C++ QPlatformWindowFormat类代码示例

bool QGLContext::chooseContext(const QGLContext* shareContext)
{
    Q_D(QGLContext);
    if(!d->paintDevice || d->paintDevice->devType() != QInternal::Widget) {
        d->valid = false;
    }else {
        QWidget *widget = static_cast<QWidget *>(d->paintDevice);
        if (!widget->platformWindow()){
            QGLFormat glformat = format();
            QPlatformWindowFormat winFormat = QGLFormat::toPlatformWindowFormat(glformat);
            if (shareContext) {
                winFormat.setSharedContext(shareContext->d_func()->platformContext);
            }
            if (widget->testAttribute(Qt::WA_TranslucentBackground))
                winFormat.setAlpha(true);
            winFormat.setWindowApi(QPlatformWindowFormat::OpenGL);
            winFormat.setWindowSurface(false);
            widget->setPlatformWindowFormat(winFormat);
            widget->winId();//make window
        }
        d->platformContext = widget->platformWindow()->glContext();
        Q_ASSERT(d->platformContext);
        d->glFormat = QGLFormat::fromPlatformWindowFormat(d->platformContext->platformWindowFormat());
        d->valid =(bool) d->platformContext;
        if (d->valid) {
            d->platformContext->setQGLContextHandle(this,qDeleteQGLContext);
        }
        d->setupSharing();
    }


    return d->valid;
}

GLXFBConfig qglx_findConfig(Display *display, int screen , const QPlatformWindowFormat &format, int drawableBit)
{
    bool reduced = true;
    GLXFBConfig chosenConfig = 0;
    QPlatformWindowFormat reducedFormat = format;
    while (!chosenConfig && reduced) {
        QVector<int> spec = qglx_buildSpec(reducedFormat, drawableBit);
        int confcount = 0;
        GLXFBConfig *configs;
        configs = glXChooseFBConfig(display, screen,spec.constData(),&confcount);
        if (confcount)
        {
            for (int i = 0; i < confcount; i++) {
                chosenConfig = configs[i];
                // Make sure we try to get an ARGB visual if the format asked for an alpha:
                if (reducedFormat.alpha()) {
                    int alphaSize;
                    glXGetFBConfigAttrib(display,configs[i],GLX_ALPHA_SIZE,&alphaSize);
                    if (alphaSize > 0)
                        break;
                } else {
                    break; // Just choose the first in the list if there's no alpha requested
                }
            }

            XFree(configs);
        }
        reducedFormat = qglx_reducePlatformWindowFormat(reducedFormat,&reduced);
    }

    if (!chosenConfig)
        qWarning("Warning: no suitable glx confiuration found");

    return chosenConfig;
}

QPlatformGLContext *QXlibWindow::glContext() const
{
    if (!QApplicationPrivate::platformIntegration()->hasCapability(QPlatformIntegration::OpenGL))
        return 0;
    if (!mGLContext) {
        QXlibWindow *that = const_cast<QXlibWindow *>(this);
#if !defined(QT_NO_OPENGL)
#if !defined(QT_OPENGL_ES_2)
        that->mGLContext = new QGLXContext(x_window, mScreen,widget()->platformWindowFormat());
#else
        EGLDisplay display = mScreen->eglDisplay();

        QPlatformWindowFormat windowFormat = correctColorBuffers(widget()->platformWindowFormat());

        EGLConfig config = q_configFromQPlatformWindowFormat(display,windowFormat);
        QVector<EGLint> eglContextAttrs;
        eglContextAttrs.append(EGL_CONTEXT_CLIENT_VERSION);
        eglContextAttrs.append(2);
        eglContextAttrs.append(EGL_NONE);

        EGLSurface eglSurface = eglCreateWindowSurface(display,config,(EGLNativeWindowType)x_window,0);
        that->mGLContext = new QEGLPlatformContext(display, config, eglContextAttrs.data(), eglSurface, EGL_OPENGL_ES_API, static_cast<QEGLPlatformContext *>(windowFormat.sharedGLContext()));
#endif
#endif
    }
    return mGLContext;
}

