tests/spec/ext_framebuffer_multisample/alpha-to-coverage-no-draw-buffer-zero.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"),
   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 "draw-buffers-common.h"
  25
  26 /**
  27  * \file alpha-to-coverage-no-draw-buffer-zero.cpp
  28  *
  29  * Verify sample alpha to coverage with multiple draw buffers when nothing
  30  * is bound to draw buffer zero.
  31  *
  32  * When nothing is bound to draw buffer zero, GL_SAMPLE_ALPHA_TO_COVERAGE
  33  * still needs to work properly for rest of the draw buffers. The alpha value
  34  * used to determine coverage should come from draw buffer zero.
  35  *
  36  * This test operates by drawing a pattern in multisample FBO to generate
  37  * reference and test images for all the draw buffers. Reference images are
  38  * drawn to right half of window system draw buffer and test images to left
  39  * half.
  40  *
  41  * Compute the expected color values for all the draw buffers.
  42  *
  43  * Probe all the draw buffers blitted to downsampled FBO (resolve_fbo) and
  44  * compare against expected color values.
  45  *
  46  * Author: Anuj Phogat <anuj.phogat@gmail.com>
  47  */
  48
  49 PIGLIT_GL_TEST_CONFIG_BEGIN
  50
  51         config.supports_gl_compat_version = 10;
  52
  53         config.window_width = 512;
  54         config.window_height = 768;
  55         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
  56         config.khr_no_error_support = PIGLIT_NO_ERRORS;
  57
  58 PIGLIT_GL_TEST_CONFIG_END
  59
  60 void
  61 print_usage_and_exit(char *prog_name)
  62 {
  63         printf("Usage: %s <num_samples>\n", prog_name);
  64         piglit_report_result(PIGLIT_FAIL);
  65 }
  66
  67 void
  68 piglit_init(int argc, char **argv)
  69 {
  70         int samples;
  71         /* At present fragment shader supports only fixed number of
  72          * attachments (3)
  73          */
  74         int num_attachments = 3;
  75
  76         if (argc < 2)
  77                 print_usage_and_exit(argv[0]);
  78         {
  79                 char *endptr = NULL;
  80                 samples = strtol(argv[1], &endptr, 0);
  81                 if (endptr != argv[1] + strlen(argv[1]))
  82                         print_usage_and_exit(argv[0]);
  83         }
  84
  85         piglit_require_gl_version(21);
  86         piglit_require_extension("GL_ARB_framebuffer_object");
  87         piglit_require_extension("GL_ARB_vertex_array_object");
  88
  89         int pattern_width = piglit_width / 2;
  90         int pattern_height = piglit_height / num_attachments;
  91
  92         piglit_ortho_projection(pattern_width,
  93                                 pattern_height,
  94                                 GL_TRUE);
  95
  96         /* Skip the test if samples > GL_MAX_SAMPLES */
  97         GLint max_samples;
  98         glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
  99
 100         if (samples > max_samples)
 101                 piglit_report_result(PIGLIT_SKIP);
 102
 103         ms_fbo_and_draw_buffers_setup(samples,
 104                                       pattern_width,
 105                                       pattern_height,
 106                                       num_attachments,
 107                                       GL_COLOR_BUFFER_BIT,
 108                                       GL_NONE /* color_buffer_zero_format */);
 109         shader_compile(true /* sample_alpha_to_coverage */,
 110                        false /* dual_src_blend */,
 111                        true /* frag_out_zero_write */);
 112 }
 113
 114 enum piglit_result
 115 piglit_display()
 116 {
 117         bool pass = true;
 118         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
 119         glClearColor(0.0, 0.0, 0.0, 1.0);
 120         glClear(GL_COLOR_BUFFER_BIT);
 121         allocate_data_arrays();
 122
 123         /* Reference image drawn when sample_alpha_to_coverage is enabled,
 124          * doesn't represent an expected image. Reference image is drawn only
 125          * to visualize the image difference caused by enabling
 126          * sample_alpha_to_coverage
 127          */
 128         draw_reference_image(true /* sample_alpha_to_coverage */,
 129                              false /* sample_alpha_to_one */);
 130
 131         draw_test_image(true /* sample_alpha_to_coverage */,
 132                         false /* sample_alpha_to_one */);
 133
 134         pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
 135
 136         /* Probe test images of all the draw_buffers blitted to resolve fbo
 137          * and compare with expected color values.  This method of verification
 138          * is appropriate for tests with sample-alpha-to-coverage enabled.
 139          * Possibility of dithering effect when the coverage value is not a
 140          * strict multiple of 1 / num_samples makes image compare (test /
 141          * reference image) unsuitable for this test.
 142          */
 143         pass = probe_framebuffer_color() && pass;
 144
 145         /* Free the memory allocated for data arrays */
 146         free_data_arrays();
 147
 148         if (!piglit_automatic)
 149                 piglit_present_results();
 150
 151         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 152 }