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Diffstat (limited to 'Client/ThirdParty/Box2D/include/box2d/b2_pulley_joint.h')
| -rw-r--r-- | Client/ThirdParty/Box2D/include/box2d/b2_pulley_joint.h | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/Client/ThirdParty/Box2D/include/box2d/b2_pulley_joint.h b/Client/ThirdParty/Box2D/include/box2d/b2_pulley_joint.h new file mode 100644 index 0000000..6b14456 --- /dev/null +++ b/Client/ThirdParty/Box2D/include/box2d/b2_pulley_joint.h @@ -0,0 +1,157 @@ +// MIT License + +// Copyright (c) 2019 Erin Catto + +// Permission is hereby granted, free of charge, to any person obtaining a copy +// of this software and associated documentation files (the "Software"), to deal +// in the Software without restriction, including without limitation the rights +// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +// copies of the Software, and to permit persons to whom the Software is +// furnished to do so, subject to the following conditions: + +// The above copyright notice and this permission notice shall be included in all +// copies or substantial portions of the Software. + +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +// SOFTWARE. + +#ifndef B2_PULLEY_JOINT_H +#define B2_PULLEY_JOINT_H + +#include "b2_api.h" +#include "b2_joint.h" + +const float b2_minPulleyLength = 2.0f; + +/// Pulley joint definition. This requires two ground anchors, +/// two dynamic body anchor points, and a pulley ratio. +struct B2_API b2PulleyJointDef : public b2JointDef +{ + b2PulleyJointDef() + { + type = e_pulleyJoint; + groundAnchorA.Set(-1.0f, 1.0f); + groundAnchorB.Set(1.0f, 1.0f); + localAnchorA.Set(-1.0f, 0.0f); + localAnchorB.Set(1.0f, 0.0f); + lengthA = 0.0f; + lengthB = 0.0f; + ratio = 1.0f; + collideConnected = true; + } + + /// Initialize the bodies, anchors, lengths, max lengths, and ratio using the world anchors. + void Initialize(b2Body* bodyA, b2Body* bodyB, + const b2Vec2& groundAnchorA, const b2Vec2& groundAnchorB, + const b2Vec2& anchorA, const b2Vec2& anchorB, + float ratio); + + /// The first ground anchor in world coordinates. This point never moves. + b2Vec2 groundAnchorA; + + /// The second ground anchor in world coordinates. This point never moves. + b2Vec2 groundAnchorB; + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The a reference length for the segment attached to bodyA. + float lengthA; + + /// The a reference length for the segment attached to bodyB. + float lengthB; + + /// The pulley ratio, used to simulate a block-and-tackle. + float ratio; +}; + +/// The pulley joint is connected to two bodies and two fixed ground points. +/// The pulley supports a ratio such that: +/// length1 + ratio * length2 <= constant +/// Yes, the force transmitted is scaled by the ratio. +/// Warning: the pulley joint can get a bit squirrelly by itself. They often +/// work better when combined with prismatic joints. You should also cover the +/// the anchor points with static shapes to prevent one side from going to +/// zero length. +class B2_API b2PulleyJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + b2Vec2 GetReactionForce(float inv_dt) const override; + float GetReactionTorque(float inv_dt) const override; + + /// Get the first ground anchor. + b2Vec2 GetGroundAnchorA() const; + + /// Get the second ground anchor. + b2Vec2 GetGroundAnchorB() const; + + /// Get the current length of the segment attached to bodyA. + float GetLengthA() const; + + /// Get the current length of the segment attached to bodyB. + float GetLengthB() const; + + /// Get the pulley ratio. + float GetRatio() const; + + /// Get the current length of the segment attached to bodyA. + float GetCurrentLengthA() const; + + /// Get the current length of the segment attached to bodyB. + float GetCurrentLengthB() const; + + /// Dump joint to dmLog + void Dump() override; + + /// Implement b2Joint::ShiftOrigin + void ShiftOrigin(const b2Vec2& newOrigin) override; + +protected: + + friend class b2Joint; + b2PulleyJoint(const b2PulleyJointDef* data); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + b2Vec2 m_groundAnchorA; + b2Vec2 m_groundAnchorB; + float m_lengthA; + float m_lengthB; + + // Solver shared + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + float m_constant; + float m_ratio; + float m_impulse; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_uA; + b2Vec2 m_uB; + b2Vec2 m_rA; + b2Vec2 m_rB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + float m_invMassA; + float m_invMassB; + float m_invIA; + float m_invIB; + float m_mass; +}; + +#endif |