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Diffstat (limited to 'src/imports/particles/turbulenceaffector.cpp')
-rw-r--r-- | src/imports/particles/turbulenceaffector.cpp | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/src/imports/particles/turbulenceaffector.cpp b/src/imports/particles/turbulenceaffector.cpp new file mode 100644 index 0000000000..d29f09d974 --- /dev/null +++ b/src/imports/particles/turbulenceaffector.cpp @@ -0,0 +1,159 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the Declarative module 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 "turbulenceaffector.h" +#include "particle.h" +#include <cmath> +#include <cstdlib> +#include <QDebug> +QT_BEGIN_NAMESPACE + +TurbulenceAffector::TurbulenceAffector(QSGItem *parent) : + ParticleAffector(parent), + m_strength(10), m_lastT(0), m_frequency(64), m_gridSize(10), m_field(0), m_inited(false) +{ + //TODO: Update grid on size change +} + +TurbulenceAffector::~TurbulenceAffector() +{ + if (m_field) { + for(int i=0; i<m_gridSize; i++) + free(m_field[i]); + free(m_field); + } +} + +static qreal magnitude(qreal x, qreal y) +{ + return sqrt(x*x + y*y); +} + +void TurbulenceAffector::setSize(int arg) +{ + if (m_gridSize != arg) { + if(m_field){ //deallocate and then reallocate grid + for(int i=0; i<m_gridSize; i++) + free(m_field[i]); + free(m_field); + m_system = 0; + } + m_gridSize = arg; + emit sizeChanged(arg); + } +} + +void TurbulenceAffector::ensureInit() +{ + if(m_inited) + return; + m_inited = true; + m_field = (QPointF**)malloc(m_gridSize * sizeof(QPointF*)); + for(int i=0; i<m_gridSize; i++) + m_field[i] = (QPointF*)malloc(m_gridSize * sizeof(QPointF)); + for(int i=0; i<m_gridSize; i++) + for(int j=0; j<m_gridSize; j++) + m_field[i][j] = QPointF(); + m_spacing = QPointF(width()/m_gridSize, height()/m_gridSize); + m_magSum = magnitude(m_spacing.x(), m_spacing.y())*2; +} + +void TurbulenceAffector::mapUpdate() +{ + QPoint pos(rand() % m_gridSize, rand() % m_gridSize); + QPointF vector(m_strength - (((qreal)rand() / RAND_MAX) * m_strength*2), + m_strength - (((qreal)rand() / RAND_MAX) * m_strength*2)); + for(int i = 0; i < m_gridSize; i++){ + for(int j = 0; j < m_gridSize; j++){ + qreal dist = magnitude(i-pos.x(), j-pos.y()); + m_field[i][j] += vector/(dist + 1); + if(magnitude(m_field[i][j].x(), m_field[i][j].y()) > m_strength){ + //Speed limit + qreal theta = atan2(m_field[i][j].y(), m_field[i][j].x()); + m_field[i][j].setX(m_strength * cos(theta)); + m_field[i][j].setY(m_strength * sin(theta)); + } + } + } +} + + +void TurbulenceAffector::affectSystem(qreal dt) +{ + if(!m_system || !m_active) + return; + ensureInit(); + qreal period = 1.0/m_frequency; + qreal time = m_system->m_timeInt / 1000.0; + while( m_lastT < time ){ + mapUpdate(); + m_lastT += period; + } + + foreach(ParticleData *d, m_system->m_data){ + if(!d || !activeGroup(d->group)) + return; + qreal fx = 0.0; + qreal fy = 0.0; + QPointF pos = QPointF(d->curX() - x(), d->curY() - y());//TODO: Offset + QPointF nodePos = QPointF(pos.x() / m_spacing.x(), pos.y() / m_spacing.y()); + QSet<QPair<int, int> > nodes; + nodes << qMakePair((int)ceil(nodePos.x()), (int)ceil(nodePos.y())); + nodes << qMakePair((int)ceil(nodePos.x()), (int)floor(nodePos.y())); + nodes << qMakePair((int)floor(nodePos.x()), (int)ceil(nodePos.y())); + nodes << qMakePair((int)floor(nodePos.x()), (int)floor(nodePos.y())); + typedef QPair<int, int> intPair; + foreach(const intPair &p, nodes){ + if(!QRect(0,0,m_gridSize-1,m_gridSize-1).contains(QPoint(p.first, p.second))) + continue; + qreal dist = magnitude(pos.x() - p.first*m_spacing.x(), pos.y() - p.second*m_spacing.y());//TODO: Mathematically valid + fx += m_field[p.first][p.second].x() * ((m_magSum - dist)/m_magSum);//Proportionally weight nodes + fy += m_field[p.first][p.second].y() * ((m_magSum - dist)/m_magSum); + } + if(fx || fy){ + d->setInstantaneousSX(d->curSX()+ fx * dt); + d->setInstantaneousSY(d->curSY()+ fy * dt); + m_system->m_needsReset << d; + } + } +} + +QT_END_NAMESPACE |