/******************************************************************************
 * Spine Runtimes Software License v2.5
 * 
 * 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.
 *****************************************************************************/

using System;
using System.Collections.Generic;

namespace SpineRuntime34 {
	public class Animation {
		internal ExposedList<Timeline> timelines;
		internal float duration;
		internal String name;

		public String Name { get { return name; } }
		public ExposedList<Timeline> Timelines { get { return timelines; } set { timelines = value; } }
		public float Duration { get { return duration; } set { duration = value; } }

		public Animation (String name, ExposedList<Timeline> timelines, float duration) {
			if (name == null) throw new ArgumentNullException("name", "name cannot be null.");
			if (timelines == null) throw new ArgumentNullException("timelines", "timelines cannot be null.");
			this.name = name;
			this.timelines = timelines;
			this.duration = duration;
		}

		/// <summary>Poses the skeleton at the specified time for this animation.</summary>
		/// <param name="lastTime">The last time the animation was applied.</param>
		/// <param name="events">Any triggered events are added. May be null.</param>
		public void Apply (Skeleton skeleton, float lastTime, float time, bool loop, ExposedList<Event> events) {
			if (skeleton == null) throw new ArgumentNullException("skeleton", "skeleton cannot be null.");

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

			ExposedList<Timeline> timelines = this.timelines;
			for (int i = 0, n = timelines.Count; i < n; i++)
				timelines.Items[i].Apply(skeleton, lastTime, time, events, 1);
		}

		/// <summary>Poses the skeleton at the specified time for this animation mixed with the current pose.</summary>
		/// <param name="lastTime">The last time the animation was applied.</param>
		/// <param name="events">Any triggered events are added. May be null.</param>
		/// <param name="alpha">The amount of this animation that affects the current pose.</param>
		public void Mix (Skeleton skeleton, float lastTime, float time, bool loop, ExposedList<Event> events, float alpha) {
			if (skeleton == null) throw new ArgumentNullException("skeleton", "skeleton cannot be null.");

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

			ExposedList<Timeline> timelines = this.timelines;
			for (int i = 0, n = timelines.Count; i < n; i++)
				timelines.Items[i].Apply(skeleton, lastTime, time, events, alpha);
		}

		/// <param name="target">After the first and before the last entry.</param>
		internal static int binarySearch (float[] values, float target, int step) {
			int low = 0;
			int high = values.Length / step - 2;
			if (high == 0) return step;
			int current = (int)((uint)high >> 1);
			while (true) {
				if (values[(current + 1) * step] <= target)
					low = current + 1;
				else
					high = current;
				if (low == high) return (low + 1) * step;
				current = (int)((uint)(low + high) >> 1);
			}
		}

		/// <param name="target">After the first and before the last entry.</param>
		internal static int binarySearch (float[] values, float target) {
			int low = 0;
			int high = values.Length - 2;
			if (high == 0) return 1;
			int current = (int)((uint)high >> 1);
			while (true) {
				if (values[(current + 1)] <= target)
					low = current + 1;
				else
					high = current;
				if (low == high) return (low + 1);
				current = (int)((uint)(low + high) >> 1);
			}
		}

		internal static int linearSearch (float[] values, float target, int step) {
			for (int i = 0, last = values.Length - step; i <= last; i += step)
				if (values[i] > target) return i;
			return -1;
		}
	}

	public interface Timeline {
		/// <summary>Sets the value(s) for the specified time.</summary>
		/// <param name="events">May be null to not collect fired events.</param>
		void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> events, float alpha);
	}

	/// <summary>Base class for frames that use an interpolation bezier curve.</summary>
	abstract public class CurveTimeline : Timeline {
		protected const float LINEAR = 0, STEPPED = 1, BEZIER = 2;
		protected const int BEZIER_SIZE = 10 * 2 - 1;

		private float[] curves; // type, x, y, ...
		public int FrameCount { get { return curves.Length / BEZIER_SIZE + 1; } }

		public CurveTimeline (int frameCount) {
			if (frameCount <= 0) throw new ArgumentException("frameCount must be > 0: " + frameCount, "frameCount");
			curves = new float[(frameCount - 1) * BEZIER_SIZE];
		}

		abstract public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha);

		public void SetLinear (int frameIndex) {
			curves[frameIndex * BEZIER_SIZE] = LINEAR;
		}

		public void SetStepped (int frameIndex) {
			curves[frameIndex * BEZIER_SIZE] = STEPPED;
		}

