progs/demos/drawpix.c

   1
   2 /*
   3  * glDrawPixels demo/test/benchmark
   4  *
   5  * Brian Paul   September 25, 1997  This file is in the public domain.
   6  */
   7
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <math.h>
  11 #include <GL/glut.h>
  12
  13 #include "readtex.c"
  14
  15 #define IMAGE_FILE "../images/girl.rgb"
  16
  17 static int ImgWidth, ImgHeight;
  18 static GLenum ImgFormat;
  19 static GLubyte *Image = NULL;
  20
  21 static int Xpos, Ypos;
  22 static int SkipPixels, SkipRows;
  23 static int DrawWidth, DrawHeight;
  24 static int Scissor = 0;
  25 static int Fog = 0;
  26 static GLfloat Zpos = -1.0;
  27 static float Xzoom, Yzoom;
  28 static GLboolean DrawFront = GL_FALSE;
  29 static GLboolean Dither = GL_TRUE;
  30
  31
  32 static void Reset( void )
  33 {
  34    Xpos = Ypos = 20;
  35    DrawWidth = ImgWidth;
  36    DrawHeight = ImgHeight;
  37    SkipPixels = SkipRows = 0;
  38    Scissor = 0;
  39    Fog = 0;
  40    Zpos = -1.0;
  41    Xzoom = Yzoom = 1.0;
  42 }
  43
  44
  45 static void Display( void )
  46 {
  47    glClear( GL_COLOR_BUFFER_BIT );
  48
  49 #if 0
  50    glRasterPos2i(Xpos, Ypos);
  51 #else
  52    /* This allows negative raster positions: */
  53    glRasterPos3f(0, 0, Zpos);
  54    glBitmap(0, 0, 0, 0, Xpos, Ypos, NULL);
  55 #endif
  56
  57    glPixelStorei(GL_UNPACK_SKIP_PIXELS, SkipPixels);
  58    glPixelStorei(GL_UNPACK_SKIP_ROWS, SkipRows);
  59
  60    glPixelZoom( Xzoom, Yzoom );
  61
  62    if (Scissor)
  63       glEnable(GL_SCISSOR_TEST);
  64
  65    if (Fog)
  66       glEnable(GL_FOG);
  67
  68    glDrawPixels(DrawWidth, DrawHeight, ImgFormat, GL_UNSIGNED_BYTE, Image);
  69
  70    glDisable(GL_SCISSOR_TEST);
  71    glDisable(GL_FOG);
  72
  73    if (!DrawFront)
  74       glutSwapBuffers();
  75 }
  76
  77
  78 static void Benchmark( void )
  79 {
  80    int startTime, endTime;
  81    int draws = 500;
  82    double seconds, pixelsPerSecond;
  83
  84    printf("Benchmarking...\n");
  85    /* GL set-up */
  86    glPixelStorei(GL_UNPACK_SKIP_PIXELS, SkipPixels);
  87    glPixelStorei(GL_UNPACK_SKIP_ROWS, SkipRows);
  88    glPixelZoom( Xzoom, Yzoom );
  89    if (Scissor)
  90       glEnable(GL_SCISSOR_TEST);
  91    if (Fog)
  92       glEnable(GL_FOG);
  93
  94    if (DrawFront)
  95       glDrawBuffer(GL_FRONT);
  96    else
  97       glDrawBuffer(GL_BACK);
  98
  99    /* Run timing test */
 100    draws = 0;
 101    startTime = glutGet(GLUT_ELAPSED_TIME);
 102    do {
 103       glDrawPixels(DrawWidth, DrawHeight, ImgFormat, GL_UNSIGNED_BYTE, Image);
 104       draws++;
 105       endTime = glutGet(GLUT_ELAPSED_TIME);
 106    } while (endTime - startTime < 4000);   /* 4 seconds */
 107
 108    /* GL clean-up */
 109    glDisable(GL_SCISSOR_TEST);
 110    glDisable(GL_FOG);
 111
 112    /* Results */
 113    seconds = (double) (endTime - startTime) / 1000.0;
 114    pixelsPerSecond = draws * DrawWidth * DrawHeight / seconds;
 115    printf("Result:  %d draws in %f seconds = %f pixels/sec\n",
 116           draws, seconds, pixelsPerSecond);
 117 }
 118
 119
 120 static void Reshape( int width, int height )
 121 {
 122    glViewport( 0, 0, width, height );
 123    glMatrixMode( GL_PROJECTION );
 124    glLoadIdentity();
