src/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  *
  31  * Brian Paul
  32  * 15 Sep 2009
  33  */
  34
  35 #include "glmain.h"
  36 #include "common.h"
  37
  38
  39 int WinWidth = 100, WinHeight = 100;
  40
  41 static GLuint VBO;
  42
  43 struct vertex
  44 {
  45    GLfloat x, y;
  46 };
  47
  48 static const struct vertex vertices[4] = {
  49    { -1.0, -1.0 },
  50    {  1.0, -1.0 },
  51    {  1.0,  1.0 },
  52    { -1.0,  1.0 }
  53 };
  54
  55
  56 /** Called from test harness/main */
  57 void
  58 PerfInit(void)
  59 {
  60    /* setup VBO w/ vertex data */
  61    glGenBuffersARB(1, &VBO);
  62    glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);
  63    glBufferDataARB(GL_ARRAY_BUFFER_ARB,
  64                    sizeof(vertices), vertices, GL_STATIC_DRAW_ARB);
  65    glVertexPointer(2, GL_FLOAT, sizeof(struct vertex), (void *) 0);
  66    glEnableClientState(GL_VERTEX_ARRAY);
  67
  68    /* misc GL state */
  69    glAlphaFunc(GL_ALWAYS, 0.0);
  70 }
  71
  72
  73 static void
  74 DrawNoStateChange(unsigned count)
  75 {
  76    unsigned i;
  77    for (i = 0; i < count; i++) {
  78       glDrawArrays(GL_POINTS, 0, 4);
  79    }
  80    glFinish();
  81 }
  82
  83
  84 static void
  85 DrawNopStateChange(unsigned count)
  86 {
  87    unsigned i;
  88    for (i = 0; i < count; i++) {
  89       glDisable(GL_ALPHA_TEST);
  90       glDrawArrays(GL_POINTS, 0, 4);
  91    }
  92    glFinish();
  93 }
  94
  95
  96 static void
  97 DrawStateChange(unsigned count)
  98 {
  99    unsigned i;
 100    for (i = 0; i < count; i++) {
 101       if (i & 1)
 102          glEnable(GL_TEXTURE_GEN_S);
 103       else
 104          glDisable(GL_TEXTURE_GEN_S);
 105       glDrawArrays(GL_POINTS, 0, 4);
 106    }
 107    glFinish();
 108 }
 109
 110 void
 111 PerfNextRound(void)
 112 {
 113 }
 114
 115 /** Called from test harness/main */
 116 void
 117 PerfDraw(void)
 118 {
 119    double rate0, rate1, rate2, overhead;
 120
 121    rate0 = PerfMeasureRate(DrawNoStateChange);
 122    perf_printf("   Draw only: %s draws/second\n",
 123                PerfHumanFloat(rate0));
 124
 125    rate1 = PerfMeasureRate(DrawNopStateChange);
 126    overhead = 1000.0 * (1.0 / rate1 - 1.0 / rate0);
 127    perf_printf("   Draw w/ nop state change: %s draws/sec (overhead: %f ms/draw)\n",
 128                PerfHumanFloat(rate1), overhead);
 129
 130    rate2 = PerfMeasureRate(DrawStateChange);
 131    overhead = 1000.0 * (1.0 / rate2 - 1.0 / rate0);
 132    perf_printf("   Draw w/ state change: %s draws/sec (overhead: %f ms/draw)\n",
 133                PerfHumanFloat(rate2), overhead);
 134
 135    exit(0);
 136 }
 137