/******************************************************************************
 * Spine Runtimes License Agreement
 * Last updated January 1, 2020. Replaces all prior versions.
 *
 * Copyright (c) 2013-2020, Esoteric Software LLC
 *
 * Integration of the Spine Runtimes into software or otherwise creating
 * derivative works of the Spine Runtimes is permitted under the terms and
 * conditions of Section 2 of the Spine Editor License Agreement:
 * http://esotericsoftware.com/spine-editor-license
 *
 * Otherwise, it is permitted to integrate the Spine Runtimes into software
 * or otherwise create derivative works of the Spine Runtimes (collectively,
 * "Products"), provided that each user of the Products must obtain their own
 * Spine Editor license and redistribution of the Products in any form must
 * include this license and copyright notice.
 *
 * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "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 LLC 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
 * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *****************************************************************************/

module spine {

	/** A simple container for a list of timelines and a name. */
	export class Animation {
		/** The animation's name, which is unique across all animations in the skeleton. */
		name: string;
		timelines: Array<Timeline>;
		timelineIds: Array<boolean>;

		/** The duration of the animation in seconds, which is the highest time of all keys in the timeline. */
		duration: number;

		constructor (name: string, timelines: Array<Timeline>, duration: number) {
			if (name == null) throw new Error("name cannot be null.");
			if (timelines == null) throw new Error("timelines cannot be null.");
			this.name = name;
			this.timelines = timelines;
			this.timelineIds = [];
			for (var i = 0; i < timelines.length; i++)
				this.timelineIds[timelines[i].getPropertyId()] = true;
			this.duration = duration;
		}

		hasTimeline (id: number) {
			return this.timelineIds[id] == true;
		}

		/** Applies all the animation's timelines to the specified skeleton.
		 *
		 * See Timeline {@link Timeline#apply(Skeleton, float, float, Array, float, MixBlend, MixDirection)}.
		 * @param loop If true, the animation repeats after {@link #getDuration()}.
		 * @param events May be null to ignore fired events. */
		apply (skeleton: Skeleton, lastTime: number, time: number, loop: boolean, events: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			if (skeleton == null) throw new Error("skeleton cannot be null.");

			if (loop && this.duration != 0) {
				time %= this.duration;
				if (lastTime > 0) lastTime %= this.duration;
			}

			let timelines = this.timelines;
			for (let i = 0, n = timelines.length; i < n; i++)
				timelines[i].apply(skeleton, lastTime, time, events, alpha, blend, direction);
		}

		/** @param target After the first and before the last value.
	 	 * @returns index of first value greater than the target. */
		static binarySearch (values: ArrayLike<number>, target: number, step: number = 1) {
			let low = 0;
			let high = values.length / step - 2;
			if (high == 0) return step;
			let current = high >>> 1;
			while (true) {
				if (values[(current + 1) * step] <= target)
					low = current + 1;
				else
					high = current;
				if (low == high) return (low + 1) * step;
				current = (low + high) >>> 1;
			}
		}

		static linearSearch (values: ArrayLike<number>, target: number, step: number) {
			for (let i = 0, last = values.length - step; i <= last; i += step)
				if (values[i] > target) return i;
			return -1;
		}
	}

	/** The interface for all timelines. */
	export interface Timeline {
		/** Applies this timeline to the skeleton.
		 * @param skeleton The skeleton the timeline is being applied to. This provides access to the bones, slots, and other
		 *           skeleton components the timeline may change.
		 * @param lastTime The time this timeline was last applied. Timelines such as {@link EventTimeline}} trigger only at specific
		 *           times rather than every frame. In that case, the timeline triggers everything between `lastTime`
		 *           (exclusive) and `time` (inclusive).
		 * @param time The time within the animation. Most timelines find the key before and the key after this time so they can
		 *           interpolate between the keys.
		 * @param events If any events are fired, they are added to this list. Can be null to ignore fired events or if the timeline
		 *           does not fire events.
		 * @param alpha 0 applies the current or setup value (depending on `blend`). 1 applies the timeline value.
		 *           Between 0 and 1 applies a value between the current or setup value and the timeline value. By adjusting
		 *           `alpha` over time, an animation can be mixed in or out. `alpha` can also be useful to
		 *           apply animations on top of each other (layering).
		 * @param blend Controls how mixing is applied when `alpha` < 1.
		 * @param direction Indicates whether the timeline is mixing in or out. Used by timelines which perform instant transitions,
		 *           such as {@link DrawOrderTimeline} or {@link AttachmentTimeline}. */
		apply (skeleton: Skeleton, lastTime: number, time: number, events: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection): void;

		/** Uniquely encodes both the type of this timeline and the skeleton property that it affects. */
		getPropertyId (): number;
	}

	/** Controls how a timeline value is mixed with the setup pose value or current pose value when a timeline's `alpha`
	 * < 1.
	 *
	 * See Timeline {@link Timeline#apply(Skeleton, float, float, Array, float, MixBlend, MixDirection)}. */
	export enum MixBlend {
		/** Transitions from the setup value to the timeline value (the current value is not used). Before the first key, the setup
		 * value is set. */
		setup,
		/** Transitions from the current value to the timeline value. Before the first key, transitions from the current value to
		 * the setup value. Timelines which perform instant transitions, such as {@link DrawOrderTimeline} or
		 * {@link AttachmentTimeline}, use the setup value before the first key.
		 *
		 * `first` is intended for the first animations applied, not for animations layered on top of those. */
		first,
		/** Transitions from the current value to the timeline value. No change is made before the first key (the current value is
		 * kept until the first key).
		 *
		 * `replace` is intended for animations layered on top of others, not for the first animations applied. */
		replace,
		/** Transitions from the current value to the current value plus the timeline value. No change is made before the first key
		 * (the current value is kept until the first key).
		 *
		 * `add` is intended for animations layered on top of others, not for the first animations applied. Properties
		 * keyed by additive animations must be set manually or by another animation before applying the additive animations, else
		 * the property values will increase continually. */
		add
	}

	/** Indicates whether a timeline's `alpha` is mixing out over time toward 0 (the setup or current pose value) or
	 * mixing in toward 1 (the timeline's value).
	 *
	 * See Timeline {@link Timeline#apply(Skeleton, float, float, Array, float, MixBlend, MixDirection)}. */
	export enum MixDirection {
		mixIn, mixOut
	}

	export enum TimelineType {
		rotate, translate, scale, shear,
		attachment, color, deform,
		event, drawOrder,
		ikConstraint, transformConstraint,
		pathConstraintPosition, pathConstraintSpacing, pathConstraintMix,
		twoColor
	}

	/** The base class for timelines that use interpolation between key frame values. */
	export abstract class CurveTimeline implements Timeline {
		static LINEAR = 0; static STEPPED = 1; static BEZIER = 2;
		static BEZIER_SIZE = 10 * 2 - 1;

		private curves: ArrayLike<number>; // type, x, y, ...

		abstract getPropertyId(): number;

		constructor (frameCount: number) {
			if (frameCount <= 0) throw new Error("frameCount must be > 0: " + frameCount);
			this.curves = Utils.newFloatArray((frameCount - 1) * CurveTimeline.BEZIER_SIZE);
		}

		/** The number of key frames for this timeline. */
		getFrameCount () {
			return this.curves.length / CurveTimeline.BEZIER_SIZE + 1;
		}

		/** Sets the specified key frame to linear interpolation. */
		setLinear (frameIndex: number) {
			this.curves[frameIndex * CurveTimeline.BEZIER_SIZE] = CurveTimeline.LINEAR;
		}

		/** Sets the specified key frame to stepped interpolation. */
		setStepped (frameIndex: number) {
			this.curves[frameIndex * CurveTimeline.BEZIER_SIZE] = CurveTimeline.STEPPED;
		}

		/** Returns the interpolation type for the specified key frame.
		 * @returns Linear is 0, stepped is 1, Bezier is 2. */
		getCurveType (frameIndex: number): number {
			let index = frameIndex * CurveTimeline.BEZIER_SIZE;
			if (index == this.curves.length) return CurveTimeline.LINEAR;
			let type = this.curves[index];
			if (type == CurveTimeline.LINEAR) return CurveTimeline.LINEAR;
			if (type == CurveTimeline.STEPPED) return CurveTimeline.STEPPED;
			return CurveTimeline.BEZIER;
		}

