/****************************************************************************

**

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** This file contains pre-release code and may not be distributed.

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** contained in the Technology Preview License Agreement accompanying

** this package.

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** GNU Lesser General Public License Usage

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** 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

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****************************************************************************/

//! [0]

QGLFormat fmt;

fmt.setAlpha(true);

fmt.setStereo(true);

QGLFormat::setDefaultFormat(fmt);

//! [0]

//! [1]

QGLFormat fmt;

fmt.setDoubleBuffer(false);                 // single buffer

fmt.setDirectRendering(false);              // software rendering

MyGLWidget* myWidget = new MyGLWidget(fmt, ...);

//! [1]

//! [2]

QGLFormat fmt;

fmt.setOverlay(true);

fmt.setStereo(true);

MyGLWidget* myWidget = new MyGLWidget(fmt, ...);

if (!myWidget->format().stereo()) {

    // ok, goggles off

    if (!myWidget->format().hasOverlay()) {

        qFatal("Cool hardware required");

    }

}

//! [2]

//! [3]

// The rendering in MyGLWidget depends on using

// stencil buffer and alpha channel

MyGLWidget::MyGLWidget(QWidget* parent)

    : QGLWidget(QGLFormat(QGL::StencilBuffer | QGL::AlphaChannel), parent)

{

    if (!format().stencil())

        qWarning("Could not get stencil buffer; results will be suboptimal");

    if (!format().alpha())

        qWarning("Could not get alpha channel; results will be suboptimal");

    ...

}

//! [3]

//! [4]

QApplication a(argc, argv);

QGLFormat f;

f.setDoubleBuffer(false);

QGLFormat::setDefaultFormat(f);

//! [4]

//! [5]

QGLFormat f = QGLFormat::defaultOverlayFormat();

f.setDoubleBuffer(true);

QGLFormat::setDefaultOverlayFormat(f);

//! [5]

//! [6]

// ...continued from above

MyGLWidget* myWidget = new MyGLWidget(QGLFormat(QGL::HasOverlay), ...);

if (myWidget->format().hasOverlay()) {

    // Yes, we got an overlay, let's check _its_ format:

    QGLContext* olContext = myWidget->overlayContext();

    if (olContext->format().doubleBuffer())

        ; // yes, we got a double buffered overlay

    else

        ; // no, only single buffered overlays are available

}

//! [6]

//! [7]

QGLContext *cx;

//  ...

QGLFormat f;

f.setStereo(true);

cx->setFormat(f);

if (!cx->create())

    exit(); // no OpenGL support, or cannot render on the specified paintdevice

if (!cx->format().stereo())

    exit(); // could not create stereo context

//! [7]

//! [8]

class MyGLDrawer : public QGLWidget

{

    Q_OBJECT        // must include this if you use Qt signals/slots

public:

    MyGLDrawer(QWidget *parent)

        : QGLWidget(parent) {}

protected:

    void initializeGL()

    {

        // Set up the rendering context, define display lists etc.:

        ...

        glClearColor(0.0, 0.0, 0.0, 0.0);

        glEnable(GL_DEPTH_TEST);

        ...

    }

    void resizeGL(int w, int h)

    {

        // setup viewport, projection etc.:

        glViewport(0, 0, (GLint)w, (GLint)h);

        ...

        glFrustum(...);

        ...

    }

    void paintGL()

    {

        // draw the scene:

        ...

        glRotatef(...);

        glMaterialfv(...);

        glBegin(GL_QUADS);

        glVertex3f(...);

        glVertex3f(...);

        ...

        glEnd();

        ...

    }

};

//! [8]