Box2D: b2MouseJoint.h Source File

| Box2D 2.3.0 A 2D Physics Engine for Games

b2MouseJoint.h
1 /*
2 * Copyright (c) 2006-2007 Erin Catto http://www.box2d.org
3 *
4 * This software is provided 'as-is', without any express or implied
5 * warranty. In no event will the authors be held liable for any damages
6 * arising from the use of this software.
7 * Permission is granted to anyone to use this software for any purpose,
8 * including commercial applications, and to alter it and redistribute it
9 * freely, subject to the following restrictions:
10 * 1. The origin of this software must not be misrepresented; you must not
11 * claim that you wrote the original software. If you use this software
12 * in a product, an acknowledgment in the product documentation would be
13 * appreciated but is not required.
14 * 2. Altered source versions must be plainly marked as such, and must not be
15 * misrepresented as being the original software.
16 * 3. This notice may not be removed or altered from any source distribution.
17 */
18
19 #ifndef B2_MOUSE_JOINT_H
20 #define B2_MOUSE_JOINT_H
21
22 #include <Box2D/Dynamics/Joints/b2Joint.h>
23
26 struct b2MouseJointDef : public b2JointDef
27 {
28 b2MouseJointDef()
29 {
30 type = e_mouseJoint;
31 target.Set(0.0f, 0.0f);
32 maxForce = 0.0f;
33 frequencyHz = 5.0f;
34 dampingRatio = 0.7f;
35 }
36
39 b2Vec2 target;
40
44 float32 maxForce;
45
47 float32 frequencyHz;
48
50 float32 dampingRatio;
51 };
52
60 class b2MouseJoint : public b2Joint
61 {
62 public:
63
65 b2Vec2 GetAnchorA() const;
66
68 b2Vec2 GetAnchorB() const;
69
71 b2Vec2 GetReactionForce(float32 inv_dt) const;
72
74 float32 GetReactionTorque(float32 inv_dt) const;
75
77 void SetTarget(const b2Vec2& target);
78 const b2Vec2& GetTarget() const;
79
81 void SetMaxForce(float32 force);
82 float32 GetMaxForce() const;
83
85 void SetFrequency(float32 hz);
86 float32 GetFrequency() const;
87
89 void SetDampingRatio(float32 ratio);
90 float32 GetDampingRatio() const;
91
93 void Dump() { b2Log("Mouse joint dumping is not supported.\n"); }
94
96 void ShiftOrigin(const b2Vec2& newOrigin);
97
98 protected:
99 friend class b2Joint;
100
101 b2MouseJoint(const b2MouseJointDef* def);
102
103 void InitVelocityConstraints(const b2SolverData& data);
104 void SolveVelocityConstraints(const b2SolverData& data);
105 bool SolvePositionConstraints(const b2SolverData& data);
106
107 b2Vec2 m_localAnchorB;
108 b2Vec2 m_targetA;
109 float32 m_frequencyHz;
110 float32 m_dampingRatio;
111 float32 m_beta;
112
113 // Solver shared
114 b2Vec2 m_impulse;
115 float32 m_maxForce;
116 float32 m_gamma;
117
118 // Solver temp
119 int32 m_indexA;
120 int32 m_indexB;
121 b2Vec2 m_rB;
122 b2Vec2 m_localCenterB;
123 float32 m_invMassB;
124 float32 m_invIB;
125 b2Mat22 m_mass;
126 b2Vec2 m_C;
127 };
128
129 #endif
b2MouseJoint::GetAnchorB
b2Vec2 GetAnchorB() const
Implements b2Joint.
Definition: b2MouseJoint.cpp:204
b2Log
void b2Log(const char *string,...)
Logging function.
Definition: b2Settings.cpp:38
b2MouseJointDef::maxForce
float32 maxForce
Definition: b2MouseJoint.h:44
b2MouseJoint::GetReactionTorque
float32 GetReactionTorque(float32 inv_dt) const
Implements b2Joint.
Definition: b2MouseJoint.cpp:214
b2MouseJointDef::dampingRatio
float32 dampingRatio
The damping ratio. 0 = no damping, 1 = critical damping.
Definition: b2MouseJoint.h:50
b2MouseJoint::SetDampingRatio
void SetDampingRatio(float32 ratio)
Set/get the damping ratio (dimensionless).
Definition: b2MouseJoint.cpp:86
b2MouseJointDef::target
b2Vec2 target
Definition: b2MouseJoint.h:39
b2Joint
Definition: b2Joint.h:103
b2MouseJoint::GetReactionForce
b2Vec2 GetReactionForce(float32 inv_dt) const
Implements b2Joint.
Definition: b2MouseJoint.cpp:209
b2MouseJoint::Dump
void Dump()
The mouse joint does not support dumping.
Definition: b2MouseJoint.h:93
b2MouseJoint
Definition: b2MouseJoint.h:60
b2Vec2::Set
void Set(float32 x_, float32 y_)
Set this vector to some specified coordinates.
Definition: b2Math.h:65
b2MouseJoint::ShiftOrigin
void ShiftOrigin(const b2Vec2 &newOrigin)
Implement b2Joint::ShiftOrigin.
Definition: b2MouseJoint.cpp:219
b2JointDef::type
b2JointType type
The joint type is set automatically for concrete joint types.
Definition: b2Joint.h:86
b2SolverData
Solver Data.
Definition: b2TimeStep.h:63
b2MouseJoint::SetMaxForce
void SetMaxForce(float32 force)
Set/get the maximum force in Newtons.
Definition: b2MouseJoint.cpp:66
b2Mat22
A 2-by-2 matrix. Stored in column-major order.
Definition: b2Math.h:183
b2MouseJoint::SetFrequency
void SetFrequency(float32 hz)
Set/get the frequency in Hertz.
Definition: b2MouseJoint.cpp:76
b2JointDef
Joint definitions are used to construct joints.
Definition: b2Joint.h:74
b2MouseJointDef::frequencyHz
float32 frequencyHz
The response speed.
Definition: b2MouseJoint.h:47
b2MouseJointDef
Definition: b2MouseJoint.h:26
b2Vec2
A 2D column vector.
Definition: b2Math.h:53
b2MouseJoint::SetTarget
void SetTarget(const b2Vec2 &target)
Use this to update the target point.
Definition: b2MouseJoint.cpp:52
b2MouseJoint::GetAnchorA
b2Vec2 GetAnchorA() const
Implements b2Joint.
Definition: b2MouseJoint.cpp:199