		/** Sets the specified key frame to Bezier interpolation. `cx1` and `cx2` are from 0 to 1,
		 * representing the percent of time between the two key frames. `cy1` and `cy2` are the percent of the
		 * difference between the key frame's values. */
		setCurve (frameIndex: number, cx1: number, cy1: number, cx2: number, cy2: number) {
			let tmpx = (-cx1 * 2 + cx2) * 0.03, tmpy = (-cy1 * 2 + cy2) * 0.03;
			let dddfx = ((cx1 - cx2) * 3 + 1) * 0.006, dddfy = ((cy1 - cy2) * 3 + 1) * 0.006;
			let ddfx = tmpx * 2 + dddfx, ddfy = tmpy * 2 + dddfy;
			let dfx = cx1 * 0.3 + tmpx + dddfx * 0.16666667, dfy = cy1 * 0.3 + tmpy + dddfy * 0.16666667;

			let i = frameIndex * CurveTimeline.BEZIER_SIZE;
			let curves = this.curves;
			curves[i++] = CurveTimeline.BEZIER;

			let x = dfx, y = dfy;
			for (let n = i + CurveTimeline.BEZIER_SIZE - 1; i < n; i += 2) {
				curves[i] = x;
				curves[i + 1] = y;
				dfx += ddfx;
				dfy += ddfy;
				ddfx += dddfx;
				ddfy += dddfy;
				x += dfx;
				y += dfy;
			}
		}

		/** Returns the interpolated percentage for the specified key frame and linear percentage. */
		getCurvePercent (frameIndex: number, percent: number) {
			percent = MathUtils.clamp(percent, 0, 1);
			let curves = this.curves;
			let i = frameIndex * CurveTimeline.BEZIER_SIZE;
			let type = curves[i];
			if (type == CurveTimeline.LINEAR) return percent;
			if (type == CurveTimeline.STEPPED) return 0;
			i++;
			let x = 0;
			for (let start = i, n = i + CurveTimeline.BEZIER_SIZE - 1; i < n; i += 2) {
				x = curves[i];
				if (x >= percent) {
					let prevX: number, prevY: number;
					if (i == start) {
						prevX = 0;
						prevY = 0;
					} else {
						prevX = curves[i - 2];
						prevY = curves[i - 1];
					}
					return prevY + (curves[i + 1] - prevY) * (percent - prevX) / (x - prevX);
				}
			}
			let y = curves[i - 1];
			return y + (1 - y) * (percent - x) / (1 - x); // Last point is 1,1.
		}

		abstract apply (skeleton: Skeleton, lastTime: number, time: number, events: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection): void;
	}

	/** Changes a bone's local {@link Bone#rotation}. */
	export class RotateTimeline extends CurveTimeline {
		static ENTRIES = 2;
		static PREV_TIME = -2; static PREV_ROTATION = -1;
		static ROTATION = 1;

		/** The index of the bone in {@link Skeleton#bones} that will be changed. */
		boneIndex: number;

		/** The time in seconds and rotation in degrees for each key frame. */
		frames: ArrayLike<number>; // time, degrees, ...

		constructor (frameCount: number) {
			super(frameCount);
			this.frames = Utils.newFloatArray(frameCount << 1);
		}

		getPropertyId () {
			return (TimelineType.rotate << 24) + this.boneIndex;
		}

		/** Sets the time and angle of the specified keyframe. */
		setFrame (frameIndex: number, time: number, degrees: number) {
			frameIndex <<= 1;
			this.frames[frameIndex] = time;
			this.frames[frameIndex + RotateTimeline.ROTATION] = degrees;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, events: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let frames = this.frames;

			let bone = skeleton.bones[this.boneIndex];
			if (!bone.active) return;
			if (time < frames[0]) {
				switch (blend) {
				case MixBlend.setup:
					bone.rotation = bone.data.rotation;
					return;
				case MixBlend.first:
					let r = bone.data.rotation - bone.rotation;
					bone.rotation += (r - (16384 - ((16384.499999999996 - r / 360) | 0)) * 360) * alpha;
				}
				return;
			}

			if (time >= frames[frames.length - RotateTimeline.ENTRIES]) { // Time is after last frame.
				let r = frames[frames.length + RotateTimeline.PREV_ROTATION];
				switch (blend) {
				case MixBlend.setup:
					bone.rotation = bone.data.rotation + r * alpha;
					break;
				case MixBlend.first:
				case MixBlend.replace:
					r += bone.data.rotation - bone.rotation;
					r -= (16384 - ((16384.499999999996 - r / 360) | 0)) * 360; // Wrap within -180 and 180.
				case MixBlend.add:
					bone.rotation += r * alpha;
				}
				return;
			}

			// Interpolate between the previous frame and the current frame.
			let frame = Animation.binarySearch(frames, time, RotateTimeline.ENTRIES);
			let prevRotation = frames[frame + RotateTimeline.PREV_ROTATION];
			let frameTime = frames[frame];
			let percent = this.getCurvePercent((frame >> 1) - 1,
				1 - (time - frameTime) / (frames[frame + RotateTimeline.PREV_TIME] - frameTime));

			let r = frames[frame + RotateTimeline.ROTATION] - prevRotation;
			r = prevRotation + (r - (16384 - ((16384.499999999996 - r / 360) | 0)) * 360) * percent;
			switch (blend) {
			case MixBlend.setup:
				bone.rotation = bone.data.rotation + (r - (16384 - ((16384.499999999996 - r / 360) | 0)) * 360) * alpha;
				break;
			case MixBlend.first:
			case MixBlend.replace:
				r += bone.data.rotation - bone.rotation;
			case MixBlend.add:
				bone.rotation += (r - (16384 - ((16384.499999999996 - r / 360) | 0)) * 360) * alpha;
			}
		}
	}

	/** Changes a bone's local {@link Bone#x} and {@link Bone#y}. */
	export class TranslateTimeline extends CurveTimeline {
		static ENTRIES = 3;
		static PREV_TIME = -3; static PREV_X = -2; static PREV_Y = -1;
		static X = 1; static Y = 2;

		/** The index of the bone in {@link Skeleton#bones} that will be changed. */
		boneIndex: number;

		/** The time in seconds, x, and y values for each key frame. */
		frames: ArrayLike<number>; // time, x, y, ...

		constructor (frameCount: number) {
			super(frameCount);
			this.frames = Utils.newFloatArray(frameCount * TranslateTimeline.ENTRIES);
		}

		getPropertyId () {
			return (TimelineType.translate << 24) + this.boneIndex;
		}

		/** Sets the time in seconds, x, and y values for the specified key frame. */
		setFrame (frameIndex: number, time: number, x: number, y: number) {
			frameIndex *= TranslateTimeline.ENTRIES;
			this.frames[frameIndex] = time;
			this.frames[frameIndex + TranslateTimeline.X] = x;
			this.frames[frameIndex + TranslateTimeline.Y] = y;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, events: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let frames = this.frames;

			let bone = skeleton.bones[this.boneIndex];
			if (!bone.active) return;
			if (time < frames[0]) {
				switch (blend) {
				case MixBlend.setup:
					bone.x = bone.data.x;
					bone.y = bone.data.y;
					return;
				case MixBlend.first:
					bone.x += (bone.data.x - bone.x) * alpha;
					bone.y += (bone.data.y - bone.y) * alpha;
				}
				return;
			}

			let x = 0, y = 0;
			if (time >= frames[frames.length - TranslateTimeline.ENTRIES]) { // Time is after last frame.
				x = frames[frames.length + TranslateTimeline.PREV_X];
				y = frames[frames.length + TranslateTimeline.PREV_Y];
			} else {
				// Interpolate between the previous frame and the current frame.
				let frame = Animation.binarySearch(frames, time, TranslateTimeline.ENTRIES);
				x = frames[frame + TranslateTimeline.PREV_X];
				y = frames[frame + TranslateTimeline.PREV_Y];
				let frameTime = frames[frame];
				let percent = this.getCurvePercent(frame / TranslateTimeline.ENTRIES - 1,
					1 - (time - frameTime) / (frames[frame + TranslateTimeline.PREV_TIME] - frameTime));

				x += (frames[frame + TranslateTimeline.X] - x) * percent;
				y += (frames[frame + TranslateTimeline.Y] - y) * percent;
			}
			switch (blend) {
			case MixBlend.setup:
				bone.x = bone.data.x + x * alpha;
				bone.y = bone.data.y + y * alpha;
				break;
			case MixBlend.first:
			case MixBlend.replace:
				bone.x += (bone.data.x + x - bone.x) * alpha;
				bone.y += (bone.data.y + y - bone.y) * alpha;
				break;
			case MixBlend.add:
				bone.x += x * alpha;
				bone.y += y * alpha;
			}
		}
	}

