progs/demos/streaming_rect.c

   1
   2 /*
   3  * GL_ARB_multitexture demo
   4  *
   5  * Command line options:
   6  *    -info      print GL implementation information
   7  *
   8  *
   9  * Brian Paul  November 1998  This program is in the public domain.
  10  * Modified on 12 Feb 2002 for > 2 texture units.
  11  */
  12
  13 #define GL_GLEXT_PROTOTYPES
  14
  15 #include <math.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <GL/glut.h>
  20
  21 #include "readtex.h"
  22
  23
  24 #define ANIMATE 10
  25 #define PBO 11
  26 #define QUIT 100
  27
  28 static GLboolean Animate = GL_TRUE;
  29 static GLboolean use_pbo = 1;
  30 static GLboolean whole_rect = 1;
  31
  32 static GLfloat Drift = 0.0;
  33 static GLfloat drift_increment = 1/255.0;
  34 static GLfloat Xrot = 20.0, Yrot = 30.0;
  35
  36 static GLuint Width = 1024;
  37 static GLuint Height = 512;
  38
  39
  40 static void Idle( void )
  41 {
  42    if (Animate) {
  43
  44       Drift += drift_increment;
  45       if (Drift >= 1.0)
  46          Drift = 0.0;
  47
  48       glutPostRedisplay();
  49    }
  50 }
  51
  52 static int max( int a, int b ) { return a > b ? a : b; }
  53 static int min( int a, int b ) { return a < b ? a : b; }
  54
  55 static void DrawObject()
  56 {
  57    GLint size = Width * Height * 4;
  58
  59    if (use_pbo) {
  60       /* XXX: This is extremely important - semantically makes the buffer
  61        * contents undefined, but in practice means that the driver can
  62        * release the old copy of the texture and allocate a new one
  63        * without waiting for outstanding rendering to complete.
  64        */
  65       glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_EXT, size, NULL, GL_STREAM_DRAW_ARB);
  66
  67       {
  68          char *image = glMapBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, GL_WRITE_ONLY_ARB);
  69
  70          printf("char %d\n", (unsigned char)(Drift * 255));
  71
  72          memset(image, size, (unsigned char)(Drift * 255));
  73
  74          glUnmapBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT);
  75       }
  76
  77
  78       /* BGRA is required for most hardware paths:
  79        */
  80       glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, Width, Height, 0,
  81                    GL_BGRA, GL_UNSIGNED_BYTE, NULL);
  82    }
  83    else {
  84       static char *image = NULL;
  85
  86       if (image == NULL)
  87          image = malloc(size);
  88
  89       memset(image, size, (unsigned char)(Drift * 255));
  90
  91       /* BGRA should be the fast path for regular uploads as well.
  92        */
  93       glTexImage2D(GL_TEXTURE_RECTANGLE_ARB, 0, GL_RGBA, Width, Height, 0,
  94                    GL_BGRA, GL_UNSIGNED_BYTE, image);
  95    }
  96
  97    {
  98       int x,y,w,h;
  99
 100       if (whole_rect) {
 101          x = y = 0;
 102          w = Width;
 103          h = Height;
 104       }
 105       else {
 106          x = y = 0;
 107          w = min(10, Width);
 108          h = min(10, Height);
 109       }
 110
 111       glBegin(GL_QUADS);
 112
 113       glTexCoord2f( x, y);
 114       glVertex2f( x, y );
 115
 116       glTexCoord2f( x, y + h);
 117       glVertex2f( x, y + h);
 118
 119       glTexCoord2f( x + w + .5, y + h);
 120       glVertex2f( x + w, y + h );
 121
 122       glTexCoord2f( x + w, y + .5);
 123       glVertex2f( x + w, y );
 124
 125       glEnd();
 126    }
 127 }
 128
 129
 130
 131 static void Display( void )
 132 {
 133    static GLint T0 = 0;
 134    static GLint Frames = 0;
 135    GLint t;
 136
 137    glClear( GL_COLOR_BUFFER_BIT );
 138
 139    glPushMatrix();
 140       DrawObject();
 141    glPopMatrix();
 142
 143    glutSwapBuffers();
 144
 145    Frames++;
 146
 147    t = glutGet(GLUT_ELAPSED_TIME);
 148    if (t - T0 >= 1000) {
 149       GLfloat seconds = (t - T0) / 1000.0;
 150
 151       GLfloat fps = Frames / seconds;
 152       printf("%d frames in %6.3f seconds = %6.3f FPS\n", Frames, seconds, fps);
 153
 154       drift_increment = 2.2 * seconds / Frames;
 155       T0 = t;
 156       Frames = 0;
 157    }
 158 }
 159
 160
 161 static void Reshape( int width, int height )
 162 {
 163    glViewport( 0, 0, width, height );
 164    glMatrixMode( GL_PROJECTION );
 165    glLoadIdentity();
