tests/spec/ext_framebuffer_multisample/sample-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"),
   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 sample-alpha-to-coverage.cpp
  28  *
  29  * Verify sample alpha to coverage with multisample FBO
  30  *
  31  * When rendering to multisample FBO, fragment's alpha value should be
  32  * used to determine the coverage value.
  33  *
  34  * This test operates by drawing a pattern in multisample FBO to generate
  35  * reference and test image. Reference image is drawn to right half of window
  36  * system frame buffer and test image to left half.
  37  *
  38  * Compute the expected color / depth values.
  39  *
  40  * Probe color / depth buffer blitted to downsampled FBO (resolve_fbo) and
  41  * compare against expected color values.
  42  *
  43  * Author: Anuj Phogat <anuj.phogat@gmail.com>
  44  */
  45
  46 PIGLIT_GL_TEST_CONFIG_BEGIN
  47
  48         config.supports_gl_compat_version = 10;
  49
  50         config.window_width = 512;
  51         config.window_height = 256;
  52         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
  53         config.khr_no_error_support = PIGLIT_NO_ERRORS;
  54
  55 PIGLIT_GL_TEST_CONFIG_END
  56
  57 static GLenum buffer_to_test;
  58
  59 void
  60 print_usage_and_exit(char *prog_name)
  61 {
  62         printf("Usage: %s <num_samples> <test_type>\n"
  63                "  where <test_type> is one of:\n"
  64                "    color\n"
  65                "    depth\n",
  66                prog_name);
  67         piglit_report_result(PIGLIT_FAIL);
  68 }
  69
  70 void
  71 piglit_init(int argc, char **argv)
  72 {
  73         const int num_attachments = 1;
  74         int samples;
  75
  76         piglit_require_gl_version(21);
  77         piglit_require_extension("GL_ARB_framebuffer_object");
  78         piglit_require_extension("GL_ARB_vertex_array_object");
  79
  80         if (argc < 3)
  81                 print_usage_and_exit(argv[0]);
  82         {
  83                 char *endptr = NULL;
  84                 samples = strtol(argv[1], &endptr, 0);
  85                 if (endptr != argv[1] + strlen(argv[1]))
  86                         print_usage_and_exit(argv[0]);
  87         }
  88         if (strcmp(argv[2], "color") == 0) {
  89                 buffer_to_test = GL_COLOR_BUFFER_BIT;
  90         } else if (strcmp(argv[2], "depth") == 0) {
  91                 buffer_to_test = GL_DEPTH_BUFFER_BIT;
  92                 glEnable(GL_DEPTH_TEST);
  93                 glDepthFunc(GL_ALWAYS);
  94         } else
  95                 print_usage_and_exit(argv[0]);
  96
  97         int pattern_width = piglit_width / 2;
  98         int pattern_height = piglit_height / num_attachments;
  99
 100         piglit_ortho_projection(pattern_width,
 101                                 pattern_height,
 102                                 GL_TRUE);
 103
 104         /* Skip the test if samples > GL_MAX_SAMPLES */
 105         GLint max_samples;
 106         glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
 107
 108         if (samples > max_samples)
 109                 piglit_report_result(PIGLIT_SKIP);
 110
 111         ms_fbo_and_draw_buffers_setup(samples,
 112                                       pattern_width,
 113                                       pattern_height,
 114                                       num_attachments,
 115                                       buffer_to_test,
 116                                       GL_RGBA);
 117         shader_compile(true /* sample_alpha_to_coverage */,
 118                        false /* dual_src_blend */,
 119                        true /* frag_out_zero_write */);
 120 }
 121
 122 enum piglit_result
 123 piglit_display()
 124 {
 125         bool pass = true;
 126         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
 127         glClearColor(0.0, 0.0, 0.0, 1.0);
 128         glClear(GL_COLOR_BUFFER_BIT);
 129         allocate_data_arrays();
 130
 131         /* Reference image drawn here doesn't represent an expected image.
 132          * Reference image is drawn only to visualize the image difference
 133          * caused by enabling sample_alpha_to_coverage in test image.
 134          */
 135         if(buffer_to_test == GL_COLOR_BUFFER_BIT)
 136                 draw_reference_image(true /* sample_alpha_to_coverage */,
 137                                      false /* sample_alpha_to_one */);
 138
 139         draw_test_image(true /* sample_alpha_to_coverage */,
 140                         false /* sample_alpha_to_one */);
 141
 142         pass = piglit_check_gl_error(GL_NO_ERROR) && pass;
 143
 144         /* Probe all the test image blitted to resolve fbo and compare with
 145          * expected color values.  This method of verification is appropriate
 146          * for tests with sample-alpha-to-coverage enabled. Possibility of
 147          * dithering effect when the coverage value is not a strict multiple
 148          * of 1 / num_samples makes image compare (test / reference image)
 149          * unsuitable for this test.
 150          */
 151         if(buffer_to_test == GL_COLOR_BUFFER_BIT)
 152                 pass = probe_framebuffer_color() && pass;
 153         else if (buffer_to_test == GL_DEPTH_BUFFER_BIT)
 154                 pass = probe_framebuffer_depth() && pass;
 155
 156         /* Free the memory allocated for data arrays */
 157         free_data_arrays();
 158
 159         if (!piglit_automatic && buffer_to_test == GL_COLOR_BUFFER_BIT)
 160                 piglit_present_results();
 161
 162         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 163 }