		/// <summary>Sets the control handle positions for an interpolation bezier curve used to transition from this keyframe to the next.
		/// cx1 and cx2 are from 0 to 1, representing the percent of time between the two keyframes. cy1 and cy2 are the percent of
		/// the difference between the keyframe's values.</summary>
		public void SetCurve (int frameIndex, float cx1, float cy1, float cx2, float cy2) {
			float tmpx = (-cx1 * 2 + cx2) * 0.03f, tmpy = (-cy1 * 2 + cy2) * 0.03f;
			float dddfx = ((cx1 - cx2) * 3 + 1) * 0.006f, dddfy = ((cy1 - cy2) * 3 + 1) * 0.006f;
			float ddfx = tmpx * 2 + dddfx, ddfy = tmpy * 2 + dddfy;
			float dfx = cx1 * 0.3f + tmpx + dddfx * 0.16666667f, dfy = cy1 * 0.3f + tmpy + dddfy * 0.16666667f;

			int i = frameIndex * BEZIER_SIZE;
			float[] curves = this.curves;
			curves[i++] = BEZIER;

			float x = dfx, y = dfy;
			for (int n = i + 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;
			}
		}

		public float GetCurvePercent (int frameIndex, float percent) {
			percent = MathUtils.Clamp (percent, 0, 1);
			float[] curves = this.curves;
			int i = frameIndex * BEZIER_SIZE;
			float type = curves[i];
			if (type == LINEAR) return percent;
			if (type == STEPPED) return 0;
			i++;
			float x = 0;
			for (int start = i, n = i + BEZIER_SIZE - 1; i < n; i += 2) {
				x = curves[i];
				if (x >= percent) {
					float prevX, prevY;
					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);
				}
			}
			float y = curves[i - 1];
			return y + (1 - y) * (percent - x) / (1 - x); // Last point is 1,1.
		}
		public float GetCurveType (int frameIndex) {
			return curves[frameIndex * BEZIER_SIZE];
		}
	}

	public class RotateTimeline : CurveTimeline {
		public const int ENTRIES = 2;
		internal const int PREV_TIME = -2, PREV_ROTATION = -1;
		internal const int ROTATION = 1;

		internal int boneIndex;
		internal float[] frames;

		public int BoneIndex { get { return boneIndex; } set { boneIndex = value; } }
		public float[] Frames { get { return frames; } set { frames = value; } } // time, angle, ...

		public RotateTimeline (int frameCount)
			: base(frameCount) {
			frames = new float[frameCount << 1];
		}

		/// <summary>Sets the time and value of the specified keyframe.</summary>
		public void SetFrame (int frameIndex, float time, float degrees) {
			frameIndex <<= 1;
			frames[frameIndex] = time;
			frames[frameIndex + ROTATION] = degrees;
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

			Bone bone = skeleton.bones.Items[boneIndex];

			float amount;

			if (time >= frames[frames.Length - ENTRIES]) { // Time is after last frame.
				amount = bone.data.rotation + frames[frames.Length + PREV_ROTATION] - bone.rotation;
				while (amount > 180)
					amount -= 360;
				while (amount < -180)
					amount += 360;
				bone.rotation += amount * alpha;
				return;
			}

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

			amount = frames[frame + ROTATION] - prevRotation;
			while (amount > 180)
				amount -= 360;
			while (amount < -180)
				amount += 360;
			amount = bone.data.rotation + (prevRotation + amount * percent) - bone.rotation;
			while (amount > 180)
				amount -= 360;
			while (amount < -180)
				amount += 360;
			bone.rotation += amount * alpha;
		}
	}

	public class TranslateTimeline : CurveTimeline {
		public const int ENTRIES = 3;
		protected const int PREV_TIME = -3, PREV_X = -2, PREV_Y = -1;
		protected const int X = 1, Y = 2;

		internal int boneIndex;
		internal float[] frames;

		public int BoneIndex { get { return boneIndex; } set { boneIndex = value; } }
		public float[] Frames { get { return frames; } set { frames = value; } } // time, value, value, ...

