| Box2D 2.3.0 A 2D Physics Engine for Games

b2ContactSolver.h
1 /*
2 * Copyright (c) 2006-2009 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_CONTACT_SOLVER_H
20 #define B2_CONTACT_SOLVER_H
21
22 #include <Box2D/Common/b2Math.h>
23 #include <Box2D/Collision/b2Collision.h>
24 #include <Box2D/Dynamics/b2TimeStep.h>
25
26 class b2Contact;
27 class b2Body;
28 class b2StackAllocator;
29 struct b2ContactPositionConstraint;
30
31 struct b2VelocityConstraintPoint
32 {
33 b2Vec2 rA;
34 b2Vec2 rB;
35 float32 normalImpulse;
36 float32 tangentImpulse;
37 float32 normalMass;
38 float32 tangentMass;
39 float32 velocityBias;
40 };
41
42 struct b2ContactVelocityConstraint
43 {
44 b2VelocityConstraintPoint points[b2_maxManifoldPoints];
45 b2Vec2 normal;
46 b2Mat22 normalMass;
47 b2Mat22 K;
48 int32 indexA;
49 int32 indexB;
50 float32 invMassA, invMassB;
51 float32 invIA, invIB;
52 float32 friction;
53 float32 restitution;
54 float32 tangentSpeed;
55 int32 pointCount;
56 int32 contactIndex;
57 };
58
59 struct b2ContactSolverDef
60 {
61 b2TimeStep step;
62 b2Contact** contacts;
63 int32 count;
64 b2Position* positions;
65 b2Velocity* velocities;
66 b2StackAllocator* allocator;
67 };
68
69 class b2ContactSolver
70 {
71 public:
72 b2ContactSolver(b2ContactSolverDef* def);
73 ~b2ContactSolver();
74
75 void InitializeVelocityConstraints();
76
77 void WarmStart();
78 void SolveVelocityConstraints();
79 void StoreImpulses();
80
81 bool SolvePositionConstraints();
82 bool SolveTOIPositionConstraints(int32 toiIndexA, int32 toiIndexB);
83
84 b2TimeStep m_step;
85 b2Position* m_positions;
86 b2Velocity* m_velocities;
87 b2StackAllocator* m_allocator;
88 b2ContactPositionConstraint* m_positionConstraints;
89 b2ContactVelocityConstraint* m_velocityConstraints;
90 b2Contact** m_contacts;
91 int m_count;
92 };
93
94 #endif
95
b2ContactPositionConstraint
Definition: b2ContactSolver.cpp:31
b2ContactSolverDef
Definition: b2ContactSolver.h:59
b2StackAllocator
Definition: b2StackAllocator.h:37
b2VelocityConstraintPoint
Definition: b2ContactSolver.h:31
b2Collision.h
b2Position
This is an internal structure.
Definition: b2TimeStep.h:49
b2TimeStep
This is an internal structure.
Definition: b2TimeStep.h:38
b2Mat22
A 2-by-2 matrix. Stored in column-major order.
Definition: b2Math.h:183
b2Body
A rigid body. These are created via b2World::CreateBody.
Definition: b2Body.h:126
b2ContactVelocityConstraint
Definition: b2ContactSolver.h:42
b2Velocity
This is an internal structure.
Definition: b2TimeStep.h:56
b2Vec2
A 2D column vector.
Definition: b2Math.h:53
b2Contact
Definition: b2Contact.h:77
b2ContactSolver
Definition: b2ContactSolver.h:69
b2_maxManifoldPoints
#define b2_maxManifoldPoints
Definition: b2Settings.h:50