paulxstretch/deps/juce/modules/juce_box2d/box2d/Dynamics/Joints/b2GearJoint.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_GEAR_JOINT_H
#define B2_GEAR_JOINT_H
#include "b2Joint.h"
/// Gear joint definition. This definition requires two existing
/// revolute or prismatic joints (any combination will work).
struct b2GearJointDef : public b2JointDef
{
b2GearJointDef()
{
type = e_gearJoint;
joint1 = NULL;
joint2 = NULL;
ratio = 1.0f;
}
/// The first revolute/prismatic joint attached to the gear joint.
b2Joint* joint1;
/// The second revolute/prismatic joint attached to the gear joint.
b2Joint* joint2;
/// The gear ratio.
/// @see b2GearJoint for explanation.
float32 ratio;
};
/// A gear joint is used to connect two joints together. Either joint
/// can be a revolute or prismatic joint. You specify a gear ratio
/// to bind the motions together:
/// coordinate1 + ratio * coordinate2 = constant
/// The ratio can be negative or positive. If one joint is a revolute joint
/// and the other joint is a prismatic joint, then the ratio will have units
/// of length or units of 1/length.
/// @warning You have to manually destroy the gear joint if joint1 or joint2
/// is destroyed.
class b2GearJoint : public b2Joint
{
public:
b2Vec2 GetAnchorA() const;
b2Vec2 GetAnchorB() const;
b2Vec2 GetReactionForce(float32 inv_dt) const;
float32 GetReactionTorque(float32 inv_dt) const;
/// Get the first joint.
b2Joint* GetJoint1() { return m_joint1; }
/// Get the second joint.
b2Joint* GetJoint2() { return m_joint2; }
/// Set/Get the gear ratio.
void SetRatio(float32 ratio);
float32 GetRatio() const;
/// Dump joint to dmLog
void Dump();
protected:
friend class b2Joint;
b2GearJoint(const b2GearJointDef* data);
void InitVelocityConstraints(const b2SolverData& data);
void SolveVelocityConstraints(const b2SolverData& data);
bool SolvePositionConstraints(const b2SolverData& data);
b2Joint* m_joint1;
b2Joint* m_joint2;
b2JointType m_typeA;
b2JointType m_typeB;
// Body A is connected to body C
// Body B is connected to body D
b2Body* m_bodyC;
b2Body* m_bodyD;
// Solver shared
b2Vec2 m_localAnchorA;
b2Vec2 m_localAnchorB;
b2Vec2 m_localAnchorC;
b2Vec2 m_localAnchorD;
b2Vec2 m_localAxisC;
b2Vec2 m_localAxisD;
float32 m_referenceAngleA;
float32 m_referenceAngleB;
float32 m_constant;
float32 m_ratio;
float32 m_impulse;
// Solver temp
juce::int32 m_indexA, m_indexB, m_indexC, m_indexD;
b2Vec2 m_lcA, m_lcB, m_lcC, m_lcD;
float32 m_mA, m_mB, m_mC, m_mD;
float32 m_iA, m_iB, m_iC, m_iD;
b2Vec2 m_JvAC, m_JvBD;
float32 m_JwA, m_JwB, m_JwC, m_JwD;
float32 m_mass;
};
#endif