internal DistanceJoint(DistanceJointDef def) : base(def) { _localAnchor1 = def.localAnchor1; _localAnchor2 = def.localAnchor2; _length = def.length; _frequencyHz = def.frequencyHz; _dampingRatio = def.dampingRatio; _impulse = 0.0f; _gamma = 0.0f; _bias = 0.0f; }