src/xdemos/glxgears_fbconfig.c

   1 /*
   2  * Copyright (C) 1999-2001  Brian Paul   All Rights Reserved.
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice shall be included
  12  * in all copies or substantial portions of the Software.
  13  *
  14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  15  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  18  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  19  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  20  */
  21
  22 /**
  23  * \file glxgears_fbconfig.c
  24  * Yet-another-version of gears.  Originally ported to GLX by Brian Paul on
  25  * 23 March 2001.  Modified to use fbconfigs by Ian Romanick on 10 Feb 2004.
  26  *
  27  * Command line options:
  28  *    -info      print GL implementation information
  29  *
  30  * \author Brian Paul
  31  * \author Ian Romanick <idr@us.ibm.com>
  32  */
  33
  34
  35 #define GLX_GLXEXT_PROTOTYPES
  36
  37 #include <math.h>
  38 #include <stdlib.h>
  39 #include <stdio.h>
  40 #include <string.h>
  41 #include <X11/Xlib.h>
  42 #include <X11/keysym.h>
  43 #include <GL/gl.h>
  44 #include <GL/glx.h>
  45 #include <GL/glxext.h>
  46 #include <assert.h>
  47 #include "pbutil.h"
  48
  49 static PFNGLXCHOOSEFBCONFIGPROC choose_fbconfig = NULL;
  50 static PFNGLXGETVISUALFROMFBCONFIGPROC get_visual_from_fbconfig = NULL;
  51 static PFNGLXCREATENEWCONTEXTPROC create_new_context = NULL;
  52 static PFNGLXCREATEWINDOWPROC create_window = NULL;
  53 static PFNGLXDESTROYWINDOWPROC destroy_window = NULL;
  54
  55 #define BENCHMARK
  56
  57 #ifdef BENCHMARK
  58
  59 /* XXX this probably isn't very portable */
  60
  61 #include <sys/time.h>
  62 #include <unistd.h>
  63
  64 /* return current time (in seconds) */
  65 static int
  66 current_time(void)
  67 {
  68    struct timeval tv;
  69 #ifdef __VMS
  70    (void) gettimeofday(&tv, NULL );
  71 #else
  72    struct timezone tz;
  73    (void) gettimeofday(&tv, &tz);
  74 #endif
  75    return (int) tv.tv_sec;
  76 }
  77
  78 #else /*BENCHMARK*/
  79
  80 /* dummy */
  81 static int
  82 current_time(void)
  83 {
  84    return 0;
  85 }
  86
  87 #endif /*BENCHMARK*/
  88
  89
  90
  91 #ifndef M_PI
  92 #define M_PI 3.14159265
  93 #endif
  94
  95
  96 static GLfloat view_rotx = 20.0, view_roty = 30.0, view_rotz = 0.0;
  97 static GLint gear1, gear2, gear3;
  98 static GLfloat angle = 0.0;
  99
 100
 101 /*
 102  *
 103  *  Draw a gear wheel.  You'll probably want to call this function when
 104  *  building a display list since we do a lot of trig here.
