progs/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_BGRA;
  36 static GLenum ReadType = GL_UNSIGNED_INT_8_8_8_8_REV;
  37
  38
  39
  40 static void
  41 CheckError(int line)
  42 {
  43    GLenum err = glGetError();
  44    if (err) {
  45       printf("GL Error 0x%x at line %d\n", (int) err, line);
  46    }
  47 }
  48
  49
  50 static void
  51 Reset( void )
  52 {
  53    APosX = 5;     APosY = 20;
  54    BPosX = APosX + ImgWidth + 5;   BPosY = 20;
  55    CPosX = BPosX + ImgWidth + 5;   CPosY = 20;
  56 }
  57
  58
  59 static void
  60 PrintString(const char *s)
  61 {
  62    while (*s) {
  63       glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
  64       s++;
  65    }
  66 }
  67
  68
  69 static void
  70 SetupPixelTransfer(GLboolean invert)
  71 {
  72    if (invert) {
  73       glPixelTransferf(GL_RED_SCALE, -1.0);
  74       glPixelTransferf(GL_RED_BIAS, 1.0);
  75       glPixelTransferf(GL_GREEN_SCALE, -1.0);
  76       glPixelTransferf(GL_GREEN_BIAS, 1.0);
  77       glPixelTransferf(GL_BLUE_SCALE, -1.0);
  78       glPixelTransferf(GL_BLUE_BIAS, 1.0);
  79    }
  80    else {
  81       glPixelTransferf(GL_RED_SCALE, 1.0);
  82       glPixelTransferf(GL_RED_BIAS, 0.0);
  83       glPixelTransferf(GL_GREEN_SCALE, 1.0);
  84       glPixelTransferf(GL_GREEN_BIAS, 0.0);
  85       glPixelTransferf(GL_BLUE_SCALE, 1.0);
  86       glPixelTransferf(GL_BLUE_BIAS, 0.0);
  87    }
  88 }
  89
  90
  91 static void
  92 Display( void )
  93 {
  94    glClearColor(.3, .3, .3, 1);
  95    glClear( GL_COLOR_BUFFER_BIT );
  96
  97    CheckError(__LINE__);
  98
  99    /** Unbind UNPACK pixel buffer before calling glBitmap */
 100    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, 0);
 101
 102    glRasterPos2i(5, ImgHeight+25);
 103    PrintString("f = toggle front/back  s = toggle scale/bias  b = benchmark");
 104
 105    glRasterPos2i(5, ImgHeight+40);
 106    PrintString("GL_EXT_pixel_buffer_object test");
 107
 108    /* draw original image */
 109    glRasterPos2i(APosX, 5);
 110    PrintString("Original");
 111    glRasterPos2i(APosX, APosY);
 112    glEnable(GL_DITHER);
 113    SetupPixelTransfer(GL_FALSE);
 114    /*** Draw from the DrawPBO */
 115    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, DrawPBO);
 116    glDrawPixels(ImgWidth, ImgHeight, ImgFormat, GL_UNSIGNED_BYTE, 0);
 117    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, 0);
 118
 119    CheckError(__LINE__);
 120
 121    /* do readpixels, drawpixels */
 122    glRasterPos2i(BPosX, 5);
 123    PrintString("Read/DrawPixels");
 124    SetupPixelTransfer(ScaleAndBias);
 125    /*** read into the Temp PBO */
 126    glBindBufferARB(GL_PIXEL_PACK_BUFFER_EXT, TempPBO);
 127    CheckError(__LINE__);
 128    if (Benchmark) {
 129       GLint reads = 0;
 130       GLint endTime;
 131       GLint startTime = glutGet(GLUT_ELAPSED_TIME);
 132       GLdouble seconds, pixelsPerSecond;
 133       printf("Benchmarking...\n");
 134       do {
 135          glReadPixels(APosX, APosY, ImgWidth, ImgHeight,
 136                       ReadFormat, ReadType, 0);
 137          reads++;
 138          endTime = glutGet(GLUT_ELAPSED_TIME);
 139       } while (endTime - startTime < 4000);   /* 4 seconds */
 140       seconds = (double) (endTime - startTime) / 1000.0;
 141       pixelsPerSecond = reads * ImgWidth * ImgHeight / seconds;
 142       printf("Result:  %d reads in %f seconds = %f pixels/sec\n",
 143              reads, seconds, pixelsPerSecond);
 144       Benchmark = GL_FALSE;
 145    }
 146    else {
 147       glReadPixels(APosX, APosY, ImgWidth, ImgHeight,
 148                    ReadFormat, ReadType, 0);
 149    }
 150    CheckError(__LINE__);
 151    glRasterPos2i(BPosX, BPosY);
 152    glDisable(GL_DITHER);
 153    SetupPixelTransfer(GL_FALSE);
 154
 155    CheckError(__LINE__);
 156
 157    /*** draw from the Temp PBO */
 158    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, TempPBO);
 159    glDrawPixels(ImgWidth, ImgHeight, ReadFormat, ReadType, 0);