		public TranslateTimeline (int frameCount)
			: base(frameCount) {
			frames = new float[frameCount * ENTRIES];
		}

		/// <summary>Sets the time and value of the specified keyframe.</summary>
		public void SetFrame (int frameIndex, float time, float x, float y) {
			frameIndex *= ENTRIES;
			frames[frameIndex] = time;
			frames[frameIndex + X] = x;
			frames[frameIndex + Y] = y;
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

			Bone bone = skeleton.bones.Items[boneIndex];

			if (time >= frames[frames.Length - ENTRIES]) { // Time is after last frame.
				bone.x += (bone.data.x + frames[frames.Length + PREV_X] - bone.x) * alpha;
				bone.y += (bone.data.y + frames[frames.Length + PREV_Y] - bone.y) * alpha;
				return;
			}

			// Interpolate between the previous frame and the current frame.
			int frame = Animation.binarySearch(frames, time, ENTRIES);
			float prevX = frames[frame + PREV_X];
			float prevY = frames[frame + PREV_Y];
			float frameTime = frames[frame];
			float percent = GetCurvePercent(frame / ENTRIES - 1, 1 - (time - frameTime) / (frames[frame + PREV_TIME] - frameTime));

			bone.x += (bone.data.x + prevX + (frames[frame + X] - prevX) * percent - bone.x) * alpha;
			bone.y += (bone.data.y + prevY + (frames[frame + Y] - prevY) * percent - bone.y) * alpha;
		}
	}

	public class ScaleTimeline : TranslateTimeline {
		public ScaleTimeline (int frameCount)
			: base(frameCount) {
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

			Bone bone = skeleton.bones.Items[boneIndex];
			if (time >= frames[frames.Length - ENTRIES]) { // Time is after last frame.
				bone.scaleX += (bone.data.scaleX * frames[frames.Length + PREV_X] - bone.scaleX) * alpha;
				bone.scaleY += (bone.data.scaleY * frames[frames.Length + PREV_Y] - bone.scaleY) * alpha;
				return;
			}

			// Interpolate between the previous frame and the current frame.
			int frame = Animation.binarySearch(frames, time, ENTRIES);
			float prevX = frames[frame + PREV_X];
			float prevY = frames[frame + PREV_Y];
			float frameTime = frames[frame];
			float percent = GetCurvePercent(frame / ENTRIES - 1, 1 - (time - frameTime) / (frames[frame + PREV_TIME] - frameTime));

			bone.scaleX += (bone.data.scaleX * (prevX + (frames[frame + X] - prevX) * percent) - bone.scaleX) * alpha;
			bone.scaleY += (bone.data.scaleY * (prevY + (frames[frame + Y] - prevY) * percent) - bone.scaleY) * alpha;
		}
	}

	public class ShearTimeline : TranslateTimeline {
		public ShearTimeline (int frameCount)
			: base(frameCount) {
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

			Bone bone = skeleton.bones.Items[boneIndex];
			if (time >= frames[frames.Length - ENTRIES]) { // Time is after last frame.
				bone.shearX += (bone.data.shearX + frames[frames.Length + PREV_X] - bone.shearX) * alpha;
				bone.shearY += (bone.data.shearY + frames[frames.Length + PREV_Y] - bone.shearY) * alpha;
				return;
			}

			// Interpolate between the previous frame and the current frame.
			int frame = Animation.binarySearch(frames, time, ENTRIES);
			float prevX = frames[frame + PREV_X];
			float prevY = frames[frame + PREV_Y];
			float frameTime = frames[frame];
			float percent = GetCurvePercent(frame / ENTRIES - 1, 1 - (time - frameTime) / (frames[frame + PREV_TIME] - frameTime));

			bone.shearX += (bone.data.shearX + (prevX + (frames[frame + X] - prevX) * percent) - bone.shearX) * alpha;
			bone.shearY += (bone.data.shearY + (prevY + (frames[frame + Y] - prevY) * percent) - bone.shearY) * alpha;
		}
	}

	public class ColorTimeline : CurveTimeline {
		public const int ENTRIES = 5;
		protected const int PREV_TIME = -5, PREV_R = -4, PREV_G = -3, PREV_B = -2, PREV_A = -1;
		protected const int R = 1, G = 2, B = 3, A = 4;

		internal int slotIndex;
		internal float[] frames;

		public int SlotIndex { get { return slotIndex; } set { slotIndex = value; } }
		public float[] Frames { get { return frames; } set { frames = value; } } // time, r, g, b, a, ...

