tests/spec/gles-2.0/glsl-fs-pointcoord.c

   1 /*
   2  * Copyright © 2009,2013 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  *
  26  */
  27
  28 /** @file glsl-fs-pointcoord.c
  29  *
  30  * Tests that gl_PointCoord produces the expected output in a GLES2
  31  * context, which treats all points as point sprite enabled (so
  32  * gl_PointCoord returns defined values).
  33  *
  34  * To compare, the GLSL 4.3 spec says:
  35  *
  36  *     "The values in gl_PointCoord are two-dimensional coordinates
  37  *      indicating where within a point primitive the current fragment
  38  *      is located, when point sprites are enabled."
  39  *
  40  * (which is tested in tests/shaders/glsl-fs-pointcoord.c) while the
  41  * GLSL ES 1.00 spec says:
  42  *
  43  *     "The values in gl_PointCoord are two-dimensional coordinates
  44  *      indicating where within a point primitive the current fragment
  45  *      is located."
  46  *
  47  * which makes sense, because the GL_POINT_SPRITE enable doesn't
  48  * exist.
  49  */
  50
  51 #include <assert.h>
  52 #include <string.h>
  53 #include <stdio.h>
  54 #include <stdlib.h>
  55 #include <errno.h>
  56 #include <sys/stat.h>
  57
  58 #include "piglit-util-gl.h"
  59
  60 PIGLIT_GL_TEST_CONFIG_BEGIN
  61
  62         config.supports_gl_es_version = 20;
  63
  64         config.window_width = 256;
  65         config.window_height = 256;
  66         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
  67
  68 PIGLIT_GL_TEST_CONFIG_END
  69
  70 static GLint prog;
  71 static GLint point_size;
  72
  73 const char *vs_source =
  74         "attribute vec4 vertex;\n"
  75         "uniform float point_size;\n"
  76         "void main()\n"
  77         "{\n"
  78         "       gl_Position = vertex;\n"
  79         "       gl_PointSize = point_size;\n"
  80         "}\n";
  81
  82 const char *fs_source =
  83         "void main()\n"
  84         "{\n"
  85         "       gl_FragColor = vec4(gl_PointCoord.xy * 1.1 - 0.05, 0, 1);\n"
  86         "}\n";
  87
  88 enum piglit_result
  89 piglit_display(void)
  90 {
  91         GLboolean pass = GL_TRUE;
  92         const float red[4] =    {1, 0, 0, 1};
  93         const float green[4] =  {0, 1, 0, 1};
  94         const float yellow[4] = {1, 1, 0, 1};
  95         const float black[4] =  {0, 0, 0, 1};
  96         const float vert[] = {
  97                 -1.0 + 2.0 * (point_size / 2.0) / piglit_width,
  98                 -1.0 + 2.0 * (point_size / 2.0) / piglit_height
  99         };
 100         GLint point_size_loc;
 101
 102         glClearColor(0.5, 0.5, 0.5, 1.0);
 103         glClear(GL_COLOR_BUFFER_BIT);
 104
 105         point_size_loc = glGetUniformLocation(prog, "point_size");
 106         glUniform1f(point_size_loc, point_size);
 107
 108         glVertexAttribPointer(PIGLIT_ATTRIB_POS, 2, GL_FLOAT, false, 0, vert);
 109         glEnableVertexAttribArray(PIGLIT_ATTRIB_POS);
 110         glDrawArrays(GL_POINTS, 0, 1);
 111
 112         pass = pass && piglit_probe_pixel_rgba(0, 0, green);
 113         pass = pass && piglit_probe_pixel_rgba(point_size - 1, 0, yellow);
 114         pass = pass && piglit_probe_pixel_rgba(0, point_size - 1, black);
 115         pass = pass && piglit_probe_pixel_rgba(point_size - 1, point_size - 1,
 116                                                red);
 117
 118         piglit_present_results();
 119
 120         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 121 }
 122
 123 void piglit_init(int argc, char**argv)
 124 {
 125         GLint point_size_limits[2];
 126
 127         glGetIntegerv(GL_ALIASED_POINT_SIZE_RANGE, point_size_limits);
 128         point_size = point_size_limits[1];
 129
 130         if (point_size > piglit_width)
 131                 point_size = piglit_width;
 132         if (point_size > piglit_height)
 133                 point_size = piglit_height;
 134
 135         prog = piglit_build_simple_program(vs_source, fs_source);
 136
 137         glUseProgram(prog);
 138 }