progs/demos/clearspd.c

   1 /* $Id: clearspd.c,v 1.4 2002/04/22 16:03:37 brianp Exp $ */
   2
   3 /*
   4  * Simple GLUT program to measure glClear() and glutSwapBuffers() speed.
   5  * Brian Paul  February 15, 1997  This file in public domain.
   6  */
   7
   8
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <math.h>
  12 #include <string.h>
  13 #include <GL/glut.h>
  14
  15
  16 static float MinPeriod = 2.0;   /* 2 seconds */
  17 static int ColorMode = GLUT_RGB;
  18 static int Width = 400.0;
  19 static int Height = 400.0;
  20 static int Loops = 100;
  21 static float ClearColor = 0.0;
  22 static GLbitfield BufferMask = GL_COLOR_BUFFER_BIT;
  23 static GLboolean SwapFlag = GL_FALSE;
  24
  25
  26
  27 static void Idle( void )
  28 {
  29    glutPostRedisplay();
  30 }
  31
  32
  33 static void Display( void )
  34 {
  35    double t0, t1;
  36    double clearRate;
  37    double pixelRate;
  38    int i;
  39
  40    glClearColor( ClearColor, ClearColor, ClearColor, 0.0 );
  41    ClearColor += 0.1;
  42    if (ClearColor>1.0)
  43       ClearColor = 0.0;
  44
  45    if (SwapFlag) {
  46       t0 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  47       for (i=0;i<Loops;i++) {
  48          glClear( BufferMask );
  49          glutSwapBuffers();
  50       }
  51       glFinish();
  52       t1 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  53    }
  54    else {
  55       t0 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  56       for (i=0;i<Loops;i++) {
  57          glClear( BufferMask );
  58       }
  59       glFinish();
  60       t1 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  61       glutSwapBuffers();
  62    }
  63
  64    if (t1-t0 < MinPeriod) {
  65       /* Next time do more clears to get longer elapsed time */
  66       Loops *= 2;
  67       return;
  68    }
  69
  70    clearRate = Loops / (t1-t0);
  71    pixelRate = clearRate * Width * Height;
  72    if (SwapFlag) {
  73       printf("Rate: %d clears+swaps in %gs = %g clears+swaps/s   %g pixels/s\n",
  74              Loops, t1-t0, clearRate, pixelRate );
  75    }
  76    else {
  77       printf("Rate: %d clears in %gs = %g clears/s   %g pixels/s\n",
  78              Loops, t1-t0, clearRate, pixelRate);
  79    }
  80 }
  81
  82
  83 static void Reshape( int width, int height )
  84 {
  85    Width = width;
  86    Height = height;
  87    glViewport( 0, 0, width, height );
  88    glMatrixMode( GL_PROJECTION );
  89    glLoadIdentity();
  90    glOrtho(0.0, width, 0.0, height, -1.0, 1.0);
  91    glMatrixMode( GL_MODELVIEW );
  92    glLoadIdentity();
  93 }
  94
  95
  96 static void Key( unsigned char key, int x, int y )
  97 {
  98    (void) x;
  99    (void) y;
 100    switch (key) {
 101       case 27:
 102          exit(0);
 103          break;
 104    }
 105    glutPostRedisplay();
 106 }
 107
 108
 109 static void Init( int argc, char *argv[] )
 110 {
 111    int i;
 112    for (i=1; i<argc; i++) {
 113       if (strcmp(argv[i],"+rgb")==0)
 114          ColorMode = GLUT_RGB;
 115       else if (strcmp(argv[i],"+ci")==0)
 116          ColorMode = GLUT_INDEX;
 117       else if (strcmp(argv[i],"-color")==0)
 118          BufferMask = 0;
 119       else if (strcmp(argv[i],"+depth")==0)
 120          BufferMask |= GL_DEPTH_BUFFER_BIT;
 121       else if (strcmp(argv[i],"+alpha")==0)
 122          ColorMode = GLUT_RGB | GLUT_ALPHA;
 123       else if (strcmp(argv[i],"+stencil")==0)
 124          BufferMask |= GL_STENCIL_BUFFER_BIT;
 125       else if (strcmp(argv[i],"+accum")==0)
 126          BufferMask |= GL_ACCUM_BUFFER_BIT;
 127       else if (strcmp(argv[i],"-width")==0) {
 128          Width = atoi(argv[i+1]);
 129          i++;
 130       }
 131       else if (strcmp(argv[i],"-height")==0) {
 132          Height = atoi(argv[i+1]);
 133          i++;
 134       }
 135       else if (strcmp(argv[i],"+swap")==0) {
 136          SwapFlag = GL_TRUE;
 137       }
 138       else if (strcmp(argv[i],"-swap")==0) {
 139          SwapFlag = GL_FALSE;
 140       }
 141       else
 142          printf("Unknown option: %s\n", argv[i]);
 143    }
 144
 145    if (ColorMode & GLUT_ALPHA)
 146       printf("Mode:  RGB + Alpha\n");
 147    else if (ColorMode==GLUT_RGB)
 148       printf("Mode:  RGB\n");
 149    else
 150       printf("Mode:  Color Index\n");
 151    printf("SwapBuffers: %s\n", SwapFlag ? "yes" : "no" );
 152    printf("Size: %d x %d\n", Width, Height);
 153    printf("Buffers: ");
 154    if (BufferMask & GL_COLOR_BUFFER_BIT)  printf("color ");
 155    if (BufferMask & GL_DEPTH_BUFFER_BIT)  printf("depth ");
 156    if (BufferMask & GL_STENCIL_BUFFER_BIT)  printf("stencil ");
 157    if (BufferMask & GL_ACCUM_BUFFER_BIT)  printf("accum ");
 158    printf("\n");
 159 }
 160
 161
 162 static void Help( const char *program )
 163 {
 164    printf("%s options:\n", program);
 165    printf("  +rgb       RGB mode\n");
 166    printf("  +ci        color index mode\n");
 167    printf("  -color     don't clear color buffer\n");
 168    printf("  +alpha     clear alpha buffer\n");
 169    printf("  +depth     clear depth buffer\n");
 170    printf("  +stencil   clear stencil buffer\n");
 171    printf("  +accum     clear accum buffer\n");
 172    printf("  +swap      also do SwapBuffers\n");
 173    printf("  -swap      don't do SwapBuffers\n");
 174 }
 175
 176
 177 int main( int argc, char *argv[] )
 178 {
 179    GLint mode;
 180
 181    printf("For options:  %s -help\n", argv[0]);
 182
 183    Init( argc, argv );
 184
 185    glutInit( &argc, argv );
 186    glutInitWindowSize( (int) Width, (int) Height );
 187    glutInitWindowPosition( 0, 0 );
 188
 189    mode = ColorMode | GLUT_DOUBLE;
 190    if (BufferMask & GL_STENCIL_BUFFER_BIT)
 191       mode |= GLUT_STENCIL;
 192    if (BufferMask & GL_ACCUM_BUFFER_BIT)
 193       mode |= GLUT_ACCUM;
 194    if (BufferMask & GL_DEPTH_BUFFER_BIT)
 195       mode |= GLUT_DEPTH;
 196
 197    glutInitDisplayMode(mode);
 198
 199    glutCreateWindow( argv[0] );
 200
 201    if (argc==2 && strcmp(argv[1],"-help")==0) {
 202       Help(argv[0]);
 203       return 0;
 204    }
 205
 206    glutReshapeFunc( Reshape );
 207    glutKeyboardFunc( Key );
 208    glutDisplayFunc( Display );
 209    glutIdleFunc( Idle );
 210
 211    glutMainLoop();
 212    return 0;
 213 }