summaryrefslogtreecommitdiffstats
path: root/Modules/FindosgUtil.cmake
Commit message (Expand)AuthorAgeFilesLines
* Convert builtin help to reStructuredText source filesKitware Robot2013-10-151-24/+28
* Find* (and some other): use ${CMAKE_CURRENT_LIST_DIR} in include()Rolf Eike Beer2012-11-041-1/+1
* Remove trailing whitespace from most CMake and C/C++ codeKitware Robot2012-08-131-4/+4
* Modules: Include builtin FindPackageHandleStandardArgs directlyBrad King2011-01-201-1/+1
* Remove usage of CMAKE_CURRENT_LIST_DIR now that we have CMP0017Alex Neundorf2011-01-041-1/+1
* Use absolute path to FindPackageHandleStandardArgs.cmake everywhereAlex Neundorf2010-09-281-1/+1
* Modules: Fix spelling 'To distributed' -> 'To distribute'Todd Gamblin2010-08-091-1/+1
* Convert CMake find-modules to BSD LicenseBrad King2009-09-281-0/+13
* BUG: The QUIET and REQUIRED find attributes on each Findosg* module were notPhilip Lowman2009-01-301-1/+1
* BUG: Fixed Issue #7331 Bugs in Findosg*.cmake. Also added OPENTHREADS_LIBRAR...Philip Lowman2009-01-191-45/+13
* ENH: Cleanup Find* modules with new HINTS featureBrad King2008-06-091-14/+3
* BUG: Remove references to CMAKE_PREFIX_PATH variable. It should not be refer...Brad King2008-01-161-11/+2
* BUG: Fixed modules to set FOO_FOUND when both headers and libraries are found.Eric Wing2007-12-211-0/+90
d='n181' href='#n181'>181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425
/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information (qt-info@nokia.com)
**
** This file is part of the QtOpenGL module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights. These rights are described in the Nokia Qt LGPL
** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3.0 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at qt-sales@nokia.com.
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qgl.h"
#include "qgl_p.h"

#include "qmap.h"
#include "qapplication.h"
#include "qcolormap.h"
#include "qdesktopwidget.h"
#include "qpixmap.h"
#include "qhash.h"
#include "qlibrary.h"
#include "qdebug.h"
#include <private/qfontengine_ft_p.h>
#include <private/qt_x11_p.h>
#ifdef Q_OS_HPUX
// for GLXPBuffer
#include <private/qglpixelbuffer_p.h>
#endif

#define INT8  dummy_INT8
#define INT32 dummy_INT32
#include <GL/glx.h>
#undef  INT8
#undef  INT32
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xos.h>
#include <X11/Xatom.h>

#if defined(Q_OS_LINUX) || defined(Q_OS_BSD4)
#include <dlfcn.h>
#endif

QT_BEGIN_NAMESPACE

extern Drawable qt_x11Handle(const QPaintDevice *pd);
extern const QX11Info *qt_x11Info(const QPaintDevice *pd);

#ifndef GLX_ARB_multisample
#define GLX_SAMPLE_BUFFERS_ARB  100000
#define GLX_SAMPLES_ARB         100001
#endif

/*
  The qt_gl_choose_cmap function is internal and used by QGLWidget::setContext()
  and GLX (not Windows).  If the application can't find any sharable
  colormaps, it must at least create as few colormaps as possible.  The
  dictionary solution below ensures only one colormap is created per visual.
  Colormaps are also deleted when the application terminates.
*/

struct QCMapEntry {
    QCMapEntry();
    ~QCMapEntry();

    Colormap cmap;
    bool alloc;
    XStandardColormap scmap;
};

QCMapEntry::QCMapEntry()
{
    cmap = 0;
    alloc = false;
    scmap.colormap = 0;
}

QCMapEntry::~QCMapEntry()
{
    if (alloc)
        XFreeColormap(X11->display, cmap);
}
typedef QHash<int, QCMapEntry *> CMapEntryHash;
typedef QHash<int, QMap<int, QRgb> > GLCMapHash;
static bool mesa_gl = false;
static bool first_time = true;

static void cleanup_cmaps();

struct QGLCMapCleanupHandler {
    QGLCMapCleanupHandler() {
        cmap_hash = new CMapEntryHash;
        qglcmap_hash = new GLCMapHash;
    }
    ~QGLCMapCleanupHandler() {
        delete cmap_hash;
        delete qglcmap_hash;
    }
    CMapEntryHash *cmap_hash;
    GLCMapHash *qglcmap_hash;
};
Q_GLOBAL_STATIC(QGLCMapCleanupHandler, cmap_handler);

static void cleanup_cmaps()
{
    CMapEntryHash *hash = cmap_handler()->cmap_hash;
    QHash<int, QCMapEntry *>::ConstIterator it = hash->constBegin();
    while (it != hash->constEnd()) {
        delete it.value();
        ++it;
    }

    hash->clear();
    cmap_handler()->qglcmap_hash->clear();
}

Colormap qt_gl_choose_cmap(Display *dpy, XVisualInfo *vi)
{
    if (first_time) {
        const char *v = glXQueryServerString(dpy, vi->screen, GLX_VERSION);
        if (v)
            mesa_gl = (strstr(v, "Mesa") != 0);
        first_time = false;
    }

    CMapEntryHash *hash = cmap_handler()->cmap_hash;
    CMapEntryHash::ConstIterator it = hash->constFind((long) vi->visualid + (vi->screen * 256));
    if (it != hash->constEnd())
        return it.value()->cmap; // found colormap for visual

    if (vi->visualid ==
        XVisualIDFromVisual((Visual *) QX11Info::appVisual(vi->screen))) {
        // qDebug("Using x11AppColormap");
        return QX11Info::appColormap(vi->screen);
    }

    QCMapEntry *x = new QCMapEntry();

    XStandardColormap *c;
    int n, i;

    // qDebug("Choosing cmap for vID %0x", vi->visualid);

    if (mesa_gl) {                                // we're using MesaGL
        Atom hp_cmaps = XInternAtom(dpy, "_HP_RGB_SMOOTH_MAP_LIST", true);
        if (hp_cmaps && vi->visual->c_class == TrueColor && vi->depth == 8) {
            if (XGetRGBColormaps(dpy,RootWindow(dpy,vi->screen),&c,&n,
                                 hp_cmaps)) {
                i = 0;
                while (i < n && x->cmap == 0) {
                    if (c[i].visualid == vi->visual->visualid) {
                        x->cmap = c[i].colormap;
                        x->scmap = c[i];
                        //qDebug("Using HP_RGB scmap");

