org.jbox2d.dynamics.joints
Class DistanceJoint

java.lang.Object
  extended by org.jbox2d.dynamics.joints.Joint
      extended by org.jbox2d.dynamics.joints.DistanceJoint

public class DistanceJoint
extends Joint

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.


Field Summary
 float m_bias
           
 float m_dampingRatio
           
 float m_frequencyHz
           
 float m_gamma
           
 float m_impulse
           
 int m_indexA
           
 int m_indexB
           
 float m_invIA
           
 float m_invIB
           
 float m_invMassA
           
 float m_invMassB
           
 float m_length
           
 Vec2 m_localAnchorA
           
 Vec2 m_localAnchorB
           
 Vec2 m_localCenterA
           
 Vec2 m_localCenterB
           
 float m_mass
           
 Vec2 m_rA
           
 Vec2 m_rB
           
 Vec2 m_u
           
 
Fields inherited from class org.jbox2d.dynamics.joints.Joint
m_bodyA, m_bodyB, m_collideConnected, m_edgeA, m_edgeB, m_index, m_islandFlag, m_next, m_prev, m_type, m_userData, pool
 
Constructor Summary
DistanceJoint(IWorldPool argWorld, DistanceJointDef def)
           
 
Method Summary
 void getAnchorA(Vec2 argOut)
          get the anchor point on bodyA in world coordinates.
 void getAnchorB(Vec2 argOut)
          get the anchor point on bodyB in world coordinates.
 float getDampingRatio()
           
 float getFrequency()
           
 float getLength()
           
 Vec2 getLocalAnchorA()
           
 Vec2 getLocalAnchorB()
           
 void getReactionForce(float inv_dt, Vec2 argOut)
          Get the reaction force given the inverse time step.
 float getReactionTorque(float inv_dt)
          Get the reaction torque given the inverse time step.
 void initVelocityConstraints(SolverData data)
           
 void setDampingRatio(float damp)
           
 void setFrequency(float hz)
           
 void setLength(float argLength)
           
 boolean solvePositionConstraints(SolverData data)
          This returns true if the position errors are within tolerance.
 void solveVelocityConstraints(SolverData data)
           
 
Methods inherited from class org.jbox2d.dynamics.joints.Joint
create, destroy, destructor, getBodyA, getBodyB, getCollideConnected, getNext, getType, getUserData, IsActive, setUserData
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

m_frequencyHz

public float m_frequencyHz

m_dampingRatio

public float m_dampingRatio

m_bias

public float m_bias

m_localAnchorA

public final Vec2 m_localAnchorA

m_localAnchorB

public final Vec2 m_localAnchorB

m_gamma

public float m_gamma

m_impulse

public float m_impulse

m_length

public float m_length

m_indexA

public int m_indexA

m_indexB

public int m_indexB

m_u

public final Vec2 m_u

m_rA

public final Vec2 m_rA

m_rB

public final Vec2 m_rB

m_localCenterA

public final Vec2 m_localCenterA

m_localCenterB

public final Vec2 m_localCenterB

m_invMassA

public float m_invMassA

m_invMassB

public float m_invMassB

m_invIA

public float m_invIA

m_invIB

public float m_invIB

m_mass

public float m_mass
Constructor Detail

DistanceJoint

public DistanceJoint(IWorldPool argWorld,
                     DistanceJointDef def)
Method Detail

setFrequency

public void setFrequency(float hz)

getFrequency

public float getFrequency()

getLength

public float getLength()

setLength

public void setLength(float argLength)

setDampingRatio

public void setDampingRatio(float damp)

getDampingRatio

public float getDampingRatio()

getAnchorA

public void getAnchorA(Vec2 argOut)
Description copied from class: Joint
get the anchor point on bodyA in world coordinates.

Specified by:
getAnchorA in class Joint

getAnchorB

public void getAnchorB(Vec2 argOut)
Description copied from class: Joint
get the anchor point on bodyB in world coordinates.

Specified by:
getAnchorB in class Joint

getLocalAnchorA

public Vec2 getLocalAnchorA()

getLocalAnchorB

public Vec2 getLocalAnchorB()

getReactionForce

public void getReactionForce(float inv_dt,
                             Vec2 argOut)
Get the reaction force given the inverse time step. Unit is N.

Specified by:
getReactionForce in class Joint

getReactionTorque

public float getReactionTorque(float inv_dt)
Get the reaction torque given the inverse time step. Unit is N*m. This is always zero for a distance joint.

Specified by:
getReactionTorque in class Joint
Returns:

initVelocityConstraints

public void initVelocityConstraints(SolverData data)
Specified by:
initVelocityConstraints in class Joint

solveVelocityConstraints

public void solveVelocityConstraints(SolverData data)
Specified by:
solveVelocityConstraints in class Joint

solvePositionConstraints

public boolean solvePositionConstraints(SolverData data)
Description copied from class: Joint
This returns true if the position errors are within tolerance.

Specified by:
solvePositionConstraints in class Joint
Returns:


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