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
26class b2Contact;
27class b2Body;
28class b2StackAllocator;
29struct b2ContactPositionConstraint;
30
31struct 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
42struct 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
59struct b2ContactSolverDef
60{
61 b2TimeStep step;
62 b2Contact** contacts;
63 int32 count;
64 b2Position* positions;
65 b2Velocity* velocities;
66 b2StackAllocator* allocator;
67};
68
69class b2ContactSolver
70{
71public:
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
96