tests/general/early-z.c

   1 /*
   2  * Copyright (c) 2011 Christoph Bumiller
   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  * on the rights to use, copy, modify, merge, publish, distribute, sub
   8  * license, and/or sell copies of the Software, and to permit persons to whom
   9  * the 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,
  16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18  * NON-INFRINGEMENT.  IN NO EVENT SHALL VMWARE AND/OR THEIR SUPPLIERS
  19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  22  * SOFTWARE.
  23  */
  24
  25 /**
  26  * @file
  27  * Test for bugs with early depth testing and early depth update.
  28  */
  29
  30 #include "piglit-util-gl.h"
  31
  32 PIGLIT_GL_TEST_CONFIG_BEGIN
  33
  34         config.supports_gl_compat_version = 10;
  35
  36         config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_DEPTH;
  37
  38 PIGLIT_GL_TEST_CONFIG_END
  39
  40 GLint u_zval;
  41
  42 static const char *fpFragDepthText =
  43    "uniform float zval; \n"
  44    "void main() \n"
  45    "{ \n"
  46    "   gl_FragColor = vec4(gl_Color.rgb, 1.0); \n"
  47    "   gl_FragDepth = zval; \n"
  48    "} \n";
  49
  50 static const char *fpDiscardText =
  51    "void main() \n"
  52    "{ \n"
  53    "   if (gl_Color.r > 0.25) \n"
  54    "      discard; \n"
  55    "   gl_FragColor = vec4(gl_Color.rgb, 1.0); \n"
  56    "} \n";
  57
  58 static const char *fpAlphaText =
  59    "void main() \n"
  60    "{ \n"
  61    "   gl_FragColor = vec4(gl_Color.rgb, 0.0); \n"
  62    "} \n";
  63
  64
  65 static GLuint shader[3];
  66 static GLuint program[3];
  67
  68 static void quad(const GLfloat z, uint32_t colour)
  69 {
  70    glColor3ub(colour & 0xff, (colour >> 8) & 0xff, (colour >> 16) & 0xff);
  71    glBegin(GL_QUADS);
  72    glVertex3f(-1.0f, -1.0f, z);
  73    glVertex3f(-1.0f,  1.0f, z);
  74    glVertex3f( 1.0f,  1.0f, z);
  75    glVertex3f( 1.0f, -1.0f, z);
  76    glEnd();
  77 }
  78
  79 static GLboolean
  80 test_early_depth(void)
  81 {
  82    glClearColor(0.0, 0.0, 0.0, 0.0);
  83    glClearDepth(1.0);
  84    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  85
  86    glEnable(GL_DEPTH_TEST);
  87    glDepthMask(GL_TRUE);
  88    glDepthFunc(GL_LESS);
  89
  90    /* 1. (blue) depth should be adjusted to 0.8 by the FP */
  91    glUseProgram(program[0]);
  92    glUniform1f(u_zval, 0.8f);
  93    quad(0.3, 0xff0000);
  94
  95    /* 2. (red) should be discarded, no depth value written */
  96    glUseProgram(program[1]);
  97    quad(0.2, 0x0000ff);
  98
  99    /* 3. (white) should be discarded by the alpha test, no depth written */
 100    glUseProgram(program[2]);
 101    glEnable(GL_ALPHA_TEST);
 102    glAlphaFunc(GL_GREATER, 0.5f);
 103    quad(0.1, 0xffffff);
 104    glDisable(GL_ALPHA_TEST);
 105
 106    /* 4. (green) should be drawn because depth is 0.8 and FragDepth is 0.5 */
 107    glUseProgram(program[0]);
 108    glUniform1f(u_zval, 0.5);
 109    quad(0.9, 0x00ff00);
 110
 111    /* 5. (yellow) should be discarded because program sets depth to 0.9 */
 112    glUniform1f(u_zval, 0.9);
 113    quad(0.2, 0x00ffff);
 114
 115    {
 116       const GLfloat color[4] = { 0.0f, 1.0f, 0.0f, 1.0f };
 117       GLint pos[4];
 118
 119       /* use glRasterPos to determine where to read a sample pixel */
 120       glRasterPos2f(0.0f, 0.0f);
 121       glGetIntegerv(GL_CURRENT_RASTER_POSITION, pos);
 122
 123       if (!piglit_probe_pixel_rgba(pos[0], pos[1], color)) {
 124          piglit_present_results();
 125          return GL_FALSE;
 126       }
 127    }
 128
 129    piglit_present_results();
 130
 131    return GL_TRUE;
 132 }
 133
 134
 135 enum piglit_result
 136 piglit_display(void)
 137 {
 138    if (!test_early_depth())
 139       return PIGLIT_FAIL;
 140
 141    return PIGLIT_PASS;
 142 }
 143
 144
 145 void
 146 piglit_init(int argc, char **argv)
 147 {
 148    int i;
 149
 150    piglit_require_gl_version(20);
 151
 152    shader[0] = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fpFragDepthText);
 153    assert(shader[0]);
 154
 155    shader[1] = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fpDiscardText);
 156    assert(shader[1]);
 157
 158    shader[2] = piglit_compile_shader_text(GL_FRAGMENT_SHADER, fpAlphaText);
 159    assert(shader[2]);
 160
 161    for (i = 0; i < 3; ++i)
 162       program[i] = piglit_link_simple_program(shader[i], 0);
 163
 164    u_zval = glGetUniformLocation(program[0], "zval");
 165 }