                    }
                    i++;
                }
                XFree((char *)c);
            }
        }
    }
    if (!x->cmap) {
        if (XGetRGBColormaps(dpy,RootWindow(dpy,vi->screen),&c,&n,
                             XA_RGB_DEFAULT_MAP)) {
            for (int i = 0; i < n && x->cmap == 0; ++i) {
                if (!c[i].red_max ||
                    !c[i].green_max ||
                    !c[i].blue_max ||
                    !c[i].red_mult ||
                    !c[i].green_mult ||
                    !c[i].blue_mult)
                    continue; // invalid stdcmap
                if (c[i].visualid == vi->visualid) {
                    x->cmap = c[i].colormap;
                    x->scmap = c[i];
                    //qDebug("Using RGB_DEFAULT scmap");
                }
            }
            XFree((char *)c);
        }
    }
    if (!x->cmap) {                                // no shared cmap found
        x->cmap = XCreateColormap(dpy, RootWindow(dpy,vi->screen), vi->visual,
                                  AllocNone);
        x->alloc = true;
        // qDebug("Allocating cmap");
    }

    // colormap hash should be cleanup only when the QApplication dtor is called
    if (hash->isEmpty())
        qAddPostRoutine(cleanup_cmaps);

    // associate cmap with visualid
    hash->insert((long) vi->visualid + (vi->screen * 256), x);
    return x->cmap;
}

struct QTransColor
{
    VisualID vis;
    int screen;
    long color;
};

static QVector<QTransColor> trans_colors;
static int trans_colors_init = false;

static void find_trans_colors()
{
    struct OverlayProp {
        long  visual;
        long  type;
        long  value;
        long  layer;
    };

    trans_colors_init = true;

    Display* appDisplay = X11->display;

    int scr;
    int lastsize = 0;
    for (scr = 0; scr < ScreenCount(appDisplay); scr++) {
        QWidget* rootWin = QApplication::desktop()->screen(scr);
        if (!rootWin)
            return;                                        // Should not happen
        Atom overlayVisualsAtom = XInternAtom(appDisplay,
                                               "SERVER_OVERLAY_VISUALS", True);
        if (overlayVisualsAtom == XNone)
            return;                                        // Server has no overlays

        Atom actualType;
        int actualFormat;
        ulong nItems;
        ulong bytesAfter;
        unsigned char *retval = 0;
        int res = XGetWindowProperty(appDisplay, rootWin->winId(),
                                      overlayVisualsAtom, 0, 10000, False,
                                      overlayVisualsAtom, &actualType,
                                      &actualFormat, &nItems, &bytesAfter,
                                      &retval);

        if (res != Success || actualType != overlayVisualsAtom
             || actualFormat != 32 || nItems < 4 || !retval)
            return;                                        // Error reading property

        OverlayProp *overlayProps = (OverlayProp *)retval;

        int numProps = nItems / 4;
        trans_colors.resize(lastsize + numProps);
        int j = lastsize;
        for (int i = 0; i < numProps; i++) {
            if (overlayProps[i].type == 1) {
                trans_colors[j].vis = (VisualID)overlayProps[i].visual;
                trans_colors[j].screen = scr;
                trans_colors[j].color = (int)overlayProps[i].value;
                j++;
            }
        }
        XFree(overlayProps);
        lastsize = j;
        trans_colors.resize(lastsize);
    }
}

/*****************************************************************************
  QGLFormat UNIX/GLX-specific code
 *****************************************************************************/

bool QGLFormat::hasOpenGL()
{
    return glXQueryExtension(X11->display, 0, 0) != 0;
}


bool QGLFormat::hasOpenGLOverlays()
{
    if (!trans_colors_init)
        find_trans_colors();
    return trans_colors.size() > 0;
}

/*****************************************************************************
  QGLContext UNIX/GLX-specific code
 *****************************************************************************/

bool QGLContext::chooseContext(const QGLContext* shareContext)
{
    Q_D(QGLContext);
    const QX11Info *xinfo = qt_x11Info(d->paintDevice);

    Display* disp = xinfo->display();
    d->vi = chooseVisual();
    if (!d->vi)
        return false;

    if (deviceIsPixmap() &&
         (((XVisualInfo*)d->vi)->depth != xinfo->depth() ||
          ((XVisualInfo*)d->vi)->screen != xinfo->screen()))
    {
        XFree(d->vi);
        XVisualInfo appVisInfo;
        memset(&appVisInfo, 0, sizeof(XVisualInfo));
        appVisInfo.visualid = XVisualIDFromVisual((Visual *) xinfo->visual());
        appVisInfo.screen = xinfo->screen();
        int nvis;
        d->vi = XGetVisualInfo(disp, VisualIDMask | VisualScreenMask, &appVisInfo, &nvis);
        if (!d->vi)
            return false;

        int useGL;
        glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_USE_GL, &useGL);
        if (!useGL)
            return false;        //# Chickening out already...
    }
    int res;
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_LEVEL, &res);
    d->glFormat.setPlane(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_DOUBLEBUFFER, &res);
    d->glFormat.setDoubleBuffer(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_DEPTH_SIZE, &res);
    d->glFormat.setDepth(res);
    if (d->glFormat.depth())
        d->glFormat.setDepthBufferSize(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_RGBA, &res);
    d->glFormat.setRgba(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_RED_SIZE, &res);
    d->glFormat.setRedBufferSize(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_GREEN_SIZE, &res);
    d->glFormat.setGreenBufferSize(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_BLUE_SIZE, &res);
    d->glFormat.setBlueBufferSize(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_ALPHA_SIZE, &res);
    d->glFormat.setAlpha(res);
    if (d->glFormat.alpha())
        d->glFormat.setAlphaBufferSize(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_ACCUM_RED_SIZE, &res);
    d->glFormat.setAccum(res);
    if (d->glFormat.accum())
        d->glFormat.setAccumBufferSize(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_STENCIL_SIZE, &res);
    d->glFormat.setStencil(res);
    if (d->glFormat.stencil())
        d->glFormat.setStencilBufferSize(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_STEREO, &res);
    d->glFormat.setStereo(res);
    glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_SAMPLE_BUFFERS_ARB, &res);
    d->glFormat.setSampleBuffers(res);
    if (d->glFormat.sampleBuffers()) {
        glXGetConfig(disp, (XVisualInfo*)d->vi, GLX_SAMPLES_ARB, &res);
        d->glFormat.setSamples(res);
    }