QGLTemporaryContext::QGLTemporaryContext(bool, QWidget *)
    : d(new QGLTemporaryContextPrivate)
{
    d->context = const_cast<QPlatformGLContext *>(QPlatformGLContext::currentContext());
    if (d->context)
        d->context->doneCurrent();
    d->widget = new QWidget;
    d->widget->setGeometry(0,0,3,3);
    QPlatformWindowFormat format = d->widget->platformWindowFormat();
    format.setWindowApi(QPlatformWindowFormat::OpenGL);
    format.setWindowSurface(false);
    d->widget->setPlatformWindowFormat(format);
    d->widget->winId();

    d->widget->platformWindow()->glContext()->makeCurrent();
}

QPlatformWindowFormat QXlibWindow::correctColorBuffers(const QPlatformWindowFormat &platformWindowFormat) const
{
    // I have only tested this setup on a dodgy intel setup, where I didn't use standard libs,
    // so this might be not what we want to do :)
    if ( !(platformWindowFormat.redBufferSize() == -1   &&
            platformWindowFormat.greenBufferSize() == -1 &&
            platformWindowFormat.blueBufferSize() == -1))
        return platformWindowFormat;

    QPlatformWindowFormat windowFormat = platformWindowFormat;
    if (mScreen->depth() == 16) {
        windowFormat.setRedBufferSize(5);
        windowFormat.setGreenBufferSize(6);
        windowFormat.setBlueBufferSize(5);
    } else {
        windowFormat.setRedBufferSize(8);
        windowFormat.setGreenBufferSize(8);
        windowFormat.setBlueBufferSize(8);
    }

    return windowFormat;
}

QGLXContext::QGLXContext(Window window, QXcbScreen *screen, const QPlatformWindowFormat &format)
    : QPlatformGLContext()
    , m_screen(screen)
    , m_drawable((Drawable)window)
    , m_context(0)
{
    Q_XCB_NOOP(m_screen->connection());
    const QPlatformGLContext *sharePlatformContext;
    sharePlatformContext = format.sharedGLContext();
    GLXContext shareGlxContext = 0;
    if (sharePlatformContext)
        shareGlxContext = static_cast<const QGLXContext*>(sharePlatformContext)->glxContext();

    GLXFBConfig config = qglx_findConfig(DISPLAY_FROM_XCB(screen),screen->screenNumber(),format);
    m_context = glXCreateNewContext(DISPLAY_FROM_XCB(screen), config, GLX_RGBA_TYPE, shareGlxContext, TRUE);
    m_windowFormat = qglx_platformWindowFromGLXFBConfig(DISPLAY_FROM_XCB(screen), config, m_context);
    Q_XCB_NOOP(m_screen->connection());
}

QWaylandGLContext::QWaylandGLContext(EGLDisplay eglDisplay, const QPlatformWindowFormat &format)
    : QPlatformGLContext()
    , mEglDisplay(eglDisplay)
    , mSurface(EGL_NO_SURFACE)
    , mConfig(q_configFromQPlatformWindowFormat(mEglDisplay,format,true))
    , mFormat(qt_qPlatformWindowFormatFromConfig(mEglDisplay,mConfig))
{
    QPlatformGLContext *sharePlatformContext = 0;
    sharePlatformContext = format.sharedGLContext();
    mFormat.setSharedContext(sharePlatformContext);
    EGLContext shareEGLContext = EGL_NO_CONTEXT;
    if (sharePlatformContext)
        shareEGLContext = static_cast<const QWaylandGLContext*>(sharePlatformContext)->mContext;

    eglBindAPI(EGL_OPENGL_ES_API);

    QVector<EGLint> eglContextAttrs;
    eglContextAttrs.append(EGL_CONTEXT_CLIENT_VERSION);
    eglContextAttrs.append(2);
    eglContextAttrs.append(EGL_NONE);

    mContext = eglCreateContext(mEglDisplay, mConfig,
                                shareEGLContext, eglContextAttrs.constData());
}

QPlatformWindowFormat qglx_reducePlatformWindowFormat(const QPlatformWindowFormat &format, bool *reduced)
{
    QPlatformWindowFormat retFormat = format;
    *reduced = true;

    if (retFormat.sampleBuffers()) {
        retFormat.setSampleBuffers(false);
    } else if (retFormat.stereo()) {
        retFormat.setStereo(false);
    } else if (retFormat.accum()) {
        retFormat.setAccum(false);
    }else if (retFormat.stencil()) {
        retFormat.setStencil(false);
    }else if (retFormat.alpha()) {
        retFormat.setAlpha(false);
    }else if (retFormat.depth()) {
        retFormat.setDepth(false);
    }else if (retFormat.doubleBuffer()) {
        retFormat.setDoubleBuffer(false);
    }else{
        *reduced = false;
    }
    return retFormat;
}

