progs/demos/clearspd.c

   1 /* $Id: clearspd.c,v 1.1 1999/08/19 00:55:40 jtg 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  * $Log: clearspd.c,v $
  10  * Revision 1.1  1999/08/19 00:55:40  jtg
  11  * Initial revision
  12  *
  13  * Revision 3.3  1999/03/28 18:18:33  brianp
  14  * minor clean-up
  15  *
  16  * Revision 3.2  1999/03/18 08:16:34  joukj
  17  *
  18  *     cmpstr needs string.h to included to avoid warnings
  19  *
  20  * Revision 3.1  1998/06/29 02:38:30  brianp
  21  * removed unneeded includes
  22  *
  23  * Revision 3.0  1998/02/14 18:42:29  brianp
  24  * initial rev
  25  *
  26  */
  27
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <math.h>
  32 #include <string.h>
  33 #include <GL/glut.h>
  34
  35
  36 static float MinPeriod = 2.0;   /* 2 seconds */
  37 static int ColorMode = GLUT_RGB;
  38 static int Width = 400.0;
  39 static int Height = 400.0;
  40 static int Loops = 100;
  41 static float ClearColor = 0.0;
  42 static GLbitfield BufferMask = GL_COLOR_BUFFER_BIT;
  43 static GLboolean SwapFlag = GL_FALSE;
  44
  45
  46
  47 static void Idle( void )
  48 {
  49    glutPostRedisplay();
  50 }
  51
  52
  53 static void Display( void )
  54 {
  55    double t0, t1;
  56    double clearRate;
  57    double pixelRate;
  58    int i;
  59
  60    glClearColor( ClearColor, ClearColor, ClearColor, 0.0 );
  61    ClearColor += 0.1;
  62    if (ClearColor>1.0)
  63       ClearColor = 0.0;
  64
  65    if (SwapFlag) {
  66       t0 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  67       for (i=0;i<Loops;i++) {
  68          glClear( BufferMask );
  69          glutSwapBuffers();
  70       }
  71       t1 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  72    }
  73    else {
  74       t0 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  75       for (i=0;i<Loops;i++) {
  76          glClear( BufferMask );
  77       }
  78       t1 = glutGet(GLUT_ELAPSED_TIME) * 0.001;
  79       glutSwapBuffers();
  80    }
  81
  82    if (t1-t0 < MinPeriod) {
  83       /* Next time do more clears to get longer elapsed time */
  84       Loops *= 2;
  85       return;
  86    }
  87
  88    clearRate = Loops / (t1-t0);
  89    pixelRate = clearRate * Width * Height;
  90    if (SwapFlag) {
  91       printf("Rate: %d clears+swaps in %gs = %g clears+swaps/s   %d pixels/s\n",
  92              Loops, t1-t0, clearRate, (int)pixelRate );
  93    }
  94    else {
  95       printf("Rate: %d clears in %gs = %g clears/s   %d pixels/s\n",
  96              Loops, t1-t0, clearRate, (int)pixelRate);
  97    }
  98 }
  99
 100
 101 static void Reshape( int width, int height )
 102 {
 103    Width = width;
 104    Height = height;
 105    glViewport( 0, 0, width, height );
 106    glMatrixMode( GL_PROJECTION );
 107    glLoadIdentity();
 108    glOrtho(0.0, width, 0.0, height, -1.0, 1.0);
 109    glMatrixMode( GL_MODELVIEW );
 110    glLoadIdentity();
 111 }
 112
 113
 114 static void Key( unsigned char key, int x, int y )
 115 {
 116    (void) x;
 117    (void) y;
 118    switch (key) {
 119       case 27:
 120          exit(0);
 121          break;
 122    }
 123    glutPostRedisplay();
 124 }
 125
 126
