tests/spec/arb_framebuffer_srgb/srgb_conformance.c

   1 /*
   2  * Copyright © 2013 VMware, Inc.
   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  *    Roland Scheidegger <sroland@vmware.com>
  25  *
  26  * Tests accuracy of srgb->linear and linear->srgb conversion,
  27  * according to d3d10 rules:
  28  * 1) srgb->linear is permitted a tolerance of 0.5 on the srgb side
  29  * (meaning the result converted back to srgb (but before float->int
  30  * conversion) using perfect formula must not deviate more than 0.5)
  31  * 2) linear->srgb is permitted a tolerance of 0.6 compared to using
  32  * perfect formula
  33  * 3) additionally all srgb values must stay the same when doing
  34  * srgb to linear and then linear to srgb conversion.
  35  * This test does not actually verify 2) (which would need exhaustive
  36  * test of all float values) so if some floats outside these generated
  37  * by srgb->linear conversion get mapped to arbitrary values that will
  38  * go unnoticed. Likewise, correct behavior for floats outside 0.0-1.0
  39  * is not verified (including INFs and NaNs - the former should get clamped
  40  * to 0/255 in the end, NaNs should also get mapped to 0).
  41  *
  42  */
  43
  44 #include "piglit-util-gl.h"
  45
  46 PIGLIT_GL_TEST_CONFIG_BEGIN
  47
  48         config.supports_gl_compat_version = 10;
  49
  50         config.window_width = 16;
  51         config.window_height = 16;
  52         config.window_visual = PIGLIT_GL_VISUAL_RGBA | PIGLIT_GL_VISUAL_DOUBLE;
  53
  54 PIGLIT_GL_TEST_CONFIG_END
  55
  56 static enum piglit_result test_format(void)
  57 {
  58         bool pass1 = true;
  59         bool pass2 = true;
  60         GLuint texsrgb, texfb, fb;
  61         GLenum status;
  62         int i;
  63         float tex_vals[256][4];
  64         float readf[256][4];
  65         float tolerance;
  66         GLubyte readb[256][4];
  67         float maxErr = 0.0f;
  68
  69         for (i = 0; i < 256; i++) {
  70                 tex_vals[i][0] = (float)i / 255.0f;
  71                 tex_vals[i][1] = tex_vals[i][2] = 0.0f;
  72                 tex_vals[i][3] = 1.0f;
  73         }
  74
  75         /* initialize texture */
  76         glGenTextures(1, &texsrgb);
  77         glBindTexture(GL_TEXTURE_2D, texsrgb);
  78         glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8_EXT,
  79                      16, 16, 0,
  80                      GL_RGBA, GL_FLOAT, &tex_vals[0][0]);
  81
  82         glGenFramebuffersEXT(1, &fb);
  83         glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
  84         glViewport(0, 0, piglit_width, piglit_height);
  85
  86         /* draw into float framebuffer and verify results */
  87         glGenTextures(1, &texfb);
  88         glBindTexture(GL_TEXTURE_2D, texfb);
  89         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA32F_ARB,
  90                      piglit_width, piglit_height, 0,
  91                      GL_RGBA, GL_FLOAT, NULL);
  92
  93         glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
  94                                   GL_COLOR_ATTACHMENT0_EXT,
  95                                   GL_TEXTURE_2D,
  96                                   texfb,
  97                                   0);
  98         if (!piglit_check_gl_error(GL_NO_ERROR))
  99                 piglit_report_result(PIGLIT_FAIL);
 100
 101         status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
 102         printf("Testing using fb float format");
 103         if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 104                 printf(" - fbo incomplete (status = %s)\n",
 105                        piglit_get_gl_enum_name(status));
 106                 piglit_report_subtest_result(PIGLIT_SKIP, "float fb");
 107                 return PIGLIT_SKIP;
 108         }
 109         printf("\n");
 110
 111         glColor4f(1, 1, 1, 1);
 112         glEnable(GL_TEXTURE_2D);
 113         glBindTexture(GL_TEXTURE_2D, texsrgb);
 114
 115         glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
 116         glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB,   GL_REPLACE);
 117         glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_REPLACE);
 118
 119         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 120         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 121
 122         piglit_draw_rect_tex(-1, -1, 2, 2,
 123                              0, 0, 1, 1);
 124
 125         glDisable(GL_TEXTURE_2D);
 126
