tests/spec/gl-1.0/long-line-loop.c

   1 /*
   2  * Copyright © 2017 Fabian Bieler
   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
  24 /**
  25  * @file long-line-loop.c
  26  * Draw cricles with line loops and a line strips blended on top of each
  27  * other and check that the renderings match.
  28  */
  29
  30 #include "piglit-util-gl.h"
  31
  32 PIGLIT_GL_TEST_CONFIG_BEGIN
  33
  34         config.supports_gl_compat_version = 10;
  35         config.window_width = 1024;
  36         config.window_height = 1024;
  37         config.window_visual = PIGLIT_GL_VISUAL_RGB;
  38         config.khr_no_error_support = PIGLIT_NO_ERRORS;
  39
  40 PIGLIT_GL_TEST_CONFIG_END
  41
  42 static int max_vertices;
  43 static int num_vertices;
  44 static int probe_location[2];
  45 static const float radius = 0.9;
  46
  47 static void
  48 print_usage_and_exit(const char *prog_name)
  49 {
  50         printf("Usage: %s [<vertex_count>]\n"
  51                "  where <vertex_count> is the number of vertices to test.\n"
  52                "\n"
  53                "  If omitted, sequentially test from 16 to max_vertices by "
  54                "quadrupling,\n"
  55                "  where max_vertices is GL_MAX_ELEMENTS_VERTICES clamped to "
  56                "[0x10000, 0x40000].\n",
  57                prog_name);
  58         piglit_report_result(PIGLIT_FAIL);
  59 }
  60
  61 void
  62 piglit_init(int argc, char **argv)
  63 {
  64         glBlendFunc(GL_ONE, GL_ONE);
  65
  66         piglit_ortho_projection(piglit_width, piglit_height, false);
  67
  68         if (argc == 1) {
  69                 /* This isn't a hard limit, but staying below should help
  70                  * performance.
  71                  *
  72                  * XXX: It could be interesting to go beyond this limit to
  73                  * test a different code path in the GL implementation.
  74                  */
  75                 glGetIntegerv(GL_MAX_ELEMENTS_VERTICES, &max_vertices);
  76                 max_vertices = CLAMP(max_vertices, 0x10000, 0x40000);
  77         } else if (argc == 2) {
  78                 char *endptr;
  79                 num_vertices = strtol(argv[1], &endptr, 0);
  80                 if (endptr != argv[1] + strlen(argv[1]))
  81                         print_usage_and_exit(argv[0]);
  82                 if (num_vertices < 6)
  83                         print_usage_and_exit(argv[0]);
  84         } else {
  85                 print_usage_and_exit(argv[0]);
  86         }
  87 }
  88
  89 static void
  90 draw_circle(int segments)
  91 {
  92         /* The first (segments - 1) vertices describe the arc of a circle
  93          * slice with central angle (360° - alpha).
  94          * The last vertex is identical to the first vertex.
  95          * alpha is chosen so that the last line segment covers two pixels.
  96          */
  97         const float alpha = asinf(2.0 / (piglit_width / 2 * radius));
  98         struct {
  99                 float pos[4];
 100                 float green[4];
 101                 float blue[4];
 102         } *vertex = malloc(sizeof(vertex[0]) * segments);
 103
 104         for (int i = 0; i < segments - 1; ++i) {
 105                 const float phi = alpha -
 106                                   (2 * M_PI - alpha) /
 107                                   (float)(segments - 2) *
 108                                   (float)i;
 109
 110                 vertex[i].pos[0] = round(piglit_width / 2 *
 111                                           (1 + radius * cosf(phi))) + 0.5;
 112                 vertex[i].pos[1] = round(piglit_height / 2 *
 113                                           (1 + radius * sinf(phi))) + 0.5;
 114                 vertex[i].pos[2] = 0;
 115                 vertex[i].pos[3] = 1;
 116                 vertex[i].green[0] = 0;
 117                 vertex[i].green[1] = 1;
 118                 vertex[i].green[2] = 0;
 119                 vertex[i].green[3] = 1;
 120                 vertex[i].blue[0] = 0;
 121                 vertex[i].blue[1] = 0;
 122                 vertex[i].blue[2] = 1;
 123                 vertex[i].blue[3] = 1;
 124         }
 125         memcpy(&vertex[segments - 1], &vertex[0], sizeof(vertex[0]));
 126
 127         /* Find a pixel in the last line segment: */
 128         for (int i = 0; i < 2; ++i)
 129                 probe_location[i] = round((vertex[segments - 2].pos[i] +
 130                                            vertex[segments - 1].pos[i] -
 131                                            1.0) / 2.0);
 132
 133         /* Render twice: */
 134         glClear(GL_COLOR_BUFFER_BIT);
 135
 136         glVertexPointer(4, GL_FLOAT, sizeof(vertex[0]), vertex[0].pos);
 137         glColorPointer(4, GL_FLOAT, sizeof(vertex[0]), vertex[0].green);
 138
 139         glEnableClientState(GL_VERTEX_ARRAY);
 140         glEnableClientState(GL_COLOR_ARRAY);
 141
 142         glDrawArrays(GL_LINE_LOOP, 0, segments - 1);
 143
 144         glEnable(GL_BLEND);
 145         glColorPointer(4, GL_FLOAT, sizeof(vertex[0]), vertex[0].blue);
 146         glDrawArrays(GL_LINE_STRIP, 0, segments);
 147         glDisable(GL_BLEND);
 148
 149         free(vertex);
 150
 151         piglit_present_results();
 152 }
 153
 154 static bool
 155 check_circle(void)
 156 {
 157         bool pass = true;
 158         const float teal[] = {0, 1, 1};
 159         const float black[] = {0, 0, 0};
 160
 161         /* check that the two renderings are identical */
 162         pass = piglit_probe_rect_two_rgb(0, 0, piglit_width, piglit_height,
 163                                          black, teal) && pass;
 164
 165         /* belt + suspenders: Additionally check that the last line segment
 166          * was drawn...
 167          */
 168         pass = piglit_probe_pixel_rgb(probe_location[0], probe_location[1],
 169                                       teal) && pass;
 170
 171         /* ...and that the center of the circle is black */
 172         const int x = ceil(piglit_width / 2 * radius / M_SQRT2) + 1;
 173         const int y = ceil(piglit_height / 2 * radius / M_SQRT2) + 1;
 174         pass = piglit_probe_rect_rgb(x, y, piglit_width - 2 * x,
 175                                      piglit_height - 2 * y, black) && pass;
 176
 177         return pass;
 178 }
 179
 180 enum piglit_result
 181 piglit_display(void)
 182 {
 183         bool pass = true;
 184
 185         if (max_vertices) {
 186                 for (int vertices = 16;
 187                      vertices <= max_vertices;
 188                      vertices <<= 2) {
 189                         draw_circle(vertices);
 190                         pass = check_circle() && pass;
 191                 }
 192         } else {
 193                 draw_circle(num_vertices);
 194                 pass = check_circle() && pass;
 195         }
 196
 197         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 198 }
 199