C++ QEglProperties类代码示例

bool QGLContext::chooseContext(const QGLContext* shareContext)
{
        Q_D(QGLContext);

    // Validate the device.
    if (!device())
        return false;
    int devType = device()->devType();
    if (devType != QInternal::Pixmap && devType != QInternal::Image && devType != QInternal::Widget) {
        qWarning("QGLContext::chooseContext(): Cannot create QGLContext's for paint device type %d", devType);
        return false;
    }

    // Get the display and initialize it.
    d->eglContext = new QEglContext();
    d->ownsEglContext = true;
    d->eglContext->setApi(QEgl::OpenGL);

    // Construct the configuration we need for this surface.
    QEglProperties configProps;
    qt_eglproperties_set_glformat(configProps, d->glFormat);
    configProps.setDeviceType(devType);
    configProps.setPaintDeviceFormat(device());
    configProps.setRenderableType(QEgl::OpenGL);

    // Search for a matching configuration, reducing the complexity
    // each time until we get something that matches.
    if (!d->eglContext->chooseConfig(configProps)) {
        delete d->eglContext;
        d->eglContext = 0;
        return false;
    }

    // Inform the higher layers about the actual format properties.
    qt_glformat_from_eglconfig(d->glFormat, d->eglContext->config());

    // Create a new context for the configuration.
    if (!d->eglContext->createContext
            (shareContext ? shareContext->d_func()->eglContext : 0)) {
        delete d->eglContext;
        d->eglContext = 0;
        return false;
    }
    d->sharing = d->eglContext->isSharing();
    if (d->sharing && shareContext)
        const_cast<QGLContext *>(shareContext)->d_func()->sharing = true;

#if defined(EGL_VERSION_1_1)
    if (d->glFormat.swapInterval() != -1 && devType == QInternal::Widget)
        eglSwapInterval(d->eglContext->display(), d->glFormat.swapInterval());
#endif

    // Create the EGL surface to draw into.
    d->eglSurface = d->eglContext->createSurface(device());
    if (d->eglSurface == EGL_NO_SURFACE) {
        delete d->eglContext;
        d->eglContext = 0;
        return false;
    }

    return true;

}

// Chooses the EGL config and creates the EGL context
bool QGLContext::chooseContext(const QGLContext* shareContext)
{
    Q_D(QGLContext);

    if (!device())
        return false;

    int devType = device()->devType();

    QX11PixmapData *x11PixmapData = 0;
    if (devType == QInternal::Pixmap) {
        QPixmapData *pmd = static_cast<QPixmap*>(device())->data_ptr().data();
        if (pmd->classId() == QPixmapData::X11Class)
            x11PixmapData = static_cast<QX11PixmapData*>(pmd);
        else {
            // TODO: Replace the pixmap's data with a new QX11PixmapData
            qWarning("WARNING: Creating a QGLContext on a QPixmap is only supported for X11 pixmap backend");
            return false;
        }
    } else if ((devType != QInternal::Widget) && (devType != QInternal::Pbuffer)) {
        qWarning("WARNING: Creating a QGLContext not supported on device type %d", devType);
        return false;
    }

    // Only create the eglContext if we don't already have one:
    if (d->eglContext == 0) {
        d->eglContext = new QEglContext();
        d->ownsEglContext = true;
        d->eglContext->setApi(QEgl::OpenGL);

        // If the device is a widget with WA_TranslucentBackground set, make sure the glFormat
        // has the alpha channel option set:
        if (devType == QInternal::Widget) {
            QWidget* widget = static_cast<QWidget*>(device());
            if (widget->testAttribute(Qt::WA_TranslucentBackground))
                d->glFormat.setAlpha(true);
        }

        // Construct the configuration we need for this surface.
        QEglProperties configProps;
        configProps.setDeviceType(devType);
        configProps.setRenderableType(QEgl::OpenGL);
        qt_eglproperties_set_glformat(configProps, d->glFormat);

        // Set buffer preserved for regular QWidgets, QGLWidgets are ok with either preserved or destroyed:
        if ((devType == QInternal::Widget) && qobject_cast<QGLWidget*>(static_cast<QWidget*>(device())) == 0)
            configProps.setValue(EGL_SWAP_BEHAVIOR, EGL_BUFFER_PRESERVED);

        if (!d->eglContext->chooseConfig(configProps, QEgl::BestPixelFormat)) {
            delete d->eglContext;
            d->eglContext = 0;
            return false;
        }

        // Create a new context for the configuration.
        QEglContext* eglSharedContext = shareContext ? shareContext->d_func()->eglContext : 0;
        if (!d->eglContext->createContext(eglSharedContext)) {
            delete d->eglContext;
            d->eglContext = 0;
            return false;
        }
        d->sharing = d->eglContext->isSharing();
        if (d->sharing && shareContext)
            const_cast<QGLContext *>(shareContext)->d_func()->sharing = true;
    }

    // Inform the higher layers about the actual format properties
    qt_glformat_from_eglconfig(d->glFormat, d->eglContext->config());

    // Do don't create the EGLSurface for everything.
    //    QWidget - yes, create the EGLSurface and store it in QGLContextPrivate::eglSurface
    //    QGLWidget - yes, create the EGLSurface and store it in QGLContextPrivate::eglSurface
    //    QPixmap - yes, create the EGLSurface but store it in QX11PixmapData::gl_surface
    //    QGLPixelBuffer - no, it creates the surface itself and stores it in QGLPixelBufferPrivate::pbuf

    if (devType == QInternal::Widget) {
        if (d->eglSurface != EGL_NO_SURFACE)
            eglDestroySurface(d->eglContext->display(), d->eglSurface);
        // extraWindowSurfaceCreationProps default to NULL unless were specifically set before
        d->eglSurface = QEgl::createSurface(device(), d->eglContext->config(), d->extraWindowSurfaceCreationProps);
        XFlush(X11->display);
        setWindowCreated(true);
    }

    if (x11PixmapData) {
        // TODO: Actually check to see if the existing surface can be re-used
        if (x11PixmapData->gl_surface)
            eglDestroySurface(d->eglContext->display(), (EGLSurface)x11PixmapData->gl_surface);

        x11PixmapData->gl_surface = (void*)QEgl::createSurface(device(), d->eglContext->config());
    }

    return true;
}