/*
* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com
*
* 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.
*/

package Box2D.Dynamics.Joints{

	
import Box2D.Common.Math.*;
import Box2D.Dynamics.Joints.*;
import Box2D.Dynamics.*;


/// Distance joint definition. This requires defining an
/// anchor point on both bodies and the non-zero length of the
/// distance joint. The definition uses local anchor points
/// so that the initial configuration can violate the constraint
/// slightly. This helps when saving and loading a game.
/// @warning Do not use a zero or short length.
public class b2DistanceJointDef extends b2JointDef
{
	public function b2DistanceJointDef()
	{
		type = b2Joint.e_distanceJoint;
		//localAnchor1.Set(0.0, 0.0);
		//localAnchor2.Set(0.0, 0.0);
		length = 1.0;
		frequencyHz = 0.0;
		dampingRatio = 0.0;
	}
	
	/// Initialize the bodies, anchors, and length using the world
	/// anchors.
	public function Initialize(b1:b2Body, b2:b2Body,
								anchor1:b2Vec2, anchor2:b2Vec2) : void
	{
		body1 = b1;
		body2 = b2;
		localAnchor1.SetV( body1.GetLocalPoint(anchor1));
		localAnchor2.SetV( body2.GetLocalPoint(anchor2));
		var dX:Number = anchor2.x - anchor1.x;
		var dY:Number = anchor2.y - anchor1.y;
		length = Math.sqrt(dX*dX + dY*dY);
		frequencyHz = 0.0;
		dampingRatio = 0.0;
	}

	/// The local anchor point relative to body1's origin.
	public var localAnchor1:b2Vec2 = new b2Vec2();

	/// The local anchor point relative to body2's origin.
	public var localAnchor2:b2Vec2 = new b2Vec2();

	/// The equilibrium length between the anchor points.
	public var length:Number;

	/// The response speed.
	public var frequencyHz:Number;

	/// The damping ratio. 0 = no damping, 1 = critical damping.
	public var dampingRatio:Number;
};

}