    Bool direct = format().directRendering() ? True : False;

    if (shareContext &&
         (!shareContext->isValid() || !shareContext->d_func()->cx)) {
            qWarning("QGLContext::chooseContext(): Cannot share with invalid context");
            shareContext = 0;
    }

    // 1. Sharing between rgba and color-index will give wrong colors.
    // 2. Contexts cannot be shared btw. direct/non-direct renderers.
    // 3. Pixmaps cannot share contexts that are set up for direct rendering.
    // 4. If the contexts are not created on the same screen, they can't be shared

    if (shareContext
        && (format().rgba() != shareContext->format().rgba()
            || (deviceIsPixmap() && glXIsDirect(disp, (GLXContext)shareContext->d_func()->cx))
            || (shareContext->d_func()->screen != xinfo->screen())))
    {
        shareContext = 0;
    }

    d->cx = 0;
    if (shareContext) {
        d->cx = glXCreateContext(disp, (XVisualInfo *)d->vi,
                               (GLXContext)shareContext->d_func()->cx, direct);
        d->screen = ((XVisualInfo*)d->vi)->screen;
        if (d->cx) {
            QGLContext *share = const_cast<QGLContext *>(shareContext);
            d->sharing = true;
            share->d_func()->sharing = true;
        }
    }
    if (!d->cx) {
        d->cx = glXCreateContext(disp, (XVisualInfo *)d->vi, NULL, direct);
        d->screen = ((XVisualInfo*)d->vi)->screen;
    }
    if (!d->cx)
        return false;
    d->glFormat.setDirectRendering(glXIsDirect(disp, (GLXContext)d->cx));
    if (deviceIsPixmap()) {
#if defined(GLX_MESA_pixmap_colormap) && defined(QGL_USE_MESA_EXT)
        d->gpm = glXCreateGLXPixmapMESA(disp, (XVisualInfo *)d->vi,
                                        qt_x11Handle(d->paintDevice),
                                        qt_gl_choose_cmap(disp, (XVisualInfo *)d->vi));
#else
        d->gpm = (quint32)glXCreateGLXPixmap(disp, (XVisualInfo *)d->vi,
                                              qt_x11Handle(d->paintDevice));
#endif
        if (!d->gpm)
            return false;
    }
    QString glxExt = QString(QLatin1String(glXGetClientString(QX11Info::display(), GLX_EXTENSIONS)));
    if (glxExt.contains(QLatin1String("GLX_SGI_video_sync"))) {
        if (d->glFormat.swapInterval() == -1)
            d->glFormat.setSwapInterval(0);
    } else {
        d->glFormat.setSwapInterval(-1);
    }
    return true;
}


/*!
  \bold{X11 only:} This virtual function tries to find a
  visual that matches the format, reducing the demands if the original
  request cannot be met.

  The algorithm for reducing the demands of the format is quite
  simple-minded, so override this method in your subclass if your
  application has spcific requirements on visual selection.

  \sa chooseContext()
*/

void *QGLContext::chooseVisual()
{
    Q_D(QGLContext);
    static const int bufDepths[] = { 8, 4, 2, 1 };        // Try 16, 12 also?
    //todo: if pixmap, also make sure that vi->depth == pixmap->depth
    void* vis = 0;
    int i = 0;
    bool fail = false;
    QGLFormat fmt = format();
    bool tryDouble = !fmt.doubleBuffer();  // Some GL impl's only have double
    bool triedDouble = false;
    bool triedSample = false;
    if (fmt.sampleBuffers())
        fmt.setSampleBuffers(QGLExtensions::glExtensions & QGLExtensions::SampleBuffers);
    while(!fail && !(vis = tryVisual(fmt, bufDepths[i]))) {
        if (!fmt.rgba() && bufDepths[i] > 1) {
            i++;
            continue;
        }
        if (tryDouble) {
            fmt.setDoubleBuffer(true);
            tryDouble = false;
            triedDouble = true;
            continue;
        } else if (triedDouble) {
            fmt.setDoubleBuffer(false);
            triedDouble = false;
        }
        if (!triedSample && fmt.sampleBuffers()) {
            fmt.setSampleBuffers(false);
            triedSample = true;
            continue;
        }
        if (fmt.stereo()) {
            fmt.setStereo(false);
            continue;
        }
        if (fmt.accum()) {
            fmt.setAccum(false);
            continue;
        }
        if (fmt.stencil()) {
            fmt.setStencil(false);
            continue;
        }
        if (fmt.alpha()) {
            fmt.setAlpha(false);
            continue;
        }
        if (fmt.depth()) {
            fmt.setDepth(false);
            continue;
        }
        if (fmt.doubleBuffer()) {
            fmt.setDoubleBuffer(false);
            continue;
        }
        fail = true;
    }
    d->glFormat = fmt;
    return vis;
}


/*!
  \internal

  \bold{X11 only:} This virtual function chooses a visual
  that matches the OpenGL \link format() format\endlink. Reimplement this
  function in a subclass if you need a custom visual.

  \sa chooseContext()
*/

void *QGLContext::tryVisual(const QGLFormat& f, int bufDepth)
{
    Q_D(QGLContext);
    int spec[40];
    int i = 0;
    spec[i++] = GLX_LEVEL;
    spec[i++] = f.plane();
    const QX11Info *xinfo = qt_x11Info(d->paintDevice);

