tests/shaders/glsl-fs-discard-02.c

   1 /*
   2  * Copyright © 2009 Marek Olšák (maraeo@gmail.com)
   3  * Copyright © 2010 Intel Corporation
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  22  * IN THE SOFTWARE.
  23  *
  24  * Authors:
  25  *    Marek Olšák <mareao@gmail.com>
  26  *    Eric Anholt <eric@anholt.net>
  27  *
  28  */
  29
  30 /** @file glsl-fs-discard-02.c
  31  *
  32  * Tests that discarding fragments doesn't let early depth writes through.
  33  */
  34
  35 #include "piglit-util-gl.h"
  36
  37 PIGLIT_GL_TEST_CONFIG_BEGIN
  38
  39         config.supports_gl_compat_version = 10;
  40
  41         config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_DEPTH;
  42
  43 PIGLIT_GL_TEST_CONFIG_END
  44
  45 static char vs_code[] =
  46         "varying vec4 color;"
  47         "\n"
  48         "void main()\n"
  49         "{\n"
  50         "       gl_Position = gl_Vertex;\n"
  51         "       if (gl_Vertex.z > 0.75)\n"
  52         "               color = vec4(1.0, 0.0, 0.0, gl_Vertex.z);\n"
  53         "       else if (gl_Vertex.z > 0.25)\n"
  54         "               color = vec4(0.0, 1.0, 0.0, gl_Vertex.z);\n"
  55         "       else\n"
  56         "               color = vec4(0.0, 0.0, 1.0, gl_Vertex.z);\n"
  57         "}\n";
  58
  59 static char fs_code[] =
  60         "varying vec4 color;\n"
  61         "\n"
  62         "void main()\n"
  63         "{\n"
  64         "       if (color.w < 0.25)\n"
  65         "               discard;"
  66         "    gl_FragColor = vec4(color.xyz, 0.0);\n"
  67         "}\n";
  68
  69 static GLuint setup_shaders()
  70 {
  71         GLuint vs, fs, prog;
  72
  73         vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vs_code);
  74         fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fs_code);
  75         prog = piglit_link_simple_program(vs, fs);
  76
  77         glUseProgram(prog);
  78         return prog;
  79 }
  80
  81 static GLboolean test()
  82 {
  83         GLint prog;
  84         GLboolean pass = GL_TRUE;
  85         float green[4] = {0, 1, 0, 0};
  86
  87         prog = setup_shaders();
  88
  89         glClear(GL_DEPTH_BUFFER_BIT);
  90
  91         glDepthFunc(GL_LEQUAL);
  92         glEnable(GL_DEPTH_TEST);
  93
  94         piglit_draw_rect_z(1.0, -1, -1, 2, 2); // red
  95         piglit_draw_rect_z(0.0, -1, -1, 2, 2); // discard
  96         piglit_draw_rect_z(0.5, -1, -1, 2, 2); // green
  97
  98         if (!piglit_check_gl_error(GL_NO_ERROR))
  99                 piglit_report_result(PIGLIT_FAIL);
 100
 101         pass = pass && piglit_probe_rect_rgba(0, 0, piglit_width, piglit_height, green);
 102
 103         glDeleteProgram(prog);
 104
 105         return pass;
 106 }
 107
 108 enum piglit_result piglit_display(void)
 109 {
 110         GLboolean pass;
 111
 112         pass = test();
 113
 114         piglit_present_results();
 115
 116         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 117 }
 118
 119 void piglit_init(int argc, char **argv)
 120 {
 121         piglit_require_vertex_shader();
 122         piglit_require_fragment_shader();
 123 }
 124