tests/spec/arb_texture_buffer_object/render-no-bo.c

   1 /* Copyright © 2012 Intel Corporation
   2  *
   3  * Permission is hereby granted, free of charge, to any person obtaining a
   4  * copy of this software and associated documentation files (the "Software"),
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   7  * and/or sell copies of the Software, and to permit persons to whom the
   8  * Software is furnished to do so, subject to the following conditions:
   9  *
  10  * The above copyright notice and this permission notice (including the next
  11  * paragraph) shall be included in all copies or substantial portions of the
  12  * Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  19  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  20  * IN THE SOFTWARE.
  21  */
  22
  23 /** @file render-no-bo.c
  24  *
  25  * Tests that we can sample from the default texture buffer or a
  26  * texture buffer with no buffer bound, and not crash.
  27  *
  28  * From the GL_ARB_texture_buffer_object spec:
  29  *
  30  *     "If no buffer object is bound to the buffer texture, the
  31  *      results of the texel access are undefined."
  32  *
  33  * we interpret this as allowing any result to come back, but not
  34  * terminate the program.  To test that, we glReadPixels the result
  35  * but don't test the values returned.
  36  */
  37
  38 #include "piglit-util-gl.h"
  39
  40 PIGLIT_GL_TEST_CONFIG_BEGIN
  41         config.supports_gl_compat_version = 10;
  42         config.supports_gl_core_version = 31;
  43         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGBA;
  44         config.khr_no_error_support = PIGLIT_NO_ERRORS;
  45 PIGLIT_GL_TEST_CONFIG_END
  46
  47 enum piglit_result
  48 piglit_display(void)
  49 {
  50         static const char *vs_source =
  51                 "#version 140\n"
  52                 "in vec4 vertex;\n"
  53                 "void main()\n"
  54                 "{\n"
  55                 "       gl_Position = vertex;\n"
  56                 "}\n";
  57
  58         static const char *fs_source =
  59                 "#version 140\n"
  60                 "uniform samplerBuffer s;\n"
  61                 "void main()\n"
  62                 "{\n"
  63                 "       gl_FragColor = texelFetch(s, 4096);\n"
  64                 "}\n";
  65
  66         GLuint tex, vbo;
  67         uint8_t junk[4];
  68         static const GLfloat verts[8] = {
  69                 -1, -1,
  70                  1, -1,
  71                  1,  1,
  72                 -1,  1
  73         };
  74         int vertex_location;
  75         GLuint prog;
  76
  77         prog = piglit_build_simple_program(vs_source, fs_source);
  78         glUseProgram(prog);
  79
  80         vertex_location = glGetAttribLocation(prog, "vertex");
  81
  82         if (piglit_get_gl_version() >= 31) {
  83                 GLuint vao;
  84                 glGenVertexArrays(1, &vao);
  85                 glBindVertexArray(vao);
  86         }
  87         glGenBuffers(1, &vbo);
  88         glBindBuffer(GL_ARRAY_BUFFER, vbo);
  89         glBufferData(GL_ARRAY_BUFFER, sizeof(verts), verts, GL_STATIC_READ);
  90         glVertexAttribPointer(vertex_location, 2, GL_FLOAT,
  91                               GL_FALSE, 0, NULL);
  92         glEnableVertexAttribArray(vertex_location);
  93
  94         /* First, draw with no texture buffer bound (so using the
  95          * default texture buffer object)
  96          */
  97         glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
  98         glReadPixels(0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &junk);
  99
 100         /* Now, do it again with a texture buffer that doesn't have
 101          * any buffer bound yet.
 102          */
 103         glGenTextures(1, &tex);
 104         glBindTexture(GL_TEXTURE_BUFFER, tex);
 105
 106         glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
 107         glReadPixels(0, 0, 1, 1, GL_RGBA, GL_UNSIGNED_BYTE, &junk);
 108
 109         glDeleteTextures(1, &tex);
 110
 111         piglit_present_results();
 112
 113         return PIGLIT_PASS;
 114 }
 115
 116 void
 117 piglit_init(int argc, char **argv)
 118 {
 119         piglit_require_GLSL_version(140);
 120         if (piglit_get_gl_version() < 31)
 121                 piglit_require_extension("GL_ARB_texture_buffer_object");
 122 }