 125    glOrtho( 0.0, width, 0.0, height, 0.0, 2.0 );
 126    glMatrixMode( GL_MODELVIEW );
 127    glLoadIdentity();
 128
 129    glScissor(width/4, height/4, width/2, height/2);
 130 }
 131
 132
 133 static void Key( unsigned char key, int x, int y )
 134 {
 135    (void) x;
 136    (void) y;
 137    switch (key) {
 138       case ' ':
 139          Reset();
 140          break;
 141       case 'd':
 142          Dither = !Dither;
 143          if (Dither)
 144             glEnable(GL_DITHER);
 145          else
 146             glDisable(GL_DITHER);
 147          break;
 148       case 'w':
 149          if (DrawWidth > 0)
 150             DrawWidth--;
 151          break;
 152       case 'W':
 153          DrawWidth++;
 154          break;
 155       case 'h':
 156          if (DrawHeight > 0)
 157             DrawHeight--;
 158          break;
 159       case 'H':
 160          DrawHeight++;
 161          break;
 162       case 'p':
 163          if (SkipPixels > 0)
 164              SkipPixels--;
 165          break;
 166       case 'P':
 167          SkipPixels++;
 168          break;
 169       case 'r':
 170          if (SkipRows > 0)
 171              SkipRows--;
 172          break;
 173       case 'R':
 174          SkipRows++;
 175          break;
 176       case 's':
 177          Scissor = !Scissor;
 178          break;
 179       case 'x':
 180          Xzoom -= 0.1;
 181          break;
 182       case 'X':
 183          Xzoom += 0.1;
 184          break;
 185       case 'y':
 186          Yzoom -= 0.1;
 187          break;
 188       case 'Y':
 189          Yzoom += 0.1;
 190          break;
 191       case 'z':
 192          Zpos -= 0.1;
 193          printf("RasterPos Z = %g\n", Zpos);
 194          break;
 195       case 'Z':
 196          Zpos += 0.1;
 197          printf("RasterPos Z = %g\n", Zpos);
 198          break;
 199       case 'b':
 200          Benchmark();
 201          break;
 202       case 'F':
 203          Fog = !Fog;
 204          printf("Fog %d\n", Fog);
 205          break;
 206       case 'f':
 207          DrawFront = !DrawFront;
 208          if (DrawFront)
 209             glDrawBuffer(GL_FRONT);
 210          else
 211             glDrawBuffer(GL_BACK);
 212          printf("glDrawBuffer(%s)\n", DrawFront ? "GL_FRONT" : "GL_BACK");
 213          break;
 214       case 27:
 215          exit(0);
 216          break;
 217    }
 218    glutPostRedisplay();
 219 }
 220
 221
 222 static void SpecialKey( int key, int x, int y )
 223 {
 224    (void) x;
 225    (void) y;
 226    switch (key) {
 227       case GLUT_KEY_UP:
 228          Ypos += 1;
 229          break;
 230       case GLUT_KEY_DOWN:
 231          Ypos -= 1;
 232          break;
 233       case GLUT_KEY_LEFT:
 234          Xpos -= 1;
 235          break;
 236       case GLUT_KEY_RIGHT:
 237          Xpos += 1;
 238          break;
 239    }
 240    glutPostRedisplay();
 241 }
 242
 243
 244 static void Init( GLboolean ciMode )
 245 {
 246    static const GLfloat fogColor[4] = {0, 1, 0, 0};
 247
 248    printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
 249    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 250
 251    Image = LoadRGBImage( IMAGE_FILE, &ImgWidth, &ImgHeight, &ImgFormat );
 252    if (!Image) {
 253       printf("Couldn't read %s\n", IMAGE_FILE);
