tests/spec/ext_framebuffer_multisample/draw-buffers-alpha-to-coverage.cpp

   1 /*
   2  * Copyright © 2012 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"),
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   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 "draw-buffers-common.h"
  25
  26 /**
  27  * \file draw-buffers-alpha-to-coverage.cpp
  28  *
  29  * Verify sample alpha to coverage with multiple draw buffers
  30  *
  31  * When rendering to multiple draw buffers, the alpha value used by
  32  * GL_SAMPLE_TO_COVERAGE should come from draw buffer zero, but it should
  33  * have an effect on all the draw buffers.
  34  *
  35  * This test operates by drawing a pattern in multisample FBO to generate
  36  * reference and test images for all the draw buffers. Reference images are drawn
  37  * to right half of window system draw buffer and test images to left half.
  38  *
  39  * Compute the expected color values for all the draw buffers.
  40  *
  41  * Probe all the draw buffers blitted to downsampled FBO (resolve_fbo) and
  42  * compare against expected color values.
  43  *
  44  * Author: Anuj Phogat <anuj.phogat@gmail.com>
  45  */
  46
  47 PIGLIT_GL_TEST_CONFIG_BEGIN
  48
  49         config.supports_gl_compat_version = 10;
  50
  51         config.window_width = 512;
  52         config.window_height = 768;
  53         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
  54         config.khr_no_error_support = PIGLIT_NO_ERRORS;
  55
  56 PIGLIT_GL_TEST_CONFIG_END
  57
  58 void
  59 print_usage_and_exit(char *prog_name)
  60 {
  61         printf("Usage: %s <num_samples>\n", prog_name);
  62         piglit_report_result(PIGLIT_FAIL);
  63 }
  64
  65 void
  66 piglit_init(int argc, char **argv)
  67 {
  68         int samples;
  69         /* At present fragment shader supports only fixed number of
  70          * attachments (3)
  71          */
  72         int num_attachments = 3;
  73
  74         if (argc < 2)
  75                 print_usage_and_exit(argv[0]);
  76         {
  77                 char *endptr = NULL;
  78                 samples = strtol(argv[1], &endptr, 0);
  79                 if (endptr != argv[1] + strlen(argv[1]))
  80                         print_usage_and_exit(argv[0]);
  81         }
  82
  83         piglit_require_gl_version(21);
  84         piglit_require_extension("GL_ARB_framebuffer_object");
  85         piglit_require_extension("GL_ARB_vertex_array_object");
  86
  87         int pattern_width = piglit_width / 2;
  88         int pattern_height = piglit_height / num_attachments;
  89
  90         piglit_ortho_projection(pattern_width,
  91                                 pattern_height,
  92                                 GL_TRUE);
  93
  94         /* Skip the test if samples > GL_MAX_SAMPLES */
  95         GLint max_samples;
  96         glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
  97
  98         if (samples > max_samples)
  99                 piglit_report_result(PIGLIT_SKIP);
 100
 101         ms_fbo_and_draw_buffers_setup(samples,
 102                                       pattern_width,
 103                                       pattern_height,
 104                                       num_attachments,
 105                                       GL_COLOR_BUFFER_BIT,
 106                                       GL_RGBA);
 107         shader_compile(true /* sample_alpha_to_coverage */,
 108                        false /* dual_src_blend */,
 109                        true /* frag_out_zero_write */);
 110 }
 111
 112 enum piglit_result
 113 piglit_display()
 114 {
 115         bool pass = true;
 116         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
 117         glClearColor(0.0, 0.0, 0.0, 1.0);
 118         glClear(GL_COLOR_BUFFER_BIT);
 119         allocate_data_arrays();
 120
 121         /* Reference image drawn when sample_alpha_to_coverage is enabled,
 122          * doesn't represent an expected image. Reference image is drawn only
 123          * to visualize the image difference caused by enabling
 124          * sample_alpha_to_coverage
 125          */
 126         draw_reference_image(true /* sample_alpha_to_coverage */,
 127                              false /* sample_alpha_to_one */);
 128
 129         draw_test_image(true /* sample_alpha_to_coverage */,
 130                         false /* sample_alpha_to_one */);
 131
 132         pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
 133
 134         /* Probe test images of all the draw_buffers blitted to resolve fbo
 135          * and compare with expected color values.  This method of verification
 136          * is appropriate for tests with sample-alpha-to-coverage enabled.
 137          * Possibility of dithering effect when the coverage value is not a
 138          * strict multiple of 1 / num_samples makes image compare (test /
 139          * reference image) unsuitable for this test.
 140          */
 141         pass = probe_framebuffer_color() && pass;
 142
 143         /* Free the memory allocated for data arrays */
 144         free_data_arrays();
 145
 146         if (!piglit_automatic)
 147                 piglit_present_results();
 148
 149         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 150 }