tests/general/triangle-guardband-viewport.c

   1 /* Copyright 2012 Google Inc.
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
  16  *
  17  * Authors:
  18  *   Stuart Abercrombie <sabercrombie@google.com>
  19 */
  20
  21 /** @file triangle-guardband-vewport.c
  22  *
  23  * Tests whether clipping of triangles to the clip volume
  24  * is reflected in what is rasterized. Specifically,
  25  * triangles (unlike some other primitives) should not be
  26  * rasterized outside the viewport extents because they should
  27  * have been clipped to the clip volume mapping to the viewport.
  28  *
  29  * Faulty guard-band clipping optimizations have been known to
  30  * not honor this requirement.
  31  */
  32
  33 #include "piglit-util-gl.h"
  34
  35 PIGLIT_GL_TEST_CONFIG_BEGIN
  36
  37         config.supports_gl_compat_version = 10;
  38
  39         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGB;
  40
  41 PIGLIT_GL_TEST_CONFIG_END
  42
  43 enum piglit_result
  44 piglit_display(void)
  45 {
  46         bool pass = true;
  47         static float green[] = {0.0, 1.0, 0.0, 0.0};
  48         static float blue[]  = {0.0, 0.0, 1.0, 0.0};
  49
  50         /* make the whole window green. */
  51         glClearColor(0.0, 1.0, 0.0, 0.0);
  52         glClear(GL_COLOR_BUFFER_BIT);
  53
  54         /* set viewport to the left half of the window */
  55         glViewport(0, 0, piglit_width / 2, piglit_height);
  56
  57         /* draw blue rect extending beyond the right edge of the
  58          * frustrum, notionally across the whole window
  59          */
  60         glColor4fv(blue);
  61         piglit_draw_rect(-1.0, -1.0, 4.0, 2.0);
  62
  63         /* check that the right half of the window, outside
  64          * the viewport, still has the clear color
  65          */
  66         pass = piglit_probe_rect_rgb(piglit_width/2, 0,
  67                                      piglit_width/2, piglit_height,
  68                                      green);
  69
  70         piglit_present_results();
  71
  72         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
  73 }
  74
  75 void
  76 piglit_init(int argc, char **argv)
  77 {
  78 }