 254       exit(0);
 255    }
 256
 257    if (ciMode) {
 258       /* Convert RGB image to grayscale */
 259       GLubyte *indexImage = (GLubyte *) malloc( ImgWidth * ImgHeight );
 260       GLint i;
 261       for (i=0; i<ImgWidth*ImgHeight; i++) {
 262          int gray = Image[i*3] + Image[i*3+1] + Image[i*3+2];
 263          indexImage[i] = gray / 3;
 264       }
 265       free(Image);
 266       Image = indexImage;
 267       ImgFormat = GL_COLOR_INDEX;
 268
 269       for (i=0;i<255;i++) {
 270          float g = i / 255.0;
 271          glutSetColor(i, g, g, g);
 272       }
 273    }
 274
 275    printf("Loaded %d by %d image\n", ImgWidth, ImgHeight );
 276
 277    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 278    glPixelStorei(GL_UNPACK_ROW_LENGTH, ImgWidth);
 279
 280    glFogi(GL_FOG_MODE, GL_LINEAR);
 281    glFogf(GL_FOG_START, 0);
 282    glFogf(GL_FOG_END, 2);
 283    glFogfv(GL_FOG_COLOR, fogColor);
 284
 285    Reset();
 286 }
 287
 288
 289 static void Usage(void)
 290 {
 291    printf("Keys:\n");
 292    printf("       SPACE  Reset Parameters\n");
 293    printf("     Up/Down  Move image up/down\n");
 294    printf("  Left/Right  Move image left/right\n");
 295    printf("           x  Decrease X-axis PixelZoom\n");
 296    printf("           X  Increase X-axis PixelZoom\n");
 297    printf("           y  Decrease Y-axis PixelZoom\n");
 298    printf("           Y  Increase Y-axis PixelZoom\n");
 299    printf("           w  Decrease glDrawPixels width*\n");
 300    printf("           W  Increase glDrawPixels width*\n");
 301    printf("           h  Decrease glDrawPixels height*\n");
 302    printf("           H  Increase glDrawPixels height*\n");
 303    printf("           p  Decrease GL_UNPACK_SKIP_PIXELS*\n");
 304    printf("           P  Increase GL_UNPACK_SKIP_PIXELS*\n");
 305    printf("           r  Decrease GL_UNPACK_SKIP_ROWS*\n");
 306    printf("           R  Increase GL_UNPACK_SKIP_ROWS*\n");
 307    printf("           s  Toggle GL_SCISSOR_TEST\n");
 308    printf("           F  Toggle GL_FOG\n");
 309    printf("           z  Decrease RasterPos Z\n");
 310    printf("           Z  Increase RasterPos Z\n");
 311
 312    printf("           f  Toggle front/back buffer drawing\n");
 313    printf("           b  Benchmark test\n");
 314    printf("         ESC  Exit\n");
 315    printf("* Warning: no limits are imposed on these parameters so it's\n");
 316    printf("  possible to cause a segfault if you go too far.\n");
 317 }
 318
 319
 320 int main( int argc, char *argv[] )
 321 {
 322    GLboolean ciMode = GL_FALSE;
 323
 324    if (argc > 1 && strcmp(argv[1], "-ci")==0) {
 325       ciMode = GL_TRUE;
 326    }
 327
 328    glutInit( &argc, argv );
 329    glutInitWindowPosition( 0, 0 );
 330    glutInitWindowSize( 500, 400 );
 331
 332    if (ciMode)
 333       glutInitDisplayMode( GLUT_INDEX | GLUT_DOUBLE );
 334    else
 335       glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE);
 336
 337    glutCreateWindow(argv[0]);
 338
 339    Init(ciMode);
 340    Usage();
 341
 342    glutReshapeFunc( Reshape );
 343    glutKeyboardFunc( Key );
 344    glutSpecialFunc( SpecialKey );
 345    glutDisplayFunc( Display );
 346
 347    glutMainLoop();
 348    return 0;
 349 }