	/** Changes a bone's local {@link Bone#scaleX)} and {@link Bone#scaleY}. */
	export class ScaleTimeline extends TranslateTimeline {
		constructor (frameCount: number) {
			super(frameCount);
		}

		getPropertyId () {
			return (TimelineType.scale << 24) + this.boneIndex;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, events: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let frames = this.frames;

			let bone = skeleton.bones[this.boneIndex];
			if (!bone.active) return;
			if (time < frames[0]) {
				switch (blend) {
				case MixBlend.setup:
					bone.scaleX = bone.data.scaleX;
					bone.scaleY = bone.data.scaleY;
					return;
				case MixBlend.first:
					bone.scaleX += (bone.data.scaleX - bone.scaleX) * alpha;
					bone.scaleY += (bone.data.scaleY - bone.scaleY) * alpha;
				}
				return;
			}

			let x = 0, y = 0;
			if (time >= frames[frames.length - ScaleTimeline.ENTRIES]) { // Time is after last frame.
				x = frames[frames.length + ScaleTimeline.PREV_X] * bone.data.scaleX;
				y = frames[frames.length + ScaleTimeline.PREV_Y] * bone.data.scaleY;
			} else {
				// Interpolate between the previous frame and the current frame.
				let frame = Animation.binarySearch(frames, time, ScaleTimeline.ENTRIES);
				x = frames[frame + ScaleTimeline.PREV_X];
				y = frames[frame + ScaleTimeline.PREV_Y];
				let frameTime = frames[frame];
				let percent = this.getCurvePercent(frame / ScaleTimeline.ENTRIES - 1,
					1 - (time - frameTime) / (frames[frame + ScaleTimeline.PREV_TIME] - frameTime));

				x = (x + (frames[frame + ScaleTimeline.X] - x) * percent) * bone.data.scaleX;
				y = (y + (frames[frame + ScaleTimeline.Y] - y) * percent) * bone.data.scaleY;
			}
			if (alpha == 1) {
				if (blend == MixBlend.add) {
					bone.scaleX += x - bone.data.scaleX;
					bone.scaleY += y - bone.data.scaleY;
				} else {
					bone.scaleX = x;
					bone.scaleY = y;
				}
			} else {
				let bx = 0, by = 0;
				if (direction == MixDirection.mixOut) {
					switch (blend) {
					case MixBlend.setup:
						bx = bone.data.scaleX;
						by = bone.data.scaleY;
						bone.scaleX = bx + (Math.abs(x) * MathUtils.signum(bx) - bx) * alpha;
						bone.scaleY = by + (Math.abs(y) * MathUtils.signum(by) - by) * alpha;
						break;
					case MixBlend.first:
					case MixBlend.replace:
						bx = bone.scaleX;
						by = bone.scaleY;
						bone.scaleX = bx + (Math.abs(x) * MathUtils.signum(bx) - bx) * alpha;
						bone.scaleY = by + (Math.abs(y) * MathUtils.signum(by) - by) * alpha;
						break;
					case MixBlend.add:
						bx = bone.scaleX;
						by = bone.scaleY;
						bone.scaleX = bx + (Math.abs(x) * MathUtils.signum(bx) - bone.data.scaleX) * alpha;
						bone.scaleY = by + (Math.abs(y) * MathUtils.signum(by) - bone.data.scaleY) * alpha;
					}
				} else {
					switch (blend) {
					case MixBlend.setup:
						bx = Math.abs(bone.data.scaleX) * MathUtils.signum(x);
						by = Math.abs(bone.data.scaleY) * MathUtils.signum(y);
						bone.scaleX = bx + (x - bx) * alpha;
						bone.scaleY = by + (y - by) * alpha;
						break;
					case MixBlend.first:
					case MixBlend.replace:
						bx = Math.abs(bone.scaleX) * MathUtils.signum(x);
						by = Math.abs(bone.scaleY) * MathUtils.signum(y);
						bone.scaleX = bx + (x - bx) * alpha;
						bone.scaleY = by + (y - by) * alpha;
						break;
					case MixBlend.add:
						bx = MathUtils.signum(x);
						by = MathUtils.signum(y);
						bone.scaleX = Math.abs(bone.scaleX) * bx + (x - Math.abs(bone.data.scaleX) * bx) * alpha;
						bone.scaleY = Math.abs(bone.scaleY) * by + (y - Math.abs(bone.data.scaleY) * by) * alpha;
					}
				}
			}
		}
	}

	/** Changes a bone's local {@link Bone#shearX} and {@link Bone#shearY}. */
	export class ShearTimeline extends TranslateTimeline {
		constructor (frameCount: number) {
			super(frameCount);
		}

		getPropertyId () {
			return (TimelineType.shear << 24) + this.boneIndex;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, events: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let frames = this.frames;

			let bone = skeleton.bones[this.boneIndex];
			if (!bone.active) return;
			if (time < frames[0]) {
				switch (blend) {
				case MixBlend.setup:
					bone.shearX = bone.data.shearX;
					bone.shearY = bone.data.shearY;
					return;
				case MixBlend.first:
					bone.shearX += (bone.data.shearX - bone.shearX) * alpha;
					bone.shearY += (bone.data.shearY - bone.shearY) * alpha;
				}
				return;
			}

			let x = 0, y = 0;
			if (time >= frames[frames.length - ShearTimeline.ENTRIES]) { // Time is after last frame.
				x = frames[frames.length + ShearTimeline.PREV_X];
				y = frames[frames.length + ShearTimeline.PREV_Y];
			} else {
				// Interpolate between the previous frame and the current frame.
				let frame = Animation.binarySearch(frames, time, ShearTimeline.ENTRIES);
				x = frames[frame + ShearTimeline.PREV_X];
				y = frames[frame + ShearTimeline.PREV_Y];
				let frameTime = frames[frame];
				let percent = this.getCurvePercent(frame / ShearTimeline.ENTRIES - 1,
					1 - (time - frameTime) / (frames[frame + ShearTimeline.PREV_TIME] - frameTime));

				x = x + (frames[frame + ShearTimeline.X] - x) * percent;
				y = y + (frames[frame + ShearTimeline.Y] - y) * percent;
			}
			switch (blend) {
			case MixBlend.setup:
				bone.shearX = bone.data.shearX + x * alpha;
				bone.shearY = bone.data.shearY + y * alpha;
				break;
			case MixBlend.first:
			case MixBlend.replace:
				bone.shearX += (bone.data.shearX + x - bone.shearX) * alpha;
				bone.shearY += (bone.data.shearY + y - bone.shearY) * alpha;
				break;
			case MixBlend.add:
				bone.shearX += x * alpha;
				bone.shearY += y * alpha;
			}
		}
	}

	/** Changes a slot's {@link Slot#color}. */
	export class ColorTimeline extends CurveTimeline {
		static ENTRIES = 5;
		static PREV_TIME = -5; static PREV_R = -4; static PREV_G = -3; static PREV_B = -2; static PREV_A = -1;
		static R = 1; static G = 2; static B = 3; static A = 4;

		/** The index of the slot in {@link Skeleton#slots} that will be changed. */
		slotIndex: number;

		/** The time in seconds, red, green, blue, and alpha values for each key frame. */
		frames: ArrayLike<number>; // time, r, g, b, a, ...