 105  *
 106  *  Input:  inner_radius - radius of hole at center
 107  *          outer_radius - radius at center of teeth
 108  *          width - width of gear
 109  *          teeth - number of teeth
 110  *          tooth_depth - depth of tooth
 111  */
 112 static void
 113 gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
 114      GLint teeth, GLfloat tooth_depth)
 115 {
 116    GLint i;
 117    GLfloat r0, r1, r2;
 118    GLfloat angle, da;
 119    GLfloat u, v, len;
 120
 121    r0 = inner_radius;
 122    r1 = outer_radius - tooth_depth / 2.0;
 123    r2 = outer_radius + tooth_depth / 2.0;
 124
 125    da = 2.0 * M_PI / teeth / 4.0;
 126
 127    glShadeModel(GL_FLAT);
 128
 129    glNormal3f(0.0, 0.0, 1.0);
 130
 131    /* draw front face */
 132    glBegin(GL_QUAD_STRIP);
 133    for (i = 0; i <= teeth; i++) {
 134       angle = i * 2.0 * M_PI / teeth;
 135       glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
 136       glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
 137       if (i < teeth) {
 138          glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
 139          glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
 140                     width * 0.5);
 141       }
 142    }
 143    glEnd();
 144
 145    /* draw front sides of teeth */
 146    glBegin(GL_QUADS);
 147    da = 2.0 * M_PI / teeth / 4.0;
 148    for (i = 0; i < teeth; i++) {
 149       angle = i * 2.0 * M_PI / teeth;
 150
 151       glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
 152       glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
 153       glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
 154                  width * 0.5);
 155       glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
 156                  width * 0.5);
 157    }
 158    glEnd();
 159
 160    glNormal3f(0.0, 0.0, -1.0);
 161
 162    /* draw back face */
 163    glBegin(GL_QUAD_STRIP);
 164    for (i = 0; i <= teeth; i++) {
 165       angle = i * 2.0 * M_PI / teeth;
 166       glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
 167       glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
 168       if (i < teeth) {
 169          glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
 170                     -width * 0.5);
 171          glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
 172       }
 173    }
 174    glEnd();
 175
 176    /* draw back sides of teeth */
 177    glBegin(GL_QUADS);
 178    da = 2.0 * M_PI / teeth / 4.0;
 179    for (i = 0; i < teeth; i++) {
 180       angle = i * 2.0 * M_PI / teeth;
 181
 182       glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
 183                  -width * 0.5);
 184       glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
 185                  -width * 0.5);
 186       glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
 187       glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
 188    }
 189    glEnd();
 190
 191    /* draw outward faces of teeth */
 192    glBegin(GL_QUAD_STRIP);
 193    for (i = 0; i < teeth; i++) {
 194       angle = i * 2.0 * M_PI / teeth;
 195
 196       glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
 197       glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
 198       u = r2 * cos(angle + da) - r1 * cos(angle);
 199       v = r2 * sin(angle + da) - r1 * sin(angle);
 200       len = sqrt(u * u + v * v);
 201       u /= len;
 202       v /= len;
 203       glNormal3f(v, -u, 0.0);
 204       glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
 205       glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
 206       glNormal3f(cos(angle), sin(angle), 0.0);
 207       glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
 208                  width * 0.5);
 209       glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
 210                  -width * 0.5);
 211       u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da);
 212       v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da);
 213       glNormal3f(v, -u, 0.0);
 214       glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
 215                  width * 0.5);
 216       glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
 217                  -width * 0.5);
 218       glNormal3f(cos(angle), sin(angle), 0.0);
 219    }
 220
