tests/shaders/glsl-fs-loop-nested.c

   1 /*
   2  * Copyright © 2009-2010 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  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *    Ian Romanick <idr@freedesktop.org>
  26  *
  27  */
  28
  29 /** @file glsl-fs-loop-nested.c
  30  *
  31  * Tests that nested loops in the fragment shader work.
  32  *
  33  * Since a value from an attribute is used as a loop counter, the compiler
  34  * cannot simply unroll the loop.  This verifies that GLSL loops can be
  35  * correctly generated in the fragment shader.
  36  *
  37  * This was conceived as a test case for freedesktop.org bug #25173.
  38  */
  39
  40 #include "piglit-util.h"
  41
  42 int piglit_width = 100, piglit_height = 100;
  43 int piglit_window_mode = GLUT_RGB | GLUT_DOUBLE;
  44
  45 static int color_location;
  46 static GLint prog;
  47
  48 enum piglit_result
  49 piglit_display(void)
  50 {
  51         GLboolean pass = GL_TRUE;
  52
  53         float color[] = {1.0, 0.0, 0.0, 0.0};
  54
  55         unsigned i;
  56         unsigned j;
  57
  58         glClearColor(0.5, 0.5, 0.5, 0.5);
  59         glClear(GL_COLOR_BUFFER_BIT);
  60
  61         for (i = 0; i < 3; i++) {
  62                 float temp;
  63                 float line_color[4];
  64                 unsigned x = 5 + (25 * i);
  65
  66                 for (j = 0; j < 3; j++) {
  67                         unsigned y = 5 + (25 * j);
  68                         int rotate;
  69
  70                         memcpy(line_color, color, sizeof(line_color));
  71                         for (rotate = 0; rotate < i * j; rotate++) {
  72                                 temp = line_color[2];
  73                                 line_color[2] = line_color[1];
  74                                 line_color[1] = line_color[0];
  75                                 line_color[0] = temp;
  76                         }
  77                         line_color[3] = (float) i * 4 + j;
  78
  79                         glUniform4fv(color_location, 1, line_color);
  80                         piglit_draw_rect(x, y, 20, 20);
  81
  82                         pass &= piglit_probe_pixel_rgb(x + 5, y + 5, color);
  83                 }
  84
  85                 temp = color[2];
  86                 color[2] = color[1];
  87                 color[1] = color[0];
  88                 color[0] = temp;
  89         }
  90
  91
  92         glutSwapBuffers();
  93
  94         return pass ? PIGLIT_SUCCESS : PIGLIT_FAILURE;
  95 }
  96
  97 void
  98 piglit_init(int argc, char **argv)
  99 {
 100         GLint vs, fs;
 101
 102         /* Set up projection matrix so we can just draw using window
 103          * coordinates.
 104          */
 105         piglit_ortho_projection(piglit_width, piglit_height, GL_FALSE);
 106
 107         if (!GLEW_VERSION_2_0) {
 108                 printf("Requires OpenGL 2.0\n");
 109                 piglit_report_result(PIGLIT_SKIP);
 110         }
 111
 112         vs = piglit_compile_shader(GL_VERTEX_SHADER,
 113                                    "shaders/glsl-mvp.vert");
 114         fs = piglit_compile_shader(GL_FRAGMENT_SHADER,
 115                                    "shaders/glsl-fs-loop-nested.frag");
 116
 117         prog = piglit_link_simple_program(vs, fs);
 118
 119         glUseProgram(prog);
 120
 121         color_location = glGetUniformLocation(prog, "color");
 122 }