1 // MIT License 2 3 // Copyright (c) 2019 Erin Catto 4 5 // Permission is hereby granted, free of charge, to any person obtaining a copy 6 // of this software and associated documentation files (the "Software"), to deal 7 // in the Software without restriction, including without limitation the rights 8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 9 // copies of the Software, and to permit persons to whom the Software is 10 // furnished to do so, subject to the following conditions: 11 12 // The above copyright notice and this permission notice shall be included in all 13 // copies or substantial portions of the Software. 14 15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 21 // SOFTWARE. 22 23 #ifndef B2_CONTACT_SOLVER_H 24 #define B2_CONTACT_SOLVER_H 25 26 #include "box2d/b2_collision.h" 27 #include "box2d/b2_math.h" 28 #include "box2d/b2_time_step.h" 29 30 class b2Contact; 31 class b2Body; 32 class b2StackAllocator; 33 struct b2ContactPositionConstraint; 34 35 struct b2VelocityConstraintPoint 36 { 37 b2Vec2 rA; 38 b2Vec2 rB; 39 float normalImpulse; 40 float tangentImpulse; 41 float normalMass; 42 float tangentMass; 43 float velocityBias; 44 }; 45 46 struct b2ContactVelocityConstraint 47 { 48 b2VelocityConstraintPoint points[b2_maxManifoldPoints]; 49 b2Vec2 normal; 50 b2Mat22 normalMass; 51 b2Mat22 K; 52 int32 indexA; 53 int32 indexB; 54 float invMassA, invMassB; 55 float invIA, invIB; 56 float friction; 57 float restitution; 58 float threshold; 59 float tangentSpeed; 60 int32 pointCount; 61 int32 contactIndex; 62 }; 63 64 struct b2ContactSolverDef 65 { 66 b2TimeStep step; 67 b2Contact** contacts; 68 int32 count; 69 b2Position* positions; 70 b2Velocity* velocities; 71 b2StackAllocator* allocator; 72 }; 73 74 class b2ContactSolver 75 { 76 public: 77 b2ContactSolver(b2ContactSolverDef* def); 78 ~b2ContactSolver(); 79 80 void InitializeVelocityConstraints(); 81 82 void WarmStart(); 83 void SolveVelocityConstraints(); 84 void StoreImpulses(); 85 86 bool SolvePositionConstraints(); 87 bool SolveTOIPositionConstraints(int32 toiIndexA, int32 toiIndexB); 88 89 b2TimeStep m_step; 90 b2Position* m_positions; 91 b2Velocity* m_velocities; 92 b2StackAllocator* m_allocator; 93 b2ContactPositionConstraint* m_positionConstraints; 94 b2ContactVelocityConstraint* m_velocityConstraints; 95 b2Contact** m_contacts; 96 int m_count; 97 }; 98 99 #endif 100 101