progs/perf/drawoverhead.c

   1 /*
   2  * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
   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 shall be included
  12  * in all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  15  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * VMWARE BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  18  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  19  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  20  */
  21
  22 /**
  23  * Measure drawing overhead
  24  *
  25  * This is the first in a series of simple performance benchmarks.
  26  * The code in this file should be as simple as possible to make it
  27  * easily portable to other APIs.
  28  *
  29  * All the window-system stuff should be contained in glmain.c (or TBDmain.c).
  30  * All the re-usable, generic code should be in common.c (XXX not done yet).
  31  *
  32  * Brian Paul
  33  * 15 Sep 2009
  34  */
  35
  36 #include "glmain.h"
  37 #include "common.h"
  38
  39
  40 int WinWidth = 100, WinHeight = 100;
  41
  42 static GLuint VBO;
  43
  44 struct vertex
  45 {
  46    GLfloat x, y;
  47 };
  48
  49 static const struct vertex vertices[4] = {
  50    { -1.0, -1.0 },
  51    {  1.0, -1.0 },
  52    {  1.0,  1.0 },
  53    { -1.0,  1.0 }
  54 };
  55
  56
  57 /** Called from test harness/main */
  58 void
  59 PerfInit(void)
  60 {
  61    /* setup VBO w/ vertex data */
  62    glGenBuffersARB(1, &VBO);
  63    glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);
  64    glBufferDataARB(GL_ARRAY_BUFFER_ARB,
  65                    sizeof(vertices), vertices, GL_STATIC_DRAW_ARB);
  66    glVertexPointer(2, GL_FLOAT, sizeof(struct vertex), (void *) 0);
  67    glEnableClientState(GL_VERTEX_ARRAY);
  68
  69    /* misc GL state */
  70    glAlphaFunc(GL_ALWAYS, 0.0);
  71 }
  72
  73
  74 static void
  75 DrawNoStateChange(unsigned count)
  76 {
  77    unsigned i;
  78    for (i = 0; i < count; i++) {
  79       glDrawArrays(GL_POINTS, 0, 4);
  80    }
  81    glFinish();
  82 }
  83
  84
  85 static void
  86 DrawNopStateChange(unsigned count)
  87 {
  88    unsigned i;
  89    for (i = 0; i < count; i++) {
  90       glDisable(GL_ALPHA_TEST);
  91       glDrawArrays(GL_POINTS, 0, 4);
  92    }
  93    glFinish();
  94 }
  95
  96
  97 static void
  98 DrawStateChange(unsigned count)
  99 {
 100    unsigned i;
 101    for (i = 0; i < count; i++) {
 102       if (i & 1)
 103          glEnable(GL_TEXTURE_GEN_S);
 104       else
 105          glDisable(GL_TEXTURE_GEN_S);
 106       glDrawArrays(GL_POINTS, 0, 4);
 107    }
 108    glFinish();
 109 }
 110
 111
 112 /** Called from test harness/main */
 113 void
 114 PerfDraw(void)
 115 {
 116    double rate0, rate1, rate2, overhead;
 117
 118    rate0 = PerfMeasureRate(DrawNoStateChange);
 119    perf_printf("   Draw only: %.1f draws/second\n", rate0);
 120
 121
 122    rate1 = PerfMeasureRate(DrawNopStateChange);
 123    overhead = 1000.0 * (1.0 / rate1 - 1.0 / rate0);
 124    perf_printf("   Draw w/ nop state change: %.1f draws/sec (overhead: %f ms/draw)\n",
 125                rate1, overhead);
 126
 127    rate2 = PerfMeasureRate(DrawStateChange);
 128    overhead = 1000.0 * (1.0 / rate2 - 1.0 / rate0);
 129    perf_printf("   Draw w/ state change: %.1f draws/sec (overhead: %f ms/draw)\n",
 130                rate2, overhead);
 131
 132    exit(0);
 133 }
 134