diff -r dee5afe5301f -r 3f74d0d4af4c doc/src/snippets/code/src_opengl_qgl.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/doc/src/snippets/code/src_opengl_qgl.cpp	Thu Apr 08 14:19:33 2010 +0300
@@ -0,0 +1,173 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the documentation 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+//! [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]