		constructor (frameCount: number) {
			super(frameCount);
			this.frames = Utils.newFloatArray(frameCount * ColorTimeline.ENTRIES);
		}

		getPropertyId () {
			return (TimelineType.color << 24) + this.slotIndex;
		}

		/** Sets the time in seconds, red, green, blue, and alpha for the specified key frame. */
		setFrame (frameIndex: number, time: number, r: number, g: number, b: number, a: number) {
			frameIndex *= ColorTimeline.ENTRIES;
			this.frames[frameIndex] = time;
			this.frames[frameIndex + ColorTimeline.R] = r;
			this.frames[frameIndex + ColorTimeline.G] = g;
			this.frames[frameIndex + ColorTimeline.B] = b;
			this.frames[frameIndex + ColorTimeline.A] = a;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, events: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let slot = skeleton.slots[this.slotIndex];
			if (!slot.bone.active) return;
			let frames = this.frames;
			if (time < frames[0]) {
				switch (blend) {
				case MixBlend.setup:
					slot.color.setFromColor(slot.data.color);
					return;
				case MixBlend.first:
					let color = slot.color, setup = slot.data.color;
					color.add((setup.r - color.r) * alpha, (setup.g - color.g) * alpha, (setup.b - color.b) * alpha,
						(setup.a - color.a) * alpha);
				}
				return;
			}

			let r = 0, g = 0, b = 0, a = 0;
			if (time >= frames[frames.length - ColorTimeline.ENTRIES]) { // Time is after last frame.
				let i = frames.length;
				r = frames[i + ColorTimeline.PREV_R];
				g = frames[i + ColorTimeline.PREV_G];
				b = frames[i + ColorTimeline.PREV_B];
				a = frames[i + ColorTimeline.PREV_A];
			} else {
				// Interpolate between the previous frame and the current frame.
				let frame = Animation.binarySearch(frames, time, ColorTimeline.ENTRIES);
				r = frames[frame + ColorTimeline.PREV_R];
				g = frames[frame + ColorTimeline.PREV_G];
				b = frames[frame + ColorTimeline.PREV_B];
				a = frames[frame + ColorTimeline.PREV_A];
				let frameTime = frames[frame];
				let percent = this.getCurvePercent(frame / ColorTimeline.ENTRIES - 1,
					1 - (time - frameTime) / (frames[frame + ColorTimeline.PREV_TIME] - frameTime));

				r += (frames[frame + ColorTimeline.R] - r) * percent;
				g += (frames[frame + ColorTimeline.G] - g) * percent;
				b += (frames[frame + ColorTimeline.B] - b) * percent;
				a += (frames[frame + ColorTimeline.A] - a) * percent;
			}
			if (alpha == 1)
				slot.color.set(r, g, b, a);
			else {
				let color = slot.color;
				if (blend == MixBlend.setup) color.setFromColor(slot.data.color);
				color.add((r - color.r) * alpha, (g - color.g) * alpha, (b - color.b) * alpha, (a - color.a) * alpha);
			}
		}
	}

	/** Changes a slot's {@link Slot#color} and {@link Slot#darkColor} for two color tinting. */
	export class TwoColorTimeline extends CurveTimeline {
		static ENTRIES = 8;
		static PREV_TIME = -8; static PREV_R = -7; static PREV_G = -6; static PREV_B = -5; static PREV_A = -4;
		static PREV_R2 = -3; static PREV_G2 = -2; static PREV_B2 = -1;
		static R = 1; static G = 2; static B = 3; static A = 4; static R2 = 5; static G2 = 6; static B2 = 7;

		/** The index of the slot in {@link Skeleton#slots()} that will be changed. The {@link Slot#darkColor()} must not be
		 * null. */
		slotIndex: number;

		/** The time in seconds, red, green, blue, and alpha values of the color, red, green, blue of the dark color, for each key frame. */
		frames: ArrayLike<number>; // time, r, g, b, a, r2, g2, b2, ...

		constructor (frameCount: number) {
			super(frameCount);
			this.frames = Utils.newFloatArray(frameCount * TwoColorTimeline.ENTRIES);
		}

		getPropertyId () {
			return (TimelineType.twoColor << 24) + this.slotIndex;
		}

		/** Sets the time in seconds, light, and dark colors for the specified key frame. */
		setFrame (frameIndex: number, time: number, r: number, g: number, b: number, a: number, r2: number, g2: number, b2: number) {
			frameIndex *= TwoColorTimeline.ENTRIES;
			this.frames[frameIndex] = time;
			this.frames[frameIndex + TwoColorTimeline.R] = r;
			this.frames[frameIndex + TwoColorTimeline.G] = g;
			this.frames[frameIndex + TwoColorTimeline.B] = b;
			this.frames[frameIndex + TwoColorTimeline.A] = a;
			this.frames[frameIndex + TwoColorTimeline.R2] = r2;
			this.frames[frameIndex + TwoColorTimeline.G2] = g2;
			this.frames[frameIndex + TwoColorTimeline.B2] = b2;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, events: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let slot = skeleton.slots[this.slotIndex];
			if (!slot.bone.active) return;
			let frames = this.frames;
			if (time < frames[0]) {
				switch (blend) {
				case MixBlend.setup:
					slot.color.setFromColor(slot.data.color);
					slot.darkColor.setFromColor(slot.data.darkColor);
					return;
				case MixBlend.first:
					let light = slot.color, dark = slot.darkColor, setupLight = slot.data.color, setupDark = slot.data.darkColor;
					light.add((setupLight.r - light.r) * alpha, (setupLight.g - light.g) * alpha, (setupLight.b - light.b) * alpha,
						(setupLight.a - light.a) * alpha);
					dark.add((setupDark.r - dark.r) * alpha, (setupDark.g - dark.g) * alpha, (setupDark.b - dark.b) * alpha, 0);
				}
				return;
			}

			let r = 0, g = 0, b = 0, a = 0, r2 = 0, g2 = 0, b2 = 0;
			if (time >= frames[frames.length - TwoColorTimeline.ENTRIES]) { // Time is after last frame.
				let i = frames.length;
				r = frames[i + TwoColorTimeline.PREV_R];
				g = frames[i + TwoColorTimeline.PREV_G];
				b = frames[i + TwoColorTimeline.PREV_B];
				a = frames[i + TwoColorTimeline.PREV_A];
				r2 = frames[i + TwoColorTimeline.PREV_R2];
				g2 = frames[i + TwoColorTimeline.PREV_G2];
				b2 = frames[i + TwoColorTimeline.PREV_B2];
			} else {
				// Interpolate between the previous frame and the current frame.
				let frame = Animation.binarySearch(frames, time, TwoColorTimeline.ENTRIES);
				r = frames[frame + TwoColorTimeline.PREV_R];
				g = frames[frame + TwoColorTimeline.PREV_G];
				b = frames[frame + TwoColorTimeline.PREV_B];
				a = frames[frame + TwoColorTimeline.PREV_A];
				r2 = frames[frame + TwoColorTimeline.PREV_R2];
				g2 = frames[frame + TwoColorTimeline.PREV_G2];
				b2 = frames[frame + TwoColorTimeline.PREV_B2];
				let frameTime = frames[frame];
				let percent = this.getCurvePercent(frame / TwoColorTimeline.ENTRIES - 1,
					1 - (time - frameTime) / (frames[frame + TwoColorTimeline.PREV_TIME] - frameTime));

				r += (frames[frame + TwoColorTimeline.R] - r) * percent;
				g += (frames[frame + TwoColorTimeline.G] - g) * percent;
				b += (frames[frame + TwoColorTimeline.B] - b) * percent;
				a += (frames[frame + TwoColorTimeline.A] - a) * percent;
				r2 += (frames[frame + TwoColorTimeline.R2] - r2) * percent;
				g2 += (frames[frame + TwoColorTimeline.G2] - g2) * percent;
				b2 += (frames[frame + TwoColorTimeline.B2] - b2) * percent;
			}
			if (alpha == 1) {
				slot.color.set(r, g, b, a);
				slot.darkColor.set(r2, g2, b2, 1);
			} else {
				let light = slot.color, dark = slot.darkColor;
				if (blend == MixBlend.setup) {
					light.setFromColor(slot.data.color);
					dark.setFromColor(slot.data.darkColor);
				}
				light.add((r - light.r) * alpha, (g - light.g) * alpha, (b - light.b) * alpha, (a - light.a) * alpha);
				dark.add((r2 - dark.r) * alpha, (g2 - dark.g) * alpha, (b2 - dark.b) * alpha, 0);
			}
		}
	}

	/** Changes a slot's {@link Slot#attachment}. */
	export class AttachmentTimeline implements Timeline {
		/** The index of the slot in {@link Skeleton#slots} that will be changed. */
		slotIndex: number;

		/** The time in seconds for each key frame. */
		frames: ArrayLike<number> // time, ...

