PulleyJoint.hpp
Go to the documentation of this file.
1 /*
2  * Original work Copyright (c) 2006-2011 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_PULLEYJOINT_HPP
23 #define PLAYRHO_DYNAMICS_JOINTS_PULLEYJOINT_HPP
24 
25 #include <PlayRho/Dynamics/Joints/Joint.hpp>
26 #include <PlayRho/Dynamics/Joints/PulleyJointConf.hpp>
27 
28 namespace playrho {
29 namespace d2 {
30 
47 class PulleyJoint : public Joint
48 {
49 public:
50 
55  PulleyJoint(const PulleyJointConf& data);
56 
57  void Accept(JointVisitor& visitor) const override;
58  void Accept(JointVisitor& visitor) override;
59  Length2 GetAnchorA() const override;
60  Length2 GetAnchorB() const override;
61  Momentum2 GetLinearReaction() const override;
62  AngularMomentum GetAngularReaction() const override;
63  bool ShiftOrigin(const Length2 newOrigin) override;
64 
66  Length2 GetLocalAnchorA() const noexcept;
67 
69  Length2 GetLocalAnchorB() const noexcept;
70 
72  Length2 GetGroundAnchorA() const noexcept;
73 
75  Length2 GetGroundAnchorB() const noexcept;
76 
78  Length GetLengthA() const noexcept;
79 
81  Length GetLengthB() const noexcept;
82 
84  Real GetRatio() const noexcept;
85 
86 private:
87 
88  void InitVelocityConstraints(BodyConstraintsMap& bodies,
89  const StepConf& step,
90  const ConstraintSolverConf&) override;
91  bool SolveVelocityConstraints(BodyConstraintsMap& bodies, const StepConf&) override;
92  bool SolvePositionConstraints(BodyConstraintsMap& bodies,
93  const ConstraintSolverConf& conf) const override;
94 
95  Length2 m_groundAnchorA;
96  Length2 m_groundAnchorB;
97  Length2 m_localAnchorA;
98  Length2 m_localAnchorB;
99  Length m_lengthA;
100  Length m_lengthB;
101  Real m_ratio;
102  Length m_constant;
103 
104  // Solver shared (between calls to InitVelocityConstraints).
105  Momentum m_impulse = 0_Ns;
106 
107  // Solver temp (recalculated every call to InitVelocityConstraints).
108  UnitVec m_uA;
109  UnitVec m_uB;
110  Length2 m_rA;
111  Length2 m_rB;
112  Mass m_mass;
113 };
114 
115 inline Length2 PulleyJoint::GetLocalAnchorA() const noexcept
116 {
117  return m_localAnchorA;
118 }
119 
120 inline Length2 PulleyJoint::GetLocalAnchorB() const noexcept
121 {
122  return m_localAnchorB;
123 }
124 
125 inline Length2 PulleyJoint::GetGroundAnchorA() const noexcept
126 {
127  return m_groundAnchorA;
128 }
129 
130 inline Length2 PulleyJoint::GetGroundAnchorB() const noexcept
131 {
132  return m_groundAnchorB;
133 }
134 
135 inline Length PulleyJoint::GetLengthA() const noexcept
136 {
137  return m_lengthA;
138 }
139 
140 inline Length PulleyJoint::GetLengthB() const noexcept
141 {
142  return m_lengthB;
143 }
144 
145 inline Real PulleyJoint::GetRatio() const noexcept
146 {
147  return m_ratio;
148 }
149 
152 Length GetCurrentLengthA(const PulleyJoint& joint);
153 
156 Length GetCurrentLengthB(const PulleyJoint& joint);
157 
158 } // namespace d2
159 } // namespace playrho
160 
161 #endif // PLAYRHO_DYNAMICS_JOINTS_PULLEYJOINT_HPP