#if defined(GLX_VERSION_1_1) && defined(GLX_EXT_visual_info)
    static bool useTranspExt = false;
    static bool useTranspExtChecked = false;
    if (f.plane() && !useTranspExtChecked && d->paintDevice) {
        QByteArray estr(glXQueryExtensionsString(xinfo->display(), xinfo->screen()));
        useTranspExt = estr.contains("GLX_EXT_visual_info");
        //# (A bit simplistic; that could theoretically be a substring)
        if (useTranspExt) {
            QByteArray cstr(glXGetClientString(xinfo->display(), GLX_VENDOR));
            useTranspExt = !cstr.contains("Xi Graphics"); // bug workaround
            if (useTranspExt) {
                // bug workaround - some systems (eg. FireGL) refuses to return an overlay
                // visual if the GLX_TRANSPARENT_TYPE_EXT attribute is specified, even if
                // the implementation supports transparent overlays
                int tmpSpec[] = { GLX_LEVEL, f.plane(), GLX_TRANSPARENT_TYPE_EXT,
                                  f.rgba() ? GLX_TRANSPARENT_RGB_EXT : GLX_TRANSPARENT_INDEX_EXT,
                                  XNone };
                XVisualInfo * vinf = glXChooseVisual(xinfo->display(), xinfo->screen(), tmpSpec);
                if (!vinf) {
                    useTranspExt = false;
                }
            }
        }

        useTranspExtChecked = true;
    }
    if (f.plane() && useTranspExt) {
        // Required to avoid non-transparent overlay visual(!) on some systems
        spec[i++] = GLX_TRANSPARENT_TYPE_EXT;
        spec[i++] = f.rgba() ? GLX_TRANSPARENT_RGB_EXT : GLX_TRANSPARENT_INDEX_EXT;
    }
#endif

    if (f.doubleBuffer())
        spec[i++] = GLX_DOUBLEBUFFER;
    if (f.depth()) {
        spec[i++] = GLX_DEPTH_SIZE;
        spec[i++] = f.depthBufferSize() == -1 ? 1 : f.depthBufferSize();
    }
    if (f.stereo()) {
        spec[i++] = GLX_STEREO;
    }
    if (f.stencil()) {
        spec[i++] = GLX_STENCIL_SIZE;
        spec[i++] = f.stencilBufferSize() == -1 ? 1 : f.stencilBufferSize();
    }
    if (f.rgba()) {
        spec[i++] = GLX_RGBA;
        spec[i++] = GLX_RED_SIZE;
        spec[i++] = f.redBufferSize() == -1 ? 1 : f.redBufferSize();
        spec[i++] = GLX_GREEN_SIZE;
        spec[i++] = f.greenBufferSize() == -1 ? 1 : f.greenBufferSize();
        spec[i++] = GLX_BLUE_SIZE;
        spec[i++] = f.blueBufferSize() == -1 ? 1 : f.blueBufferSize();
        if (f.alpha()) {
            spec[i++] = GLX_ALPHA_SIZE;
            spec[i++] = f.alphaBufferSize() == -1 ? 1 : f.alphaBufferSize();
        }
        if (f.accum()) {
            spec[i++] = GLX_ACCUM_RED_SIZE;
            spec[i++] = f.accumBufferSize() == -1 ? 1 : f.accumBufferSize();
            spec[i++] = GLX_ACCUM_GREEN_SIZE;
            spec[i++] = f.accumBufferSize() == -1 ? 1 : f.accumBufferSize();
            spec[i++] = GLX_ACCUM_BLUE_SIZE;
            spec[i++] = f.accumBufferSize() == -1 ? 1 : f.accumBufferSize();
            if (f.alpha()) {
                spec[i++] = GLX_ACCUM_ALPHA_SIZE;
                spec[i++] = f.accumBufferSize() == -1 ? 1 : f.accumBufferSize();
            }
        }
    } else {
        spec[i++] = GLX_BUFFER_SIZE;
        spec[i++] = bufDepth;
    }

    if (f.sampleBuffers()) {
        spec[i++] = GLX_SAMPLE_BUFFERS_ARB;
        spec[i++] = 1;
        spec[i++] = GLX_SAMPLES_ARB;
        spec[i++] = f.samples() == -1 ? 4 : f.samples();
    }

    spec[i] = XNone;
    return glXChooseVisual(xinfo->display(), xinfo->screen(), spec);
}


void QGLContext::reset()
{
    Q_D(QGLContext);
    if (!d->valid)
        return;
    d->cleanup();
    const QX11Info *xinfo = qt_x11Info(d->paintDevice);
    doneCurrent();
    if (d->gpm)
        glXDestroyGLXPixmap(xinfo->display(), (GLXPixmap)d->gpm);
    d->gpm = 0;
    glXDestroyContext(xinfo->display(), (GLXContext)d->cx);
    if (d->vi)
        XFree(d->vi);
    d->vi = 0;
    d->cx = 0;
    d->crWin = false;
    d->sharing = false;
    d->valid = false;
    d->transpColor = QColor();
    d->initDone = false;
    qgl_share_reg()->removeShare(this);
}


void QGLContext::makeCurrent()
{
    Q_D(QGLContext);
    if (!d->valid) {
        qWarning("QGLContext::makeCurrent(): Cannot make invalid context current.");
        return;
    }
    const QX11Info *xinfo = qt_x11Info(d->paintDevice);
    bool ok = true;
    if (d->paintDevice->devType() == QInternal::Pixmap) {
        ok = glXMakeCurrent(xinfo->display(), (GLXPixmap)d->gpm, (GLXContext)d->cx);
    } else if (d->paintDevice->devType() == QInternal::Pbuffer) {
        ok = glXMakeCurrent(xinfo->display(), (GLXPbuffer)d->pbuf, (GLXContext)d->cx);
    } else if (d->paintDevice->devType() == QInternal::Widget) {
        ok = glXMakeCurrent(xinfo->display(), ((QWidget *)d->paintDevice)->winId(), (GLXContext)d->cx);
    }
    if (!ok)
        qWarning("QGLContext::makeCurrent(): Failed.");

    if (ok) {
        if (!qgl_context_storage.hasLocalData() && QThread::currentThread())
            qgl_context_storage.setLocalData(new QGLThreadContext);
        if (qgl_context_storage.hasLocalData())
            qgl_context_storage.localData()->context = this;
        currentCtx = this;
    }
}

void QGLContext::doneCurrent()
{
    Q_D(QGLContext);
    glXMakeCurrent(qt_x11Info(d->paintDevice)->display(), 0, 0);
    if (qgl_context_storage.hasLocalData())
        qgl_context_storage.localData()->context = 0;
    currentCtx = 0;
}