		/** The attachment name for each key frame. May contain null values to clear the attachment. */
		attachmentNames: Array<string>;

		constructor (frameCount: number) {
			this.frames = Utils.newFloatArray(frameCount);
			this.attachmentNames = new Array<string>(frameCount);
		}

		getPropertyId () {
			return (TimelineType.attachment << 24) + this.slotIndex;
		}

		/** The number of key frames for this timeline. */
		getFrameCount () {
			return this.frames.length;
		}

		/** Sets the time in seconds and the attachment name for the specified key frame. */
		setFrame (frameIndex: number, time: number, attachmentName: string) {
			this.frames[frameIndex] = time;
			this.attachmentNames[frameIndex] = attachmentName;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, events: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let slot = skeleton.slots[this.slotIndex];
			if (!slot.bone.active) return;
			if (direction == MixDirection.mixOut) {
				if (blend == MixBlend.setup)
					this.setAttachment(skeleton, slot, slot.data.attachmentName);
				return;
			}

			let frames = this.frames;
			if (time < frames[0]) {
				if (blend == MixBlend.setup || blend == MixBlend.first) this.setAttachment(skeleton, slot, slot.data.attachmentName);
				return;
			}

			let frameIndex = 0;
			if (time >= frames[frames.length - 1]) // Time is after last frame.
				frameIndex = frames.length - 1;
			else
				frameIndex = Animation.binarySearch(frames, time, 1) - 1;

			let attachmentName = this.attachmentNames[frameIndex];
			skeleton.slots[this.slotIndex]
				.setAttachment(attachmentName == null ? null : skeleton.getAttachment(this.slotIndex, attachmentName));
		}

		setAttachment(skeleton: Skeleton, slot: Slot, attachmentName: string) {
			slot.setAttachment(attachmentName == null ? null : skeleton.getAttachment(this.slotIndex, attachmentName));
		}
	}

	let zeros : ArrayLike<number> = null;

	/** Changes a slot's {@link Slot#deform} to deform a {@link VertexAttachment}. */
	export class DeformTimeline extends CurveTimeline {
		/** The index of the slot in {@link Skeleton#getSlots()} that will be changed. */
		slotIndex: number;

		/** The attachment that will be deformed. */
		attachment: VertexAttachment;

		/** The time in seconds for each key frame. */
		frames: ArrayLike<number>; // time, ...

		/** The vertices for each key frame. */
		frameVertices: Array<ArrayLike<number>>;

		constructor (frameCount: number) {
			super(frameCount);
			this.frames = Utils.newFloatArray(frameCount);
			this.frameVertices = new Array<ArrayLike<number>>(frameCount);
			if (zeros == null) zeros = Utils.newFloatArray(64);
		}

		getPropertyId () {
			return (TimelineType.deform << 27) + + this.attachment.id + this.slotIndex;
		}

		/** Sets the time in seconds and the vertices for the specified key frame.
		 * @param vertices Vertex positions for an unweighted VertexAttachment, or deform offsets if it has weights. */
		setFrame (frameIndex: number, time: number, vertices: ArrayLike<number>) {
			this.frames[frameIndex] = time;
			this.frameVertices[frameIndex] = vertices;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, firedEvents: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let slot: Slot = skeleton.slots[this.slotIndex];
			if (!slot.bone.active) return;
			let slotAttachment: Attachment = slot.getAttachment();
			if (!(slotAttachment instanceof VertexAttachment) || !((<VertexAttachment>slotAttachment).deformAttachment == this.attachment)) return;

			let deformArray: Array<number> = slot.deform;
			if (deformArray.length == 0) blend = MixBlend.setup;

			let frameVertices = this.frameVertices;
			let vertexCount = frameVertices[0].length;

			let frames = this.frames;
			if (time < frames[0]) {
				let vertexAttachment = <VertexAttachment>slotAttachment;
				switch (blend) {
				case MixBlend.setup:
					deformArray.length = 0;
					return;
				case MixBlend.first:
					if (alpha == 1) {
						deformArray.length = 0;
						break;
					}
					let deform: Array<number> = Utils.setArraySize(deformArray, vertexCount);
					if (vertexAttachment.bones == null) {
						// Unweighted vertex positions.
						let setupVertices = vertexAttachment.vertices;
						for (var i = 0; i < vertexCount; i++)
							deform[i] += (setupVertices[i] - deform[i]) * alpha;
					} else {
						// Weighted deform offsets.
						alpha = 1 - alpha;
						for (var i = 0; i < vertexCount; i++)
							deform[i] *= alpha;
					}
				}
				return;
			}

			let deform: Array<number> = Utils.setArraySize(deformArray, vertexCount);
			if (time >= frames[frames.length - 1]) { // Time is after last frame.
				let lastVertices = frameVertices[frames.length - 1];
				if (alpha == 1) {
					if (blend == MixBlend.add) {
						let vertexAttachment = slotAttachment as VertexAttachment;
						if (vertexAttachment.bones == null) {
							// Unweighted vertex positions, with alpha.
							let setupVertices = vertexAttachment.vertices;
							for (let i = 0; i < vertexCount; i++) {
								deform[i] += lastVertices[i] - setupVertices[i];
							}
						} else {
							// Weighted deform offsets, with alpha.
							for (let i = 0; i < vertexCount; i++)
								deform[i] += lastVertices[i];
						}
					} else {
						Utils.arrayCopy(lastVertices, 0, deform, 0, vertexCount);
					}
				} else {
					switch (blend) {
					case MixBlend.setup: {
						let vertexAttachment = slotAttachment as VertexAttachment;
						if (vertexAttachment.bones == null) {
							// Unweighted vertex positions, with alpha.
							let setupVertices = vertexAttachment.vertices;
							for (let i = 0; i < vertexCount; i++) {
								let setup = setupVertices[i];
								deform[i] = setup + (lastVertices[i] - setup) * alpha;
							}
						} else {
							// Weighted deform offsets, with alpha.
							for (let i = 0; i < vertexCount; i++)
								deform[i] = lastVertices[i] * alpha;
						}
						break;
					}
					case MixBlend.first:
					case MixBlend.replace:
						for (let i = 0; i < vertexCount; i++)
							deform[i] += (lastVertices[i] - deform[i]) * alpha;
						break;
					case MixBlend.add:
						let vertexAttachment = slotAttachment as VertexAttachment;
						if (vertexAttachment.bones == null) {
							// Unweighted vertex positions, with alpha.
							let setupVertices = vertexAttachment.vertices;
							for (let i = 0; i < vertexCount; i++) {
								deform[i] += (lastVertices[i] - setupVertices[i]) * alpha;
							}
						} else {
							// Weighted deform offsets, with alpha.
							for (let i = 0; i < vertexCount; i++)
								deform[i] += lastVertices[i] * alpha;
						}
					}
				}
				return;
			}

			// Interpolate between the previous frame and the current frame.
			let frame = Animation.binarySearch(frames, time);
			let prevVertices = frameVertices[frame - 1];
			let nextVertices = frameVertices[frame];
			let frameTime = frames[frame];
			let percent = this.getCurvePercent(frame - 1, 1 - (time - frameTime) / (frames[frame - 1] - frameTime));

			if (alpha == 1) {
				if (blend == MixBlend.add) {
					let vertexAttachment = slotAttachment as VertexAttachment;
					if (vertexAttachment.bones == null) {
						// Unweighted vertex positions, with alpha.
						let setupVertices = vertexAttachment.vertices;
						for (let i = 0; i < vertexCount; i++) {
							let prev = prevVertices[i];
							deform[i] += prev + (nextVertices[i] - prev) * percent - setupVertices[i];
						}
					} else {
						// Weighted deform offsets, with alpha.
						for (let i = 0; i < vertexCount; i++) {
							let prev = prevVertices[i];
							deform[i] += prev + (nextVertices[i] - prev) * percent;
						}
					}
				} else {
					for (let i = 0; i < vertexCount; i++) {
						let prev = prevVertices[i];
						deform[i] = prev + (nextVertices[i] - prev) * percent;
					}
				}
			} else {
				switch (blend) {
				case MixBlend.setup: {
					let vertexAttachment = slotAttachment as VertexAttachment;
					if (vertexAttachment.bones == null) {
						// Unweighted vertex positions, with alpha.
						let setupVertices = vertexAttachment.vertices;
						for (let i = 0; i < vertexCount; i++) {
							let prev = prevVertices[i], setup = setupVertices[i];
							deform[i] = setup + (prev + (nextVertices[i] - prev) * percent - setup) * alpha;
						}
					} else {
						// Weighted deform offsets, with alpha.
						for (let i = 0; i < vertexCount; i++) {
							let prev = prevVertices[i];
							deform[i] = (prev + (nextVertices[i] - prev) * percent) * alpha;
						}
					}
					break;
				}
				case MixBlend.first:
				case MixBlend.replace:
					for (let i = 0; i < vertexCount; i++) {
						let prev = prevVertices[i];
						deform[i] += (prev + (nextVertices[i] - prev) * percent - deform[i]) * alpha;
					}
					break;
				case MixBlend.add:
					let vertexAttachment = slotAttachment as VertexAttachment;
					if (vertexAttachment.bones == null) {
						// Unweighted vertex positions, with alpha.
						let setupVertices = vertexAttachment.vertices;
						for (let i = 0; i < vertexCount; i++) {
							let prev = prevVertices[i];
							deform[i] += (prev + (nextVertices[i] - prev) * percent - setupVertices[i]) * alpha;
						}
					} else {
						// Weighted deform offsets, with alpha.
						for (let i = 0; i < vertexCount; i++) {
							let prev = prevVertices[i];
							deform[i] += (prev + (nextVertices[i] - prev) * percent) * alpha;
						}
					}
				}
			}
		}
	}

	/** Fires an {@link Event} when specific animation times are reached. */
	export class EventTimeline implements Timeline {
		/** The time in seconds for each key frame. */
		frames: ArrayLike<number>; // time, ...

