progs/demos/clearspd.c

   1 /* $Id: clearspd.c,v 1.5 2002/10/31 12:38:32 keithw 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    /* NOTE: If clearspd doesn't map it's window immediately on
  65     * starting, swaps will be istantaneous, so this will send Loops
  66     * towards infinity.  When a window is finally mapped, it may be
  67     * minutes before the first call to glutSwapBuffers, making it look
  68     * like there's a driver bug.
  69     */
  70    if (t1-t0 < MinPeriod) {
  71       /* Next time do more clears to get longer elapsed time */
  72       Loops *= 2;
  73       return;
  74    }
  75
  76    clearRate = Loops / (t1-t0);
  77    pixelRate = clearRate * Width * Height;
  78    if (SwapFlag) {
  79       printf("Rate: %d clears+swaps in %gs = %g clears+swaps/s   %g pixels/s\n",
  80              Loops, t1-t0, clearRate, pixelRate );
  81    }
  82    else {
  83       printf("Rate: %d clears in %gs = %g clears/s   %g pixels/s\n",
  84              Loops, t1-t0, clearRate, pixelRate);
  85    }
  86 }
  87
  88
  89 static void Reshape( int width, int height )
  90 {
  91    Width = width;
  92    Height = height;
  93    glViewport( 0, 0, width, height );
  94    glMatrixMode( GL_PROJECTION );
  95    glLoadIdentity();
  96    glOrtho(0.0, width, 0.0, height, -1.0, 1.0);
  97    glMatrixMode( GL_MODELVIEW );
  98    glLoadIdentity();
  99 }
 100
 101
 102 static void Key( unsigned char key, int x, int y )
 103 {
 104    (void) x;
 105    (void) y;
 106    switch (key) {
 107       case 27:
 108          exit(0);
 109          break;
 110    }
 111    glutPostRedisplay();
 112 }
 113
 114
 115 static void Init( int argc, char *argv[] )
 116 {
 117    int i;
 118    for (i=1; i<argc; i++) {
 119       if (strcmp(argv[i],"+rgb")==0)
 120          ColorMode = GLUT_RGB;
 121       else if (strcmp(argv[i],"+ci")==0)
 122          ColorMode = GLUT_INDEX;
 123       else if (strcmp(argv[i],"-color")==0)
 124          BufferMask = 0;
 125       else if (strcmp(argv[i],"+depth")==0)
 126          BufferMask |= GL_DEPTH_BUFFER_BIT;
 127       else if (strcmp(argv[i],"+alpha")==0)
 128          ColorMode = GLUT_RGB | GLUT_ALPHA;
 129       else if (strcmp(argv[i],"+stencil")==0)
 130          BufferMask |= GL_STENCIL_BUFFER_BIT;
 131       else if (strcmp(argv[i],"+accum")==0)
 132          BufferMask |= GL_ACCUM_BUFFER_BIT;
 133       else if (strcmp(argv[i],"-width")==0) {
 134          Width = atoi(argv[i+1]);
 135          i++;
 136       }
 137       else if (strcmp(argv[i],"-height")==0) {
 138          Height = atoi(argv[i+1]);
 139          i++;
 140       }
 141       else if (strcmp(argv[i],"+swap")==0) {
 142          SwapFlag = GL_TRUE;
 143       }
 144       else if (strcmp(argv[i],"-swap")==0) {
 145          SwapFlag = GL_FALSE;
 146       }
 147       else
 148          printf("Unknown option: %s\n", argv[i]);
 149    }
 150
 151    if (ColorMode & GLUT_ALPHA)
 152       printf("Mode:  RGB + Alpha\n");
 153    else if (ColorMode==GLUT_RGB)
 154       printf("Mode:  RGB\n");
 155    else
 156       printf("Mode:  Color Index\n");
 157    printf("SwapBuffers: %s\n", SwapFlag ? "yes" : "no" );
 158    printf("Size: %d x %d\n", Width, Height);
 159    printf("Buffers: ");
 160    if (BufferMask & GL_COLOR_BUFFER_BIT)  printf("color ");
 161    if (BufferMask & GL_DEPTH_BUFFER_BIT)  printf("depth ");
 162    if (BufferMask & GL_STENCIL_BUFFER_BIT)  printf("stencil ");
 163    if (BufferMask & GL_ACCUM_BUFFER_BIT)  printf("accum ");
 164    printf("\n");
 165 }
 166
 167
 168 static void Help( const char *program )
 169 {
 170    printf("%s options:\n", program);
 171    printf("  +rgb       RGB mode\n");
 172    printf("  +ci        color index mode\n");
 173    printf("  -color     don't clear color buffer\n");
 174    printf("  +alpha     clear alpha buffer\n");
 175    printf("  +depth     clear depth buffer\n");
 176    printf("  +stencil   clear stencil buffer\n");
 177    printf("  +accum     clear accum buffer\n");
 178    printf("  +swap      also do SwapBuffers\n");
 179    printf("  -swap      don't do SwapBuffers\n");
 180 }
 181
 182
 183 int main( int argc, char *argv[] )
 184 {
 185    GLint mode;
 186
 187    printf("For options:  %s -help\n", argv[0]);
 188
 189    Init( argc, argv );
 190
 191    glutInit( &argc, argv );
 192    glutInitWindowSize( (int) Width, (int) Height );
 193    glutInitWindowPosition( 0, 0 );
 194
 195    mode = ColorMode | GLUT_DOUBLE;
 196    if (BufferMask & GL_STENCIL_BUFFER_BIT)
 197       mode |= GLUT_STENCIL;
 198    if (BufferMask & GL_ACCUM_BUFFER_BIT)
 199       mode |= GLUT_ACCUM;
 200    if (BufferMask & GL_DEPTH_BUFFER_BIT)
 201       mode |= GLUT_DEPTH;
 202
 203    glutInitDisplayMode(mode);
 204
 205    glutCreateWindow( argv[0] );
 206
 207    if (argc==2 && strcmp(argv[1],"-help")==0) {
 208       Help(argv[0]);
 209       return 0;
 210    }
 211
 212    glutReshapeFunc( Reshape );
 213    glutKeyboardFunc( Key );
 214    glutDisplayFunc( Display );
 215    glutIdleFunc( Idle );
 216
 217    glutMainLoop();
 218    return 0;
 219 }