/******************************************************************************
 * Spine Runtimes Software License
 * Version 2.3
 * 
 * Copyright (c) 2013-2015, Esoteric Software
 * All rights reserved.
 * 
 * You are granted a perpetual, non-exclusive, non-sublicensable and
 * non-transferable license to use, install, execute and perform the Spine
 * Runtimes Software (the "Software") and derivative works solely for personal
 * or internal use. Without the written permission of Esoteric Software (see
 * Section 2 of the Spine Software License Agreement), you may not (a) modify,
 * translate, adapt or otherwise create derivative works, improvements of the
 * Software or develop new applications using the Software or (b) remove,
 * delete, alter or obscure any trademarks or any copyright, trademark, patent
 * or other intellectual property or proprietary rights notices on or in the
 * Software, including any copy thereof. Redistributions in binary or source
 * form must include this license and terms.
 * 
 * THIS SOFTWARE IS PROVIDED BY ESOTERIC SOFTWARE "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
 * EVENT SHALL ESOTERIC SOFTWARE BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/

using System;
using System.Collections.Generic;

namespace Spine {
	public class TransformConstraint : IUpdatable {
		internal TransformConstraintData data;
		internal Bone bone, target;
		internal float translateMix;
		internal float x, y;

		public TransformConstraintData Data { get { return data; } }
		public Bone Bone { get { return bone; } set { bone = value; } }
		public Bone Target { get { return target; } set { target = value; } }
		public float TranslateMix { get { return translateMix; } set { translateMix = value; } }
		public float X { get { return x; } set { x = value; } }
		public float Y { get { return y; } set { y = value; } }

		public TransformConstraint (TransformConstraintData data, Skeleton skeleton) {
			if (data == null) throw new ArgumentNullException("data cannot be null.");
			if (skeleton == null) throw new ArgumentNullException("skeleton cannot be null.");
			this.data = data;
			translateMix = data.translateMix;
			x = data.x;
			y = data.y;

			bone = skeleton.FindBone(data.bone.name);
			target = skeleton.FindBone(data.target.name);
		}

		public void Update () {
			Apply();
		}

		public void Apply () {
			float translateMix = this.translateMix;
			if (translateMix > 0) {
				Bone bone = this.bone;
				float tx, ty;
				target.LocalToWorld(x, y, out tx, out ty);
				bone.worldX += (tx - bone.worldX) * translateMix;
				bone.worldY += (ty - bone.worldY) * translateMix;
			}
		}

		override public String ToString () {
			return data.name;
		}
	}
}