FrictionJoint.hpp
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1 /*
2  * Original work Copyright (c) 2006-2007 Erin Catto http://www.box2d.org
3  * Modified work Copyright (c) 2017 Louis Langholtz https://github.com/louis-langholtz/PlayRho
4  *
5  * This software is provided 'as-is', without any express or implied
6  * warranty. In no event will the authors be held liable for any damages
7  * arising from the use of this software.
8  *
9  * Permission is granted to anyone to use this software for any purpose,
10  * including commercial applications, and to alter it and redistribute it
11  * freely, subject to the following restrictions:
12  *
13  * 1. The origin of this software must not be misrepresented; you must not
14  * claim that you wrote the original software. If you use this software
15  * in a product, an acknowledgment in the product documentation would be
16  * appreciated but is not required.
17  * 2. Altered source versions must be plainly marked as such, and must not be
18  * misrepresented as being the original software.
19  * 3. This notice may not be removed or altered from any source distribution.
20  */
21 
22 #ifndef PLAYRHO_DYNAMICS_JOINTS_FRICTIONJOINT_HPP
23 #define PLAYRHO_DYNAMICS_JOINTS_FRICTIONJOINT_HPP
24 
25 #include <PlayRho/Dynamics/Joints/Joint.hpp>
26 #include <PlayRho/Dynamics/Joints/FrictionJointConf.hpp>
27 #include <PlayRho/Common/BoundedValue.hpp>
28 
29 namespace playrho {
30 namespace d2 {
31 
39 class FrictionJoint : public Joint
40 {
41 public:
42 
47  FrictionJoint(const FrictionJointConf& def);
48 
49  void Accept(JointVisitor& visitor) const override;
50  void Accept(JointVisitor& visitor) override;
51 
52  Length2 GetAnchorA() const override;
53  Length2 GetAnchorB() const override;
54 
55  Momentum2 GetLinearReaction() const override;
56  AngularMomentum GetAngularReaction() const override;
57 
59  Length2 GetLocalAnchorA() const { return m_localAnchorA; }
60 
62  Length2 GetLocalAnchorB() const { return m_localAnchorB; }
63 
65  void SetMaxForce(NonNegative<Force> force);
66 
68  NonNegative<Force> GetMaxForce() const;
69 
71  void SetMaxTorque(NonNegative<Torque> torque);
72 
74  NonNegative<Torque> GetMaxTorque() const;
75 
76 private:
77 
78  void InitVelocityConstraints(BodyConstraintsMap& bodies, const StepConf& step,
79  const ConstraintSolverConf& conf) override;
80  bool SolveVelocityConstraints(BodyConstraintsMap& bodies, const StepConf& step) override;
81  bool SolvePositionConstraints(BodyConstraintsMap& bodies,
82  const ConstraintSolverConf& conf) const override;
83 
84  Length2 m_localAnchorA;
85  Length2 m_localAnchorB;
86  NonNegative<Force> m_maxForce = NonNegative<Force>{0_N};
87  NonNegative<Torque> m_maxTorque = NonNegative<Torque>{0_Nm};
88 
89  // Solver shared data - data saved & updated over multiple InitVelocityConstraints calls.
90  Momentum2 m_linearImpulse = Momentum2{};
91  AngularMomentum m_angularImpulse = AngularMomentum{0};
92 
93  // Solver temp
94  Length2 m_rA;
95  Length2 m_rB;
96  Mass22 m_linearMass;
97  RotInertia m_angularMass;
98 };
99 
100 inline void FrictionJoint::SetMaxForce(NonNegative<Force> force)
101 {
102  m_maxForce = force;
103 }
104 
105 inline NonNegative<Force> FrictionJoint::GetMaxForce() const
106 {
107  return m_maxForce;
108 }
109 
110 inline void FrictionJoint::SetMaxTorque(NonNegative<Torque> torque)
111 {
112  m_maxTorque = torque;
113 }
114 
115 inline NonNegative<Torque> FrictionJoint::GetMaxTorque() const
116 {
117  return m_maxTorque;
118 }
119 
120 } // namespace d2
121 } // namespace playrho
122 
123 #endif // PLAYRHO_DYNAMICS_JOINTS_FRICTIONJOINT_HPP