QPlatformWindowFormat qglx_platformWindowFromGLXFBConfig(Display *display, GLXFBConfig config, GLXContext ctx)
{
    QPlatformWindowFormat format;
    int redSize     = 0;
    int greenSize   = 0;
    int blueSize    = 0;
    int alphaSize   = 0;
    int depthSize   = 0;
    int stencilSize = 0;
    int sampleBuffers = 0;
    int sampleCount = 0;
    int level       = 0;
    int rgba        = 0;
    int stereo      = 0;
    int accumSizeA  = 0;
    int accumSizeR  = 0;
    int accumSizeG  = 0;
    int accumSizeB  = 0;

    XVisualInfo *vi = glXGetVisualFromFBConfig(display,config);
    glXGetConfig(display,vi,GLX_RGBA,&rgba);
    XFree(vi);
    glXGetFBConfigAttrib(display, config, GLX_RED_SIZE,     &redSize);
    glXGetFBConfigAttrib(display, config, GLX_GREEN_SIZE,   &greenSize);
    glXGetFBConfigAttrib(display, config, GLX_BLUE_SIZE,    &blueSize);
    glXGetFBConfigAttrib(display, config, GLX_ALPHA_SIZE,   &alphaSize);
    glXGetFBConfigAttrib(display, config, GLX_DEPTH_SIZE,   &depthSize);
    glXGetFBConfigAttrib(display, config, GLX_STENCIL_SIZE, &stencilSize);
    glXGetFBConfigAttrib(display, config, GLX_SAMPLES,      &sampleBuffers);
    glXGetFBConfigAttrib(display, config, GLX_LEVEL,        &level);
    glXGetFBConfigAttrib(display, config, GLX_STEREO,       &stereo);
    glXGetFBConfigAttrib(display, config, GLX_ACCUM_ALPHA_SIZE, &accumSizeA);
    glXGetFBConfigAttrib(display, config, GLX_ACCUM_RED_SIZE, &accumSizeR);
    glXGetFBConfigAttrib(display, config, GLX_ACCUM_GREEN_SIZE, &accumSizeG);
    glXGetFBConfigAttrib(display, config, GLX_ACCUM_BLUE_SIZE, &accumSizeB);

    format.setRedBufferSize(redSize);
    format.setGreenBufferSize(greenSize);
    format.setBlueBufferSize(blueSize);
    format.setAlphaBufferSize(alphaSize);
    format.setDepthBufferSize(depthSize);
    format.setStencilBufferSize(stencilSize);
    format.setSampleBuffers(sampleBuffers);
    if (format.sampleBuffers()) {
        glXGetFBConfigAttrib(display, config, GLX_SAMPLES_ARB, &sampleCount);
        format.setSamples(sampleCount);
    }

    format.setDirectRendering(glXIsDirect(display, ctx));
    format.setRgba(rgba);
    format.setStereo(stereo);
    format.setAccumBufferSize(accumSizeB);

    return format;
}

QOpenKODEWindow::QOpenKODEWindow(QWidget *tlw)
    : QPlatformWindow(tlw), isFullScreen(false)
{
    if (tlw->platformWindowFormat().windowApi() == QPlatformWindowFormat::OpenVG) {
        m_eglApi = EGL_OPENVG_API;
    } else {
        m_eglContextAttrs.append(EGL_CONTEXT_CLIENT_VERSION);
        m_eglContextAttrs.append(2);

        m_eglApi = EGL_OPENGL_ES_API;
    }
    eglBindAPI(m_eglApi);

    m_eglContextAttrs.append(EGL_NONE);
    m_eglWindowAttrs.append(EGL_NONE);

    QList<QPlatformScreen *> screens = QApplicationPrivate::platformIntegration()->screens();
    //XXXX: jl figure out how to pick the correct screen.
//    Q_ASSERT(screens.size() > tlw->d_func()->screenNumber);
//    QOpenKODEScreen *screen = qobject_cast<QOpenKODEScreen *>(screens.at(tlw->d_func()->screenNumber));
    QOpenKODEScreen *screen = qobject_cast<QOpenKODEScreen *>(screens.at(0));
    if (!screen) {
        qErrnoWarning("Could not make QOpenKODEWindow without a screen");
    }

