1 /****************************************************************************
3 ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
4 ** Contact: http://www.qt-project.org/
6 ** This file is part of the QtQuick module of the Qt Toolkit.
8 ** $QT_BEGIN_LICENSE:LGPL$
9 ** GNU Lesser General Public License Usage
10 ** This file may be used under the terms of the GNU Lesser General Public
11 ** License version 2.1 as published by the Free Software Foundation and
12 ** appearing in the file LICENSE.LGPL included in the packaging of this
13 ** file. Please review the following information to ensure the GNU Lesser
14 ** General Public License version 2.1 requirements will be met:
15 ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
17 ** In addition, as a special exception, Nokia gives you certain additional
18 ** rights. These rights are described in the Nokia Qt LGPL Exception
19 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
21 ** GNU General Public License Usage
22 ** Alternatively, this file may be used under the terms of the GNU General
23 ** Public License version 3.0 as published by the Free Software Foundation
24 ** and appearing in the file LICENSE.GPL included in the packaging of this
25 ** file. Please review the following information to ensure the GNU General
26 ** Public License version 3.0 requirements will be met:
27 ** http://www.gnu.org/copyleft/gpl.html.
30 ** Alternatively, this file may be used in accordance with the terms and
31 ** conditions contained in a signed written agreement between you and Nokia.
40 ****************************************************************************/
42 #include "qquicktargetdirection_p.h"
43 #include "qquickparticleemitter_p.h"
49 \qmlclass TargetDirection QQuickTargetDirection
50 \inqmlmodule QtQuick.Particles 2
51 \ingroup qtquick-particles
53 \brief For specifying a direction towards the target point
57 \qmlproperty real QtQuick.Particles2::TargetDirection::targetX
60 \qmlproperty real QtQuick.Particles2::TargetDirection::targetY
63 \qmlproperty Item QtQuick.Particles2::TargetDirection::targetItem
64 If specified, this will take precedence over targetX and targetY.
65 The targeted point will be the center of the specified Item
68 \qmlproperty real QtQuick.Particles2::TargetDirection::targetVariation
71 \qmlproperty real QtQuick.Particles2::TargetDirection::magnitude
74 \qmlproperty real QtQuick.Particles2::TargetDirection::magnitudeVariation
77 \qmlproperty bool QtQuick.Particles2::TargetDirection::proportionalMagnitude
79 If true, then the value of magnitude and magnitudeVariation shall be interpreted as multiples
80 of the distance between the source point and the target point, per second.
82 If false(default), then the value of magnitude and magnitudeVariation shall be interpreted as
86 QQuickTargetDirection::QQuickTargetDirection(QObject *parent) :
87 QQuickDirection(parent)
90 , m_targetVariation(0)
91 , m_proportionalMagnitude(false)
93 , m_magnitudeVariation(0)
98 const QPointF QQuickTargetDirection::sample(const QPointF &from)
100 //###This approach loses interpolating the last position of the target (like we could with the emitter) is it worthwhile?
105 QQuickParticleEmitter* parentEmitter = qobject_cast<QQuickParticleEmitter*>(parent());
106 targetX = m_targetItem->width()/2;
107 targetY = m_targetItem->height()/2;
109 qWarning() << "Directed vector is not a child of the emitter. Mapping of target item coordinates may fail.";
110 targetX += m_targetItem->x();
111 targetY += m_targetItem->y();
113 ret = parentEmitter->mapFromItem(m_targetItem, QPointF(targetX, targetY));
121 targetX += 0 - from.x() - m_targetVariation + rand()/(float)RAND_MAX * m_targetVariation*2;
122 targetY += 0 - from.y() - m_targetVariation + rand()/(float)RAND_MAX * m_targetVariation*2;
123 qreal theta = atan2(targetY, targetX);
124 qreal mag = m_magnitude + rand()/(float)RAND_MAX * m_magnitudeVariation * 2 - m_magnitudeVariation;
125 if (m_proportionalMagnitude)
126 mag *= sqrt(targetX * targetX + targetY * targetY);
127 ret.setX(mag * cos(theta));
128 ret.setY(mag * sin(theta));