tests/spec/ext_framebuffer_multisample/alpha-to-coverage-no-draw-buffer-zero-write.cpp

   1 /*
   2  * Copyright © 2016 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-write.cpp
  28  *
  29  * Verify sample alpha to coverage with multiple draw buffers when nothing
  30  * is written to draw buffer zero.
  31  *
  32  * When nothing is written to draw buffer zero, GL_SAMPLE_ALPHA_TO_COVERAGE
  33  * usage shouldn't hang the system. The alpha value used to determine
  34  * coverage will be undefined which will result in to pixels with undefined
  35  * colors. So, pixels can't be probed for color in this test.
  36  *
  37  * From OpenGL 2.1 specification:
  38  * "If a fragment shader writes to neither gl FragColor nor gl FragData,
  39  * the values of the fragment colors following shader execution are
  40  * undefined, and may differ for each fragment color."
  41  *
  42  * It is a significant edge case for i965 driver.
  43  */
  44
  45 PIGLIT_GL_TEST_CONFIG_BEGIN
  46
  47         config.supports_gl_compat_version = 21;
  48
  49         config.window_width = 512;
  50         config.window_height = 768;
  51         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
  52         config.khr_no_error_support = PIGLIT_NO_ERRORS;
  53
  54 PIGLIT_GL_TEST_CONFIG_END
  55
  56 void
  57 print_usage_and_exit(char *prog_name)
  58 {
  59         printf("Usage: %s <num_samples>\n", prog_name);
  60         piglit_report_result(PIGLIT_FAIL);
  61 }
  62
  63 void
  64 piglit_init(int argc, char **argv)
  65 {
  66         int samples;
  67         /* At present fragment shader supports only fixed number of
  68          * attachments (3)
  69          */
  70         int num_attachments = 3;
  71
  72         if (argc < 2)
  73                 print_usage_and_exit(argv[0]);
  74
  75         {
  76                 char *endptr = NULL;
  77                 samples = strtol(argv[1], &endptr, 0);
  78                 if (endptr != argv[1] + strlen(argv[1]))
  79                         print_usage_and_exit(argv[0]);
  80         }
  81
  82         piglit_require_extension("GL_ARB_framebuffer_object");
  83         piglit_require_extension("GL_ARB_vertex_array_object");
  84         piglit_require_extension("GL_EXT_framebuffer_multisample");
  85
  86         int pattern_width = piglit_width / 2;
  87         int pattern_height = piglit_height / num_attachments;
  88
  89         piglit_ortho_projection(pattern_width,
  90                                 pattern_height,
  91                                 GL_TRUE);
  92
  93         /* Skip the test if samples > GL_MAX_SAMPLES */
  94         GLint max_samples;
  95         glGetIntegerv(GL_MAX_SAMPLES, &max_samples);
  96
  97         if (samples < 1 || samples > max_samples)
  98                 piglit_report_result(PIGLIT_SKIP);
  99
 100         ms_fbo_and_draw_buffers_setup(samples,
 101                                       pattern_width,
 102                                       pattern_height,
 103                                       num_attachments,
 104                                       GL_COLOR_BUFFER_BIT,
 105                                       GL_RGBA /* color_buffer_zero_format */);
 106         shader_compile(true /* sample_alpha_to_coverage */,
 107                        false /* dual_src_blend */,
 108                        false /* frag_out_zero_write */);
 109 }
 110
 111 enum piglit_result
 112 piglit_display()
 113 {
 114         bool pass;
 115
 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         draw_test_image(true /* sample_alpha_to_coverage */,
 122                         false /* sample_alpha_to_one */);
 123
 124         pass = piglit_check_gl_error(GL_NO_ERROR);
 125
 126         /* Free the memory allocated for data arrays */
 127         free_data_arrays();
 128
 129         if (!piglit_automatic)
 130                 piglit_present_results();
 131
 132         /* The fragment colors are undefined in this test. So, we can't probe
 133          * the pixels. If test executes to completion without error, return
 134          * PIGLIT_PASS.
 135          */
 136         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 137 }