--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/opengl/overpainting/bubble.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,113 @@
+/****************************************************************************
+**
+** 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 examples 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.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtGui>
+
+#include "bubble.h"
+
+Bubble::Bubble(const QPointF &position, qreal radius, const QPointF &velocity)
+    : position(position), vel(velocity), radius(radius)
+{
+    innerColor = randomColor();
+    outerColor = randomColor();
+    updateBrush();
+}
+
+void Bubble::updateBrush()
+{
+    QRadialGradient gradient(QPointF(radius, radius), radius,
+                             QPointF(radius*0.5, radius*0.5));
+
+    gradient.setColorAt(0, QColor(255, 255, 255, 255));
+    gradient.setColorAt(0.25, innerColor);
+    gradient.setColorAt(1, outerColor);
+    brush = QBrush(gradient);
+}
+
+void Bubble::drawBubble(QPainter *painter)
+{
+    painter->save();
+    painter->translate(position.x() - radius, position.y() - radius);
+    painter->setBrush(brush);
+    painter->drawEllipse(0, 0, int(2*radius), int(2*radius));
+    painter->restore();
+}
+
+QColor Bubble::randomColor()
+{
+    int red = int(205 + 50.0*qrand()/(RAND_MAX+1.0));
+    int green = int(205 + 50.0*qrand()/(RAND_MAX+1.0));
+    int blue = int(205 + 50.0*qrand()/(RAND_MAX+1.0));
+    int alpha = int(91 + 100.0*qrand()/(RAND_MAX+1.0));
+
+    return QColor(red, green, blue, alpha);
+}
+
+void Bubble::move(const QRect &bbox)
+{
+    position += vel;
+    qreal leftOverflow = position.x() - radius - bbox.left();
+    qreal rightOverflow = position.x() + radius - bbox.right();
+    qreal topOverflow = position.y() - radius - bbox.top();
+    qreal bottomOverflow = position.y() + radius - bbox.bottom();
+    
+    if (leftOverflow < 0.0) {
+        position.setX(position.x() - 2 * leftOverflow);
+        vel.setX(-vel.x());
+    } else if (rightOverflow > 0.0) {
+        position.setX(position.x() - 2 * rightOverflow);
+        vel.setX(-vel.x());
+    }
+
+    if (topOverflow < 0.0) {
+        position.setY(position.y() - 2 * topOverflow);
+        vel.setY(-vel.y());
+    } else if (bottomOverflow > 0.0) {
+        position.setY(position.y() - 2 * bottomOverflow);
+        vel.setY(-vel.y());
+    }
+}
+
+QRectF Bubble::rect()
+{
+    return QRectF(position.x() - radius, position.y() - radius,
+                  2 * radius, 2 * radius);
+}