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42 #include "qquickwander_p.h"
43 #include "qquickparticlesystem_p.h"//for ParticlesVertices
46 \qmlclass Wander QQuickWanderAffector
47 \inqmlmodule QtQuick.Particles 2
49 \brief The Wander affector allows particles to randomly vary their trajectory.
53 \qmlproperty real QtQuick.Particles2::Wander::pace
55 Maximum attribute change per second.
58 \qmlproperty real QtQuick.Particles2::Wander::xVariance
60 Maximum attribute x value (as a result of Wander).
62 If unset, Wander will not affect x values.
65 \qmlproperty real QtQuick.Particles2::Wander::yVariance
67 Maximum attribute y value (as a result of Wander).
69 If unset, Wander will not affect y values.
72 \qmlproperty AffectableParameter QtQuick.Particles2::Wander::affectedParameter
74 What attribute of particles is directly affected.
76 \o PointAttractor.Position
77 \o PointAttractor.Velocity
78 \o PointAttractor.Acceleration
82 QQuickWanderAffector::QQuickWanderAffector(QQuickItem *parent) :
83 QQuickParticleAffector(parent), m_xVariance(0), m_yVariance(0), m_pace(0)
84 , m_affectedParameter(Velocity)
89 QQuickWanderAffector::~QQuickWanderAffector()
91 for (QHash<int, WanderData*>::const_iterator iter=m_wanderData.constBegin();
92 iter != m_wanderData.constEnd(); iter++)
96 WanderData* QQuickWanderAffector::getData(int idx)
98 if (m_wanderData.contains(idx))
99 return m_wanderData[idx];
100 WanderData* d = new WanderData;
103 d->x_peak = m_xVariance;
104 d->y_peak = m_yVariance;
105 d->x_var = m_pace * qreal(qrand()) / RAND_MAX;
106 d->y_var = m_pace * qreal(qrand()) / RAND_MAX;
108 m_wanderData.insert(idx, d);
112 void QQuickWanderAffector::reset(int systemIdx)
114 if (m_wanderData.contains(systemIdx))
115 delete m_wanderData[systemIdx];
116 m_wanderData.remove(systemIdx);
119 bool QQuickWanderAffector::affectParticle(QQuickParticleData* data, qreal dt)
121 /*TODO: Add a mode which does basically this - picking a direction, going in it (random speed) and then going back
122 WanderData* d = getData(data->systemIndex);
123 if (m_xVariance != 0.) {
124 if ((d->x_vel > d->x_peak && d->x_var > 0.0) || (d->x_vel < -d->x_peak && d->x_var < 0.0)) {
125 d->x_var = -d->x_var;
126 d->x_peak = m_xVariance + m_xVariance * qreal(qrand()) / RAND_MAX;
128 d->x_vel += d->x_var * dt;
130 qreal dx = dt * d->x_vel;
132 if (m_yVariance != 0.) {
133 if ((d->y_vel > d->y_peak && d->y_var > 0.0) || (d->y_vel < -d->y_peak && d->y_var < 0.0)) {
134 d->y_var = -d->y_var;
135 d->y_peak = m_yVariance + m_yVariance * qreal(qrand()) / RAND_MAX;
137 d->y_vel += d->y_var * dt;
139 qreal dy = dt * d->x_vel;
141 //### Should we be amending vel instead?
142 ParticleVertex* p = &(data->pv);
148 qreal dx = dt * m_pace * (2 * qreal(qrand())/RAND_MAX - 1);
149 qreal dy = dt * m_pace * (2 * qreal(qrand())/RAND_MAX - 1);
151 switch (m_affectedParameter){
153 newX = data->curX() + dx;
154 if (m_xVariance > qAbs(newX) )
156 newY = data->curY() + dy;
157 if (m_yVariance > qAbs(newY) )
162 newX = data->curVX() + dx;
163 if (m_xVariance > qAbs(newX) )
164 data->setInstantaneousVX(newX);
165 newY = data->curVY() + dy;
166 if (m_yVariance > qAbs(newY) )
167 data->setInstantaneousVY(newY);
170 newX = data->ax + dx;
171 if (m_xVariance > qAbs(newX) )
172 data->setInstantaneousAX(newX);
173 newY = data->ay + dy;
174 if (m_yVariance > qAbs(newY) )
175 data->setInstantaneousAY(newY);