		/** The event for each key frame. */
		events: Array<Event>;

		constructor (frameCount: number) {
			this.frames = Utils.newFloatArray(frameCount);
			this.events = new Array<Event>(frameCount);
		}

		getPropertyId () {
			return TimelineType.event << 24;
		}

		/** The number of key frames for this timeline. */
		getFrameCount () {
			return this.frames.length;
		}

		/** Sets the time in seconds and the event for the specified key frame. */
		setFrame (frameIndex: number, event: Event) {
			this.frames[frameIndex] = event.time;
			this.events[frameIndex] = event;
		}

		/** Fires events for frames > `lastTime` and <= `time`. */
		apply (skeleton: Skeleton, lastTime: number, time: number, firedEvents: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			if (firedEvents == null) return;
			let frames = this.frames;
			let frameCount = this.frames.length;

			if (lastTime > time) { // Fire events after last time for looped animations.
				this.apply(skeleton, lastTime, Number.MAX_VALUE, firedEvents, alpha, blend, direction);
				lastTime = -1;
			} else if (lastTime >= frames[frameCount - 1]) // Last time is after last frame.
				return;
			if (time < frames[0]) return; // Time is before first frame.

			let frame = 0;
			if (lastTime < frames[0])
				frame = 0;
			else {
				frame = Animation.binarySearch(frames, lastTime);
				let frameTime = frames[frame];
				while (frame > 0) { // Fire multiple events with the same frame.
					if (frames[frame - 1] != frameTime) break;
					frame--;
				}
			}
			for (; frame < frameCount && time >= frames[frame]; frame++)
				firedEvents.push(this.events[frame]);
		}
	}

	/** Changes a skeleton's {@link Skeleton#drawOrder}. */
	export class DrawOrderTimeline implements Timeline {
		/** The time in seconds for each key frame. */
		frames: ArrayLike<number>; // time, ...

		/** The draw order for each key frame. See {@link #setFrame(int, float, int[])}. */
		drawOrders: Array<Array<number>>;

		constructor (frameCount: number) {
			this.frames = Utils.newFloatArray(frameCount);
			this.drawOrders = new Array<Array<number>>(frameCount);
		}

		getPropertyId () {
			return TimelineType.drawOrder << 24;
		}

		/** The number of key frames for this timeline. */
		getFrameCount () {
			return this.frames.length;
		}

		/** Sets the time in seconds and the draw order for the specified key frame.
		 * @param drawOrder For each slot in {@link Skeleton#slots}, the index of the new draw order. May be null to use setup pose
		 *           draw order. */
		setFrame (frameIndex: number, time: number, drawOrder: Array<number>) {
			this.frames[frameIndex] = time;
			this.drawOrders[frameIndex] = drawOrder;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, firedEvents: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let drawOrder: Array<Slot> = skeleton.drawOrder;
			let slots: Array<Slot> = skeleton.slots;
			if (direction == MixDirection.mixOut) {
				if (blend == MixBlend.setup) Utils.arrayCopy(skeleton.slots, 0, skeleton.drawOrder, 0, skeleton.slots.length);
				return;
			}

			let frames = this.frames;
			if (time < frames[0]) {
				if (blend == MixBlend.setup || blend == MixBlend.first) Utils.arrayCopy(skeleton.slots, 0, skeleton.drawOrder, 0, skeleton.slots.length);
				return;
			}

			let frame = 0;
			if (time >= frames[frames.length - 1]) // Time is after last frame.
				frame = frames.length - 1;
			else
				frame = Animation.binarySearch(frames, time) - 1;

			let drawOrderToSetupIndex = this.drawOrders[frame];
			if (drawOrderToSetupIndex == null)
				Utils.arrayCopy(slots, 0, drawOrder, 0, slots.length);
			else {
				for (let i = 0, n = drawOrderToSetupIndex.length; i < n; i++)
					drawOrder[i] = slots[drawOrderToSetupIndex[i]];
			}
		}
	}

	/** Changes an IK constraint's {@link IkConstraint#mix}, {@link IkConstraint#softness},
	 * {@link IkConstraint#bendDirection}, {@link IkConstraint#stretch}, and {@link IkConstraint#compress}. */
	export class IkConstraintTimeline extends CurveTimeline {
		static ENTRIES = 6;
		static PREV_TIME = -6; static PREV_MIX = -5; static PREV_SOFTNESS = -4; static PREV_BEND_DIRECTION = -3; static PREV_COMPRESS = -2; static PREV_STRETCH = -1;
		static MIX = 1; static SOFTNESS = 2; static BEND_DIRECTION = 3; static COMPRESS = 4; static STRETCH = 5;

		/** The index of the IK constraint slot in {@link Skeleton#ikConstraints} that will be changed. */
		ikConstraintIndex: number;

		/** The time in seconds, mix, softness, bend direction, compress, and stretch for each key frame. */
		frames: ArrayLike<number>; // time, mix, softness, bendDirection, compress, stretch, ...

		constructor (frameCount: number) {
			super(frameCount);
			this.frames = Utils.newFloatArray(frameCount * IkConstraintTimeline.ENTRIES);
		}

		getPropertyId () {
			return (TimelineType.ikConstraint << 24) + this.ikConstraintIndex;
		}

		/** Sets the time in seconds, mix, softness, bend direction, compress, and stretch for the specified key frame. */
		setFrame (frameIndex: number, time: number, mix: number, softness: number, bendDirection: number, compress: boolean, stretch: boolean) {
			frameIndex *= IkConstraintTimeline.ENTRIES;
			this.frames[frameIndex] = time;
			this.frames[frameIndex + IkConstraintTimeline.MIX] = mix;
			this.frames[frameIndex + IkConstraintTimeline.SOFTNESS] = softness;
			this.frames[frameIndex + IkConstraintTimeline.BEND_DIRECTION] = bendDirection;
			this.frames[frameIndex + IkConstraintTimeline.COMPRESS] = compress ? 1 : 0;
			this.frames[frameIndex + IkConstraintTimeline.STRETCH] = stretch ? 1 : 0;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, firedEvents: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let frames = this.frames;
			let constraint: IkConstraint = skeleton.ikConstraints[this.ikConstraintIndex];
			if (!constraint.active) return;
			if (time < frames[0]) {
				switch (blend) {
				case MixBlend.setup:
					constraint.mix = constraint.data.mix;
					constraint.softness = constraint.data.softness;
					constraint.bendDirection = constraint.data.bendDirection;
					constraint.compress = constraint.data.compress;
					constraint.stretch = constraint.data.stretch;
					return;
				case MixBlend.first:
					constraint.mix += (constraint.data.mix - constraint.mix) * alpha;
					constraint.softness += (constraint.data.softness - constraint.softness) * alpha;
					constraint.bendDirection = constraint.data.bendDirection;
					constraint.compress = constraint.data.compress;
					constraint.stretch = constraint.data.stretch;
				}
				return;
			}

			if (time >= frames[frames.length - IkConstraintTimeline.ENTRIES]) { // Time is after last frame.
				if (blend == MixBlend.setup) {
					constraint.mix = constraint.data.mix + (frames[frames.length + IkConstraintTimeline.PREV_MIX] - constraint.data.mix) * alpha;
					constraint.softness = constraint.data.softness
						+ (frames[frames.length + IkConstraintTimeline.PREV_SOFTNESS] - constraint.data.softness) * alpha;
					if (direction == MixDirection.mixOut) {
						constraint.bendDirection = constraint.data.bendDirection;
						constraint.compress = constraint.data.compress;
						constraint.stretch = constraint.data.stretch;
					} else {
						constraint.bendDirection = frames[frames.length + IkConstraintTimeline.PREV_BEND_DIRECTION]
						constraint.compress = frames[frames.length + IkConstraintTimeline.PREV_COMPRESS] != 0;
						constraint.stretch = frames[frames.length + IkConstraintTimeline.PREV_STRETCH] != 0;
					}
				} else {
					constraint.mix += (frames[frames.length + IkConstraintTimeline.PREV_MIX] - constraint.mix) * alpha;
					constraint.softness += (frames[frames.length + IkConstraintTimeline.PREV_SOFTNESS] - constraint.softness) * alpha;
					if (direction == MixDirection.mixIn) {
						constraint.bendDirection = frames[frames.length + IkConstraintTimeline.PREV_BEND_DIRECTION];
						constraint.compress = frames[frames.length + IkConstraintTimeline.PREV_COMPRESS] != 0;
						constraint.stretch = frames[frames.length + IkConstraintTimeline.PREV_STRETCH] != 0;
					}
				}
				return;
			}