		public ColorTimeline (int frameCount)
			: base(frameCount) {
			frames = new float[frameCount * ENTRIES];
		}

		/// <summary>Sets the time and value of the specified keyframe.</summary>
		public void SetFrame (int frameIndex, float time, float r, float g, float b, float a) {
			frameIndex *= ENTRIES;
			frames[frameIndex] = time;
			frames[frameIndex + R] = r;
			frames[frameIndex + G] = g;
			frames[frameIndex + B] = b;
			frames[frameIndex + A] = a;
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

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

				r += (frames[frame + R] - r) * percent;
				g += (frames[frame + G] - g) * percent;
				b += (frames[frame + B] - b) * percent;
				a += (frames[frame + A] - a) * percent;
			}
			Slot slot = skeleton.slots.Items[slotIndex];
			if (alpha < 1) {
				slot.r += (r - slot.r) * alpha;
				slot.g += (g - slot.g) * alpha;
				slot.b += (b - slot.b) * alpha;
				slot.a += (a - slot.a) * alpha;
			} else {
				slot.r = r;
				slot.g = g;
				slot.b = b;
				slot.a = a;
			}
		}
	}

	public class AttachmentTimeline : Timeline {
		internal int slotIndex;
		internal float[] frames;
		private String[] attachmentNames;

		public int SlotIndex { get { return slotIndex; } set { slotIndex = value; } }
		public float[] Frames { get { return frames; } set { frames = value; } } // time, ...
		public String[] AttachmentNames { get { return attachmentNames; } set { attachmentNames = value; } }
		public int FrameCount { get { return frames.Length; } }

		public AttachmentTimeline (int frameCount) {
			frames = new float[frameCount];
			attachmentNames = new String[frameCount];
		}

		/// <summary>Sets the time and value of the specified keyframe.</summary>
		public void SetFrame (int frameIndex, float time, String attachmentName) {
			frames[frameIndex] = time;
			attachmentNames[frameIndex] = attachmentName;
		}

		public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

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

			String attachmentName = attachmentNames[frameIndex];
			skeleton.slots.Items[slotIndex]
				.Attachment = attachmentName == null ? null : skeleton.GetAttachment(slotIndex, attachmentName);
		}
	}

	public class EventTimeline : Timeline {
		internal float[] frames;
		private Event[] events;

		public float[] Frames { get { return frames; } set { frames = value; } } // time, ...
		public Event[] Events { get { return events; } set { events = value; } }
		public int FrameCount { get { return frames.Length; } }

		public EventTimeline (int frameCount) {
			frames = new float[frameCount];
			events = new Event[frameCount];
		}

		/// <summary>Sets the time and value of the specified keyframe.</summary>
		public void SetFrame (int frameIndex, Event e) {
			frames[frameIndex] = e.Time;
			events[frameIndex] = e;
		}

		/// <summary>Fires events for frames &gt; lastTime and &lt;= time.</summary>
		public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			if (firedEvents == null) return;
			float[] frames = this.frames;
			int frameCount = frames.Length;

			if (lastTime > time) { // Fire events after last time for looped animations.
				Apply(skeleton, lastTime, int.MaxValue, firedEvents, alpha);
				lastTime = -1f;
			} else if (lastTime >= frames[frameCount - 1]) // Last time is after last frame.
				return;
			if (time < frames[0]) return; // Time is before first frame.

			int frame;
			if (lastTime < frames[0])
				frame = 0;
			else {
				frame = Animation.binarySearch(frames, lastTime);
				float 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.Add(events[frame]);
		}
	}

	public class DrawOrderTimeline : Timeline {
		internal float[] frames;
		private int[][] drawOrders;

		public float[] Frames { get { return frames; } set { frames = value; } } // time, ...
		public int[][] DrawOrders { get { return drawOrders; } set { drawOrders = value; } }
		public int FrameCount { get { return frames.Length; } }

		public DrawOrderTimeline (int frameCount) {
			frames = new float[frameCount];
			drawOrders = new int[frameCount][];
		}

