| 1 | // Copyright (C) 2021 The Qt Company Ltd. |
|---|---|
| 2 | // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only |
| 3 | |
| 4 | #include "qquick3dparticlegravity_p.h" |
| 5 | |
| 6 | QT_BEGIN_NAMESPACE |
| 7 | |
| 8 | /*! |
| 9 | \qmltype Gravity3D |
| 10 | \inherits Affector3D |
| 11 | \inqmlmodule QtQuick3D.Particles3D |
| 12 | \brief Accelerates particles to a vector of the specified magnitude in the specified direction. |
| 13 | \since 6.2 |
| 14 | |
| 15 | This element models the gravity of a massive object whose center of gravity is far away (and thus the |
| 16 | gravitational pull is effectively constant across the scene). To model the gravity of an object near |
| 17 | or inside the scene, use \l Attractor3D. |
| 18 | */ |
| 19 | |
| 20 | QQuick3DParticleGravity::QQuick3DParticleGravity(QQuick3DNode *parent) |
| 21 | : QQuick3DParticleAffector(parent) |
| 22 | { |
| 23 | } |
| 24 | |
| 25 | /*! |
| 26 | \qmlproperty real Gravity3D::magnitude |
| 27 | |
| 28 | This property defines the magnitude in position change per second. Negative magnitude |
| 29 | accelerates the opposite way from the \l {Gravity3D::direction}{direction}. |
| 30 | |
| 31 | The default value is \c 100.0. |
| 32 | */ |
| 33 | float QQuick3DParticleGravity::magnitude() const |
| 34 | { |
| 35 | return m_magnitude; |
| 36 | } |
| 37 | |
| 38 | void QQuick3DParticleGravity::setMagnitude(float magnitude) |
| 39 | { |
| 40 | if (qFuzzyCompare(p1: m_magnitude, p2: magnitude)) |
| 41 | return; |
| 42 | |
| 43 | m_magnitude = magnitude; |
| 44 | Q_EMIT magnitudeChanged(); |
| 45 | Q_EMIT update(); |
| 46 | } |
| 47 | |
| 48 | /*! |
| 49 | \qmlproperty vector3d Gravity3D::direction |
| 50 | |
| 51 | This property defines the direction the gravity will affect toward. Values will be |
| 52 | automatically normalized to a unit vector. |
| 53 | |
| 54 | The default value is \c (0.0, -1.0, 0.0) (downwards). |
| 55 | */ |
| 56 | const QVector3D &QQuick3DParticleGravity::direction() const |
| 57 | { |
| 58 | return m_direction; |
| 59 | } |
| 60 | |
| 61 | void QQuick3DParticleGravity::setDirection(const QVector3D &direction) |
| 62 | { |
| 63 | if (m_direction == direction) |
| 64 | return; |
| 65 | |
| 66 | m_direction = direction; |
| 67 | m_directionNormalized = m_direction.normalized(); |
| 68 | Q_EMIT directionChanged(); |
| 69 | Q_EMIT update(); |
| 70 | } |
| 71 | |
| 72 | void QQuick3DParticleGravity::affectParticle(const QQuick3DParticleData &sd, QQuick3DParticleDataCurrent *d, float time) |
| 73 | { |
| 74 | Q_UNUSED(sd); |
| 75 | float velocity = 0.5f * m_magnitude * (time * time); |
| 76 | d->position += velocity * m_directionNormalized; |
| 77 | } |
| 78 | |
| 79 | QT_END_NAMESPACE |
| 80 |