    QPlatformWindowFormat format = tlw->platformWindowFormat();
    format.setRedBufferSize(5);
    format.setGreenBufferSize(6);
    format.setBlueBufferSize(5);

    m_eglConfig = q_configFromQPlatformWindowFormat(screen->eglDisplay(),format);

    m_kdWindow = kdCreateWindow(screen->eglDisplay(),
                              m_eglConfig,
                              this);
    kdInstallCallback(kdProcessMouseEvents,KD_EVENT_INPUT_POINTER,this);
#ifdef KD_ATX_keyboard
    kdInstallCallback(kdProcessKeyEvents, KD_EVENT_INPUT_KEY_ATX,this);
#endif //KD_ATX_keyboard

    if (!m_kdWindow) {
        qErrnoWarning(kdGetError(), "Error creating native window");
        return;
    }

    KDboolean exclusive(false);
    if (kdSetWindowPropertybv(m_kdWindow,KD_WINDOWPROPERTY_DESKTOP_EXCLUSIVE_NV, &exclusive)) {
        isFullScreen = true;
    }

    if (isFullScreen) {
        tlw->setGeometry(screen->geometry());
        screen->setFullScreen(isFullScreen);
    }else {
        const KDint windowSize[2]  = { tlw->width(), tlw->height() };
        if (kdSetWindowPropertyiv(m_kdWindow, KD_WINDOWPROPERTY_SIZE, windowSize)) {
            qErrnoWarning(kdGetError(), "Could not set native window size");
        }
        KDboolean visibillity(false);
        if (kdSetWindowPropertybv(m_kdWindow, KD_WINDOWPROPERTY_VISIBILITY, &visibillity)) {
            qErrnoWarning(kdGetError(), "Could not set visibillity to false");
        }

        const KDint windowPos[2] = { tlw->x(), tlw->y() };
        if (kdSetWindowPropertyiv(m_kdWindow, KD_WINDOWPROPERTY_DESKTOP_OFFSET_NV, windowPos)) {
            qErrnoWarning(kdGetError(), "Could not set native window position");
            return;
        }
    }


    QOpenKODEIntegration *integration = static_cast<QOpenKODEIntegration *>(QApplicationPrivate::platformIntegration());

    if (!isFullScreen || (isFullScreen && !integration->mainGLContext())) {
        if (kdRealizeWindow(m_kdWindow, &m_eglWindow)) {
            qErrnoWarning(kdGetError(), "Could not realize native window");
            return;
        }

        EGLSurface surface = eglCreateWindowSurface(screen->eglDisplay(),m_eglConfig,m_eglWindow,m_eglWindowAttrs.constData());
        m_platformGlContext = new QEGLPlatformContext(screen->eglDisplay(), m_eglConfig,
                                                      m_eglContextAttrs.data(), surface, m_eglApi);
        integration->setMainGLContext(m_platformGLContext);
    } else {
        m_platformGlContext = integration->mainGLContext();
        kdDestroyWindow(m_kdWindow);
        m_kdWindow = 0;
    }
}

void QEglFSScreen::createAndSetPlatformContext()
{
    QPlatformWindowFormat platformFormat = QPlatformWindowFormat::defaultFormat();

    platformFormat.setWindowApi(QPlatformWindowFormat::OpenGL);

    QByteArray depthString = qgetenv("QT_QPA_EGLFS_DEPTH");
    if (depthString.toInt() == 16) {
        platformFormat.setDepth(16);
        platformFormat.setRedBufferSize(5);
        platformFormat.setGreenBufferSize(6);
        platformFormat.setBlueBufferSize(5);
        m_depth = 16;
        m_format = QImage::Format_RGB16;
    } else {
        platformFormat.setDepth(32);
        platformFormat.setRedBufferSize(8);
        platformFormat.setGreenBufferSize(8);
        platformFormat.setBlueBufferSize(8);
        m_depth = 32;
        m_format = QImage::Format_RGB32;
    }
    if (!qgetenv("QT_QPA_EGLFS_MULTISAMPLE").isEmpty()) {
        platformFormat.setSampleBuffers(true);
    }


    EGLConfig config = q_configFromQPlatformWindowFormat(m_dpy, platformFormat);

