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Diffstat (limited to 'Client/ThirdParty/Box2D/include/box2d/b2_distance_joint.h')
| -rw-r--r-- | Client/ThirdParty/Box2D/include/box2d/b2_distance_joint.h | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/Client/ThirdParty/Box2D/include/box2d/b2_distance_joint.h b/Client/ThirdParty/Box2D/include/box2d/b2_distance_joint.h new file mode 100644 index 0000000..cfc75fe --- /dev/null +++ b/Client/ThirdParty/Box2D/include/box2d/b2_distance_joint.h @@ -0,0 +1,176 @@ +// 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_DISTANCE_JOINT_H +#define B2_DISTANCE_JOINT_H + +#include "b2_api.h" +#include "b2_joint.h" + +/// Distance joint definition. This requires defining an anchor point on both +/// bodies and the non-zero distance of the distance joint. The definition uses +/// local anchor points so that the initial configuration can violate the +/// constraint slightly. This helps when saving and loading a game. +struct B2_API b2DistanceJointDef : public b2JointDef +{ + b2DistanceJointDef() + { + type = e_distanceJoint; + localAnchorA.Set(0.0f, 0.0f); + localAnchorB.Set(0.0f, 0.0f); + length = 1.0f; + minLength = 0.0f; + maxLength = FLT_MAX; + stiffness = 0.0f; + damping = 0.0f; + } + + /// Initialize the bodies, anchors, and rest length using world space anchors. + /// The minimum and maximum lengths are set to the rest length. + void Initialize(b2Body* bodyA, b2Body* bodyB, + const b2Vec2& anchorA, const b2Vec2& anchorB); + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The rest length of this joint. Clamped to a stable minimum value. + float length; + + /// Minimum length. Clamped to a stable minimum value. + float minLength; + + /// Maximum length. Must be greater than or equal to the minimum length. + float maxLength; + + /// The linear stiffness in N/m. + float stiffness; + + /// The linear damping in N*s/m. + float damping; +}; + +/// A distance joint constrains two points on two bodies to remain at a fixed +/// distance from each other. You can view this as a massless, rigid rod. +class B2_API b2DistanceJoint : public b2Joint +{ +public: + + b2Vec2 GetAnchorA() const override; + b2Vec2 GetAnchorB() const override; + + /// Get the reaction force given the inverse time step. + /// Unit is N. + b2Vec2 GetReactionForce(float inv_dt) const override; + + /// Get the reaction torque given the inverse time step. + /// Unit is N*m. This is always zero for a distance joint. + float GetReactionTorque(float inv_dt) const override; + + /// The local anchor point relative to bodyA's origin. + const b2Vec2& GetLocalAnchorA() const { return m_localAnchorA; } + + /// The local anchor point relative to bodyB's origin. + const b2Vec2& GetLocalAnchorB() const { return m_localAnchorB; } + + /// Get the rest length + float GetLength() const { return m_length; } + + /// Set the rest length + /// @returns clamped rest length + float SetLength(float length); + + /// Get the minimum length + float GetMinLength() const { return m_minLength; } + + /// Set the minimum length + /// @returns the clamped minimum length + float SetMinLength(float minLength); + + /// Get the maximum length + float GetMaxLength() const { return m_maxLength; } + + /// Set the maximum length + /// @returns the clamped maximum length + float SetMaxLength(float maxLength); + + /// Get the current length + float GetCurrentLength() const; + + /// Set/get the linear stiffness in N/m + void SetStiffness(float stiffness) { m_stiffness = stiffness; } + float GetStiffness() const { return m_stiffness; } + + /// Set/get linear damping in N*s/m + void SetDamping(float damping) { m_damping = damping; } + float GetDamping() const { return m_damping; } + + /// Dump joint to dmLog + void Dump() override; + + /// + void Draw(b2Draw* draw) const override; + +protected: + + friend class b2Joint; + b2DistanceJoint(const b2DistanceJointDef* data); + + void InitVelocityConstraints(const b2SolverData& data) override; + void SolveVelocityConstraints(const b2SolverData& data) override; + bool SolvePositionConstraints(const b2SolverData& data) override; + + float m_stiffness; + float m_damping; + float m_bias; + float m_length; + float m_minLength; + float m_maxLength; + + // Solver shared + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + float m_gamma; + float m_impulse; + float m_lowerImpulse; + float m_upperImpulse; + + // Solver temp + int32 m_indexA; + int32 m_indexB; + b2Vec2 m_u; + b2Vec2 m_rA; + b2Vec2 m_rB; + b2Vec2 m_localCenterA; + b2Vec2 m_localCenterB; + float m_currentLength; + float m_invMassA; + float m_invMassB; + float m_invIA; + float m_invIB; + float m_softMass; + float m_mass; +}; + +#endif |