 166 /*    glFrustum( -1.0, 1.0, -1.0, 1.0, 10.0, 100.0 ); */
 167    gluOrtho2D( 0, width, height, 0 );
 168    glMatrixMode( GL_MODELVIEW );
 169    glLoadIdentity();
 170    glTranslatef(0.375, 0.375, 0);
 171 }
 172
 173
 174 static void ModeMenu(int entry)
 175 {
 176    if (entry==ANIMATE) {
 177       Animate = !Animate;
 178    }
 179    else if (entry==PBO) {
 180       use_pbo = !use_pbo;
 181    }
 182    else if (entry==QUIT) {
 183       exit(0);
 184    }
 185
 186    glutPostRedisplay();
 187 }
 188
 189
 190 static void Key( unsigned char key, int x, int y )
 191 {
 192    (void) x;
 193    (void) y;
 194    switch (key) {
 195       case 27:
 196          exit(0);
 197          break;
 198    }
 199    glutPostRedisplay();
 200 }
 201
 202
 203 static void SpecialKey( int key, int x, int y )
 204 {
 205    float step = 3.0;
 206    (void) x;
 207    (void) y;
 208
 209    switch (key) {
 210       case GLUT_KEY_UP:
 211          Xrot += step;
 212          break;
 213       case GLUT_KEY_DOWN:
 214          Xrot -= step;
 215          break;
 216       case GLUT_KEY_LEFT:
 217          Yrot += step;
 218          break;
 219       case GLUT_KEY_RIGHT:
 220          Yrot -= step;
 221          break;
 222    }
 223    glutPostRedisplay();
 224 }
 225
 226
 227 static void Init( int argc, char *argv[] )
 228 {
 229    const char *exten = (const char *) glGetString(GL_EXTENSIONS);
 230    GLuint texObj, DrawPBO;
 231    GLint size;
 232
 233
 234    if (!strstr(exten, "GL_ARB_multitexture")) {
 235       printf("Sorry, GL_ARB_multitexture not supported by this renderer.\n");
 236       exit(1);
 237    }
 238
 239    glGetIntegerv(GL_MAX_TEXTURE_SIZE, &size);
 240    printf("%d x %d max texture size\n", size, size);
 241
 242    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 243
 244    /* allocate two texture objects */
 245    glGenTextures(1, &texObj);
 246
 247    /* setup the texture objects */
 248    glActiveTextureARB(GL_TEXTURE0_ARB);
 249    glBindTexture(GL_TEXTURE_RECTANGLE_ARB, texObj);
 250
 251    glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 252    glTexParameteri(GL_TEXTURE_RECTANGLE_ARB, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 253
 254    glGenBuffersARB(1, &DrawPBO);
 255
 256    glBindBufferARB(GL_PIXEL_UNPACK_BUFFER_EXT, DrawPBO);
 257    glBufferDataARB(GL_PIXEL_UNPACK_BUFFER_EXT,
 258                    Width * Height * 4, NULL, GL_STREAM_DRAW);
 259
 260    glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
 261
 262    glEnable(GL_TEXTURE_RECTANGLE_ARB);
 263
 264    glShadeModel(GL_SMOOTH);
 265    glClearColor(0.3, 0.3, 0.4, 1.0);
 266
 267    if (argc > 1 && strcmp(argv[1], "-info")==0) {
 268       printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
 269       printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
 270       printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
 271       printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
 272    }
 273 }
 274
 275
 276 int main( int argc, char *argv[] )
 277 {
 278    GLint i;
 279
 280    glutInit( &argc, argv );
 281
 282    for (i = 1; i < argc; i++) {
 283       if (strcmp(argv[i], "-w") == 0) {
 284          Width = atoi(argv[i+1]);
 285          if (Width <= 0) {
 286             printf("Error, bad width\n");
 287             exit(1);
 288          }
 289          i++;
 290       }
 291       else if (strcmp(argv[i], "-h") == 0) {
 292          Height = atoi(argv[i+1]);
 293          if (Height <= 0) {
 294             printf("Error, bad height\n");
 295             exit(1);
 296          }
 297          i++;
 298       }
 299    }
 300
 301    glutInitWindowSize( Width, Height );
 302    glutInitWindowPosition( 0, 0 );
 303    glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
 304    glutCreateWindow(argv[0] );
 305
 306    Init( argc, argv );
 307
 308    glutReshapeFunc( Reshape );
 309    glutKeyboardFunc( Key );
 310    glutSpecialFunc( SpecialKey );
 311    glutDisplayFunc( Display );
 312    glutIdleFunc( Idle );
 313
 314    glutCreateMenu(ModeMenu);
 315    glutAddMenuEntry("Toggle Animation", ANIMATE);
 316    glutAddMenuEntry("Toggle PBO", PBO);
 317    glutAddMenuEntry("Quit", QUIT);
 318    glutAttachMenu(GLUT_RIGHT_BUTTON);
 319
 320    glutMainLoop();
 321    return 0;
 322 }