src/tests/pbo.c

   1 /*
   2  * GL_EXT_pixel_buffer_object test
   3  *
   4  * Brian Paul
   5  * 11 March 2004
   6  */
   7
   8 #define GL_GLEXT_PROTOTYPES
   9
  10 #include <assert.h>
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <math.h>
  14 #include <GL/glut.h>
  15
  16 #include "../util/readtex.c"  /* a hack, I know */
  17
  18 #define IMAGE_FILE "../images/girl.rgb"
  19
  20 static int ImgWidth, ImgHeight;
  21 static GLenum ImgFormat;
  22 static GLubyte *Image = NULL;
  23
  24 static int APosX, APosY;  /* simple drawpixels */
  25 static int BPosX, BPosY;  /* read/draw pixels */
  26 static int CPosX, CPosY;  /* copypixels */
  27
  28 static GLboolean DrawFront = GL_FALSE;
  29 static GLboolean ScaleAndBias = GL_FALSE;
  30 static GLboolean Benchmark = GL_FALSE;
  31
  32 static GLuint DrawPBO, TempPBO;
  33
  34
  35 static GLenum ReadFormat = GL_RGBA;
  36 static GLenum ReadType = GL_UNSIGNED_BYTE;
  37
  38
  39
  40
  41 static void
  42 Reset( void )
  43 {
  44    APosX = 5;     APosY = 20;
  45    BPosX = APosX + ImgWidth + 5;   BPosY = 20;
  46    CPosX = BPosX + ImgWidth + 5;   CPosY = 20;
  47 }
  48
  49
  50 static void
  51 PrintString(const char *s)
  52 {
  53    while (*s) {
  54       glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
  55       s++;
  56    }
  57 }
  58
  59
  60 static void
  61 SetupPixelTransfer(GLboolean invert)
  62 {
  63    if (invert) {
  64       glPixelTransferf(GL_RED_SCALE, -1.0);
  65       glPixelTransferf(GL_RED_BIAS, 1.0);
  66       glPixelTransferf(GL_GREEN_SCALE, -1.0);
  67       glPixelTransferf(GL_GREEN_BIAS, 1.0);
  68       glPixelTransferf(GL_BLUE_SCALE, -1.0);
  69       glPixelTransferf(GL_BLUE_BIAS, 1.0);
  70    }
  71    else {
  72       glPixelTransferf(GL_RED_SCALE, 1.0);
  73       glPixelTransferf(GL_RED_BIAS, 0.0);
  74       glPixelTransferf(GL_GREEN_SCALE, 1.0);
  75       glPixelTransferf(GL_GREEN_BIAS, 0.0);
  76       glPixelTransferf(GL_BLUE_SCALE, 1.0);
  77       glPixelTransferf(GL_BLUE_BIAS, 0.0);
  78    }
  79 }
  80
  81
  82 static void
  83 Display( void )
  84 {
  85    glClearColor(.3, .3, .3, 1);
  86    glClear( GL_COLOR_BUFFER_BIT );
  87
  88    /** Unbind UNPACK pixel buffer before calling glBitmap */
  89    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, 0);
  90
  91    glRasterPos2i(5, ImgHeight+25);
  92    PrintString("f = toggle front/back  s = toggle scale/bias  b = benchmark");
  93
  94    glRasterPos2i(5, ImgHeight+40);
  95    PrintString("GL_EXT_pixel_buffer_object test");
  96
  97    /* draw original image */
  98    glRasterPos2i(APosX, 5);
  99    PrintString("Original");
 100    glRasterPos2i(APosX, APosY);
 101    glEnable(GL_DITHER);
 102    SetupPixelTransfer(GL_FALSE);
 103    /*** Draw from the DrawPBO */
 104    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, DrawPBO);
 105    glDrawPixels(ImgWidth, ImgHeight, ImgFormat, GL_UNSIGNED_BYTE, 0);
 106    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, 0);
 107
 108    /* do readpixels, drawpixels */
 109    glRasterPos2i(BPosX, 5);
 110    PrintString("Read/DrawPixels");
 111    SetupPixelTransfer(ScaleAndBias);
 112    /*** read into the Temp PBO */
 113    glBindBufferARB(GL_PIXEL_PACK_BUFFER_EXT, TempPBO);
 114    if (Benchmark) {
 115       GLint reads = 0;
 116       GLint endTime;
 117       GLint startTime = glutGet(GLUT_ELAPSED_TIME);
 118       GLdouble seconds, pixelsPerSecond;
 119       printf("Benchmarking...\n");
 120       do {
 121          glReadPixels(APosX, APosY, ImgWidth, ImgHeight,
 122                       ReadFormat, ReadType, 0);
 123          reads++;
 124          endTime = glutGet(GLUT_ELAPSED_TIME);
 125       } while (endTime - startTime < 4000);   /* 4 seconds */
 126       seconds = (double) (endTime - startTime) / 1000.0;
 127       pixelsPerSecond = reads * ImgWidth * ImgHeight / seconds;
 128       printf("Result:  %d reads in %f seconds = %f pixels/sec\n",
 129              reads, seconds, pixelsPerSecond);
 130       Benchmark = GL_FALSE;
 131    }
 132    else {
 133       glReadPixels(APosX, APosY, ImgWidth, ImgHeight,
 134                    ReadFormat, ReadType, 0);
 135    }
 136    glRasterPos2i(BPosX, BPosY);
 137    glDisable(GL_DITHER);
 138    SetupPixelTransfer(GL_FALSE);
 139    /*** draw from the Temp PBO */
 140    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, TempPBO);
