progs/demos/clearspd.c

   1
   2 /*
   3  * Simple GLUT program to measure glClear() and glutSwapBuffers() speed.
   4  * Brian Paul  February 15, 1997  This file in public domain.
   5  */
   6
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <math.h>
  11 #include <string.h>
  12 #include <GL/glut.h>
  13
  14
  15 static float MinPeriod = 2.0;   /* 2 seconds */
  16 static int ColorMode = GLUT_RGB;
  17 static int Width = 400.0;
  18 static int Height = 400.0;
  19 static int Loops = 100;
  20 static float ClearColor = 0.0;
  21 static GLbitfield BufferMask = GL_COLOR_BUFFER_BIT;
  22 static GLboolean SwapFlag = GL_FALSE;
  23
  24
  25
  26 static void Idle( void )
  27 {
  28    glutPostRedisplay();
  29 }
  30
  31
  32 static void Display( void )
  33 {
  34    double t0, t1;
  35    double clearRate;
  36    double pixelRate;
  37    int i;
  38
  39    glClearColor( ClearColor, ClearColor, ClearColor, 0.0 );
  40    ClearColor += 0.1;
  41    if (ClearColor>1.0)
  42       ClearColor = 0.0;
  43
  44    if (SwapFlag) {
  45       t0 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  46       for (i=0;i<Loops;i++) {
  47          glClear( BufferMask );
  48          glutSwapBuffers();
  49       }
  50       glFinish();
  51       t1 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  52    }
  53    else {
  54       t0 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  55       for (i=0;i<Loops;i++) {
  56          glClear( BufferMask );
  57       }
  58       glFinish();
  59       t1 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  60       glutSwapBuffers();
  61    }
  62
  63    /* NOTE: If clearspd doesn't map it's window immediately on
  64     * starting, swaps will be istantaneous, so this will send Loops
  65     * towards infinity.  When a window is finally mapped, it may be
  66     * minutes before the first call to glutSwapBuffers, making it look
  67     * like there's a driver bug.
  68     */
  69    if (t1-t0 < MinPeriod) {
  70       /* Next time do more clears to get longer elapsed time */
  71       Loops *= 2;
  72       return;
  73    }
  74
  75    clearRate = Loops / (t1-t0);
  76    pixelRate = clearRate * Width * Height;
  77    if (SwapFlag) {
  78       printf("Rate: %d clears+swaps in %gs = %g clears+swaps/s   %g pixels/s\n",
  79              Loops, t1-t0, clearRate, pixelRate );
  80    }
  81    else {
  82       printf("Rate: %d clears in %gs = %g clears/s   %g pixels/s\n",
  83              Loops, t1-t0, clearRate, pixelRate);
  84    }
  85 }
  86
  87
  88 static void Reshape( int width, int height )
  89 {
  90    Width = width;
  91    Height = height;
  92    glViewport( 0, 0, width, height );
  93    glMatrixMode( GL_PROJECTION );
  94    glLoadIdentity();
  95    glOrtho(0.0, width, 0.0, height, -1.0, 1.0);
  96    glMatrixMode( GL_MODELVIEW );
  97    glLoadIdentity();
  98 }
  99
 100
 101 static void Key( unsigned char key, int x, int y )
 102 {
 103    (void) x;
 104    (void) y;
 105    switch (key) {
 106       case 27:
 107          exit(0);
 108          break;
 109    }
 110    glutPostRedisplay();
 111 }
 112
 113
 114 static void Init( int argc, char *argv[] )
 115 {
 116    int i;
 117    for (i=1; i<argc; i++) {
 118       if (strcmp(argv[i],"+rgb")==0)
