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42 #include "qquicktargetdirection_p.h"
43 #include "qquickparticleemitter_p.h"
49 \qmlclass TargetDirection QQuickTargetDirection
50 \inqmlmodule QtQuick.Particles 2
52 \brief The TargetDirection element allows you to specify a direction towards the target point
56 \qmlproperty real QtQuick.Particles2::TargetDirection::targetX
59 \qmlproperty real QtQuick.Particles2::TargetDirection::targetY
62 \qmlproperty Item QtQuick.Particles2::TargetDirection::targetItem
63 If specified, this will take precedence over targetX and targetY.
64 The targeted point will be the center of the specified Item
67 \qmlproperty real QtQuick.Particles2::TargetDirection::targetVariation
70 \qmlproperty real QtQuick.Particles2::TargetDirection::magnitude
73 \qmlproperty real QtQuick.Particles2::TargetDirection::magnitudeVariation
76 \qmlproperty bool QtQuick.Particles2::TargetDirection::proportionalMagnitude
78 If true, then the value of magnitude and magnitudeVariation shall be interpreted as multiples
79 of the distance between the source point and the target point, per second.
81 If false(default), then the value of magnitude and magnitudeVariation shall be interpreted as
85 QQuickTargetDirection::QQuickTargetDirection(QObject *parent) :
86 QQuickDirection(parent)
89 , m_targetVariation(0)
90 , m_proportionalMagnitude(false)
92 , m_magnitudeVariation(0)
97 const QPointF QQuickTargetDirection::sample(const QPointF &from)
99 //###This approach loses interpolating the last position of the target (like we could with the emitter) is it worthwhile?
104 QQuickParticleEmitter* parentEmitter = qobject_cast<QQuickParticleEmitter*>(parent());
105 targetX = m_targetItem->width()/2;
106 targetY = m_targetItem->height()/2;
108 qWarning() << "Directed vector is not a child of the emitter. Mapping of target item coordinates may fail.";
109 targetX += m_targetItem->x();
110 targetY += m_targetItem->y();
112 ret = parentEmitter->mapFromItem(m_targetItem, QPointF(targetX, targetY));
120 targetX += 0 - from.x() - m_targetVariation + rand()/(float)RAND_MAX * m_targetVariation*2;
121 targetY += 0 - from.y() - m_targetVariation + rand()/(float)RAND_MAX * m_targetVariation*2;
122 qreal theta = atan2(targetY, targetX);
123 qreal mag = m_magnitude + rand()/(float)RAND_MAX * m_magnitudeVariation * 2 - m_magnitudeVariation;
124 if (m_proportionalMagnitude)
125 mag *= sqrt(targetX * targetX + targetY * targetY);
126 ret.setX(mag * cos(theta));
127 ret.setY(mag * sin(theta));