void QGLContext::swapBuffers() const
{
    Q_D(const QGLContext);
    if (!d->valid)
        return;
    if (!deviceIsPixmap()) {
        int interval = d->glFormat.swapInterval();
        if (interval > 0) {
            typedef int (*qt_glXGetVideoSyncSGI)(uint *);
            typedef int (*qt_glXWaitVideoSyncSGI)(int, int, uint *);
            static qt_glXGetVideoSyncSGI glXGetVideoSyncSGI = 0;
            static qt_glXWaitVideoSyncSGI glXWaitVideoSyncSGI = 0;
            static bool resolved = false;
            if (!resolved) {
                QString glxExt = QString(QLatin1String(glXGetClientString(QX11Info::display(), GLX_EXTENSIONS)));
                if (glxExt.contains(QLatin1String("GLX_SGI_video_sync"))) {
#if defined(Q_OS_LINUX) || defined(Q_OS_BSD4)
                    void *handle = dlopen(NULL, RTLD_LAZY);
                    if (handle) {
                        glXGetVideoSyncSGI = (qt_glXGetVideoSyncSGI) dlsym(handle, "glXGetVideoSyncSGI");
                        glXWaitVideoSyncSGI = (qt_glXWaitVideoSyncSGI) dlsym(handle, "glXWaitVideoSyncSGI");
                        dlclose(handle);
                    }
                    if (!glXGetVideoSyncSGI)
#endif
                    {
                        extern const QString qt_gl_library_name();
                        QLibrary lib(qt_gl_library_name());
                        glXGetVideoSyncSGI = (qt_glXGetVideoSyncSGI) lib.resolve("glXGetVideoSyncSGI");
                        glXWaitVideoSyncSGI = (qt_glXWaitVideoSyncSGI) lib.resolve("glXWaitVideoSyncSGI");
                    }
                }
                resolved = true;
            }
            if (glXGetVideoSyncSGI && glXWaitVideoSyncSGI) {
                uint counter;
                if (!glXGetVideoSyncSGI(&counter))
                    glXWaitVideoSyncSGI(interval + 1, (counter + interval) % (interval + 1), &counter);
            }
        }
        glXSwapBuffers(qt_x11Info(d->paintDevice)->display(),
                       static_cast<QWidget *>(d->paintDevice)->winId());
    }
}

QColor QGLContext::overlayTransparentColor() const
{
    if (isValid())
        return Qt::transparent;
    return QColor();                // Invalid color
}

static uint qt_transparent_pixel(VisualID id, int screen)
{
    for (int i = 0; i < trans_colors.size(); i++) {
        if (trans_colors[i].vis == id && trans_colors[i].screen == screen)
            return trans_colors[i].color;
    }
    return 0;
}

uint QGLContext::colorIndex(const QColor& c) const
{
    Q_D(const QGLContext);
    int screen = ((XVisualInfo *)d->vi)->screen;
    QColormap colmap = QColormap::instance(screen);
    if (isValid()) {
        if (format().plane() && c == Qt::transparent) {
            return qt_transparent_pixel(((XVisualInfo *)d->vi)->visualid,
                                        ((XVisualInfo *)d->vi)->screen);
        }
        if (((XVisualInfo*)d->vi)->visualid ==
             XVisualIDFromVisual((Visual *) QX11Info::appVisual(screen)))
            return colmap.pixel(c);                // We're using QColor's cmap

        XVisualInfo *info = (XVisualInfo *) d->vi;
        CMapEntryHash *hash = cmap_handler()->cmap_hash;
        CMapEntryHash::ConstIterator it = hash->constFind(long(info->visualid)
                + (info->screen * 256));
        QCMapEntry *x = 0;
        if (it != hash->constEnd())
            x = it.value();
        if (x && !x->alloc) {                // It's a standard colormap
            int rf = (int)(((float)c.red() * (x->scmap.red_max+1))/256.0);
            int gf = (int)(((float)c.green() * (x->scmap.green_max+1))/256.0);
            int bf = (int)(((float)c.blue() * (x->scmap.blue_max+1))/256.0);
            uint p = x->scmap.base_pixel
                     + (rf * x->scmap.red_mult)
                     + (gf * x->scmap.green_mult)
                     + (bf * x->scmap.blue_mult);
            return p;
        } else {
            QMap<int, QRgb> &cmap = (*cmap_handler()->qglcmap_hash)[(long)info->visualid];

            // already in the map?
            QRgb target = c.rgb();
            QMap<int, QRgb>::Iterator it = cmap.begin();
            for (; it != cmap.end(); ++it) {
                if ((*it) == target)
                    return it.key();
            }

            // need to alloc color
            unsigned long plane_mask[2];
            unsigned long color_map_entry;
            if (!XAllocColorCells (QX11Info::display(), x->cmap, true, plane_mask, 0,
                                   &color_map_entry, 1))
                return colmap.pixel(c);

            XColor col;
            col.flags = DoRed | DoGreen | DoBlue;
            col.pixel = color_map_entry;
            col.red   = (ushort)((qRed(c.rgb()) / 255.0) * 65535.0 + 0.5);
            col.green = (ushort)((qGreen(c.rgb()) / 255.0) * 65535.0 + 0.5);
            col.blue  = (ushort)((qBlue(c.rgb()) / 255.0) * 65535.0 + 0.5);
            XStoreColor(QX11Info::display(), x->cmap, &col);

            cmap.insert(color_map_entry, target);
            return color_map_entry;
        }
    }
    return 0;
}

#ifndef QT_NO_FONTCONFIG
/*! \internal
    This is basically a substitute for glxUseXFont() which can only
    handle XLFD fonts. This version relies on freetype to render the
    glyphs, but it works with all fonts that fontconfig provides - both
    antialiased and aliased bitmap and outline fonts.
*/
static void qgl_use_font(QFontEngineFT *engine, int first, int count, int listBase)
{
    GLfloat color[4];
    glGetFloatv(GL_CURRENT_COLOR, color);

    // save the pixel unpack state
    GLint gl_swapbytes, gl_lsbfirst, gl_rowlength, gl_skiprows, gl_skippixels, gl_alignment;
    glGetIntegerv (GL_UNPACK_SWAP_BYTES, &gl_swapbytes);
    glGetIntegerv (GL_UNPACK_LSB_FIRST, &gl_lsbfirst);
    glGetIntegerv (GL_UNPACK_ROW_LENGTH, &gl_rowlength);
    glGetIntegerv (GL_UNPACK_SKIP_ROWS, &gl_skiprows);
    glGetIntegerv (GL_UNPACK_SKIP_PIXELS, &gl_skippixels);
    glGetIntegerv (GL_UNPACK_ALIGNMENT, &gl_alignment);

    glPixelStorei(GL_UNPACK_SWAP_BYTES, GL_FALSE);
    glPixelStorei(GL_UNPACK_LSB_FIRST, GL_FALSE);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
    glPixelStorei(GL_UNPACK_SKIP_ROWS, 0);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, 0);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

    const bool antialiased = engine->drawAntialiased();
    FT_Face face = engine->lockFace();