 221    glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5);
 222    glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5);
 223
 224    glEnd();
 225
 226    glShadeModel(GL_SMOOTH);
 227
 228    /* draw inside radius cylinder */
 229    glBegin(GL_QUAD_STRIP);
 230    for (i = 0; i <= teeth; i++) {
 231       angle = i * 2.0 * M_PI / teeth;
 232       glNormal3f(-cos(angle), -sin(angle), 0.0);
 233       glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
 234       glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
 235    }
 236    glEnd();
 237 }
 238
 239
 240 static void
 241 draw(void)
 242 {
 243    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 244
 245    glPushMatrix();
 246    glRotatef(view_rotx, 1.0, 0.0, 0.0);
 247    glRotatef(view_roty, 0.0, 1.0, 0.0);
 248    glRotatef(view_rotz, 0.0, 0.0, 1.0);
 249
 250    glPushMatrix();
 251    glTranslatef(-3.0, -2.0, 0.0);
 252    glRotatef(angle, 0.0, 0.0, 1.0);
 253    glCallList(gear1);
 254    glPopMatrix();
 255
 256    glPushMatrix();
 257    glTranslatef(3.1, -2.0, 0.0);
 258    glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0);
 259    glCallList(gear2);
 260    glPopMatrix();
 261
 262    glPushMatrix();
 263    glTranslatef(-3.1, 4.2, 0.0);
 264    glRotatef(-2.0 * angle - 25.0, 0.0, 0.0, 1.0);
 265    glCallList(gear3);
 266    glPopMatrix();
 267
 268    glPopMatrix();
 269 }
 270
 271
 272 /* new window size or exposure */
 273 static void
 274 reshape(int width, int height)
 275 {
 276    GLfloat h = (GLfloat) height / (GLfloat) width;
 277
 278    glViewport(0, 0, (GLint) width, (GLint) height);
 279    glMatrixMode(GL_PROJECTION);
 280    glLoadIdentity();
 281    glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0);
 282    glMatrixMode(GL_MODELVIEW);
 283    glLoadIdentity();
 284    glTranslatef(0.0, 0.0, -40.0);
 285 }
 286
 287
 288 static void
 289 init(void)
 290 {
 291    static GLfloat pos[4] = { 5.0, 5.0, 10.0, 0.0 };
 292    static GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
 293    static GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 };
 294    static GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };
 295
 296    glLightfv(GL_LIGHT0, GL_POSITION, pos);
 297    glEnable(GL_CULL_FACE);
 298    glEnable(GL_LIGHTING);
 299    glEnable(GL_LIGHT0);
 300    glEnable(GL_DEPTH_TEST);
 301
 302    /* make the gears */
 303    gear1 = glGenLists(1);
 304    glNewList(gear1, GL_COMPILE);
 305    glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
 306    gear(1.0, 4.0, 1.0, 20, 0.7);
 307    glEndList();
 308
 309    gear2 = glGenLists(1);
 310    glNewList(gear2, GL_COMPILE);
 311    glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green);
 312    gear(0.5, 2.0, 2.0, 10, 0.7);
 313    glEndList();
 314
 315    gear3 = glGenLists(1);
 316    glNewList(gear3, GL_COMPILE);
 317    glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue);
 318    gear(1.3, 2.0, 0.5, 10, 0.7);
 319    glEndList();
 320
 321    glEnable(GL_NORMALIZE);
 322 }
 323
 324
 325 static GLXWindow
 326 dummy_create_window(Display *dpy, GLXFBConfig config, Window win,
 327                    const int *attrib_list)
 328 {
 329    (void) dpy;
 330    (void) config;
 331    (void) attrib_list;
 332
 333    return (GLXWindow) win;
 334 }
 335
 336
 337 static void
 338 dummy_destroy_window(Display *dpy, GLXWindow win)
 339 {
 340    (void) dpy;
 341    (void) win;
 342 }
 343
 344
 345 /**
 346  * Initialize fbconfig related function pointers.
 347  */
 348 static void
 349 init_fbconfig_functions(Display *dpy, int scrnum)
 350 {
 351    const char * glx_extensions;
 352    const char * match;
 353    static const char ext_name[] = "GLX_SGIX_fbconfig";
 354    const size_t len = strlen( ext_name );
 355    int major;
 356    int minor;
 357    GLboolean ext_version_supported;
 358    GLboolean glx_1_3_supported;
 359
 360
 361    /* Determine if GLX 1.3 or greater is supported.
 362     */
 363    glXQueryVersion(dpy, & major, & minor);
 364    glx_1_3_supported = (major == 1) && (minor >= 3);
 365
 366    /* Determine if GLX_SGIX_fbconfig is supported.
 367     */
 368    glx_extensions = glXQueryExtensionsString(dpy, scrnum);
 369    match = strstr( glx_extensions, ext_name );
 370
 371    ext_version_supported = (match != NULL)
 372        && ((match[len] == '\0') || (match[len] == ' '));