 127 static void Init( int argc, char *argv[] )
 128 {
 129    int i;
 130    for (i=1; i<argc; i++) {
 131       if (strcmp(argv[i],"+rgb")==0)
 132          ColorMode = GLUT_RGB;
 133       else if (strcmp(argv[i],"+ci")==0)
 134          ColorMode = GLUT_INDEX;
 135       else if (strcmp(argv[i],"-color")==0)
 136          BufferMask = 0;
 137       else if (strcmp(argv[i],"+depth")==0)
 138          BufferMask |= GL_DEPTH_BUFFER_BIT;
 139       else if (strcmp(argv[i],"+alpha")==0)
 140          ColorMode = GLUT_RGB | GLUT_ALPHA;
 141       else if (strcmp(argv[i],"+stencil")==0)
 142          BufferMask |= GL_STENCIL_BUFFER_BIT;
 143       else if (strcmp(argv[i],"+accum")==0)
 144          BufferMask |= GL_ACCUM_BUFFER_BIT;
 145       else if (strcmp(argv[i],"-width")==0) {
 146          Width = atoi(argv[i+1]);
 147          i++;
 148       }
 149       else if (strcmp(argv[i],"-height")==0) {
 150          Height = atoi(argv[i+1]);
 151          i++;
 152       }
 153       else if (strcmp(argv[i],"+swap")==0) {
 154          SwapFlag = GL_TRUE;
 155       }
 156       else if (strcmp(argv[i],"-swap")==0) {
 157          SwapFlag = GL_FALSE;
 158       }
 159       else
 160          printf("Unknown option: %s\n", argv[i]);
 161    }
 162
 163    if (ColorMode & GLUT_ALPHA)
 164       printf("Mode:  RGB + Alpha\n");
 165    else if (ColorMode==GLUT_RGB)
 166       printf("Mode:  RGB\n");
 167    else
 168       printf("Mode:  Color Index\n");
 169    printf("SwapBuffers: %s\n", SwapFlag ? "yes" : "no" );
 170    printf("Size: %d x %d\n", Width, Height);
 171    printf("Buffers: ");
 172    if (BufferMask & GL_COLOR_BUFFER_BIT)  printf("color ");
 173    if (BufferMask & GL_DEPTH_BUFFER_BIT)  printf("depth ");
 174    if (BufferMask & GL_STENCIL_BUFFER_BIT)  printf("stencil ");
 175    if (BufferMask & GL_ACCUM_BUFFER_BIT)  printf("accum ");
 176    printf("\n");
 177 }
 178
 179
 180 static void Help( const char *program )
 181 {
 182    printf("%s options:\n", program);
 183    printf("  +rgb       RGB mode\n");
 184    printf("  +ci        color index mode\n");
 185    printf("  -color     don't clear color buffer\n");
 186    printf("  +alpha     clear alpha buffer\n");
 187    printf("  +depth     clear depth buffer\n");
 188    printf("  +stencil   clear stencil buffer\n");
 189    printf("  +accum     clear accum buffer\n");
 190    printf("  +swap      also do SwapBuffers\n");
 191    printf("  -swap      don't do SwapBuffers\n");
 192 }
 193
 194
 195 int main( int argc, char *argv[] )
 196 {
 197    printf("For options:  %s -help\n", argv[0]);
 198
 199    Init( argc, argv );
 200
 201    glutInit( &argc, argv );
 202    glutInitWindowSize( (int) Width, (int) Height );
 203    glutInitWindowPosition( 0, 0 );
 204
 205    glutInitDisplayMode( ColorMode | GLUT_DOUBLE | GLUT_DEPTH | GLUT_STENCIL | GLUT_ACCUM );
 206
 207    glutCreateWindow( argv[0] );
 208
 209    if (argc==2 && strcmp(argv[1],"-help")==0) {
 210       Help(argv[0]);
 211       return 0;
 212    }
 213
 214    glutReshapeFunc( Reshape );
 215    glutKeyboardFunc( Key );
 216    glutDisplayFunc( Display );
 217    glutIdleFunc( Idle );
 218
 219    glutMainLoop();
 220    return 0;
 221 }