| 1 | // Copyright (C) 2016 The Qt Company Ltd. |
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| 2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only |
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| 3 | |
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| 4 | #include "qquickage_p.h" |
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| 5 | #include "qquickparticleemitter_p.h" |
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| 6 | QT_BEGIN_NAMESPACE |
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| 7 | /*! |
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| 8 | \qmltype Age |
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| 9 | \nativetype QQuickAgeAffector |
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| 10 | \inqmlmodule QtQuick.Particles |
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| 11 | \inherits ParticleAffector |
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| 12 | \brief For altering particle ages. |
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| 13 | \ingroup qtquick-particles |
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| 14 | |
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| 15 | The Age affector allows you to alter where the particle is in its lifecycle. Common uses |
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| 16 | are to expire particles prematurely, possibly giving them time to animate out. |
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| 17 | |
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| 18 | The Age affector is also sometimes known as a 'Kill' affector, because with the default |
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| 19 | parameters it will immediately expire all particles which it affects. |
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| 20 | |
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| 21 | The Age affector only applies to particles which are still alive. |
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| 22 | */ |
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| 23 | /*! |
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| 24 | \qmlproperty int QtQuick.Particles::Age::lifeLeft |
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| 25 | |
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| 26 | The amount of life to set the particle to have. Affected particles |
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| 27 | will advance to a point in their life where they will have this many |
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| 28 | milliseconds left to live. |
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| 29 | */ |
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| 30 | |
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| 31 | /*! |
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| 32 | \qmlproperty bool QtQuick.Particles::Age::advancePosition |
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| 33 | |
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| 34 | advancePosition determines whether position, veclocity and acceleration are included in |
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| 35 | the simulated aging done by the affector. If advancePosition is false, |
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| 36 | then the position, velocity and acceleration will remain the same and only |
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| 37 | other attributes (such as opacity) will advance in the simulation to where |
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| 38 | it would normally be for that point in the particle's life. With advancePosition set to |
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| 39 | true the position, velocity and acceleration will also advance to where it would |
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| 40 | normally be by that point in the particle's life, making it advance its position |
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| 41 | on screen. |
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| 42 | |
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| 43 | Default value is true. |
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| 44 | */ |
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| 45 | |
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| 46 | QQuickAgeAffector::QQuickAgeAffector(QQuickItem *parent) : |
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| 47 | QQuickParticleAffector(parent), m_lifeLeft(0), m_advancePosition(true) |
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| 48 | { |
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| 49 | } |
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| 50 | |
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| 51 | |
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| 52 | bool QQuickAgeAffector::affectParticle(QQuickParticleData *d, qreal dt) |
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| 53 | { |
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| 54 | Q_UNUSED(dt); |
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| 55 | if (d->stillAlive(system: m_system)){ |
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| 56 | float curT = m_system->timeInt / 1000.0f; |
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| 57 | float ttl = m_lifeLeft / 1000.0f; |
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| 58 | if (!m_advancePosition && ttl > 0){ |
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| 59 | float x = d->curX(particleSystem: m_system); |
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| 60 | float vx = d->curVX(particleSystem: m_system); |
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| 61 | float ax = d->curAX(); |
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| 62 | float y = d->curY(particleSystem: m_system); |
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| 63 | float vy = d->curVY(particleSystem: m_system); |
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| 64 | float ay = d->curAY(); |
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| 65 | d->t = curT - (d->lifeSpan - ttl); |
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| 66 | d->setInstantaneousX(x, particleSystem: m_system); |
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| 67 | d->setInstantaneousVX(vx, particleSystem: m_system); |
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| 68 | d->setInstantaneousAX(ax, particleSystem: m_system); |
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| 69 | d->setInstantaneousY(y, particleSystem: m_system); |
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| 70 | d->setInstantaneousVY(vy, particleSystem: m_system); |
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| 71 | d->setInstantaneousAY(ay, particleSystem: m_system); |
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| 72 | } else { |
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| 73 | d->t = curT - (d->lifeSpan - ttl); |
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| 74 | } |
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| 75 | return true; |
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| 76 | } |
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| 77 | return false; |
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| 78 | } |
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| 79 | QT_END_NAMESPACE |
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| 80 | |
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| 81 | #include "moc_qquickage_p.cpp" |
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| 82 | |
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