tests/spec/arb_sampler_objects/sampler-incomplete.c

   1 /*
   2  * Copyright (c) 2012 VMware, Inc.
   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 sampler-incomplete.c
  26  *
  27  * With GL_ARB_sampler_objects it's possible for a texture to be both complete
  28  * and incomplete depending on the samplers used to access it.
  29  * Test that we get the right results in this situation.
  30  *
  31  * Brian Paul
  32  * March 2012
  33  */
  34
  35
  36 #include "piglit-util-gl.h"
  37
  38 PIGLIT_GL_TEST_CONFIG_BEGIN
  39
  40         config.supports_gl_compat_version = 10;
  41
  42         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGB;
  43
  44 PIGLIT_GL_TEST_CONFIG_END
  45
  46 static void
  47 setup(void)
  48 {
  49         static const GLfloat red[2][2][4] = {
  50                 { {0.25, 0, 0, 0}, {0.25, 0, 0, 0} },
  51                 { {0.25, 0, 0, 0}, {0.25, 0, 0, 0} } };
  52         static const char *fragShaderText =
  53                 "uniform sampler2D tex0, tex1;\n"
  54                 "void main()\n"
  55                 "{\n"
  56                 "   vec2 coord = vec2(0.5, 0.5); \n"
  57                 "   gl_FragColor = texture2D(tex0, coord) \n"
  58                 "                + texture2D(tex1, coord);\n"
  59                 "}\n";
  60         GLuint samplers[2];
  61         GLuint prog;
  62         GLint u;
  63         GLuint tex;
  64
  65         /* Create fragment shader that adds the two textures */
  66         prog = piglit_build_simple_program(NULL, fragShaderText);
  67
  68         glUseProgram(prog);
  69         u = glGetUniformLocation(prog, "tex0");
  70         glUniform1i(u, 0);
  71         u = glGetUniformLocation(prog, "tex1");
  72         glUniform1i(u, 1);
  73
  74         /* create texture with one mipmap level */
  75         glGenTextures(1, &tex);
  76         glBindTexture(GL_TEXTURE_2D, tex);
  77         glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 2, 2, 0,
  78                      GL_RGBA, GL_FLOAT, red);
  79         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  80         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  81
  82         /* bind the texture to units 0 and 1 */
  83         glActiveTexture(GL_TEXTURE0);
  84         glBindTexture(GL_TEXTURE_2D, tex);
  85         glEnable(GL_TEXTURE_2D);
  86
  87         glActiveTexture(GL_TEXTURE1);
  88         glBindTexture(GL_TEXTURE_2D, tex);
  89         glEnable(GL_TEXTURE_2D);
  90
  91
  92         glGenSamplers(2, samplers);
  93
  94         /* sampler[0] - nearest filtering, no mipmap.
  95          * The result of sampling the texture should be (0.25, 0, 0, 0)
  96          */
  97         glBindSampler(0, samplers[0]);
  98         glSamplerParameteri(samplers[0], GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  99         glSamplerParameteri(samplers[0], GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 100
 101         /* sampler[1] - nearest filtering, with mipmapping.
 102          * The result of sampling the texture should be (0, 0, 0, 1) since the
 103          * texture is incomplete with respect to this sampler (no mipmap).
 104          */
 105         glBindSampler(1, samplers[1]);
 106         glSamplerParameteri(samplers[1], GL_TEXTURE_MIN_FILTER,
 107                             GL_NEAREST_MIPMAP_NEAREST);
 108         glSamplerParameteri(samplers[1], GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 109 }
 110
 111
 112 enum piglit_result
 113 piglit_display(void)
 114 {
 115         /* NOTE: We're not checking the alpha value here.
 116          * Some drivers (like NVIDIA) seem to return (0,0,0,0) when sampling
 117          * an incomplete texture, but the spec says (0,0,0,1) should be
 118          * returned.  That's not really important for this test though so
 119          * just ignore alpha.
 120          */
 121         GLfloat expected[3] = {0.25, 0, 0};
 122         bool p;
 123
 124         glClear(GL_COLOR_BUFFER_BIT);
 125
 126         piglit_draw_rect_tex(-1, -1, 2, 2,  0, 0, 1, 1);
 127
 128         p = piglit_probe_pixel_rgb(piglit_width / 2, piglit_height / 2,
 129                                    expected);
 130
 131         piglit_present_results();
 132
 133         return p ? PIGLIT_PASS : PIGLIT_FAIL;
 134 }
 135
 136
 137 void
 138 piglit_init(int argc, char**argv)
 139 {
 140         piglit_require_extension("GL_ARB_sampler_objects");
 141         piglit_require_fragment_shader();
 142         setup();
 143 }