    EGLNativeWindowType eglWindow = 0;
#ifdef Q_OPENKODE
    if (kdInitializeNV() == KD_ENOTINITIALIZED) {
        qFatal("Did not manage to initialize openkode");
    }
    KDWindow *window = kdCreateWindow(m_dpy,config,0);

    kdRealizeWindow(window,&eglWindow);
#endif

    m_surface = eglCreateWindowSurface(m_dpy, config, eglWindow, NULL);
    if (m_surface == EGL_NO_SURFACE) {
        qWarning("Could not create the egl surface: error = 0x%x\n", eglGetError());
        eglTerminate(m_dpy);
        qFatal("EGL error");
    }
    //    qWarning("Created surface %dx%d\n", w, h);

#ifdef QEGL_EXTRA_DEBUG
    qWarning("Configuration %d matches requirements\n", (int)config);

    for (index = 0; attrs[index].attr != -1; ++index) {
        EGLint value;
        if (eglGetConfigAttrib(m_dpy, config, attrs[index].attr, &value)) {
            qWarning("\t%s: %d\n", attrs[index].name, (int)value);
        }
    }
    qWarning("\n");
#endif

    EGLint temp;
    EGLint attribList[32];

    temp = 0;

    attribList[temp++] = EGL_CONTEXT_CLIENT_VERSION;
    attribList[temp++] = 2; // GLES version 2
    attribList[temp++] = EGL_NONE;

    QEGLPlatformContext *platformContext = new QEGLPlatformContext(m_dpy,config,attribList,m_surface,EGL_OPENGL_ES_API);
    m_platformContext = platformContext;

    EGLint w,h;                    // screen size detection
    eglQuerySurface(m_dpy, m_surface, EGL_WIDTH, &w);
    eglQuerySurface(m_dpy, m_surface, EGL_HEIGHT, &h);

    m_geometry = QRect(0,0,w,h);

}

QT_BEGIN_NAMESPACE

QVector<EGLint> q_createConfigAttributesFromFormat(const QPlatformWindowFormat &format)
{
    int redSize     = format.redBufferSize();
    int greenSize   = format.greenBufferSize();
    int blueSize    = format.blueBufferSize();
    int alphaSize   = format.alphaBufferSize();
    int depthSize   = format.depthBufferSize();
    int stencilSize = format.stencilBufferSize();
    int sampleCount = format.samples();

    // QPlatformWindowFormat uses a magic value of -1 to indicate "don't care", even when a buffer of that
    // type has been requested. So we must check QPlatformWindowFormat's booleans too if size is -1:
    if (format.alpha() && alphaSize <= 0)
        alphaSize = 1;
    if (format.depth() && depthSize <= 0)
        depthSize = 1;
    if (format.stencil() && stencilSize <= 0)
        stencilSize = 1;
    if (format.sampleBuffers() && sampleCount <= 0)
        sampleCount = 1;

    // We want to make sure 16-bit configs are chosen over 32-bit configs as they will provide
    // the best performance. The EGL config selection algorithm is a bit stange in this regard:
    // The selection criteria for EGL_BUFFER_SIZE is "AtLeast", so we can't use it to discard
    // 32-bit configs completely from the selection. So it then comes to the sorting algorithm.
    // The red/green/blue sizes have a sort priority of 3, so they are sorted by first. The sort
    // order is special and described as "by larger _total_ number of color bits.". So EGL will
    // put 32-bit configs in the list before the 16-bit configs. However, the spec also goes on
    // to say "If the requested number of bits in attrib_list for a particular component is 0,
    // then the number of bits for that component is not considered". This part of the spec also
    // seems to imply that setting the red/green/blue bits to zero means none of the components
    // are considered and EGL disregards the entire sorting rule. It then looks to the next
    // highest priority rule, which is EGL_BUFFER_SIZE. Despite the selection criteria being
    // "AtLeast" for EGL_BUFFER_SIZE, it's sort order is "smaller" meaning 16-bit configs are
    // put in the list before 32-bit configs. So, to make sure 16-bit is preffered over 32-bit,
    // we must set the red/green/blue sizes to zero. This has an unfortunate consequence that
    // if the application sets the red/green/blue size to 5/6/5 on the QPlatformWindowFormat,
    // they will probably get a 32-bit config, even when there's an RGB565 config available.