 127         /* have to make up our own error measuring, since we
 128            measure error on srgb side (so with values mapped back to srgb
 129            using accurate formula) */
 130
 131         tolerance = 0.5f; /* as required by d3d10 */
 132         glReadPixels(0, 0, 16, 16, GL_RGBA, GL_FLOAT, &readf[0][0]);
 133
 134         for (i = 0; i < 256; i++) {
 135                 float err = fabs(piglit_linear_to_srgb(readf[i][0])*255 - (float)i);
 136                 if (0)
 137                         printf("readback: %f observed: %f expected: %f\n", readf[i][0],
 138                                 piglit_linear_to_srgb(readf[i][0]), (float)i);
 139                 if (err > maxErr) {
 140                         maxErr = err;
 141                 }
 142                 if (err > tolerance) {
 143                         printf("  failed when testing srgb->float result\n");
 144                         pass1 = false;
 145                         break;
 146                 }
 147         }
 148         printf("max error srgb->linear was %f\n", maxErr);
 149
 150         piglit_present_results();
 151
 152         piglit_report_subtest_result(pass1 ? PIGLIT_PASS : PIGLIT_FAIL,
 153                                      "srgb->linear");
 154
 155         /* draw into srgb framebuffer and verify results */
 156         glBindTexture(GL_TEXTURE_2D, texfb);
 157         glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8_ALPHA8_EXT,
 158                      piglit_width, piglit_height, 0,
 159                      GL_RGBA, GL_FLOAT, NULL);
 160
 161         glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
 162                                   GL_COLOR_ATTACHMENT0_EXT,
 163                                   GL_TEXTURE_2D,
 164                                   texfb,
 165                                   0);
 166
 167         if (!piglit_check_gl_error(GL_NO_ERROR))
 168                 piglit_report_result(PIGLIT_FAIL);
 169
 170         glEnable(GL_FRAMEBUFFER_SRGB_EXT);
 171         status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
 172         printf("Testing using fb srgb format");
 173         if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
 174                 printf(" - fbo incomplete (status = %s)\n",
 175                        piglit_get_gl_enum_name(status));
 176                 piglit_report_subtest_result(PIGLIT_SKIP, "srgb fb");
 177                 return PIGLIT_SKIP;
 178         }
 179         printf("\n");
 180
 181         glEnable(GL_TEXTURE_2D);
 182         glBindTexture(GL_TEXTURE_2D, texsrgb);
 183         piglit_draw_rect_tex(-1, -1, 2, 2,
 184                              0, 0, 1, 1);
 185         glDisable(GL_TEXTURE_2D);
 186
 187         tolerance = 0.6f; /* as required by d3d10 */
 188         /* TODO: should test this tolerance too really right now only test
 189            the previously converted from srgb values, so we only enforce
 190            any value stays the same when doing srgb->linear->srgb, which
 191            corresponds to 0.5 tolerance but only for these exact values. */
 192         glReadPixels(0, 0, 16, 16, GL_RGBA, GL_UNSIGNED_BYTE, &readb[0][0]);
 193
 194         for (i = 0; i < 256; i++) {
 195                 if (0)
 196                         printf("observed: %d expected: %d\n", readb[i][0], i);
 197                 if (readb[i][0] != i) {
 198                         printf("  failed when testing srgb->float->srgb result\n");
 199                         pass2 = GL_FALSE;
 200                         break;
 201                 }
 202         }
 203
 204         piglit_present_results();
 205
 206         piglit_report_subtest_result(pass2 ? PIGLIT_PASS : PIGLIT_FAIL,
 207                                      "srgb->linear->srgb");
 208
 209         glDeleteTextures(1, &texfb);
 210         glDeleteTextures(1, &texsrgb);
 211         glDeleteFramebuffersEXT(1, &fb);
 212
 213         return (pass1 && pass2) ? PIGLIT_PASS : PIGLIT_FAIL;
 214 }
 215
 216 enum piglit_result piglit_display(void)
 217 {
 218         return test_format();
 219 }
 220
 221 void piglit_init(int argc, char **argv)
 222 {
 223         piglit_require_extension("GL_EXT_framebuffer_object");
 224         piglit_require_extension("GL_ARB_texture_env_combine");
 225         piglit_require_extension("GL_EXT_texture_sRGB");
 226         piglit_require_extension("GL_ARB_framebuffer_sRGB");
 227         piglit_require_extension("GL_ARB_color_buffer_float");
 228         glDisable(GL_DITHER);
 229 }