 141    glDrawPixels(ImgWidth, ImgHeight, ReadFormat, ReadType, 0);
 142    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, 0);
 143
 144    /* do copypixels */
 145    glRasterPos2i(CPosX, 5);
 146    PrintString("CopyPixels");
 147    glRasterPos2i(CPosX, CPosY);
 148    glDisable(GL_DITHER);
 149    SetupPixelTransfer(ScaleAndBias);
 150    glCopyPixels(APosX, APosY, ImgWidth, ImgHeight, GL_COLOR);
 151
 152    if (!DrawFront)
 153       glutSwapBuffers();
 154    else
 155       glFinish();
 156 }
 157
 158
 159 static void
 160 Reshape( int width, int height )
 161 {
 162    glViewport( 0, 0, width, height );
 163    glMatrixMode( GL_PROJECTION );
 164    glLoadIdentity();
 165    glOrtho( 0.0, width, 0.0, height, -1.0, 1.0 );
 166    glMatrixMode( GL_MODELVIEW );
 167    glLoadIdentity();
 168 }
 169
 170
 171 static void
 172 Key( unsigned char key, int x, int y )
 173 {
 174    (void) x;
 175    (void) y;
 176    switch (key) {
 177       case 'b':
 178          Benchmark = GL_TRUE;
 179          break;
 180       case 's':
 181          ScaleAndBias = !ScaleAndBias;
 182          break;
 183       case 'f':
 184          DrawFront = !DrawFront;
 185          if (DrawFront) {
 186             glDrawBuffer(GL_FRONT);
 187             glReadBuffer(GL_FRONT);
 188          }
 189          else {
 190             glDrawBuffer(GL_BACK);
 191             glReadBuffer(GL_BACK);
 192          }
 193          printf("glDrawBuffer(%s)\n", DrawFront ? "GL_FRONT" : "GL_BACK");
 194          break;
 195       case 27:
 196          exit(0);
 197          break;
 198    }
 199    glutPostRedisplay();
 200 }
 201
 202
 203 static void
 204 Init( GLboolean ciMode )
 205 {
 206    printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
 207    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 208
 209    if (!glutExtensionSupported("GL_EXT_pixel_buffer_object")) {
 210       printf("Sorry, this demo requires GL_EXT_pixel_buffer_object\n");
 211       exit(0);
 212    }
 213
 214    Image = LoadRGBImage( IMAGE_FILE, &ImgWidth, &ImgHeight, &ImgFormat );
 215    if (!Image) {
 216       printf("Couldn't read %s\n", IMAGE_FILE);
 217       exit(0);
 218    }
 219
 220    if (ciMode) {
 221       /* Convert RGB image to grayscale */
 222       GLubyte *indexImage = (GLubyte *) malloc( ImgWidth * ImgHeight );
 223       GLint i;
 224       for (i=0; i<ImgWidth*ImgHeight; i++) {
 225          int gray = Image[i*3] + Image[i*3+1] + Image[i*3+2];
 226          indexImage[i] = gray / 3;
 227       }
 228       free(Image);
 229       Image = indexImage;
 230       ImgFormat = GL_COLOR_INDEX;
 231
 232       for (i=0;i<255;i++) {
 233          float g = i / 255.0;
 234          glutSetColor(i, g, g, g);
 235       }
 236    }
 237
 238    printf("Loaded %d by %d image\n", ImgWidth, ImgHeight );
 239
 240    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 241    glPixelStorei(GL_UNPACK_ROW_LENGTH, ImgWidth);
 242    glPixelStorei(GL_PACK_ALIGNMENT, 1);
 243    glPixelStorei(GL_PACK_ROW_LENGTH, ImgWidth);
 244
 245    Reset();
 246
 247    /* put image into DrawPBO */
 248    glGenBuffersARB(1, &DrawPBO);
 249    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, DrawPBO);
 250    glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_EXT,
 251                    ImgWidth * ImgHeight * 4, Image, GL_STATIC_DRAW);
 252
 253    /* Setup TempPBO - used for glReadPixels & glDrawPixels */
 254    glGenBuffersARB(1, &TempPBO);
 255    glBindBufferARB(GL_PIXEL_PACK_BUFFER_EXT, TempPBO);
 256    glBufferDataARB(GL_PIXEL_PACK_BUFFER_EXT,
 257                    ImgWidth * ImgHeight * 4, NULL, GL_DYNAMIC_COPY);
 258
 259 }
 260
 261
 262 int
 263 main( int argc, char *argv[] )
 264 {
 265    GLboolean ciMode = GL_FALSE;
 266    if (argc > 1 && strcmp(argv[1], "-ci")==0) {
 267       ciMode = GL_TRUE;
 268    }
 269    glutInit( &argc, argv );
 270    glutInitWindowPosition( 0, 0 );
 271    glutInitWindowSize( 750, 250 );
 272    if (ciMode)
 273       glutInitDisplayMode( GLUT_INDEX | GLUT_DOUBLE );
 274    else
 275       glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 276    glutCreateWindow(argv[0]);
 277    Init(ciMode);
 278    glutReshapeFunc( Reshape );
 279    glutKeyboardFunc( Key );
 280    glutDisplayFunc( Display );
 281    glutMainLoop();
 282    return 0;
 283 }