    // Now normalize the values so -1 becomes 0
    redSize   = redSize   > 0 ? redSize   : 0;
    greenSize = greenSize > 0 ? greenSize : 0;
    blueSize  = blueSize  > 0 ? blueSize  : 0;
    alphaSize = alphaSize > 0 ? alphaSize : 0;
    depthSize = depthSize > 0 ? depthSize : 0;
    stencilSize = stencilSize > 0 ? stencilSize : 0;
    sampleCount = sampleCount > 0 ? sampleCount : 0;

    QVector<EGLint> configAttributes;

    configAttributes.append(EGL_RED_SIZE);
    configAttributes.append(redSize);

    configAttributes.append(EGL_GREEN_SIZE);
    configAttributes.append(greenSize);

    configAttributes.append(EGL_BLUE_SIZE);
    configAttributes.append(blueSize);

    configAttributes.append(EGL_ALPHA_SIZE);
    configAttributes.append(alphaSize);

    configAttributes.append(EGL_DEPTH_SIZE);
    configAttributes.append(depthSize);

    configAttributes.append(EGL_STENCIL_SIZE);
    configAttributes.append(stencilSize);

    configAttributes.append(EGL_SAMPLES);
    configAttributes.append(sampleCount);

    configAttributes.append(EGL_SAMPLE_BUFFERS);
    configAttributes.append(sampleCount? 1:0);

    return configAttributes;
}

EGLConfig q_configFromQPlatformWindowFormat(EGLDisplay display, const QPlatformWindowFormat &format, bool highestPixelFormat, int surfaceType)
{
    EGLConfig cfg = 0;
    QVector<EGLint> configureAttributes = q_createConfigAttributesFromFormat(format);
    configureAttributes.append(EGL_SURFACE_TYPE); //we only support eglconfigs for windows for now
    configureAttributes.append(surfaceType);

    configureAttributes.append(EGL_RENDERABLE_TYPE);
    if (format.windowApi() == QPlatformWindowFormat::OpenVG) {
        configureAttributes.append(EGL_OPENVG_BIT);        
    } else {
        configureAttributes.append(EGL_OPENGL_ES2_BIT);
    }
    configureAttributes.append(EGL_NONE);

    do {
        // Get the number of matching configurations for this set of properties.
        EGLint matching = 0;
        if (!eglChooseConfig(display, configureAttributes.constData(), 0, 0, &matching) || !matching)
            continue;

        // If we want the best pixel format, then return the first
        // matching configuration.
        if (highestPixelFormat) {
            eglChooseConfig(display, configureAttributes.constData(), &cfg, 1, &matching);
            if (matching < 1)
                continue;
            return cfg;
        }

        // Fetch all of the matching configurations and find the
        // first that matches the pixel format we wanted.
        int i = configureAttributes.indexOf(EGL_RED_SIZE);
        int confAttrRed = configureAttributes.at(i+1);
        i = configureAttributes.indexOf(EGL_GREEN_SIZE);
        int confAttrGreen = configureAttributes.at(i+1);
        i = configureAttributes.indexOf(EGL_BLUE_SIZE);
        int confAttrBlue = configureAttributes.at(i+1);
        i = configureAttributes.indexOf(EGL_ALPHA_SIZE);
        int confAttrAlpha = configureAttributes.at(i+1);

        EGLint size = matching;
        EGLConfig *configs = new EGLConfig [size];
        eglChooseConfig(display, configureAttributes.constData(), configs, size, &matching);
        for (EGLint index = 0; index < size; ++index) {
            EGLint red, green, blue, alpha;
            eglGetConfigAttrib(display, configs[index], EGL_RED_SIZE, &red);
            eglGetConfigAttrib(display, configs[index], EGL_GREEN_SIZE, &green);
            eglGetConfigAttrib(display, configs[index], EGL_BLUE_SIZE, &blue);
            eglGetConfigAttrib(display, configs[index], EGL_ALPHA_SIZE, &alpha);
            if (red == confAttrRed &&
                    green == confAttrGreen &&
                    blue == confAttrBlue &&
                    (confAttrAlpha == 0 ||
                     alpha == confAttrAlpha)) {
                cfg = configs[index];
                delete [] configs;
                return cfg;
            }
        }
        delete [] configs;
    } while (q_reduceConfigAttributes(&configureAttributes));
    qWarning("Cant find EGLConfig, returning null config");
    return 0;
}

