controller.cpp Example File

 /****************************************************************************
 **
 ** 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 Qt Mobility Components.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** You may use this file under the terms of the BSD license as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
 ** met:
 **   * Redistributions of source code must retain the above copyright
 **     notice, this list of conditions and the following disclaimer.
 **   * Redistributions in binary form must reproduce the above copyright
 **     notice, this list of conditions and the following disclaimer in
 **     the documentation and/or other materials provided with the
 **     distribution.
 **   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
 **     the names of its contributors may be used to endorse or promote
 **     products derived from this software without specific prior written
 **     permission.
 **
 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include "controller.h"

 #include <QDateTime>
 #include <QDebug>

 #define FRAME_RATE 60

 Controller::Controller(QObject *parent) :
     QObject(parent), timer(new QTimer), elapsed(new QTime), elapsedPaddle(new QTime),
     score_left(0), score_right(0),
     col_x(0), col_y(0),
     rightPaddleForce(0), leftPaddleForce(0),
     rightPaddleLast(0), leftPaddleLast(0),
     rightPowerUp(0), leftPowerUp(0)
 {

     qsrand(QDateTime::currentDateTime().time().msec());

     timer->setInterval(1000/FRAME_RATE);
     connect(timer, SIGNAL(timeout()), SLOT(tick()));
     srand(QDateTime::currentDateTime().time().msec());

     timer->start();
     elapsedPaddle->start();
     restart_ball();
 }

 void Controller::tick()
 {
     if(col_x)
         col_x--;
     if(col_y)
         col_y--;

     int msec = elapsed->elapsed();
     elapsed->restart();

     ball_x += speed_x*msec/1000;
     ball_y += speed_y*msec/1000;

     const int decay = 5;

     if(leftPaddleForce > decay)
         leftPaddleForce-=decay;
     else if(leftPaddleForce < -decay)
         leftPaddleForce+=decay;
     if(rightPaddleForce > decay)
         rightPaddleForce-=decay;
     else if(rightPaddleForce < -decay)
         rightPaddleForce+=decay;

     if(rightPaddleForce <= decay)
         rightPowerUp++;

     if(leftPaddleForce <= decay)
         leftPowerUp++;

 //    ttf++;
 //    if(msec > 1000/FRAME_RATE+2 || msec < 1000/FRAME_RATE-2)
 //        dev++;

 //    if(!(i++%120)) {
 //        qDebug() << "powerUp: " << leftPowerUp << rightPowerUp << leftPaddleForce << rightPaddleForce << speed_x*msec/1000 << speed_y*msec/1000 << msec << dev;
 //        ttf = dev =0;
 //    }

     emit moveBall(ball_x, ball_y);
 }

 static inline int paddle_boost(int force){
     if(force > 30)
         return -3*FRAME_RATE;
     else if(force > 20)
         return -2*FRAME_RATE;
     else if(force > 6)
         return -1*FRAME_RATE;
     else if(force < -30)
         return 3*FRAME_RATE;
     else if(force < -20)
         return 2*FRAME_RATE;
     else if(force < -6)
         return 1*FRAME_RATE;
     return 0;
 }

 void Controller::ballCollision(int pos)
 {

     if((pos == TOP || pos == BOTTOM) && !col_y) {
         speed_y *= -1;
         col_y = 10;
     }

     if(pos == LEFT && !col_x) {
         speed_x *= -1;
         speed_y += paddle_boost(leftPaddleForce);
         if(abs(speed_y) < FRAME_RATE)
             speed_y += speed_y < 0 ? -FRAME_RATE : FRAME_RATE;
         col_x = 10;

         speed_x *= 1.15;

         if(leftPowerUp > 75 && speed_x < 8*FRAME_RATE){
             speed_x *= 2;
             leftPowerUp = 0;
         }
     }
     else if(pos == RIGHT && !col_x) {
         speed_x *= -1;
         speed_y += paddle_boost(rightPaddleForce);
         if(abs(speed_y) < FRAME_RATE)
             speed_y += speed_y < 0 ? -FRAME_RATE : FRAME_RATE;

         col_x = 10;

         speed_x *= 1.15;

         if(rightPowerUp > 75 && speed_x > -8*FRAME_RATE){
             speed_x *= 2;
             rightPowerUp = 0;
         }

     }
 //    tick();
 //    QMetaObject::invokeMethod(this, "moveBall", Qt::QueuedConnection, Q_ARG(int, ball_x), Q_ARG(int, ball_y));
 //    emit moveBall(ball_x, ball_y);

 }

 void Controller::scored(int pos)
 {
     if(!timer->isActive())
         return;

     if(pos == LEFT)
         emit score(score_left, ++score_right);
     else if(pos == RIGHT)
         emit score(++score_left, score_right);

     restart_ball();
 }

 void Controller::restart_ball()
 {
     if(!timer->isActive())
         return;

     elapsed->start();

     ball_x = Board::Width/2;
     ball_y = Board::Height/2;

 //    ball_y = (qrand()%(Board::Height/2))+Board::Height/4;
     ball_y = (qrand()%(Board::Height-48))+24;

     // Speed in in pixels/second

     const int max = 4*FRAME_RATE;
     const int min_x = 2*FRAME_RATE;
     const int min_y = 1.5*FRAME_RATE;

     speed_y = min_y+qrand()%(max-min_y);
     if(speed_y%2)
         speed_y *= -1;

     speed_x = min_x+qrand()%(max-min_y);
     if(speed_x%2)
         speed_x *= -1;

     leftPowerUp = rightPowerUp = 0;

     emit moveBall(ball_x, ball_y);
 }

 void Controller::resetBoard()
 {
     if(!timer->isActive())
         return;

     score_left = score_right = 0;
     restart_ball();
 }

 void Controller::stop()
 {
     timer->stop();
 }

 void Controller::start()
 {
     timer->start();
 }

 void Controller::moveLeftPaddle(int y)
 {
     if(elapsedPaddle->elapsed() < 50)
         return;

     elapsedPaddle->restart();

     leftPaddleForce += leftPaddleLast-y;
     leftPaddleLast = y;
     leftPowerUp = 0;
 }

 void Controller::moveRightPaddle(int y)
 {
     if(elapsedPaddle->elapsed() < 50)
         return;

     elapsedPaddle->restart();

     rightPaddleForce += rightPaddleLast-y;
     rightPaddleLast =y;
     rightPowerUp = 0;
 }

 void Controller::refresh()
 {
     emit moveBall(ball_x, ball_y);
     emit score(score_left, score_right);
 }