 119          ColorMode = GLUT_RGB;
 120       else if (strcmp(argv[i],"+ci")==0)
 121          ColorMode = GLUT_INDEX;
 122       else if (strcmp(argv[i],"-color")==0)
 123          BufferMask = 0;
 124       else if (strcmp(argv[i],"+depth")==0)
 125          BufferMask |= GL_DEPTH_BUFFER_BIT;
 126       else if (strcmp(argv[i],"+alpha")==0)
 127          ColorMode = GLUT_RGB | GLUT_ALPHA;
 128       else if (strcmp(argv[i],"+stencil")==0)
 129          BufferMask |= GL_STENCIL_BUFFER_BIT;
 130       else if (strcmp(argv[i],"+accum")==0)
 131          BufferMask |= GL_ACCUM_BUFFER_BIT;
 132       else if (strcmp(argv[i],"-width")==0) {
 133          Width = atoi(argv[i+1]);
 134          i++;
 135       }
 136       else if (strcmp(argv[i],"-height")==0) {
 137          Height = atoi(argv[i+1]);
 138          i++;
 139       }
 140       else if (strcmp(argv[i],"+swap")==0) {
 141          SwapFlag = GL_TRUE;
 142       }
 143       else if (strcmp(argv[i],"-swap")==0) {
 144          SwapFlag = GL_FALSE;
 145       }
 146       else
 147          printf("Unknown option: %s\n", argv[i]);
 148    }
 149
 150    if (ColorMode & GLUT_ALPHA)
 151       printf("Mode:  RGB + Alpha\n");
 152    else if (ColorMode==GLUT_RGB)
 153       printf("Mode:  RGB\n");
 154    else
 155       printf("Mode:  Color Index\n");
 156    printf("SwapBuffers: %s\n", SwapFlag ? "yes" : "no" );
 157    printf("Size: %d x %d\n", Width, Height);
 158    printf("Buffers: ");
 159    if (BufferMask & GL_COLOR_BUFFER_BIT)  printf("color ");
 160    if (BufferMask & GL_DEPTH_BUFFER_BIT)  printf("depth ");
 161    if (BufferMask & GL_STENCIL_BUFFER_BIT)  printf("stencil ");
 162    if (BufferMask & GL_ACCUM_BUFFER_BIT)  printf("accum ");
 163    printf("\n");
 164 }
 165
 166
 167 static void Help( const char *program )
 168 {
 169    printf("%s options:\n", program);
 170    printf("  +rgb       RGB mode\n");
 171    printf("  +ci        color index mode\n");
 172    printf("  -color     don't clear color buffer\n");
 173    printf("  +alpha     clear alpha buffer\n");
 174    printf("  +depth     clear depth buffer\n");
 175    printf("  +stencil   clear stencil buffer\n");
 176    printf("  +accum     clear accum buffer\n");
 177    printf("  +swap      also do SwapBuffers\n");
 178    printf("  -swap      don't do SwapBuffers\n");
 179 }
 180
 181
 182 int main( int argc, char *argv[] )
 183 {
 184    GLint mode;
 185
 186    printf("For options:  %s -help\n", argv[0]);
 187
 188    Init( argc, argv );
 189
 190    glutInitWindowSize( (int) Width, (int) Height );
 191    glutInit( &argc, argv );
 192
 193    mode = ColorMode | GLUT_DOUBLE;
 194    if (BufferMask & GL_STENCIL_BUFFER_BIT)
 195       mode |= GLUT_STENCIL;
 196    if (BufferMask & GL_ACCUM_BUFFER_BIT)
 197       mode |= GLUT_ACCUM;
 198    if (BufferMask & GL_DEPTH_BUFFER_BIT)
 199       mode |= GLUT_DEPTH;
 200
 201    glutInitDisplayMode(mode);
 202
 203    glutCreateWindow( argv[0] );
 204
 205    if (argc==2 && strcmp(argv[1],"-help")==0) {
 206       Help(argv[0]);
 207       return 0;
 208    }
 209
 210    glutReshapeFunc( Reshape );
 211    glutKeyboardFunc( Key );
 212    glutDisplayFunc( Display );
 213    glutIdleFunc( Idle );
 214
 215    glutMainLoop();
 216    return 0;
 217 }