/*!
    \since 4.8

    Returns a platform window format for the OpenGL format specified by \a format.
*/
QPlatformWindowFormat QGLFormat::toPlatformWindowFormat(const QGLFormat &format)
{
    QPlatformWindowFormat retFormat;
    retFormat.setAccum(format.accum());
    if (format.accumBufferSize() >= 0)
        retFormat.setAccumBufferSize(format.accumBufferSize());
    retFormat.setAlpha(format.alpha());
    if (format.alphaBufferSize() >= 0)
        retFormat.setAlphaBufferSize(format.alphaBufferSize());
    if (format.blueBufferSize() >= 0)
        retFormat.setBlueBufferSize(format.blueBufferSize());
    retFormat.setDepth(format.depth());
    if (format.depthBufferSize() >= 0)
        retFormat.setDepthBufferSize(format.depthBufferSize());
    retFormat.setDirectRendering(format.directRendering());
    retFormat.setDoubleBuffer(format.doubleBuffer());
    if (format.greenBufferSize() >= 0)
        retFormat.setGreenBufferSize(format.greenBufferSize());
    if (format.redBufferSize() >= 0)
        retFormat.setRedBufferSize(format.redBufferSize());
    retFormat.setRgba(format.rgba());
    retFormat.setSampleBuffers(format.sampleBuffers());
    if (format.samples() >= 0)
        retFormat.setSamples(format.samples());
    retFormat.setStencil(format.stencil());
    if (format.stencilBufferSize() >= 0)
        retFormat.setStencilBufferSize(format.stencilBufferSize());
    retFormat.setStereo(format.stereo());
    retFormat.setSwapInterval(format.swapInterval());
    return retFormat;
}

QVector<int> qglx_buildSpec(const QPlatformWindowFormat &format, int drawableBit)
{
    QVector<int> spec(48);
    int i = 0;

    spec[i++] = GLX_LEVEL;
    spec[i++] = 0;
    spec[i++] = GLX_DRAWABLE_TYPE; spec[i++] = drawableBit;

    if (format.rgba()) {
        spec[i++] = GLX_RENDER_TYPE; spec[i++] = GLX_RGBA_BIT;
        spec[i++] = GLX_RED_SIZE; spec[i++] = (format.redBufferSize() == -1) ? 1 : format.redBufferSize();
        spec[i++] = GLX_GREEN_SIZE; spec[i++] =  (format.greenBufferSize() == -1) ? 1 : format.greenBufferSize();
        spec[i++] = GLX_BLUE_SIZE; spec[i++] = (format.blueBufferSize() == -1) ? 1 : format.blueBufferSize();
        if (format.alpha()) {
                spec[i++] = GLX_ALPHA_SIZE; spec[i++] = (format.alphaBufferSize() == -1) ? 1 : format.alphaBufferSize();
            }

        spec[i++] = GLX_ACCUM_RED_SIZE; spec[i++] = (format.accumBufferSize() == -1) ? 1 : format.accumBufferSize();
        spec[i++] = GLX_ACCUM_GREEN_SIZE; spec[i++] = (format.accumBufferSize() == -1) ? 1 : format.accumBufferSize();
        spec[i++] = GLX_ACCUM_BLUE_SIZE; spec[i++] = (format.accumBufferSize() == -1) ? 1 : format.accumBufferSize();

        if (format.alpha()) {
            spec[i++] = GLX_ACCUM_ALPHA_SIZE; spec[i++] = (format.accumBufferSize() == -1) ? 1 : format.accumBufferSize();
        }

    } else {
        spec[i++] = GLX_RENDER_TYPE; spec[i++] = GLX_COLOR_INDEX_BIT; //I'm really not sure if this works....
        spec[i++] = GLX_BUFFER_SIZE; spec[i++] = 8;
    }

    spec[i++] = GLX_DOUBLEBUFFER; spec[i++] = format.doubleBuffer() ? True : False;
    spec[i++] = GLX_STEREO; spec[i++] =  format.stereo() ? True : False;

    if (format.depth()) {
        spec[i++] = GLX_DEPTH_SIZE; spec[i++] = (format.depthBufferSize() == -1) ? 1 : format.depthBufferSize();
    }

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

    spec[i++] = XNone;
    return spec;
}