qquick3dparticlescaleaffector.cpp

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// Copyright (C) 2022 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
 
#include "qquick3dparticlescaleaffector_p.h"
#include <qmath.h>
 
QT_BEGIN_NAMESPACE
 
QQuick3DParticleScaleAffector::QQuick3DParticleScaleAffector(QQuick3DNode *parent)
    : QQuick3DParticleAffector(parent)
{
 
}
 
float QQuick3DParticleScaleAffector::minSize() const
{
    return m_minSize;
}
 
float QQuick3DParticleScaleAffector::maxSize() const
{
    return m_maxSize;
}
 
int QQuick3DParticleScaleAffector::duration() const
{
    return m_duration;
}
 
QQuick3DParticleScaleAffector::ScalingType QQuick3DParticleScaleAffector::type() const
{
    return m_type;
}
 
QEasingCurve QQuick3DParticleScaleAffector::easingCurve() const
{
    return m_easing;
}
 
void QQuick3DParticleScaleAffector::setMinSize(float size)
{
    if (qFuzzyCompare(size, m_minSize))
        return;
    m_minSize = size;
    Q_EMIT minSizeChanged();
}
 
void QQuick3DParticleScaleAffector::setMaxSize(float size)
{
    if (qFuzzyCompare(size, m_maxSize))
        return;
    m_maxSize = size;
    Q_EMIT maxSizeChanged();
}
 
void QQuick3DParticleScaleAffector::setDuration(int duration)
{
    duration = qMax(0, duration);
    if (duration == m_duration)
        return;
    m_duration = duration;
    Q_EMIT durationChanged();
}
 
void QQuick3DParticleScaleAffector::setType(ScalingType type)
{
    if (m_type == type)
        return;
    m_type = type;
    Q_EMIT typeChanged();
}
 
void QQuick3DParticleScaleAffector::setEasingCurve(const QEasingCurve &curve)
{
    if (m_easing == curve)
        return;
    m_easing = curve;
    Q_EMIT easingCurveChanged();
}
 
void QQuick3DParticleScaleAffector::prepareToAffect()
{
 
}
 
void QQuick3DParticleScaleAffector::affectParticle(const QQuick3DParticleData &, QQuick3DParticleDataCurrent *d, float time)
{
    float scale = 1.0f;
 
    const auto fract = [](const float v) -> float {
        return v - qFloor(v);
    };
    const auto lerp = [](const float a, const float b, const float f) -> float {
        return a + (b - a) * f;
    };
    const auto smoothstep = [](const float a, const float b, const float f) -> float {
        return a + (b - a) * f * f * (3.0f - 2.0f * f);
    };
 
    float pos = fract(time / float(m_duration * 0.001f));
    switch (m_type) {
    case Linear:
        scale = lerp(m_minSize, m_maxSize, m_easing.valueForProgress(pos));
        scale = qMax(scale, 0.0f);
        break;
    case SewSaw:
        if (pos < 0.5f)
            scale = lerp(m_minSize, m_maxSize, m_easing.valueForProgress(pos * 2.0f));
        else
            scale = lerp(m_maxSize, m_minSize, m_easing.valueForProgress((pos - 0.5) * 2.0f));
        scale = qMax(scale, 0.0f);
        break;
    case SineWave:
        scale = m_minSize + (m_maxSize - m_minSize) * (1.0f + qSin(2.0f * M_PI * pos)) * 0.5f;
        break;
    case AbsSineWave:
        scale = m_minSize + (m_maxSize - m_minSize) * qAbs(qSin(2.0f * M_PI * pos));
        break;
    case Step:
        if (pos < 0.5f)
            scale = m_minSize;
        else
            scale = m_maxSize;
        break;
    case SmoothStep:
        scale = smoothstep(m_minSize, m_maxSize, pos);
        break;
    }
 
    d->scale *= scale;
}
 
QT_END_NAMESPACE