		/// <summary>Sets the time and value of the specified keyframe.</summary>
		/// <param name="drawOrder">May be null to use bind pose draw order.</param>
		public void SetFrame (int frameIndex, float time, int[] drawOrder) {
			frames[frameIndex] = time;
			drawOrders[frameIndex] = drawOrder;
		}

		public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

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

			ExposedList<Slot> drawOrder = skeleton.drawOrder;
			ExposedList<Slot> slots = skeleton.slots;
			int[] drawOrderToSetupIndex = drawOrders[frame];
			if (drawOrderToSetupIndex == null) {
				drawOrder.Clear();
				for (int i = 0, n = slots.Count; i < n; i++)
					drawOrder.Add(slots.Items[i]);
			} else {
				var drawOrderItems = drawOrder.Items;
				var slotsItems = slots.Items;
				for (int i = 0, n = drawOrderToSetupIndex.Length; i < n; i++)
					drawOrderItems[i] = slotsItems[drawOrderToSetupIndex[i]];
			}
		}
	}

	public class DeformTimeline : CurveTimeline {
		internal int slotIndex;
		internal float[] frames;
		private float[][] frameVertices;
		internal VertexAttachment attachment;

		public int SlotIndex { get { return slotIndex; } set { slotIndex = value; } }
		public float[] Frames { get { return frames; } set { frames = value; } } // time, ...
		public float[][] Vertices { get { return frameVertices; } set { frameVertices = value; } }
		public VertexAttachment Attachment { get { return attachment; } set { attachment = value; } }

		public DeformTimeline (int frameCount)
			: base(frameCount) {
			frames = new float[frameCount];
			frameVertices = new float[frameCount][];
		}

		/// <summary>Sets the time and value of the specified keyframe.</summary>
		public void SetFrame (int frameIndex, float time, float[] vertices) {
			frames[frameIndex] = time;
			frameVertices[frameIndex] = vertices;
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			Slot slot = skeleton.slots.Items[slotIndex];
			VertexAttachment slotAttachment = slot.attachment as VertexAttachment;
			if (slotAttachment == null || !slotAttachment.ApplyDeform(attachment)) return;

			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

			float[][] frameVertices = this.frameVertices;
			int vertexCount = frameVertices[0].Length;

			var verticesArray = slot.attachmentVertices;
			if (verticesArray.Count != vertexCount) alpha = 1; // Don't mix from uninitialized slot vertices.
			// verticesArray.SetSize(vertexCount) // Ensure size and preemptively set count.
			if (verticesArray.Capacity < vertexCount) verticesArray.Capacity = vertexCount;
			verticesArray.Count = vertexCount;
			float[] vertices = verticesArray.Items;

			if (time >= frames[frames.Length - 1]) { // Time is after last frame.
				float[] lastVertices = frameVertices[frames.Length - 1];
				if (alpha < 1) {
					for (int i = 0; i < vertexCount; i++) {
						float vertex = vertices[i];
						vertices[i] = vertex + (lastVertices[i] - vertex) * alpha;
					}
				} else
					Array.Copy(lastVertices, 0, vertices, 0, vertexCount);
				return;
			}

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

			if (alpha < 1) {
				for (int i = 0; i < vertexCount; i++) {
					float prev = prevVertices[i];
					float vertex = vertices[i];
					vertices[i] = vertex + (prev + (nextVertices[i] - prev) * percent - vertex) * alpha;
				}
			} else {
				for (int i = 0; i < vertexCount; i++) {
					float prev = prevVertices[i];
					vertices[i] = prev + (nextVertices[i] - prev) * percent;
				}
			}
		}
	}

	public class IkConstraintTimeline : CurveTimeline {
		public const int ENTRIES = 3;
		private const int PREV_TIME = -3, PREV_MIX = -2, PREV_BEND_DIRECTION = -1;
		private const int MIX = 1, BEND_DIRECTION = 2;

		internal int ikConstraintIndex;
		internal float[] frames;

		public int IkConstraintIndex { get { return ikConstraintIndex; } set { ikConstraintIndex = value; } }
		public float[] Frames { get { return frames; } set { frames = value; } } // time, mix, bendDirection, ...

