Box2D: /build/box2d/src/box2d-adaedf1772ede7420bc9ee569c8cba7952db91a0/include/box2d/b2_friction_joint.h Source File

| Box2D 2.4.0 A 2D physics engine for games

b2_friction_joint.h
1 // MIT License
2
3 // Copyright (c) 2019 Erin Catto
4
5 // Permission is hereby granted, free of charge, to any person obtaining a copy
6 // of this software and associated documentation files (the "Software"), to deal
7 // in the Software without restriction, including without limitation the rights
8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 // copies of the Software, and to permit persons to whom the Software is
10 // furnished to do so, subject to the following conditions:
11
12 // The above copyright notice and this permission notice shall be included in all
13 // copies or substantial portions of the Software.
14
15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 // SOFTWARE.
22
23 #ifndef B2_FRICTION_JOINT_H
24 #define B2_FRICTION_JOINT_H
25
26 #include "b2_api.h"
27 #include "b2_joint.h"
28
30 struct B2_API b2FrictionJointDef : public b2JointDef
31 {
32 b2FrictionJointDef()
33 {
34 type = e_frictionJoint;
35 localAnchorA.SetZero();
36 localAnchorB.SetZero();
37 maxForce = 0.0f;
38 maxTorque = 0.0f;
39 }
40
43 void Initialize(b2Body* bodyA, b2Body* bodyB, const b2Vec2& anchor);
44
46 b2Vec2 localAnchorA;
47
49 b2Vec2 localAnchorB;
50
52 float maxForce;
53
55 float maxTorque;
56 };
57
60 class B2_API b2FrictionJoint : public b2Joint
61 {
62 public:
63 b2Vec2 GetAnchorA() const override;
64 b2Vec2 GetAnchorB() const override;
65
66 b2Vec2 GetReactionForce(float inv_dt) const override;
67 float GetReactionTorque(float inv_dt) const override;
68
70 const b2Vec2& GetLocalAnchorA() const { return m_localAnchorA; }
71
73 const b2Vec2& GetLocalAnchorB() const { return m_localAnchorB; }
74
76 void SetMaxForce(float force);
77
79 float GetMaxForce() const;
80
82 void SetMaxTorque(float torque);
83
85 float GetMaxTorque() const;
86
88 void Dump() override;
89
90 protected:
91
92 friend class b2Joint;
93
94 b2FrictionJoint(const b2FrictionJointDef* def);
95
96 void InitVelocityConstraints(const b2SolverData& data) override;
97 void SolveVelocityConstraints(const b2SolverData& data) override;
98 bool SolvePositionConstraints(const b2SolverData& data) override;
99
100 b2Vec2 m_localAnchorA;
101 b2Vec2 m_localAnchorB;
102
103 // Solver shared
104 b2Vec2 m_linearImpulse;
105 float m_angularImpulse;
106 float m_maxForce;
107 float m_maxTorque;
108
109 // Solver temp
110 int32 m_indexA;
111 int32 m_indexB;
112 b2Vec2 m_rA;
113 b2Vec2 m_rB;
114 b2Vec2 m_localCenterA;
115 b2Vec2 m_localCenterB;
116 float m_invMassA;
117 float m_invMassB;
118 float m_invIA;
119 float m_invIB;
120 b2Mat22 m_linearMass;
121 float m_angularMass;
122 };
123
124 #endif
b2Vec2
A 2D column vector.
Definition: b2_math.h:42
b2FrictionJoint
Definition: b2_friction_joint.h:61
b2Body
A rigid body. These are created via b2World::CreateBody.
Definition: b2_body.h:133
b2FrictionJointDef::maxTorque
float maxTorque
The maximum friction torque in N-m.
Definition: b2_friction_joint.h:55
b2FrictionJoint::GetReactionTorque
float GetReactionTorque(float inv_dt) const override
Get the reaction torque on bodyB in N*m.
b2FrictionJointDef::localAnchorA
b2Vec2 localAnchorA
The local anchor point relative to bodyA's origin.
Definition: b2_friction_joint.h:46
b2JointDef
Joint definitions are used to construct joints.
Definition: b2_joint.h:73
b2FrictionJoint::Dump
void Dump() override
Dump joint to dmLog.
b2FrictionJointDef::Initialize
void Initialize(b2Body *bodyA, b2Body *bodyB, const b2Vec2 &anchor)
b2FrictionJoint::SetMaxTorque
void SetMaxTorque(float torque)
Set the maximum friction torque in N*m.
b2FrictionJointDef::maxForce
float maxForce
The maximum friction force in N.
Definition: b2_friction_joint.h:52
b2FrictionJoint::GetMaxForce
float GetMaxForce() const
Get the maximum friction force in N.
b2FrictionJoint::GetLocalAnchorA
const b2Vec2 & GetLocalAnchorA() const
The local anchor point relative to bodyA's origin.
Definition: b2_friction_joint.h:70
b2FrictionJoint::GetAnchorA
b2Vec2 GetAnchorA() const override
Get the anchor point on bodyA in world coordinates.
b2FrictionJointDef::localAnchorB
b2Vec2 localAnchorB
The local anchor point relative to bodyB's origin.
Definition: b2_friction_joint.h:49
b2Mat22
A 2-by-2 matrix. Stored in column-major order.
Definition: b2_math.h:172
b2SolverData
Solver Data.
Definition: b2_time_step.h:68
b2FrictionJoint::GetReactionForce
b2Vec2 GetReactionForce(float inv_dt) const override
Get the reaction force on bodyB at the joint anchor in Newtons.
b2FrictionJoint::SetMaxForce
void SetMaxForce(float force)
Set the maximum friction force in N.
b2Joint
Definition: b2_joint.h:112
b2FrictionJoint::GetAnchorB
b2Vec2 GetAnchorB() const override
Get the anchor point on bodyB in world coordinates.
b2FrictionJointDef
Friction joint definition.
Definition: b2_friction_joint.h:31
b2FrictionJoint::GetMaxTorque
float GetMaxTorque() const
Get the maximum friction torque in N*m.
b2FrictionJoint::GetLocalAnchorB
const b2Vec2 & GetLocalAnchorB() const
The local anchor point relative to bodyB's origin.
Definition: b2_friction_joint.h:73