tests/spec/ext_transform_feedback/discard-copypixels.c

   1 /*
   2  * Copyright © 2011 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
  24 #include "piglit-util-gl.h"
  25
  26 /**
  27  * @file discard-copypixels.c
  28  *
  29  * Tests that GL_RASTERIZER_DISCARD appropriately affects glCopyPixels().
  30  *
  31  * From the EXT_transform_feedback spec:
  32  *
  33  *     "Primitives can be optionally discarded before rasterization by
  34  *      calling Enable and Disable with RASTERIZER_DISCARD_EXT. When
  35  *      enabled, primitives are discarded right before the
  36  *      rasterization stage, but after the optional transform feedback
  37  *      stage. When disabled, primitives are passed through to the
  38  *      rasterization stage to be processed
  39  *      normally. RASTERIZER_DISCARD_EXT applies to the DrawPixels,
  40  *      CopyPixels, Bitmap, Clear and Accum commands as well."
  41  */
  42
  43 PIGLIT_GL_TEST_CONFIG_BEGIN
  44
  45         config.supports_gl_compat_version = 10;
  46
  47         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
  48         config.khr_no_error_support = PIGLIT_NO_ERRORS;
  49
  50 PIGLIT_GL_TEST_CONFIG_END
  51
  52 enum piglit_result
  53 piglit_display(void)
  54 {
  55         bool pass = true;
  56         float green[4] = {0.0, 1.0, 0.0, 0.0};
  57
  58         /* Clear red. */
  59         glClearColor(1.0, 0.0, 0.0, 0.0);
  60         glClear(GL_COLOR_BUFFER_BIT);
  61
  62         /* Draw top half of screen green. */
  63         glColor4f(0.0, 1.0, 0.0, 0.0);
  64         piglit_draw_rect(-1, 0, 2, 1);
  65
  66         /* Discard a copy over the bottom red over the top green. */
  67         glEnable(GL_RASTERIZER_DISCARD);
  68         glRasterPos2i(-1, 0);
  69         glCopyPixels(0, 0, piglit_width, piglit_height / 2, GL_COLOR);
  70
  71         /* Don't discard a copy of the green over the remaining red. */
  72         glDisable(GL_RASTERIZER_DISCARD);
  73         glRasterPos2i(-1, -1);
  74         glCopyPixels(0, piglit_height / 2, piglit_width, piglit_height / 2,
  75                      GL_COLOR);
  76
  77         pass = piglit_probe_rect_rgba(0, 0, piglit_width, piglit_height, green);
  78
  79         piglit_present_results();
  80
  81         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
  82 }
  83
  84 void
  85 piglit_init(int argc, char **argv)
  86 {
  87         piglit_require_transform_feedback();
  88 }