 373
 374    printf( "GLX 1.3 is %ssupported.\n",
 375            (glx_1_3_supported) ? "" : "not " );
 376    printf( "%s is %ssupported.\n",
 377            ext_name, (ext_version_supported) ? "" : "not " );
 378
 379    if ( glx_1_3_supported ) {
 380       choose_fbconfig = (PFNGLXCHOOSEFBCONFIGPROC)
 381          glXGetProcAddressARB((GLubyte *) "glXChooseFBConfig");
 382       get_visual_from_fbconfig = (PFNGLXGETVISUALFROMFBCONFIGPROC)
 383          glXGetProcAddressARB((GLubyte *) "glXGetVisualFromFBConfig");
 384       create_new_context = (PFNGLXCREATENEWCONTEXTPROC)
 385          glXGetProcAddressARB((GLubyte *) "glXCreateNewContext");
 386       create_window = (PFNGLXCREATEWINDOWPROC)
 387          glXGetProcAddressARB((GLubyte *) "glXCreateWindow");
 388       destroy_window = (PFNGLXDESTROYWINDOWPROC)
 389          glXGetProcAddressARB((GLubyte *) "glXDestroyWindow");
 390    }
 391    else if ( ext_version_supported ) {
 392       choose_fbconfig = (PFNGLXCHOOSEFBCONFIGPROC)
 393          glXGetProcAddressARB((GLubyte *) "glXChooseFBConfigSGIX");
 394       get_visual_from_fbconfig = (PFNGLXGETVISUALFROMFBCONFIGPROC)
 395          glXGetProcAddressARB((GLubyte *) "glXGetVisualFromFBConfigSGIX");
 396       create_new_context = (PFNGLXCREATENEWCONTEXTPROC)
 397          glXGetProcAddressARB((GLubyte *) "glXCreateContextWithConfigSGIX");
 398       create_window = dummy_create_window;
 399       destroy_window = dummy_destroy_window;
 400    }
 401    else {
 402       printf( "This demo requires either GLX 1.3 or %s be supported.\n",
 403               ext_name );
 404       exit(1);
 405    }
 406
 407    if ( choose_fbconfig == NULL ) {
 408       printf( "glXChooseFBConfig not found!\n" );
 409       exit(1);
 410    }
 411
 412    if ( get_visual_from_fbconfig == NULL ) {
 413       printf( "glXGetVisualFromFBConfig not found!\n" );
 414       exit(1);
 415    }
 416
 417    if ( create_new_context == NULL ) {
 418       printf( "glXCreateNewContext not found!\n" );
 419       exit(1);
 420    }
 421 }
 422
 423
 424 /*
 425  * Create an RGB, double-buffered window.
 426  * Return the window and context handles.
 427  */
 428 static void
 429 make_window( Display *dpy, const char *name,
 430              int x, int y, int width, int height,
 431              Window *winRet, GLXWindow *glxWinRet, GLXContext *ctxRet)
 432 {
 433    int attrib[] = { GLX_DRAWABLE_TYPE, GLX_WINDOW_BIT,
 434                     GLX_RENDER_TYPE,   GLX_RGBA_BIT,
 435                     GLX_RED_SIZE,      1,
 436                     GLX_GREEN_SIZE,    1,
 437                     GLX_BLUE_SIZE,     1,
 438                     GLX_DOUBLEBUFFER,  GL_TRUE,
 439                     GLX_DEPTH_SIZE,    1,
 440                     None };
 441    GLXFBConfig * fbconfig;
 442    int num_configs;
 443    int scrnum;
 444    int i;
 445    XSetWindowAttributes attr;
 446    unsigned long mask;
 447    Window root;
 448    Window win;
 449    GLXWindow glxWin;
 450    GLXContext ctx;
 451    XVisualInfo *visinfo;
 452
 453    scrnum = DefaultScreen( dpy );
 454    root = RootWindow( dpy, scrnum );
 455
 456    init_fbconfig_functions(dpy, scrnum);
 457    fbconfig = (*choose_fbconfig)(dpy, scrnum, attrib, & num_configs);
 458    if (fbconfig == NULL) {
 459       printf("Error: couldn't get an RGB, Double-buffered visual\n");
 460       exit(1);
 461    }
 462
 463    printf("\nThe following fbconfigs meet the requirements.  The first one "
 464           "will be used.\n\n");
 465    for ( i = 0 ; i < num_configs ; i++ ) {
 466       PrintFBConfigInfo(dpy, scrnum, fbconfig[i], GL_TRUE);
 467    }
 468
 469    /* window attributes */
 470    visinfo = (*get_visual_from_fbconfig)(dpy, fbconfig[0]);
 471    assert(visinfo != NULL);
 472    attr.background_pixel = 0;
 473    attr.border_pixel = 0;
 474    attr.colormap = XCreateColormap( dpy, root, visinfo->visual, AllocNone);
 475    attr.event_mask = StructureNotifyMask | ExposureMask | KeyPressMask;
 476    mask = CWBackPixel | CWBorderPixel | CWColormap | CWEventMask;
 477
 478    win = XCreateWindow( dpy, root, 0, 0, width, height,
 479                         0, visinfo->depth, InputOutput,
 480                         visinfo->visual, mask, &attr );
 481
 482    /* set hints and properties */
 483    {
 484       XSizeHints sizehints;
