qquickpointattractor.cpp

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// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qquickpointattractor_p.h"
#include <cmath>
#include <QDebug>
QT_BEGIN_NAMESPACE
QQuickAttractorAffector::QQuickAttractorAffector(QQuickItem *parent) :
    QQuickParticleAffector(parent), m_strength(0.0), m_x(0), m_y(0)
  , m_physics(Velocity), m_proportionalToDistance(Linear)
{
}
 
bool QQuickAttractorAffector::affectParticle(QQuickParticleData *d, qreal dt)
{
    if (m_strength == 0.0)
        return false;
    qreal dx = m_x+m_offset.x() - d->curX(m_system);
    qreal dy = m_y+m_offset.y() - d->curY(m_system);
    qreal r = std::sqrt((dx*dx) + (dy*dy));
    qreal theta = std::atan2(dy,dx);
    qreal ds = 0;
    switch (m_proportionalToDistance){
    case InverseQuadratic:
        ds = (m_strength / qMax<qreal>(1.,r*r));
        break;
    case InverseLinear:
        ds = (m_strength / qMax<qreal>(1.,r));
        break;
    case Quadratic:
        ds = (m_strength * qMax<qreal>(1.,r*r));
        break;
    case Linear:
        ds = (m_strength * qMax<qreal>(1.,r));
        break;
    default: //also Constant
        ds = m_strength;
    }
    ds *= dt;
    dx = ds * std::cos(theta);
    dy = ds * std::sin(theta);
    qreal vx,vy;
    switch (m_physics){
    case Position:
        d->x = (d->x + dx);
        d->y = (d->y + dy);
        break;
    case Acceleration:
        d->setInstantaneousAX(d->ax + dx, m_system);
        d->setInstantaneousAY(d->ay + dy, m_system);
        break;
    case Velocity: //also default
    default:
        vx = d->curVX(m_system);
        vy = d->curVY(m_system);
        d->setInstantaneousVX(vx + dx, m_system);
        d->setInstantaneousVY(vy + dy, m_system);
    }
 
    return true;
}
QT_END_NAMESPACE
 
#include "moc_qquickpointattractor_p.cpp"