tests/fbo/fbo-alpha.c

   1 /*
   2  * Copyright © 2010 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  * Authors:
  24  *    Eric Anholt <eric@anholt.net>
  25  *
  26  */
  27
  28 /** @file fbo-alpha.c
  29  *
  30  * Tests that rendering to and blending on a GL_ALPHA FBO works with
  31  * GL_ARB_framebuffer_object.
  32  */
  33
  34 #include "piglit-util.h"
  35
  36 int piglit_width = 128;
  37 int piglit_height = 128;
  38 int piglit_window_mode = GLUT_RGB | GLUT_ALPHA | GLUT_DOUBLE;
  39
  40 enum piglit_result
  41 piglit_display(void)
  42 {
  43         GLboolean pass = GL_TRUE;
  44         GLuint tex, fb;
  45         GLenum status;
  46         float fbo_white[] = {0.0, 0.0, 0.0, 1.0};
  47         float fbo_black[] = {0.0, 0.0, 0.0, 0.0};
  48         float fbo_gray[] =  {0.0, 0.0, 0.0, 0.5};
  49         float white[] = {1.0, 1.0, 1.0, 1.0};
  50         float black[] = {0.0, 0.0, 0.0, 0.0};
  51         float gray[] =  {0.5, 0.5, 0.5, 0.5};
  52         int fbo_width = 64;
  53         int fbo_height = 64;
  54
  55         glGenFramebuffersEXT(1, &fb);
  56         glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb);
  57         glViewport(0, 0, fbo_width, fbo_height);
  58
  59         glGenTextures(1, &tex);
  60         glBindTexture(GL_TEXTURE_2D, tex);
  61         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  62         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  63         glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA,
  64                      fbo_width, fbo_height, 0,
  65                      GL_ALPHA, GL_UNSIGNED_BYTE, NULL);
  66
  67         glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT,
  68                                   GL_COLOR_ATTACHMENT0_EXT,
  69                                   GL_TEXTURE_2D,
  70                                   tex,
  71                                   0);
  72         assert(glGetError() == 0);
  73
  74         status = glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT);
  75         if (status != GL_FRAMEBUFFER_COMPLETE_EXT) {
  76                 fprintf(stderr, "fbo incomplete (status = 0x%04x)\n", status);
  77                 piglit_report_result(PIGLIT_SKIP);
  78         }
  79
  80         /* Clear to no alpha. */
  81         glClearColor(0.0, 0.0, 0.0, 0.0);
  82         glClear(GL_COLOR_BUFFER_BIT);
  83
  84         glColor4f(0.0, 0.0, 0.0, 0.0);
  85         piglit_draw_rect(-1.0, -1.0, 0.5, 2.0);
  86
  87         glColor4f(0.0, 0.0, 0.0, 1.0);
  88         piglit_draw_rect(-0.5, -1.0, 0.5, 2.0);
  89
  90         glColor4f(0.0, 0.0, 0.0, 0.5);
  91         piglit_draw_rect(0.0, -1.0, 0.5, 2.0);
  92         glEnable(GL_BLEND);
  93         glBlendFunc(GL_DST_ALPHA, GL_ZERO);
  94         glColor4f(0.0, 0.0, 0.0, 1.0);
  95         piglit_draw_rect(0.0, -1.0, 0.5, 2.0);
  96         glDisable(GL_BLEND);
  97
  98         glColor4f(0.0, 0.0, 0.0, 0.5);
  99         piglit_draw_rect(0.5, -1.0, 0.5, 2.0);
 100         glEnable(GL_BLEND);
 101         glBlendFunc(GL_ZERO, GL_SRC_ALPHA);
 102         glColor4f(0.0, 0.0, 0.0, 1.0);
 103         piglit_draw_rect(0.5, -1.0, 0.5, 2.0);
 104         glDisable(GL_BLEND);
 105
 106         printf("Testing FBO result.\n");
 107         pass = piglit_probe_pixel_rgba(fbo_width * 1 / 8, 0, fbo_black) && pass;
 108         pass = piglit_probe_pixel_rgba(fbo_width * 3 / 8, 0, fbo_white) && pass;
 109         pass = piglit_probe_pixel_rgba(fbo_width * 5 / 8, 0, fbo_gray) && pass;
 110         pass = piglit_probe_pixel_rgba(fbo_width * 7 / 8, 0, fbo_gray) && pass;
 111
 112         /* Draw the two textures to halves of the window. */
 113         glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
 114         glViewport(0, 0, piglit_width, piglit_height);
 115
 116         glEnable(GL_TEXTURE_2D);
 117         glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_COMBINE);
 118         glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_RGB, GL_REPLACE);
 119         glTexEnvi(GL_TEXTURE_ENV, GL_COMBINE_ALPHA, GL_REPLACE);
 120         glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND0_RGB, GL_SRC_ALPHA);
 121         glTexEnvi (GL_TEXTURE_ENV, GL_SOURCE0_RGB, GL_TEXTURE);
 122         glTexEnvi (GL_TEXTURE_ENV, GL_OPERAND0_ALPHA, GL_SRC_ALPHA);
 123         glTexEnvi (GL_TEXTURE_ENV, GL_SOURCE0_ALPHA, GL_TEXTURE);
 124
 125         glBindTexture(GL_TEXTURE_2D, tex);
 126         piglit_draw_rect_tex(-1, -1, 2, 2,
 127                              0, 0, 1, 1);
 128
 129         glDisable(GL_TEXTURE_2D);
 130         glDeleteTextures(1, &tex);
 131         glDeleteFramebuffersEXT(1, &fb);
 132
 133         printf("Testing window result.\n");
 134         pass = piglit_probe_pixel_rgba(piglit_width * 1 / 8, 0, black) && pass;
 135         pass = piglit_probe_pixel_rgba(piglit_width * 3 / 8, 0, white) && pass;
 136         pass = piglit_probe_pixel_rgba(piglit_width * 5 / 8, 0, gray) && pass;
 137         pass = piglit_probe_pixel_rgba(piglit_width * 7 / 8, 0, gray) && pass;
 138
 139         glutSwapBuffers();
 140
 141         return pass ? PIGLIT_SUCCESS : PIGLIT_FAILURE;
 142 }
 143
 144 void
 145 piglit_init(int argc, char **argv)
 146 {
 147         piglit_require_extension("GL_ARB_framebuffer_object");
 148         piglit_require_extension("GL_ARB_texture_env_combine");
 149 }