tests/spec/ext_transform_feedback/immediate-reuse-uniform-buffer.c

   1 /*
   2  * Copyright © 2011 Intel Corporation
   3  * Copyright © 2014 Advanced Micro Devices, Inc.
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software"),
   7  * to deal in the Software without restriction, including without limitation
   8  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   9  * and/or sell copies of the Software, and to permit persons to whom the
  10  * Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  21  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  22  * DEALINGS IN THE SOFTWARE.
  23  */
  24
  25 /**
  26  * \file immediate-reuse-uniform-buffer.c
  27  *
  28  * Verify that if a transform feedback output buffer is immediately re-used
  29  * as an uniform buffer (changing no GL settings except for buffer bindings),
  30  * rendering is correct.
  31  *
  32  * The test operates by using a uniform buffer <-> transform feedback loop
  33  * that increments a uniform in each draw call. The test starts
  34  * with value 0 and transform feedback writes (value+1). Then it uses
  35  * the output as an input again and the value should be 1.
  36  */
  37
  38 #include "piglit-util-gl.h"
  39
  40 PIGLIT_GL_TEST_CONFIG_BEGIN
  41
  42         config.supports_gl_compat_version = 10;
  43
  44         config.window_width = 256;
  45         config.window_height = 16;
  46         config.window_visual = PIGLIT_GL_VISUAL_DOUBLE | PIGLIT_GL_VISUAL_RGB;
  47         config.khr_no_error_support = PIGLIT_NO_ERRORS;
  48
  49 PIGLIT_GL_TEST_CONFIG_END
  50
  51 static const char *vstext =
  52         "#version 130\n"
  53         "#extension GL_ARB_uniform_buffer_object : require\n"
  54         "varying vec4 out_color;\n"
  55         "varying int index;\n"
  56         "uniform u { int u_const; };"
  57         "\n"
  58         "void main()\n"
  59         "{\n"
  60         "  int x = 8 + 16 * u_const;\n"
  61         "  gl_Position = vec4(x / 128.0 - 1.0, 0, 0, 1);\n"
  62         "  out_color = vec4(float(u_const) / 16.0, \n"
  63         "                   float(16 - u_const) / 16.0, \n"
  64         "                   float(u_const) / 16.0, 1.0);\n"
  65         "  index = u_const + 1;\n"
  66         "}\n";
  67
  68 static const char *fstext =
  69         "#version 130\n"
  70         "varying vec4 out_color;\n"
  71         "\n"
  72         "void main()\n"
  73         "{\n"
  74         "  gl_FragColor = out_color;\n"
  75         "}\n";
  76
  77 static const char *varyings[] = { "index" };
  78
  79 static GLuint bufs[2];
  80 static GLuint prog;
  81
  82 void
  83 piglit_init(int argc, char **argv)
  84 {
  85         piglit_require_gl_version(30);
  86         piglit_require_extension("GL_ARB_uniform_buffer_object");
  87
  88         prog = piglit_build_simple_program_unlinked(vstext, fstext);
  89         glTransformFeedbackVaryings(prog, 1, varyings, GL_INTERLEAVED_ATTRIBS);
  90         glLinkProgram(prog);
  91         if (!piglit_link_check_status(prog)) {
  92                 glDeleteProgram(prog);
  93                 piglit_report_result(PIGLIT_FAIL);
  94         }
  95
  96         glGenBuffers(2, bufs);
  97 }
  98
  99 enum piglit_result
 100 piglit_display(void)
 101 {
 102         int i;
 103         bool pass = true;
 104         unsigned zero = 0;
 105
 106         /* Setup program and initial buffer contents */
 107         glBindBuffer(GL_ARRAY_BUFFER, bufs[0]);
 108         glBufferData(GL_ARRAY_BUFFER, 4, &zero, GL_STREAM_COPY);
 109         glBindBuffer(GL_TRANSFORM_FEEDBACK_BUFFER, bufs[1]);
 110         glBufferData(GL_TRANSFORM_FEEDBACK_BUFFER, 4, &zero, GL_STREAM_COPY);
 111
 112         glUseProgram(prog);
 113         glClear(GL_COLOR_BUFFER_BIT);
 114         glPointSize(16);
 115
 116         /* Draw 16 times, swapping transform feedback and uniform data
 117          * so that transform feedback output is fed back to uniform
 118          * input.
 119          */
 120         for (i = 0; i < 16; ++i) {
 121                 glBindBufferBase(GL_UNIFORM_BUFFER, 0, bufs[i % 2]);
 122                 glBindBufferBase(GL_TRANSFORM_FEEDBACK_BUFFER, 0,
 123                                  bufs[(i + 1) % 2]);
 124                 glBeginTransformFeedback(GL_POINTS);
 125                 glDrawArrays(GL_POINTS, 0, 1);
 126                 glEndTransformFeedback();
 127         }
 128
 129         /* Check that the proper gradient was drawn */
 130         for (i = 0; i < 16; ++i) {
 131                 float expected_color[3] = {i/16.0, (16 - i)/16.0, i/16.0 };
 132                 pass = piglit_probe_rect_rgb(16 * i, 0, 16, 16,
 133                                              expected_color) && pass;
 134         }
 135
 136         piglit_present_results();
 137
 138         return pass ? PIGLIT_PASS : PIGLIT_FAIL;
 139 }