			// Interpolate between the previous frame and the current frame.
			let frame = Animation.binarySearch(frames, time, IkConstraintTimeline.ENTRIES);
			let mix = frames[frame + IkConstraintTimeline.PREV_MIX];
			let softness = frames[frame + IkConstraintTimeline.PREV_SOFTNESS];
			let frameTime = frames[frame];
			let percent = this.getCurvePercent(frame / IkConstraintTimeline.ENTRIES - 1,
				1 - (time - frameTime) / (frames[frame + IkConstraintTimeline.PREV_TIME] - frameTime));

			if (blend == MixBlend.setup) {
				constraint.mix = constraint.data.mix + (mix + (frames[frame + IkConstraintTimeline.MIX] - mix) * percent - constraint.data.mix) * alpha;
				constraint.softness = constraint.data.softness
					+ (softness + (frames[frame + IkConstraintTimeline.SOFTNESS] - softness) * percent - constraint.data.softness) * alpha;
				if (direction == MixDirection.mixOut) {
					constraint.bendDirection = constraint.data.bendDirection;
					constraint.compress = constraint.data.compress;
					constraint.stretch = constraint.data.stretch;
				} else {
					constraint.bendDirection = frames[frame + IkConstraintTimeline.PREV_BEND_DIRECTION];
					constraint.compress = frames[frame + IkConstraintTimeline.PREV_COMPRESS] != 0;
					constraint.stretch = frames[frame + IkConstraintTimeline.PREV_STRETCH] != 0;
				}
			} else {
				constraint.mix += (mix + (frames[frame + IkConstraintTimeline.MIX] - mix) * percent - constraint.mix) * alpha;
				constraint.softness += (softness + (frames[frame + IkConstraintTimeline.SOFTNESS] - softness) * percent - constraint.softness) * alpha;
				if (direction == MixDirection.mixIn) {
					constraint.bendDirection = frames[frame + IkConstraintTimeline.PREV_BEND_DIRECTION];
					constraint.compress = frames[frame + IkConstraintTimeline.PREV_COMPRESS] != 0;
					constraint.stretch = frames[frame + IkConstraintTimeline.PREV_STRETCH] != 0;
				}
			}
		}
	}

	/** Changes a transform constraint's {@link TransformConstraint#rotateMix}, {@link TransformConstraint#translateMix},
	 * {@link TransformConstraint#scaleMix}, and {@link TransformConstraint#shearMix}. */
	export class TransformConstraintTimeline extends CurveTimeline {
		static ENTRIES = 5;
		static PREV_TIME = -5; static PREV_ROTATE = -4; static PREV_TRANSLATE = -3; static PREV_SCALE = -2; static PREV_SHEAR = -1;
		static ROTATE = 1; static TRANSLATE = 2; static SCALE = 3; static SHEAR = 4;

		/** The index of the transform constraint slot in {@link Skeleton#transformConstraints} that will be changed. */
		transformConstraintIndex: number;

		/** The time in seconds, rotate mix, translate mix, scale mix, and shear mix for each key frame. */
		frames: ArrayLike<number>; // time, rotate mix, translate mix, scale mix, shear mix, ...

		constructor (frameCount: number) {
			super(frameCount);
			this.frames = Utils.newFloatArray(frameCount * TransformConstraintTimeline.ENTRIES);
		}

		getPropertyId () {
			return (TimelineType.transformConstraint << 24) + this.transformConstraintIndex;
		}

		/** The time in seconds, rotate mix, translate mix, scale mix, and shear mix for the specified key frame. */
		setFrame (frameIndex: number, time: number, rotateMix: number, translateMix: number, scaleMix: number, shearMix: number) {
			frameIndex *= TransformConstraintTimeline.ENTRIES;
			this.frames[frameIndex] = time;
			this.frames[frameIndex + TransformConstraintTimeline.ROTATE] = rotateMix;
			this.frames[frameIndex + TransformConstraintTimeline.TRANSLATE] = translateMix;
			this.frames[frameIndex + TransformConstraintTimeline.SCALE] = scaleMix;
			this.frames[frameIndex + TransformConstraintTimeline.SHEAR] = shearMix;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, firedEvents: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let frames = this.frames;

			let constraint: TransformConstraint = skeleton.transformConstraints[this.transformConstraintIndex];
			if (!constraint.active) return;
			if (time < frames[0]) {
				let data = constraint.data;
				switch (blend) {
				case MixBlend.setup:
					constraint.rotateMix = data.rotateMix;
					constraint.translateMix = data.translateMix;
					constraint.scaleMix = data.scaleMix;
					constraint.shearMix = data.shearMix;
					return;
				case MixBlend.first:
					constraint.rotateMix += (data.rotateMix - constraint.rotateMix) * alpha;
					constraint.translateMix += (data.translateMix - constraint.translateMix) * alpha;
					constraint.scaleMix += (data.scaleMix - constraint.scaleMix) * alpha;
					constraint.shearMix += (data.shearMix - constraint.shearMix) * alpha;
				}
				return;
			}

			let rotate = 0, translate = 0, scale = 0, shear = 0;
			if (time >= frames[frames.length - TransformConstraintTimeline.ENTRIES]) { // Time is after last frame.
				let i = frames.length;
				rotate = frames[i + TransformConstraintTimeline.PREV_ROTATE];
				translate = frames[i + TransformConstraintTimeline.PREV_TRANSLATE];
				scale = frames[i + TransformConstraintTimeline.PREV_SCALE];
				shear = frames[i + TransformConstraintTimeline.PREV_SHEAR];
			} else {
				// Interpolate between the previous frame and the current frame.
				let frame = Animation.binarySearch(frames, time, TransformConstraintTimeline.ENTRIES);
				rotate = frames[frame + TransformConstraintTimeline.PREV_ROTATE];
				translate = frames[frame + TransformConstraintTimeline.PREV_TRANSLATE];
				scale = frames[frame + TransformConstraintTimeline.PREV_SCALE];
				shear = frames[frame + TransformConstraintTimeline.PREV_SHEAR];
				let frameTime = frames[frame];
				let percent = this.getCurvePercent(frame / TransformConstraintTimeline.ENTRIES - 1,
					1 - (time - frameTime) / (frames[frame + TransformConstraintTimeline.PREV_TIME] - frameTime));

				rotate += (frames[frame + TransformConstraintTimeline.ROTATE] - rotate) * percent;
				translate += (frames[frame + TransformConstraintTimeline.TRANSLATE] - translate) * percent;
				scale += (frames[frame + TransformConstraintTimeline.SCALE] - scale) * percent;
				shear += (frames[frame + TransformConstraintTimeline.SHEAR] - shear) * percent;
			}
			if (blend == MixBlend.setup) {
				let data = constraint.data;
				constraint.rotateMix = data.rotateMix + (rotate - data.rotateMix) * alpha;
				constraint.translateMix = data.translateMix + (translate - data.translateMix) * alpha;
				constraint.scaleMix = data.scaleMix + (scale - data.scaleMix) * alpha;
				constraint.shearMix = data.shearMix + (shear - data.shearMix) * alpha;
			} else {
				constraint.rotateMix += (rotate - constraint.rotateMix) * alpha;
				constraint.translateMix += (translate - constraint.translateMix) * alpha;
				constraint.scaleMix += (scale - constraint.scaleMix) * alpha;
				constraint.shearMix += (shear - constraint.shearMix) * alpha;
			}
		}
	}

