1// Copyright (C) 2021 The Qt Company Ltd.
2// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
3
4#include "qphysicsmaterial_p.h"
5
6#include <foundation/PxSimpleTypes.h>
7
8static float clamp(float value, float min, float max)
9{
10 return std::max(a: std::min(a: value, b: max), b: min);
11}
12
13QT_BEGIN_NAMESPACE
14
15/*!
16 \qmltype PhysicsMaterial
17 \inqmlmodule QtQuick3D.Physics
18 \since 6.4
19 \brief Defines the physics material of a body.
20
21 The PhysicsMaterial type determines how objects interact when they touch.
22
23 Friction uses the Coulomb friction model, which is based around
24 the concepts of 2 coefficients: the static friction coefficient and the dynamic friction
25 coefficient (sometimes called kinetic friction). Friction resists relative lateral motion of two
26 solid surfaces in contact. These two coefficients define a relationship between the normal force
27 exerted by each surface on the other and the amount of friction force that is applied to resist
28 lateral motion. While most real-world materials have friction coefficients between \c{0} and
29 \c{1}, values above \c{1} are not uncommon. The properties accept any real number greater or
30 equal to \c{0}.
31
32 Restitution determines how objects bounce when they collide.
33*/
34
35/*!
36 \qmlproperty real PhysicsMaterial::staticFriction
37 This property defines the amount of friction that is applied between surfaces that are not
38 moving lateral to each-other.
39
40 Default value: \c 0.5
41
42 Range: \c{[0, inf]}
43*/
44
45/*!
46 \qmlproperty real PhysicsMaterial::dynamicFriction
47 This property defines the amount of friction applied between surfaces that are moving relative
48 to each-other.
49
50 Default value: \c 0.5
51
52 Range: \c{[0, inf]}
53*/
54
55/*!
56 \qmlproperty real PhysicsMaterial::restitution
57 This property defines the coefficient of restitution, or how bouncy the material is.
58 The coefficient of restitution of two
59 colliding objects is a fractional value representing the ratio of speeds after and before an
60 impact, taken along the line of impact. A coefficient of restitution of 1 is said to collide
61 elastically, while a coefficient of restitution < 1 is said to be inelastic.
62
63 Default value: \c 0.5
64
65 Range: \c{[0, 1]}
66*/
67
68QPhysicsMaterial::QPhysicsMaterial(QObject *parent) : QObject(parent) { }
69
70float QPhysicsMaterial::staticFriction() const
71{
72 return m_staticFriction;
73}
74
75void QPhysicsMaterial::setStaticFriction(float staticFriction)
76{
77 staticFriction = clamp(value: staticFriction, min: 0.f, PX_MAX_F32);
78
79 if (qFuzzyCompare(p1: m_staticFriction, p2: staticFriction))
80 return;
81 m_staticFriction = staticFriction;
82 emit staticFrictionChanged();
83}
84
85float QPhysicsMaterial::dynamicFriction() const
86{
87 return m_dynamicFriction;
88}
89
90void QPhysicsMaterial::setDynamicFriction(float dynamicFriction)
91{
92 dynamicFriction = clamp(value: dynamicFriction, min: 0.f, PX_MAX_F32);
93
94 if (qFuzzyCompare(p1: m_dynamicFriction, p2: dynamicFriction))
95 return;
96 m_dynamicFriction = dynamicFriction;
97 emit dynamicFrictionChanged();
98}
99
100float QPhysicsMaterial::restitution() const
101{
102 return m_restitution;
103}
104
105void QPhysicsMaterial::setRestitution(float restitution)
106{
107 restitution = clamp(value: restitution, min: 0.f, max: 1.f);
108
109 if (qFuzzyCompare(p1: m_restitution, p2: restitution))
110 return;
111 m_restitution = restitution;
112 emit restitutionChanged();
113}
114
115QT_END_NAMESPACE
116

source code of qtquick3dphysics/src/quick3dphysics/qphysicsmaterial.cpp