		public IkConstraintTimeline (int frameCount)
			: base(frameCount) {
			frames = new float[frameCount * ENTRIES];
		}
			
		/// <summary>Sets the time, mix and bend direction of the specified keyframe.</summary>
		public void SetFrame (int frameIndex, float time, float mix, int bendDirection) {
			frameIndex *= ENTRIES;
			frames[frameIndex] = time;
			frames[frameIndex + MIX] = mix;
			frames[frameIndex + BEND_DIRECTION] = bendDirection;
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

			IkConstraint constraint = skeleton.ikConstraints.Items[ikConstraintIndex];

			if (time >= frames[frames.Length - ENTRIES]) { // Time is after last frame.
				constraint.mix += (frames[frames.Length + PREV_MIX] - constraint.mix) * alpha;
				constraint.bendDirection = (int)frames[frames.Length + PREV_BEND_DIRECTION];
				return;
			}

			// Interpolate between the previous frame and the current frame.
			int frame = Animation.binarySearch(frames, time, ENTRIES);
			float mix = frames[frame + PREV_MIX];
			float frameTime = frames[frame];
			float percent = GetCurvePercent(frame / ENTRIES - 1, 1 - (time - frameTime) / (frames[frame + PREV_TIME] - frameTime));

			constraint.mix += (mix + (frames[frame + MIX] - mix) * percent - constraint.mix) * alpha;
			constraint.bendDirection = (int)frames[frame + PREV_BEND_DIRECTION];
		}
	}

	public class TransformConstraintTimeline : CurveTimeline {
		public const int ENTRIES = 5;
		private const int PREV_TIME = -5, PREV_ROTATE = -4, PREV_TRANSLATE = -3, PREV_SCALE = -2, PREV_SHEAR = -1;
		private const int ROTATE = 1, TRANSLATE = 2, SCALE = 3, SHEAR = 4;

		internal int transformConstraintIndex;
		internal float[] frames;

		public int TransformConstraintIndex { get { return transformConstraintIndex; } set { transformConstraintIndex = value; } }
		public float[] Frames { get { return frames; } set { frames = value; } } // time, rotate mix, translate mix, scale mix, shear mix, ...

		public TransformConstraintTimeline (int frameCount)
			: base(frameCount) {
			frames = new float[frameCount * ENTRIES];
		}

		public void SetFrame (int frameIndex, float time, float rotateMix, float translateMix, float scaleMix, float shearMix) {
			frameIndex *= ENTRIES;
			frames[frameIndex] = time;
			frames[frameIndex + ROTATE] = rotateMix;
			frames[frameIndex + TRANSLATE] = translateMix;
			frames[frameIndex + SCALE] = scaleMix;
			frames[frameIndex + SHEAR] = shearMix;
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> firedEvents, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

			TransformConstraint constraint = skeleton.transformConstraints.Items[transformConstraintIndex];

			if (time >= frames[frames.Length - ENTRIES]) { // Time is after last frame.
				int i = frames.Length;
				constraint.rotateMix += (frames[i + PREV_ROTATE] - constraint.rotateMix) * alpha;
				constraint.translateMix += (frames[i + PREV_TRANSLATE] - constraint.translateMix) * alpha;
				constraint.scaleMix += (frames[i + PREV_SCALE] - constraint.scaleMix) * alpha;
				constraint.shearMix += (frames[i + PREV_SHEAR] - constraint.shearMix) * alpha;
				return;
			}

