--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/demos/boxes/trackball.h	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,79 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the demonstration applications 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.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef TRACKBALL_H
+#define TRACKBALL_H
+
+#include <QtGui>
+
+#include <QtGui/qvector3d.h>
+#include <QtGui/qquaternion.h>
+
+class TrackBall
+{
+public:
+    enum TrackMode
+    {
+        Plane,
+        Sphere,
+    };
+    TrackBall(TrackMode mode = Sphere);
+    TrackBall(float angularVelocity, const QVector3D& axis, TrackMode mode = Sphere);
+    // coordinates in [-1,1]x[-1,1]
+    void push(const QPointF& p, const QQuaternion &transformation);
+    void move(const QPointF& p, const QQuaternion &transformation);
+    void release(const QPointF& p, const QQuaternion &transformation);
+    void start(); // starts clock
+    void stop(); // stops clock
+    QQuaternion rotation() const;
+private:
+    QQuaternion m_rotation;
+    QVector3D m_axis;
+    float m_angularVelocity;
+
+    QPointF m_lastPos;
+    QTime m_lastTime;
+    bool m_paused;
+    bool m_pressed;
+    TrackMode m_mode;
+};
+
+#endif