	/** Changes a path constraint's {@link PathConstraint#position}. */
	export class PathConstraintPositionTimeline extends CurveTimeline {
		static ENTRIES = 2;
		static PREV_TIME = -2; static PREV_VALUE = -1;
		static VALUE = 1;

		/** The index of the path constraint slot in {@link Skeleton#pathConstraints} that will be changed. */
		pathConstraintIndex: number;

		/** The time in seconds and path constraint position for each key frame. */
		frames: ArrayLike<number>; // time, position, ...

		constructor (frameCount: number) {
			super(frameCount);
			this.frames = Utils.newFloatArray(frameCount * PathConstraintPositionTimeline.ENTRIES);
		}

		getPropertyId () {
			return (TimelineType.pathConstraintPosition << 24) + this.pathConstraintIndex;
		}

		/** Sets the time in seconds and path constraint position for the specified key frame. */
		setFrame (frameIndex: number, time: number, value: number) {
			frameIndex *= PathConstraintPositionTimeline.ENTRIES;
			this.frames[frameIndex] = time;
			this.frames[frameIndex + PathConstraintPositionTimeline.VALUE] = value;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, firedEvents: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let frames = this.frames;
			let constraint: PathConstraint = skeleton.pathConstraints[this.pathConstraintIndex];
			if (!constraint.active) return;
			if (time < frames[0]) {
				switch (blend) {
				case MixBlend.setup:
					constraint.position = constraint.data.position;
					return;
				case MixBlend.first:
					constraint.position += (constraint.data.position - constraint.position) * alpha;
				}
				return;
			}

			let position = 0;
			if (time >= frames[frames.length - PathConstraintPositionTimeline.ENTRIES]) // Time is after last frame.
				position = frames[frames.length + PathConstraintPositionTimeline.PREV_VALUE];
			else {
				// Interpolate between the previous frame and the current frame.
				let frame = Animation.binarySearch(frames, time, PathConstraintPositionTimeline.ENTRIES);
				position = frames[frame + PathConstraintPositionTimeline.PREV_VALUE];
				let frameTime = frames[frame];
				let percent = this.getCurvePercent(frame / PathConstraintPositionTimeline.ENTRIES - 1,
					1 - (time - frameTime) / (frames[frame + PathConstraintPositionTimeline.PREV_TIME] - frameTime));

				position += (frames[frame + PathConstraintPositionTimeline.VALUE] - position) * percent;
			}
			if (blend == MixBlend.setup)
				constraint.position = constraint.data.position + (position - constraint.data.position) * alpha;
			else
				constraint.position += (position - constraint.position) * alpha;
		}
	}

	/** Changes a path constraint's {@link PathConstraint#spacing}. */
	export class PathConstraintSpacingTimeline extends PathConstraintPositionTimeline {
		constructor (frameCount: number) {
			super(frameCount);
		}

		getPropertyId () {
			return (TimelineType.pathConstraintSpacing << 24) + this.pathConstraintIndex;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, firedEvents: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let frames = this.frames;
			let constraint: PathConstraint = skeleton.pathConstraints[this.pathConstraintIndex];
			if (!constraint.active) return;
			if (time < frames[0]) {
				switch (blend) {
				case MixBlend.setup:
					constraint.spacing = constraint.data.spacing;
					return;
				case MixBlend.first:
					constraint.spacing += (constraint.data.spacing - constraint.spacing) * alpha;
				}
				return;
			}

			let spacing = 0;
			if (time >= frames[frames.length - PathConstraintSpacingTimeline.ENTRIES]) // Time is after last frame.
				spacing = frames[frames.length + PathConstraintSpacingTimeline.PREV_VALUE];
			else {
				// Interpolate between the previous frame and the current frame.
				let frame = Animation.binarySearch(frames, time, PathConstraintSpacingTimeline.ENTRIES);
				spacing = frames[frame + PathConstraintSpacingTimeline.PREV_VALUE];
				let frameTime = frames[frame];
				let percent = this.getCurvePercent(frame / PathConstraintSpacingTimeline.ENTRIES - 1,
					1 - (time - frameTime) / (frames[frame + PathConstraintSpacingTimeline.PREV_TIME] - frameTime));

				spacing += (frames[frame + PathConstraintSpacingTimeline.VALUE] - spacing) * percent;
			}

			if (blend == MixBlend.setup)
				constraint.spacing = constraint.data.spacing + (spacing - constraint.data.spacing) * alpha;
			else
				constraint.spacing += (spacing - constraint.spacing) * alpha;
		}
	}

	/** Changes a transform constraint's {@link PathConstraint#rotateMix} and
	 * {@link TransformConstraint#translateMix}. */
	export class PathConstraintMixTimeline extends CurveTimeline {
		static ENTRIES = 3;
		static PREV_TIME = -3; static PREV_ROTATE = -2; static PREV_TRANSLATE = -1;
		static ROTATE = 1; static TRANSLATE = 2;

		/** The index of the path constraint slot in {@link Skeleton#getPathConstraints()} that will be changed. */
		pathConstraintIndex: number;

		/** The time in seconds, rotate mix, and translate mix for each key frame. */
		frames: ArrayLike<number>; // time, rotate mix, translate mix, ...

		constructor (frameCount: number) {
			super(frameCount);
			this.frames = Utils.newFloatArray(frameCount * PathConstraintMixTimeline.ENTRIES);
		}

		getPropertyId () {
			return (TimelineType.pathConstraintMix << 24) + this.pathConstraintIndex;
		}

		/** The time in seconds, rotate mix, and translate mix for the specified key frame. */
		setFrame (frameIndex: number, time: number, rotateMix: number, translateMix: number) {
			frameIndex *= PathConstraintMixTimeline.ENTRIES;
			this.frames[frameIndex] = time;
			this.frames[frameIndex + PathConstraintMixTimeline.ROTATE] = rotateMix;
			this.frames[frameIndex + PathConstraintMixTimeline.TRANSLATE] = translateMix;
		}

		apply (skeleton: Skeleton, lastTime: number, time: number, firedEvents: Array<Event>, alpha: number, blend: MixBlend, direction: MixDirection) {
			let frames = this.frames;
			let constraint: PathConstraint = skeleton.pathConstraints[this.pathConstraintIndex];
			if (!constraint.active) return;
			if (time < frames[0]) {
				switch (blend) {
				case MixBlend.setup:
					constraint.rotateMix = constraint.data.rotateMix;
					constraint.translateMix = constraint.data.translateMix;
					return;
				case MixBlend.first:
					constraint.rotateMix += (constraint.data.rotateMix - constraint.rotateMix) * alpha;
					constraint.translateMix += (constraint.data.translateMix - constraint.translateMix) * alpha;
				}
				return;
			}

			let rotate = 0, translate = 0;
			if (time >= frames[frames.length - PathConstraintMixTimeline.ENTRIES]) { // Time is after last frame.
				rotate = frames[frames.length + PathConstraintMixTimeline.PREV_ROTATE];
				translate = frames[frames.length + PathConstraintMixTimeline.PREV_TRANSLATE];
			} else {
				// Interpolate between the previous frame and the current frame.
				let frame = Animation.binarySearch(frames, time, PathConstraintMixTimeline.ENTRIES);
				rotate = frames[frame + PathConstraintMixTimeline.PREV_ROTATE];
				translate = frames[frame + PathConstraintMixTimeline.PREV_TRANSLATE];
				let frameTime = frames[frame];
				let percent = this.getCurvePercent(frame / PathConstraintMixTimeline.ENTRIES - 1,
					1 - (time - frameTime) / (frames[frame + PathConstraintMixTimeline.PREV_TIME] - frameTime));

				rotate += (frames[frame + PathConstraintMixTimeline.ROTATE] - rotate) * percent;
				translate += (frames[frame + PathConstraintMixTimeline.TRANSLATE] - translate) * percent;
			}

			if (blend == MixBlend.setup) {
				constraint.rotateMix = constraint.data.rotateMix + (rotate - constraint.data.rotateMix) * alpha;
				constraint.translateMix = constraint.data.translateMix + (translate - constraint.data.translateMix) * alpha;
			} else {
				constraint.rotateMix += (rotate - constraint.rotateMix) * alpha;
				constraint.translateMix += (translate - constraint.translateMix) * alpha;
			}
		}
	}
}
