paulxstretch/deps/juce/modules/juce_box2d/box2d/Dynamics/Joints/b2RopeJoint.h

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/*
* Copyright (c) 2006-2011 Erin Catto http://www.box2d.org
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
#ifndef B2_ROPE_JOINT_H
#define B2_ROPE_JOINT_H
#include "b2Joint.h"
/// Rope joint definition. This requires two body anchor points and
/// a maximum lengths.
/// Note: by default the connected objects will not collide.
/// see collideConnected in b2JointDef.
struct b2RopeJointDef : public b2JointDef
{
b2RopeJointDef()
{
type = e_ropeJoint;
localAnchorA.Set(-1.0f, 0.0f);
localAnchorB.Set(1.0f, 0.0f);
maxLength = 0.0f;
}
/// The local anchor point relative to bodyA's origin.
b2Vec2 localAnchorA;
/// The local anchor point relative to bodyB's origin.
b2Vec2 localAnchorB;
/// The maximum length of the rope.
/// Warning: this must be larger than b2_linearSlop or
/// the joint will have no effect.
float32 maxLength;
};
/// A rope joint enforces a maximum distance between two points
/// on two bodies. It has no other effect.
/// Warning: if you attempt to change the maximum length during
/// the simulation you will get some non-physical behavior.
/// A model that would allow you to dynamically modify the length
/// would have some sponginess, so I chose not to implement it
/// that way. See b2DistanceJoint if you want to dynamically
/// control length.
class b2RopeJoint : public b2Joint
{
public:
b2Vec2 GetAnchorA() const;
b2Vec2 GetAnchorB() const;
b2Vec2 GetReactionForce(float32 inv_dt) const;
float32 GetReactionTorque(float32 inv_dt) const;
/// 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; }
/// Set/Get the maximum length of the rope.
void SetMaxLength(float32 length) { m_maxLength = length; }
float32 GetMaxLength() const;
b2LimitState GetLimitState() const;
/// Dump joint to dmLog
void Dump();
protected:
friend class b2Joint;
b2RopeJoint(const b2RopeJointDef* data);
void InitVelocityConstraints(const b2SolverData& data);
void SolveVelocityConstraints(const b2SolverData& data);
bool SolvePositionConstraints(const b2SolverData& data);
// Solver shared
b2Vec2 m_localAnchorA;
b2Vec2 m_localAnchorB;
float32 m_maxLength;
float32 m_length;
float32 m_impulse;
// Solver temp
juce::int32 m_indexA;
juce::int32 m_indexB;
b2Vec2 m_u;
b2Vec2 m_rA;
b2Vec2 m_rB;
b2Vec2 m_localCenterA;
b2Vec2 m_localCenterB;
float32 m_invMassA;
float32 m_invMassB;
float32 m_invIA;
float32 m_invIB;
float32 m_mass;
b2LimitState m_state;
};
#endif