    // start generating font glyphs
    for (int i = first; i < count; ++i) {
        int list = listBase + i;
        GLfloat x0, y0, dx, dy;

        FT_Error err;

        err = FT_Load_Glyph(face, FT_Get_Char_Index(face, i), FT_LOAD_DEFAULT);
        if (err) {
            qDebug("failed loading glyph %d from font", i);
            Q_ASSERT(!err);
        }
        err = FT_Render_Glyph(face->glyph, (antialiased ? FT_RENDER_MODE_NORMAL
                                            : FT_RENDER_MODE_MONO));
        if (err) {
            qDebug("failed rendering glyph %d from font", i);
            Q_ASSERT(!err);
        }

        FT_Bitmap bm = face->glyph->bitmap;
        x0 = face->glyph->metrics.horiBearingX >> 6;
        y0 = (face->glyph->metrics.height - face->glyph->metrics.horiBearingY) >> 6;
        dx = face->glyph->metrics.horiAdvance >> 6;
        dy = 0;
        int sz = bm.pitch * bm.rows;
        uint *aa_glyph = 0;
        uchar *ua_glyph = 0;

        if (antialiased)
            aa_glyph = new uint[sz];
        else
            ua_glyph = new uchar[sz];

        // convert to GL format
        for (int y = 0; y < bm.rows; ++y) {
            for (int x = 0; x < bm.pitch; ++x) {
                int c1 = y*bm.pitch + x;
                int c2 = (bm.rows - y - 1) > 0 ? (bm.rows-y-1)*bm.pitch + x : x;
                if (antialiased) {
                    aa_glyph[c1] = (int(color[0]*255) << 24)
                                   | (int(color[1]*255) << 16)
                                   | (int(color[2]*255) << 8) | bm.buffer[c2];
                } else {
                    ua_glyph[c1] = bm.buffer[c2];
                }
            }
        }

        glNewList(list, GL_COMPILE);
        if (antialiased) {
            // calling glBitmap() is just a trick to move the current
            // raster pos, since glGet*() won't work in display lists
            glBitmap(0, 0, 0, 0, x0, -y0, 0);
            glDrawPixels(bm.pitch, bm.rows, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8, aa_glyph);
            glBitmap(0, 0, 0, 0, dx-x0, y0, 0);
        } else {
            glBitmap(bm.pitch*8, bm.rows, -x0, y0, dx, dy, ua_glyph);
        }
        glEndList();
        antialiased ? delete[] aa_glyph : delete[] ua_glyph;
    }

    engine->unlockFace();

    // restore pixel unpack settings
    glPixelStorei(GL_UNPACK_SWAP_BYTES, gl_swapbytes);
    glPixelStorei(GL_UNPACK_LSB_FIRST, gl_lsbfirst);
    glPixelStorei(GL_UNPACK_ROW_LENGTH, gl_rowlength);
    glPixelStorei(GL_UNPACK_SKIP_ROWS, gl_skiprows);
    glPixelStorei(GL_UNPACK_SKIP_PIXELS, gl_skippixels);
    glPixelStorei(GL_UNPACK_ALIGNMENT, gl_alignment);
}
#endif

#undef d
void QGLContext::generateFontDisplayLists(const QFont & fnt, int listBase)
{
    QFont f(fnt);
    QFontEngine *engine = f.d->engineForScript(QUnicodeTables::Common);

    if (engine->type() == QFontEngine::Multi)
        engine = static_cast<QFontEngineMulti *>(engine)->engine(0);
#ifndef QT_NO_FONTCONFIG
    if(engine->type() == QFontEngine::Freetype) {
        qgl_use_font(static_cast<QFontEngineFT *>(engine), 0, 256, listBase);
        return;
    }
#endif
    // glXUseXFont() only works with XLFD font structures and a few GL
    // drivers crash if 0 is passed as the font handle
    f.setStyleStrategy(QFont::OpenGLCompatible);
    if (f.handle() && engine->type() == QFontEngine::XLFD)
        glXUseXFont(static_cast<Font>(f.handle()), 0, 256, listBase);
}

void *QGLContext::getProcAddress(const QString &proc) const
{
    typedef void *(*qt_glXGetProcAddressARB)(const GLubyte *);
    static qt_glXGetProcAddressARB glXGetProcAddressARB = 0;
    static bool resolved = false;

    if (resolved && !glXGetProcAddressARB)
        return 0;
    if (!glXGetProcAddressARB) {
        QString glxExt = QString(QLatin1String(glXGetClientString(QX11Info::display(), GLX_EXTENSIONS)));
        if (glxExt.contains(QLatin1String("GLX_ARB_get_proc_address"))) {
#if defined(Q_OS_LINUX) || defined(Q_OS_BSD4)
            void *handle = dlopen(NULL, RTLD_LAZY);
            if (handle) {
                glXGetProcAddressARB = (qt_glXGetProcAddressARB) dlsym(handle, "glXGetProcAddressARB");
                dlclose(handle);
            }
            if (!glXGetProcAddressARB)
#endif
            {
                extern const QString qt_gl_library_name();
                QLibrary lib(qt_gl_library_name());
                glXGetProcAddressARB = (qt_glXGetProcAddressARB) lib.resolve("glXGetProcAddressARB");
            }
        }
        resolved = true;
    }
    if (!glXGetProcAddressARB)
        return 0;
    return glXGetProcAddressARB(reinterpret_cast<const GLubyte *>(proc.toLatin1().data()));
}

/*****************************************************************************
  QGLOverlayWidget (Internal overlay class for X11)
 *****************************************************************************/

class QGLOverlayWidget : public QGLWidget
{
    Q_OBJECT
public:
    QGLOverlayWidget(const QGLFormat& format, QGLWidget* parent, const QGLWidget* shareWidget=0);

protected:
    void                initializeGL();
    void                paintGL();
    void                resizeGL(int w, int h);
    bool                x11Event(XEvent *e) { return realWidget->x11Event(e); }

private:
    QGLWidget*                realWidget;

private:
    Q_DISABLE_COPY(QGLOverlayWidget)
};


