tests/shaders/glsl-fs-fogscale.c

   1 /*
   2  * Copyright © 2013 Henri Verbeet <hverbeet@gmail.com>
   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 /** @file glsl-fs-fogscale.c
  25  *
  26  * Tests that gl_Fog.scale is equivalent to
  27  * "1.0 / (gl_Fog.end - gl_Fog.start)" when fog start and end are equal. The
  28  * expectation is that 1.0 / 0.0 will produce a value similar to +INF. This
  29  * takes into account that some GPUs may not have a representation for INF.
  30  */
  31
  32 #include "piglit-util-gl.h"
  33
  34 PIGLIT_GL_TEST_CONFIG_BEGIN
  35
  36         config.supports_gl_compat_version = 20;
  37
  38         config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;
  39
  40 PIGLIT_GL_TEST_CONFIG_END
  41
  42 const char * tests[4] = { "vs and fs", "gs-out and fs", "vs, gs and fs", NULL };
  43
  44 static const char vs_source[] =
  45         "void main()\n"
  46         "{\n"
  47         "       gl_Position = gl_Vertex;\n"
  48         "       gl_FogFragCoord = gl_Position.x;\n"
  49         "}\n";
  50
  51 static const char *dummy_vs_source =
  52         "void main()\n"
  53         "{\n"
  54         "       gl_Position = gl_Vertex;\n"
  55         "}\n";
  56
  57 static const char fs_source[] =
  58         "void main()\n"
  59         "{\n"
  60         "       gl_FragColor = vec4(gl_FogFragCoord * gl_Fog.scale * vec2(1.0, -1.0), 0.0, 1.0);\n"
  61         "}\n";
  62
  63 static bool
  64 test_prog(unsigned prog, const char *test_name)
  65 {
  66         static const float green[] = {0.0f, 1.0f, 0.0f, 1.0f};
  67         static const float red[] = {1.0f, 0.0f, 0.0f, 1.0f};
  68         bool pass = true;
  69
  70         glUseProgram(prog);
  71
  72         glClearColor(0.0, 0.0, 1.0, 0.0);
  73         glClear(GL_COLOR_BUFFER_BIT);
  74
  75         piglit_draw_rect(-1, -1, 2, 2);
  76         pass = piglit_probe_rect_rgba(0, 0,
  77                                       piglit_width / 2, piglit_height,
  78                                       green) && pass;
  79         pass = piglit_probe_rect_rgba(piglit_width / 2, 0,
  80                                       piglit_width / 2, piglit_height,
  81                                       red) && pass;
  82
  83         piglit_report_subtest_result(pass ? PIGLIT_PASS : PIGLIT_FAIL, "%s",
  84                                      test_name);
  85
  86         return pass;
  87 }
  88
  89 static void
  90 create_gs_source(char **gs_source, char *fogFragCoordValue)
  91 {
  92         (void)!asprintf(gs_source,
  93                 "#version 150 compatibility\n"
  94                 "layout(triangles) in;\n"
  95                 "layout(triangle_strip, max_vertices = 3) out;\n"
  96                 "\n"
  97                 "void main()\n"
  98                 "{\n"
  99                 "       for (int i = 0; i < 3; i++) {\n"
 100                 "               gl_Position = gl_in[i].gl_Position;\n"
 101                 "               gl_FogFragCoord = %s;\n"
 102                 "               EmitVertex();\n"
 103                 "       }\n"
 104                 "}\n",
 105                 fogFragCoordValue);
 106 }
 107
 108 enum piglit_result
 109 piglit_display(void)
 110 {
 111         bool pass = true;
 112         char *gs_source;
 113         char *gs_source2;
 114
 115         /* Test simple vs and fs program */
 116         GLuint prog = piglit_build_simple_program(vs_source, fs_source);
 117         test_prog(prog, tests[0]);
 118
 119         /* Test passing gl_FogFragCoord via the Geometry Shader */
 120         if (piglit_get_gl_version() >= 32) {
 121                 /* Test gl_FogFragCoord gs output only */
 122                 create_gs_source(&gs_source, "gl_Position.x");
 123                 prog = piglit_build_simple_program_multiple_shaders(
 124                         GL_VERTEX_SHADER, dummy_vs_source,
 125                         GL_GEOMETRY_SHADER, gs_source,
 126                         GL_FRAGMENT_SHADER, fs_source,
 127                         0);
 128                 pass = pass && test_prog(prog, tests[1]);
 129
 130                 /* Test gl_FogFragCoord both as a gs output and input */
 131                 create_gs_source(&gs_source2, "gl_in[i].gl_FogFragCoord");
 132                 prog = piglit_build_simple_program_multiple_shaders(
 133                         GL_VERTEX_SHADER, vs_source,
 134                         GL_GEOMETRY_SHADER, gs_source2,
 135                         GL_FRAGMENT_SHADER, fs_source,
 136                         0);
 137                 pass = pass && test_prog(prog, tests[2]);
 138
 139         } else {
 140                 piglit_report_subtest_result(PIGLIT_SKIP, "%s", tests[1]);
 141                 piglit_report_subtest_result(PIGLIT_SKIP, "%s", tests[2]);
 142         }
 143
 144         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 145 }
 146
 147 void
 148 piglit_init(int argc, char **argv)
 149 {
 150         piglit_register_subtests(tests);
 151
 152         glFogf(GL_FOG_START, 0.0f);
 153         glFogf(GL_FOG_END, 0.0f);
 154 }