferStorageEXT
  53  *           had been called instead of
  54  *           RenderbufferStorageMultisampleEXT.  One means minimum
  55  *           number of samples supported by implementation.
  56  *
  57  *           There was a question if one should mean the same thing as
  58  *           single-sample (one sample), or if it should mean the
  59  *           minimum supported number of samples for multisample
  60  *           rendering.  The rules for rasterizing in "multisample"
  61  *           mode are different than "non-multisample" mode.  In the
  62  *           end, we decided that some implementations may wish to
  63  *           support a "one-sample" multisample buffer to allow for
  64  *           multipass multisampling where the sample location can be
  65  *           varied either by the implementation or perhaps explicitly
  66  *           by a "multisample location" extension."
  67  */
  68
  69 PIGLIT_GL_TEST_CONFIG_BEGIN
  70
  71         config.supports_gl_compat_version = 10;
  72
  73         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
  74         config.khr_no_error_support = PIGLIT_NO_ERRORS;
  75
  76 PIGLIT_GL_TEST_CONFIG_END
  77
  78 enum piglit_result
  79 piglit_display(void)
  80 {
  81         /* UNREACHED */
  82         return PIGLIT_FAIL;
  83 }
  84
  85 void
  86 piglit_init(int argc, char **argv)
  87 {
  88         GLint max_samples, samples, prev_rb_samples = 0;
  89         GLuint rb;
  90         bool pass = true;
  91
  92         piglit_require_extension("GL_EXT_framebuffer_multisample");
  93
  94         glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
  95
  96         glGenRenderbuffersEXT(1, &rb);
  97         glBindRenderbufferEXT(GL_RENDERBUFFER, rb);
  98         printf("%10s %10s\n", "requested", "result");
  99         for (samples = 0; samples <= max_samples; samples++) {
 100                 GLint rb_samples;
 101
 102                 glRenderbufferStorageMultisampleEXT(GL_RENDERBUFFER,
 103                                                     samples,
 104                                                     GL_RGBA,
 105                                                     1, 1);
 106
 107                 glGetRenderbufferParameterivEXT(GL_RENDERBUFFER,
 108                                                 GL_RENDERBUFFER_SAMPLES,
 109                                                 &rb_samples);
 110
 111                 if ((rb_samples < prev_rb_samples) ||
 112                     (samples == 0 && rb_samples != 0) ||
 113                     (samples > 0 && rb_samples < samples)) {
 114                         fprintf(stderr, "%10d %10d (ERROR)\n", samples, rb_samples);
 115                         pass = false;
 116                 } else {
 117                         printf("%10d %10d\n", samples, rb_samples);
 118                 }
 119
 120                 prev_rb_samples = rb_samples;
 121         }
 122         glDeleteRenderbuffersEXT(1, &rb);
 123
 124         piglit_report_result(pass ? PIGLIT_PASS : PIGLIT_FAIL);
 125 }