 160    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, 0);
 161
 162    CheckError(__LINE__);
 163
 164    /* do copypixels */
 165    glRasterPos2i(CPosX, 5);
 166    PrintString("CopyPixels");
 167    glRasterPos2i(CPosX, CPosY);
 168    glDisable(GL_DITHER);
 169    SetupPixelTransfer(ScaleAndBias);
 170    glCopyPixels(APosX, APosY, ImgWidth, ImgHeight, GL_COLOR);
 171
 172    CheckError(__LINE__);
 173
 174    if (!DrawFront)
 175       glutSwapBuffers();
 176    else
 177       glFinish();
 178 }
 179
 180
 181 static void
 182 Reshape( int width, int height )
 183 {
 184    glViewport( 0, 0, width, height );
 185    glMatrixMode( GL_PROJECTION );
 186    glLoadIdentity();
 187    glOrtho( 0.0, width, 0.0, height, -1.0, 1.0 );
 188    glMatrixMode( GL_MODELVIEW );
 189    glLoadIdentity();
 190 }
 191
 192
 193 static void
 194 Key( unsigned char key, int x, int y )
 195 {
 196    (void) x;
 197    (void) y;
 198    switch (key) {
 199       case 'b':
 200          Benchmark = GL_TRUE;
 201          break;
 202       case 's':
 203          ScaleAndBias = !ScaleAndBias;
 204          break;
 205       case 'f':
 206          DrawFront = !DrawFront;
 207          if (DrawFront) {
 208             glDrawBuffer(GL_FRONT);
 209             glReadBuffer(GL_FRONT);
 210          }
 211          else {
 212             glDrawBuffer(GL_BACK);
 213             glReadBuffer(GL_BACK);
 214          }
 215          printf("glDrawBuffer(%s)\n", DrawFront ? "GL_FRONT" : "GL_BACK");
 216          break;
 217       case 27:
 218          exit(0);
 219          break;
 220    }
 221    glutPostRedisplay();
 222 }
 223
 224
 225 static void
 226 Init(void)
 227 {
 228    printf("GL_VERSION = %s\n", (char *) glGetString(GL_VERSION));
 229    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
 230
 231    if (!glutExtensionSupported("GL_EXT_pixel_buffer_object")) {
 232       printf("Sorry, this demo requires GL_EXT_pixel_buffer_object\n");
 233       exit(0);
 234    }
 235
 236    Image = LoadRGBImage( IMAGE_FILE, &ImgWidth, &ImgHeight, &ImgFormat );
 237    if (!Image) {
 238       printf("Couldn't read %s\n", IMAGE_FILE);
 239       exit(0);
 240    }
 241
 242    printf("Loaded %d by %d image\n", ImgWidth, ImgHeight );
 243
 244    if (ImgFormat == GL_RGB) {
 245       /* convert to RGBA */
 246       int i;
 247       GLubyte *image2 = (GLubyte *) malloc(ImgWidth * ImgHeight * 4);
 248       printf("Converting RGB image to RGBA\n");
 249       for (i = 0; i < ImgWidth * ImgHeight; i++) {
 250          image2[i*4+0] = Image[i*3+0];
 251          image2[i*4+1] = Image[i*3+1];
 252          image2[i*4+2] = Image[i*3+2];
 253          image2[i*4+3] = 255;
 254       }
 255       free(Image);
 256       Image = image2;
 257       ImgFormat = GL_RGBA;
 258    }
 259
 260    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 261    glPixelStorei(GL_UNPACK_ROW_LENGTH, ImgWidth);
 262    glPixelStorei(GL_PACK_ALIGNMENT, 1);
 263    glPixelStorei(GL_PACK_ROW_LENGTH, ImgWidth);
 264
 265    Reset();
 266
 267    /* put image into DrawPBO */
 268    glGenBuffersARB(1, &DrawPBO);
 269    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, DrawPBO);
 270    glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_EXT,
 271                    ImgWidth * ImgHeight * 4, Image, GL_STATIC_DRAW);
 272
 273    /* Setup TempPBO - used for glReadPixels & glDrawPixels */
 274    glGenBuffersARB(1, &TempPBO);
 275    glBindBufferARB(GL_PIXEL_PACK_BUFFER_EXT, TempPBO);
 276    glBufferDataARB(GL_PIXEL_PACK_BUFFER_EXT,
 277                    ImgWidth * ImgHeight * 4, NULL, GL_DYNAMIC_COPY);
 278
 279 }
 280
 281
 282 int
 283 main( int argc, char *argv[] )
 284 {
 285    glutInit( &argc, argv );
 286    glutInitWindowPosition( 0, 0 );
 287    glutInitWindowSize( 750, 250 );
 288    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 289    glutCreateWindow(argv[0]);
 290    Init();
 291    glutReshapeFunc( Reshape );
 292    glutKeyboardFunc( Key );
 293    glutDisplayFunc( Display );
 294    glutMainLoop();
 295    return 0;
 296 }