QGLOverlayWidget::QGLOverlayWidget(const QGLFormat& format, QGLWidget* parent,
                                   const QGLWidget* shareWidget)
    : QGLWidget(format, parent, shareWidget ? shareWidget->d_func()->olw : 0)
{
    setAttribute(Qt::WA_X11OpenGLOverlay);
    realWidget = parent;
}



void QGLOverlayWidget::initializeGL()
{
    QColor transparentColor = context()->overlayTransparentColor();
    if (transparentColor.isValid())
        qglClearColor(transparentColor);
    else
        qWarning("QGLOverlayWidget::initializeGL(): Could not get transparent color");
    realWidget->initializeOverlayGL();
}


void QGLOverlayWidget::resizeGL(int w, int h)
{
    glViewport(0, 0, w, h);
    realWidget->resizeOverlayGL(w, h);
}


void QGLOverlayWidget::paintGL()
{
    realWidget->paintOverlayGL();
}

#undef Bool
QT_BEGIN_INCLUDE_NAMESPACE
#include "qgl_x11.moc"
QT_END_INCLUDE_NAMESPACE

/*****************************************************************************
  QGLWidget UNIX/GLX-specific code
 *****************************************************************************/
void QGLWidgetPrivate::init(QGLContext *context, const QGLWidget *shareWidget)
{
    Q_Q(QGLWidget);
    initContext(context, shareWidget);
    olw = 0;

    if (q->isValid() && context->format().hasOverlay()) {
        QString olwName = q->objectName();
        olwName += QLatin1String("-QGL_internal_overlay_widget");
        olw = new QGLOverlayWidget(QGLFormat::defaultOverlayFormat(), q, shareWidget);
        olw->setObjectName(olwName);
        if (olw->isValid()) {
            olw->setAutoBufferSwap(false);
            olw->setFocusProxy(q);
        }
        else {
            delete olw;
            olw = 0;
            glcx->d_func()->glFormat.setOverlay(false);
        }
    }
}

bool QGLWidgetPrivate::renderCxPm(QPixmap* pm)
{
    Q_Q(QGLWidget);
    if (((XVisualInfo*)glcx->d_func()->vi)->depth != pm->depth())
        return false;

    GLXPixmap glPm;
#if defined(GLX_MESA_pixmap_colormap) && defined(QGL_USE_MESA_EXT)
    glPm = glXCreateGLXPixmapMESA(X11->display,
                                   (XVisualInfo*)glcx->vi,
                                   (Pixmap)pm->handle(),
                                   qt_gl_choose_cmap(pm->X11->display,
                                                (XVisualInfo*)glcx->vi));
#else
    glPm = (quint32)glXCreateGLXPixmap(X11->display,
                                         (XVisualInfo*)glcx->d_func()->vi,
                                         (Pixmap)pm->handle());
#endif

    if (!glXMakeCurrent(X11->display, glPm, (GLXContext)glcx->d_func()->cx)) {
        glXDestroyGLXPixmap(X11->display, glPm);
        return false;
    }

    glDrawBuffer(GL_FRONT);
    if (!glcx->initialized())
        q->glInit();
    q->resizeGL(pm->width(), pm->height());
    q->paintGL();
    glFlush();
    q->makeCurrent();
    glXDestroyGLXPixmap(X11->display, glPm);
    q->resizeGL(q->width(), q->height());
    return true;
}

/*! \internal
  Free up any allocated colormaps. This fn is only called for
  top-level widgets.
*/
void QGLWidgetPrivate::cleanupColormaps()
{
    if (!cmap.handle()) {
        return;
    } else {
        XFreeColormap(X11->display, (Colormap) cmap.handle());
        cmap.setHandle(0);
    }
}

void QGLWidget::setMouseTracking(bool enable)
{
    Q_D(QGLWidget);
    if (d->olw)
        d->olw->setMouseTracking(enable);
    QWidget::setMouseTracking(enable);
}


void QGLWidget::resizeEvent(QResizeEvent *)
{
    Q_D(QGLWidget);
    if (!isValid())
        return;
    makeCurrent();
    if (!d->glcx->initialized())
        glInit();
    glXWaitX();
    resizeGL(width(), height());
    if (d->olw)
        d->olw->setGeometry(rect());
}

const QGLContext* QGLWidget::overlayContext() const
{
    Q_D(const QGLWidget);
    if (d->olw)
        return d->olw->context();
    else
        return 0;
}


void QGLWidget::makeOverlayCurrent()
{
    Q_D(QGLWidget);
    if (d->olw)
        d->olw->makeCurrent();
}


void QGLWidget::updateOverlayGL()
{
    Q_D(QGLWidget);
    if (d->olw)
        d->olw->updateGL();
}

/*!
    \internal

    Sets a new QGLContext, \a context, for this QGLWidget, using the
    shared context, \a shareContext. If \a deleteOldContext is true,
    the original context is deleted; otherwise it is overridden.
*/
void QGLWidget::setContext(QGLContext *context,
                            const QGLContext* shareContext,
                            bool deleteOldContext)
{
    Q_D(QGLWidget);
    if (context == 0) {
        qWarning("QGLWidget::setContext: Cannot set null context");
        return;
    }
    if (!context->deviceIsPixmap() && context->device() != this) {
        qWarning("QGLWidget::setContext: Context must refer to this widget");
        return;
    }

    if (d->glcx)
        d->glcx->doneCurrent();
    QGLContext* oldcx = d->glcx;
    d->glcx = context;


    if (parentWidget()) {
        // force creation of delay-created widgets
        parentWidget()->winId();
        if (parentWidget()->x11Info().screen() != x11Info().screen())
            d_func()->xinfo = parentWidget()->d_func()->xinfo;
    }

    bool createFailed = false;
    if (!d->glcx->isValid()) {
        if (!d->glcx->create(shareContext ? shareContext : oldcx))
            createFailed = true;
    }
    if (createFailed) {
        if (deleteOldContext)
            delete oldcx;
        return;
    }

    if (d->glcx->windowCreated() || d->glcx->deviceIsPixmap()) {
        if (deleteOldContext)
            delete oldcx;
        return;
    }

    bool visible = isVisible();
    if (visible)
        hide();

    XVisualInfo *vi = (XVisualInfo*)d->glcx->d_func()->vi;
    XSetWindowAttributes a;

    QColormap colmap = QColormap::instance(vi->screen);
    a.colormap = qt_gl_choose_cmap(QX11Info::display(), vi);        // find best colormap
    a.background_pixel = colmap.pixel(palette().color(backgroundRole()));
    a.border_pixel = colmap.pixel(Qt::black);
    Window p = RootWindow(X11->display, vi->screen);
    if (parentWidget())
        p = parentWidget()->winId();