 485       sizehints.x = x;
 486       sizehints.y = y;
 487       sizehints.width  = width;
 488       sizehints.height = height;
 489       sizehints.flags = USSize | USPosition;
 490       XSetNormalHints(dpy, win, &sizehints);
 491       XSetStandardProperties(dpy, win, name, name,
 492                               None, (char **)NULL, 0, &sizehints);
 493    }
 494
 495    glxWin = (*create_window)(dpy, fbconfig[0], win, NULL);
 496
 497    ctx = (*create_new_context)(dpy, fbconfig[0], GLX_RGBA_TYPE, NULL, GL_TRUE);
 498    if (!ctx) {
 499       printf("Error: glXCreateNewContext failed\n");
 500       exit(1);
 501    }
 502
 503    XFree(fbconfig);
 504
 505    *glxWinRet = glxWin;
 506    *winRet = win;
 507    *ctxRet = ctx;
 508 }
 509
 510
 511 static void
 512 event_loop(Display *dpy, GLXWindow win)
 513 {
 514    while (1) {
 515       while (XPending(dpy) > 0) {
 516          XEvent event;
 517          XNextEvent(dpy, &event);
 518          switch (event.type) {
 519          case Expose:
 520             /* we'll redraw below */
 521             break;
 522          case ConfigureNotify:
 523             reshape(event.xconfigure.width, event.xconfigure.height);
 524             break;
 525          case KeyPress:
 526             {
 527                char buffer[10];
 528                int code;
 529                code = XLookupKeysym(&event.xkey, 0);
 530                if (code == XK_Left) {
 531                   view_roty += 5.0;
 532                }
 533                else if (code == XK_Right) {
 534                   view_roty -= 5.0;
 535                }
 536                else if (code == XK_Up) {
 537                   view_rotx += 5.0;
 538                }
 539                else if (code == XK_Down) {
 540                   view_rotx -= 5.0;
 541                }
 542                else {
 543                   XLookupString(&event.xkey, buffer, sizeof(buffer),
 544                                 NULL, NULL);
 545                   if (buffer[0] == 27) {
 546                      /* escape */
 547                      return;
 548                   }
 549                }
 550             }
 551          }
 552       }
 553
 554       /* next frame */
 555       angle += 2.0;
 556
 557       draw();
 558       glXSwapBuffers(dpy, win);
 559
 560       /* calc framerate */
 561       {
 562          static int t0 = -1;
 563          static int frames = 0;
 564          int t = current_time();
 565
 566          if (t0 < 0)
 567             t0 = t;
 568
 569          frames++;
 570
 571          if (t - t0 >= 5.0) {
 572             GLfloat seconds = t - t0;
 573             GLfloat fps = frames / seconds;
 574             printf("%d frames in %3.1f seconds = %6.3f FPS\n", frames, seconds,
 575                    fps);
 576             fflush(stdout);
 577             t0 = t;
 578             frames = 0;
 579          }
 580       }
 581    }
 582 }
 583
 584
 585 int
 586 main(int argc, char *argv[])
 587 {
 588    Display *dpy;
 589    Window win;
 590    GLXWindow glxWin;
 591    GLXContext ctx;
 592    const char *dpyName = NULL;
 593    GLboolean printInfo = GL_FALSE;
 594    int i;
 595
 596    for (i = 1; i < argc; i++) {
 597       if (strcmp(argv[i], "-display") == 0) {
 598          dpyName = argv[i+1];
 599          i++;
 600       }
 601       else if (strcmp(argv[i], "-info") == 0) {
 602          printInfo = GL_TRUE;
 603       }
 604    }
 605
 606    dpy = XOpenDisplay(dpyName);
 607    if (!dpy) {
 608       printf("Error: couldn't open display %s\n", XDisplayName(dpyName));
 609       return -1;
 610    }
 611
 612    make_window(dpy, "glxgears", 0, 0, 300, 300, &win, &glxWin, &ctx);
 613    XMapWindow(dpy, win);
 614    glXMakeCurrent(dpy, glxWin, ctx);
 615
 616    if (printInfo) {
 617       printf("GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
 618       printf("GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
 619       printf("GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
 620       printf("GL_EXTENSIONS = %s\n", (char *) glGetString(GL_EXTENSIONS));
 621    }
 622
 623    init();
 624
 625    event_loop(dpy, glxWin);
 626
 627    glXDestroyContext(dpy, ctx);
 628    destroy_window(dpy, glxWin);
 629    XDestroyWindow(dpy, win);
 630    XCloseDisplay(dpy);
 631
 632    return 0;
 633 }