tests/fbo/fbo-deriv.c

   1 /*
   2  * Copyright © 2012 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 /**
  25  * \file fbo-deriv.c
  26  *
  27  * Verify that the implementation produces correct values for the GLSL
  28  * dFdx() and dFdy() functions, both in fbos and in the default
  29  * framebuffer.
  30  *
  31  * Note: the reason that we test both fbos and the default framebuffer
  32  * in the same test is that some implementations (e.g. Mesa/i965) need
  33  * to compile the dFdy() function differently depending whether we are
  34  * rendering to an FBO or to the default framebuffer; testing both in
  35  * the same test allows us to verify that the implementation
  36  * recompiles the shader if necessary.
  37  *
  38  * This test draws a pair of squares in which dFdx and dFdy are
  39  * expected to both be 1.0.  It colors the rectangles red=0.5*dFdx and
  40  * green=0.5*dFdy, so the expected color is (0.5, 0.5, 0, 0).  The
  41  * left rectangle is drawn in the default framebuffer; the right
  42  * rectangle is drawn in an FBO and then blitted to the default
  43  * framebuffer.
  44  */
  45
  46 #include "piglit-util-gl.h"
  47
  48 PIGLIT_GL_TEST_CONFIG_BEGIN
  49
  50         config.supports_gl_compat_version = 10;
  51
  52         config.window_width = 256;
  53         config.window_height = 128;
  54         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGB;
  55         config.khr_no_error_support = PIGLIT_NO_ERRORS;
  56
  57 PIGLIT_GL_TEST_CONFIG_END
  58
  59 static const int fbo_width = 128, fbo_height = 128;
  60
  61 static GLuint fbo;
  62 static GLint prog;
  63
  64 static const char *vert =
  65         "void main()\n"
  66         "{\n"
  67         "  gl_Position = gl_Vertex;\n"
  68         "}\n";
  69
  70 static const char *frag =
  71         "void main()\n"
  72         "{\n"
  73         "  gl_FragColor = vec4(0.5*dFdx(gl_FragCoord.x),\n"
  74         "                      0.5*dFdy(gl_FragCoord.y), 0.0, 0.0);\n"
  75         "}\n";
  76
  77 static void
  78 create_fbo()
  79 {
  80         GLenum status;
  81         GLuint rb;
  82
  83         glGenRenderbuffers(1, &rb);
  84         glBindRenderbuffer(GL_RENDERBUFFER, rb);
  85         glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA, fbo_width, fbo_height);
  86         glGenFramebuffers(1, &fbo);
  87         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo);
  88         glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
  89                                   GL_RENDERBUFFER, rb);
  90         status = glCheckFramebufferStatusEXT (GL_FRAMEBUFFER_EXT);
  91
  92         if (!piglit_check_gl_error(GL_NO_ERROR))
  93                 piglit_report_result(PIGLIT_FAIL);
  94
  95         switch (status) {
  96         case GL_FRAMEBUFFER_UNSUPPORTED:
  97                 printf("Framebuffer unsupported\n");
  98                 piglit_report_result(PIGLIT_SKIP);
  99                 break;
 100         case GL_FRAMEBUFFER_COMPLETE:
 101                 break;
 102         default:
 103                 printf("Framebuffer incomplete\n");
 104                 piglit_report_result(PIGLIT_FAIL);
 105                 break;
 106         }
 107 }
 108
 109 void
 110 piglit_init(int argc, char **argv)
 111 {
 112         GLint vs, fs;
 113
 114         piglit_require_gl_version(20);
 115         piglit_require_extension("GL_ARB_framebuffer_object");
 116
 117         vs = piglit_compile_shader_text(GL_VERTEX_SHADER, vert);
 118         fs = piglit_compile_shader_text(GL_FRAGMENT_SHADER, frag);
 119         prog = piglit_link_simple_program(vs, fs);
 120
 121         create_fbo();
 122 }
 123
 124 enum piglit_result
 125 piglit_display(void)
 126 {
 127         float expected[3] = { 0.5, 0.5, 0.0 };
 128         GLboolean pass = GL_TRUE;
 129
 130         glUseProgram(prog);
 131
 132         /* Draw a square to the left half of the window */
 133         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
 134         glViewport(0, 0, piglit_width, piglit_height);
 135         piglit_draw_rect(-1, -1, 1, 2);
 136
 137         /* Draw a square to the FBO */
 138         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, fbo);
 139         glViewport(0, 0, fbo_width, fbo_height);
 140         piglit_draw_rect(-1, -1, 2, 2);
 141
 142         /* Blit the square from the FBO to the right half of the window */
 143         glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);
 144         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, piglit_winsys_fbo);
 145         glBlitFramebuffer(0, 0, fbo_width, fbo_height,
 146                           piglit_width/2, 0, piglit_width, piglit_height,
 147                           GL_COLOR_BUFFER_BIT, GL_NEAREST);
 148
 149         /* Check that both squares have the correct color */
 150         glBindFramebuffer(GL_READ_FRAMEBUFFER, piglit_winsys_fbo);
 151         pass = piglit_probe_rect_rgb(0, 0, piglit_width, piglit_height,
 152                                      expected) && pass;
 153
 154         piglit_present_results();
 155
 156         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 157 }