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/****************************************************************************
**
** 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.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
** 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.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms and
** conditions contained in a signed written agreement between you and Nokia.
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qsgtargeteddirection_p.h"
#include "qsgparticleemitter_p.h"
#include <cmath>
#include <QDebug>
QT_BEGIN_NAMESPACE
QSGTargetedDirection::QSGTargetedDirection(QObject *parent) :
QSGStochasticDirection(parent)
, m_targetX(0)
, m_targetY(0)
, m_targetVariation(0)
, m_proportionalMagnitude(false)
, m_magnitude(0)
, m_magnitudeVariation(0)
, m_targetItem(0)
{
}
const QPointF &QSGTargetedDirection::sample(const QPointF &from)
{
//###This approach loses interpolating the last position of the target (like we could with the emitter) is it worthwhile?
qreal targetX;
qreal targetY;
if (m_targetItem){
QSGParticleEmitter* parentEmitter = qobject_cast<QSGParticleEmitter*>(parent());
targetX = m_targetItem->width()/2;
targetY = m_targetItem->height()/2;
if (!parentEmitter){
qWarning() << "Directed vector is not a child of the emitter. Mapping of target item coordinates may fail.";
targetX += m_targetItem->x();
targetY += m_targetItem->y();
}else{
m_ret = parentEmitter->mapFromItem(m_targetItem, QPointF(targetX, targetY));
targetX = m_ret.x();
targetY = m_ret.y();
}
}else{
targetX = m_targetX;
targetY = m_targetY;
}
targetX += 0 - from.x() - m_targetVariation + rand()/(float)RAND_MAX * m_targetVariation*2;
targetY += 0 - from.y() - m_targetVariation + rand()/(float)RAND_MAX * m_targetVariation*2;
qreal theta = atan2(targetY, targetX);
qreal mag = m_magnitude + rand()/(float)RAND_MAX * m_magnitudeVariation * 2 - m_magnitudeVariation;
if (m_proportionalMagnitude)
mag *= sqrt(targetX * targetX + targetY * targetY);
m_ret.setX(mag * cos(theta));
m_ret.setY(mag * sin(theta));
return m_ret;
}
QT_END_NAMESPACE
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