attach method
void
attach()
Attach the constraint to the bodies.
Implementation
void attach(){
p1=body1!.position;
p2=body2!.position;
lv1=body1!.linearVelocity;
av1=body1!.angularVelocity;
lv2=body2!.linearVelocity;
av2=body2!.angularVelocity;
i1=body1!.inverseInertia;
i2=body2!.inverseInertia;
}