    Window w = XCreateWindow(X11->display, p, x(), y(), width(), height(),
                              0, vi->depth, InputOutput, vi->visual,
                              CWBackPixel|CWBorderPixel|CWColormap, &a);
    Window *cmw;
    Window *cmwret;
    int count;
    if (XGetWMColormapWindows(X11->display, window()->winId(),
                                &cmwret, &count)) {
        cmw = new Window[count+1];
        memcpy((char *)cmw, (char *)cmwret, sizeof(Window)*count);
        XFree((char *)cmwret);
        int i;
        for (i=0; i<count; i++) {
            if (cmw[i] == winId()) {                // replace old window
                cmw[i] = w;
                break;
            }
        }
        if (i >= count)                        // append new window
            cmw[count++] = w;
    } else {
        count = 1;
        cmw = new Window[count];
        cmw[0] = w;
    }

#if defined(GLX_MESA_release_buffers) && defined(QGL_USE_MESA_EXT)
    if (oldcx && oldcx->windowCreated())
        glXReleaseBuffersMESA(X11->display, winId());
#endif
    if (deleteOldContext)
        delete oldcx;
    oldcx = 0;

    if (testAttribute(Qt::WA_WState_Created))
        create(w);
    else
        d->createWinId(w);
    XSetWMColormapWindows(X11->display, window()->winId(), cmw, count);
    delete [] cmw;

    // calling QWidget::create() will always result in a new paint
    // engine being created - get rid of it and replace it with our
    // own

    if (visible)
        show();
    XFlush(X11->display);
    d->glcx->setWindowCreated(true);
}

const QGLColormap & QGLWidget::colormap() const
{
    Q_D(const QGLWidget);
    return d->cmap;
}

/*\internal
  Store color values in the given colormap.
*/
static void qStoreColors(QWidget * tlw, Colormap cmap,
                          const QGLColormap & cols)
{
    Q_UNUSED(tlw);
    XColor c;
    QRgb color;

    for (int i = 0; i < cols.size(); i++) {
        color = cols.entryRgb(i);
        c.pixel = i;
        c.red   = (ushort)((qRed(color) / 255.0) * 65535.0 + 0.5);
        c.green = (ushort)((qGreen(color) / 255.0) * 65535.0 + 0.5);
        c.blue  = (ushort)((qBlue(color) / 255.0) * 65535.0 + 0.5);
        c.flags = DoRed | DoGreen | DoBlue;
        XStoreColor(X11->display, cmap, &c);
    }
}

/*\internal
  Check whether the given visual supports dynamic colormaps or not.
*/
static bool qCanAllocColors(QWidget * w)
{
    bool validVisual = false;
    int  numVisuals;
    long mask;
    XVisualInfo templ;
    XVisualInfo * visuals;
    VisualID id = XVisualIDFromVisual((Visual *) w->window()->x11Info().visual());

    mask = VisualScreenMask;
    templ.screen = w->x11Info().screen();
    visuals = XGetVisualInfo(X11->display, mask, &templ, &numVisuals);

    for (int i = 0; i < numVisuals; i++) {
        if (visuals[i].visualid == id) {
            switch (visuals[i].c_class) {
                case TrueColor:
                case StaticColor:
                case StaticGray:
                case XGrayScale:
                    validVisual = false;
                    break;
                case DirectColor:
                case PseudoColor:
                    validVisual = true;
                    break;
            }
            break;
        }
    }
    XFree(visuals);

    if (!validVisual)
        return false;
    return true;
}


void QGLWidget::setColormap(const QGLColormap & c)
{
    Q_D(QGLWidget);
    QWidget * tlw = window(); // must return a valid widget

    d->cmap = c;
    if (!d->cmap.handle())
        return;

    if (!qCanAllocColors(this)) {
        qWarning("QGLWidget::setColormap: Cannot create a read/write "
                  "colormap for this visual");
        return;
    }

    // If the child GL widget is not of the same visual class as the
    // toplevel widget we will get in trouble..
    Window wid = tlw->winId();
    Visual * vis = (Visual *) tlw->x11Info().visual();;
    VisualID cvId = XVisualIDFromVisual((Visual *) x11Info().visual());
    VisualID tvId = XVisualIDFromVisual((Visual *) tlw->x11Info().visual());
    if (cvId != tvId) {
        wid = winId();
        vis = (Visual *) x11Info().visual();
    }

    if (!d->cmap.handle()) // allocate a cmap if necessary
        d->cmap.setHandle(XCreateColormap(X11->display, wid, vis, AllocAll));

    qStoreColors(this, (Colormap) d->cmap.handle(), c);
    XSetWindowColormap(X11->display, wid, (Colormap) d->cmap.handle());

    // tell the wm that this window has a special colormap
    Window * cmw;
    Window * cmwret;
    int count;
    if (XGetWMColormapWindows(X11->display, tlw->winId(), &cmwret, &count))
    {
        cmw = new Window[count+1];
        memcpy((char *) cmw, (char *) cmwret, sizeof(Window) * count);
        XFree((char *) cmwret);
        int i;
        for (i = 0; i < count; i++) {
            if (cmw[i] == winId()) {
                break;
            }
        }
        if (i >= count)   // append new window only if not in the list
            cmw[count++] = winId();
    } else {
        count = 1;
        cmw = new Window[count];
        cmw[0] = winId();
    }
    XSetWMColormapWindows(X11->display, tlw->winId(), cmw, count);
    delete [] cmw;
}

void QGLExtensions::init()
{
    static bool init_done = false;

    if (init_done)
        return;
    init_done = true;

    QGLWidget dmy;
    dmy.makeCurrent();
    init_extensions();

    // nvidia 9x.xx unix drivers contain a bug which requires us to call glFinish before releasing an fbo
    // to avoid painting artifacts
    const QByteArray versionString(reinterpret_cast<const char*>(glGetString(GL_VERSION)));
    const int pos = versionString.indexOf("NVIDIA");
    if (pos >= 0) {
        const float nvidiaDriverVersion = versionString.mid(pos + strlen("NVIDIA")).toFloat();
        nvidiaFboNeedsFinish = nvidiaDriverVersion >= 90.0 && nvidiaDriverVersion < 100.0;
    }
}

QT_END_NAMESPACE