/******************************************************************************
 * Spine Runtimes Software License
 * Version 2.5
 * 
 * Copyright (c) 2013-2016, 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 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 develop new applications using the Spine Runtimes or otherwise
 * create derivative works or improvements of the Spine Runtimes 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, BUSINESS INTERRUPTION, OR LOSS OF
 * USE, DATA, OR PROFITS) 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.
 *****************************************************************************/

module spine {
	export class TransformConstraint implements Updatable {
		data: TransformConstraintData;
		bones: Array<Bone>;
		target: Bone;
		rotateMix = 0; translateMix = 0; scaleMix = 0; shearMix = 0;
		temp = new Vector2();

		constructor (data: TransformConstraintData, skeleton: Skeleton) {
			if (data == null) throw new Error("data cannot be null.");
			if (skeleton == null) throw new Error("skeleton cannot be null.");
			this.data = data;
			this.rotateMix = data.rotateMix;
			this.translateMix = data.translateMix;
			this.scaleMix = data.scaleMix;
			this.shearMix = data.shearMix;
			this.bones = new Array<Bone>();
			for (let i = 0; i < data.bones.length; i++)
				this.bones.push(skeleton.findBone(data.bones[i].name));
			this.target = skeleton.findBone(data.target.name);
		}

		apply () {
			this.update();
		}

		update () {
			let rotateMix = this.rotateMix, translateMix = this.translateMix, scaleMix = this.scaleMix, shearMix = this.shearMix;
			let target = this.target;
			let ta = target.a, tb = target.b, tc = target.c, td = target.d;
			let bones = this.bones;
			for (let i = 0, n = bones.length; i < n; i++) {
				let bone = bones[i];

				if (rotateMix > 0) {
					let a = bone.a, b = bone.b, c = bone.c, d = bone.d;
					let r = Math.atan2(tc, ta) - Math.atan2(c, a) + this.data.offsetRotation * MathUtils.degRad;
					if (r > MathUtils.PI)
						r -= MathUtils.PI2;
					else if (r < -MathUtils.PI)
						r += MathUtils.PI2;
					r *= rotateMix;
					let cos = Math.cos(r), sin = Math.sin(r);
					bone.a = cos * a - sin * c;
					bone.b = cos * b - sin * d;
					bone.c = sin * a + cos * c;
					bone.d = sin * b + cos * d;
				}

				if (translateMix > 0) {
					let temp = this.temp;
					target.localToWorld(temp.set(this.data.offsetX, this.data.offsetY));
					bone.worldX += (temp.x - bone.worldX) * translateMix;
					bone.worldY += (temp.y - bone.worldY) * translateMix;
				}

				if (scaleMix > 0) {
					let bs = Math.sqrt(bone.a * bone.a + bone.c * bone.c);
					let ts = Math.sqrt(ta * ta + tc * tc);
					let s = bs > 0.00001 ? (bs + (ts - bs + this.data.offsetScaleX) * scaleMix) / bs : 0;
					bone.a *= s;
					bone.c *= s;
					bs = Math.sqrt(bone.b * bone.b + bone.d * bone.d);
					ts = Math.sqrt(tb * tb + td * td);
					s = bs > 0.00001 ? (bs + (ts - bs + this.data.offsetScaleY) * scaleMix) / bs : 0;
					bone.b *= s;
					bone.d *= s;
				}

				if (shearMix > 0) {
					let b = bone.b, d = bone.d;
					let by = Math.atan2(d, b);
					let r = Math.atan2(td, tb) - Math.atan2(tc, ta) - (by - Math.atan2(bone.c, bone.a));
					if (r > MathUtils.PI)
						r -= MathUtils.PI2;
					else if (r < -MathUtils.PI)
						r += MathUtils.PI2;
					r = by + (r + this.data.offsetShearY * MathUtils.degRad) * shearMix;
					let s = Math.sqrt(b * b + d * d);
					bone.b = Math.cos(r) * s;
					bone.d = Math.sin(r) * s;
				}
			}
		}
	}
}