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42 #include "qsgwander_p.h"
43 #include "qsgparticlesystem_p.h"//for ParticlesVertices
46 \qmlclass Wander QSGWanderAffector
47 \inqmlmodule QtQuick.Particles 2
48 \since QtQuick.Particles 2.0
50 \brief The Wander affector allows particles to randomly vary their trajectory.
54 QSGWanderAffector::QSGWanderAffector(QSGItem *parent) :
55 QSGParticleAffector(parent), m_xVariance(0), m_yVariance(0), m_pace(0)
61 QSGWanderAffector::~QSGWanderAffector()
63 for (QHash<int, WanderData*>::const_iterator iter=m_wanderData.constBegin();
64 iter != m_wanderData.constEnd(); iter++)
68 WanderData* QSGWanderAffector::getData(int idx)
70 if (m_wanderData.contains(idx))
71 return m_wanderData[idx];
72 WanderData* d = new WanderData;
75 d->x_peak = m_xVariance;
76 d->y_peak = m_yVariance;
77 d->x_var = m_pace * qreal(qrand()) / RAND_MAX;
78 d->y_var = m_pace * qreal(qrand()) / RAND_MAX;
80 m_wanderData.insert(idx, d);
84 void QSGWanderAffector::reset(int systemIdx)
86 if (m_wanderData.contains(systemIdx))
87 delete m_wanderData[systemIdx];
88 m_wanderData.remove(systemIdx);
91 bool QSGWanderAffector::affectParticle(QSGParticleData* data, qreal dt)
93 /*TODO: Add a mode which does basically this - picking a direction, going in it (random speed) and then going back
94 WanderData* d = getData(data->systemIndex);
95 if (m_xVariance != 0.) {
96 if ((d->x_vel > d->x_peak && d->x_var > 0.0) || (d->x_vel < -d->x_peak && d->x_var < 0.0)) {
98 d->x_peak = m_xVariance + m_xVariance * qreal(qrand()) / RAND_MAX;
100 d->x_vel += d->x_var * dt;
102 qreal dx = dt * d->x_vel;
104 if (m_yVariance != 0.) {
105 if ((d->y_vel > d->y_peak && d->y_var > 0.0) || (d->y_vel < -d->y_peak && d->y_var < 0.0)) {
106 d->y_var = -d->y_var;
107 d->y_peak = m_yVariance + m_yVariance * qreal(qrand()) / RAND_MAX;
109 d->y_vel += d->y_var * dt;
111 qreal dy = dt * d->x_vel;
113 //### Should we be amending vel instead?
114 ParticleVertex* p = &(data->pv);
120 qreal dx = dt * m_pace * (2 * qreal(qrand())/RAND_MAX - 1);
121 qreal dy = dt * m_pace * (2 * qreal(qrand())/RAND_MAX - 1);
125 newX = data->curX() + dx;
126 if (m_xVariance > qAbs(newX) )
128 newY = data->curY() + dy;
129 if (m_yVariance > qAbs(newY) )
134 newX = data->curVX() + dx;
135 if (m_xVariance > qAbs(newX) )
136 data->setInstantaneousVX(newX);
137 newY = data->curVY() + dy;
138 if (m_yVariance > qAbs(newY) )
139 data->setInstantaneousVY(newY);
142 newX = data->ax + dx;
143 if (m_xVariance > qAbs(newX) )
144 data->setInstantaneousAX(newX);
145 newY = data->ay + dy;
146 if (m_yVariance > qAbs(newY) )
147 data->setInstantaneousAY(newY);