Home · All Classes · All Functions · Overviews

bubble.cpp Example File
opengl/overpainting/bubble.cpp

 /****************************************************************************
 **
 ** 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 examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:LGPL$
 ** Commercial Usage
 ** Licensees holding valid Qt Commercial licenses may use this file in
 ** accordance with the Qt Commercial License Agreement provided with the
 ** Software or, alternatively, in accordance with the terms contained in
 ** a written agreement between you and Nokia.
 **
 ** 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.
 **
 ** GNU General Public License Usage
 ** Alternatively, this file may be used under the terms of the GNU
 ** General Public License version 3.0 as published by the Free Software
 ** Foundation and appearing in the file LICENSE.GPL included in the
 ** packaging of this file.  Please review the following information to
 ** ensure the GNU General Public License version 3.0 requirements will be
 ** met: http://www.gnu.org/copyleft/gpl.html.
 **
 ** 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);
 }


Copyright © 2010 Nokia Corporation and/or its subsidiary(-ies) Trademarks
Qt 4.6.3