tests/general/line-smooth-stipple.c

   1 /*
   2  * Copyright © 2022 Collabora Ltd
   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  *    Erik Faye-Lund <erik.faye-lund@collabora.com>
  25  *
  26  */
  27
  28 /*
  29  * Test the coverage of stippled multiple line-segments
  30  */
  31
  32 #include "piglit-util-gl.h"
  33
  34 PIGLIT_GL_TEST_CONFIG_BEGIN
  35
  36         config.supports_gl_compat_version = 10;
  37
  38         config.window_width = 300;
  39         config.window_height = 100;
  40         config.window_visual = PIGLIT_GL_VISUAL_RGB | PIGLIT_GL_VISUAL_DOUBLE;
  41
  42 PIGLIT_GL_TEST_CONFIG_END
  43
  44 float stipple_pattern(float counter, int factor)
  45 {
  46         counter += 0.5;
  47         counter = counter - floor(counter / (2 * factor)) * 2 * factor;
  48         return MIN2(MAX2(fabs(counter - 8.0) - (factor * 0.5) + 0.5,
  49                                          0.0f), 1.0f);
  50 }
  51
  52 enum piglit_result
  53 piglit_display(void)
  54 {
  55         glClearColor(0.0, 0.0, 0.0, 0.0);
  56         glClear(GL_COLOR_BUFFER_BIT);
  57
  58         glEnable(GL_LINE_SMOOTH);
  59         /* GL AA lines produce an alpha value */
  60         glEnable(GL_BLEND);
  61         glBlendFunc(GL_SRC_ALPHA, GL_ONE);
  62
  63         glLineWidth(3.0f);
  64         glEnable(GL_LINE_STIPPLE);
  65
  66         int y;
  67         for (y = 0; y * 4 < piglit_height; y++) {
  68                 float offset = 1.0 + y / 4.0f;
  69                 glLineStipple(8, 0x5555);
  70                 glColor4f(0.5, 0.0, 0.5, 1.0);
  71                 glBegin(GL_LINES);
  72                 glVertex2f(offset, 1.5 + y * 4);
  73                 glVertex2f(piglit_width - 1.0, 1.5 + y * 4);
  74                 glEnd();
  75
  76                 glLineStipple(8, ~0x5555);
  77                 glColor4f(0.0, 0.5, 0.0, 1.0);
  78                 glBegin(GL_LINES);
  79                 glVertex2f(offset, 1.5 + y * 4);
  80                 glVertex2f(piglit_width - 1.0, 1.5 + y * 4);
  81                 glEnd();
  82         }
  83
  84         GLboolean pass = GL_TRUE;
  85
  86         float *expected = malloc(piglit_width * sizeof(float) * 3);
  87         for (y = 0; y * 4 < piglit_height; y++) {
  88                 float offset = 1.0 + y / 4.0f;
  89                 int start_x = ceil(offset);
  90                 for (int x = 0; x < piglit_width; ++x) {
  91                         expected[x * 3 + 0] = stipple_pattern(x - offset - 4, 8) * 0.5;
  92                         expected[x * 3 + 1] = stipple_pattern(x - offset + 4, 8) * 0.5;
  93                         expected[x * 3 + 2] = stipple_pattern(x - offset - 4, 8) * 0.5;
  94                 }
  95                 pass = pass && piglit_probe_rect_rgb_varying(start_x, y * 4 + 1, piglit_width - start_x - 2, 1, expected + start_x * 3, 0);
  96         }
  97         free(expected);
  98
  99         piglit_present_results();
 100
 101         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 102 }
 103
 104 void
 105 piglit_init(int argc, char **argv)
 106 {
 107         piglit_ortho_projection(piglit_width, piglit_height, GL_FALSE);
 108 }