|  | Home · All Classes · All Functions · Overviews

# bubble.cpp Example File
opengl/hellogl_es/bubble.cpp

     /****************************************************************************
     **
     ** 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.
     **
     ** $QT_BEGIN_LICENSE:LGPL$
     ** 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();
         cache = 0;
         updateBrush();
     }

     void Bubble::updateCache()
     {
         if (cache)
             delete cache;
         cache = new QImage(qRound(radius * 2 + 2), qRound(radius * 2 + 2), QImage::Format_ARGB32);
         cache->fill(0x00000000);
         QPainter p(cache);
         p.setRenderHint(QPainter::HighQualityAntialiasing);
         QPen pen(Qt::white);
         pen.setWidth(2);
         p.setPen(pen);
         p.setBrush(brush);
         p.drawEllipse(0, 0, int(2*radius), int(2*radius));
     }

     Bubble::~Bubble()
     {
         if (cache)
             delete cache;
     }

     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);
         updateCache();
     }

     void Bubble::drawBubble(QPainter *painter)
     {
         painter->save();
         painter->translate(position.x() - radius, position.y() - radius);
         painter->setOpacity(0.8);
         painter->drawImage(0, 0, *cache);
         painter->restore();
     }

     QColor Bubble::randomColor()
     {
         int red = int(185 + 70.0*qrand()/(RAND_MAX+1.0));
         int green = int(185 + 70.0*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);
     }