			// Interpolate between the previous frame and the current frame.
			int frame = Animation.binarySearch(frames, time, ENTRIES);
			float frameTime = frames[frame];
			float percent = GetCurvePercent(frame / ENTRIES - 1, 1 - (time - frameTime) / (frames[frame + PREV_TIME] - frameTime));

			float rotate = frames[frame + PREV_ROTATE];
			float translate = frames[frame + PREV_TRANSLATE];
			float scale = frames[frame + PREV_SCALE];
			float shear = frames[frame + PREV_SHEAR];
			constraint.rotateMix += (rotate + (frames[frame + ROTATE] - rotate) * percent - constraint.rotateMix) * alpha;
			constraint.translateMix += (translate + (frames[frame + TRANSLATE] - translate) * percent - constraint.translateMix)
				* alpha;
			constraint.scaleMix += (scale + (frames[frame + SCALE] - scale) * percent - constraint.scaleMix) * alpha;
			constraint.shearMix += (shear + (frames[frame + SHEAR] - shear) * percent - constraint.shearMix) * alpha;
		}
	}

	public class PathConstraintPositionTimeline : CurveTimeline {
		public const int ENTRIES = 2;
		protected const int PREV_TIME = -2, PREV_VALUE = -1;
		protected const int VALUE = 1;

		internal int pathConstraintIndex;
		internal float[] frames;

		public PathConstraintPositionTimeline (int frameCount)
			: base(frameCount) {
			frames = new float[frameCount * ENTRIES];
		}

		public int PathConstraintIndex { get { return pathConstraintIndex; } set { pathConstraintIndex = value; } }
		public float[] Frames { get { return frames; } set { frames = value; } } // time, position, ...

		/// <summary>Sets the time and value of the specified keyframe.</summary>
		public void SetFrame (int frameIndex, float time, float value) {
			frameIndex *= ENTRIES;
			frames[frameIndex] = time;
			frames[frameIndex + VALUE] = value;
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> events, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

			PathConstraint constraint = skeleton.pathConstraints.Items[pathConstraintIndex];

			if (time >= frames[frames.Length - ENTRIES]) { // Time is after last frame.
				int i = frames.Length;
				constraint.position += (frames[i + PREV_VALUE] - constraint.position) * alpha;
				return;
			}

			// Interpolate between the previous frame and the current frame.
			int frame = Animation.binarySearch(frames, time, ENTRIES);
			float position = frames[frame + PREV_VALUE];
			float frameTime = frames[frame];
			float percent = GetCurvePercent(frame / ENTRIES - 1, 1 - (time - frameTime) / (frames[frame + PREV_TIME] - frameTime));

			constraint.position += (position + (frames[frame + VALUE] - position) * percent - constraint.position) * alpha;
		}
	}

	public class PathConstraintSpacingTimeline : PathConstraintPositionTimeline {
		public PathConstraintSpacingTimeline (int frameCount)
			: base(frameCount) {
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> events, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

			PathConstraint constraint = skeleton.pathConstraints.Items[pathConstraintIndex];

			if (time >= frames[frames.Length - ENTRIES]) { // Time is after last frame.
				int i = frames.Length;
				constraint.spacing += (frames[i + PREV_VALUE] - constraint.spacing) * alpha;
				return;
			}

			// Interpolate between the previous frame and the current frame.
			int frame = Animation.binarySearch(frames, time, ENTRIES);
			float spacing = frames[frame + PREV_VALUE];
			float frameTime = frames[frame];
			float percent = GetCurvePercent(frame / ENTRIES - 1, 1 - (time - frameTime) / (frames[frame + PREV_TIME] - frameTime));

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

	public class PathConstraintMixTimeline : CurveTimeline {
		public const int ENTRIES = 3;
		private const int PREV_TIME = -3, PREV_ROTATE = -2, PREV_TRANSLATE = -1;
		private const int ROTATE = 1, TRANSLATE = 2;

		internal int pathConstraintIndex;
		internal float[] frames;

		public int PathConstraintIndex { get { return pathConstraintIndex; } set { pathConstraintIndex = value; } }
		public float[] Frames { get { return frames; } set { frames = value; } } // time, rotate mix, translate mix, ...

		public PathConstraintMixTimeline (int frameCount)
			: base(frameCount) {
			frames = new float[frameCount * ENTRIES];
		}			

		/** Sets the time and mixes of the specified keyframe. */
		public void SetFrame (int frameIndex, float time, float rotateMix, float translateMix) {
			frameIndex *= ENTRIES;
			frames[frameIndex] = time;
			frames[frameIndex + ROTATE] = rotateMix;
			frames[frameIndex + TRANSLATE] = translateMix;
		}

		override public void Apply (Skeleton skeleton, float lastTime, float time, ExposedList<Event> events, float alpha) {
			float[] frames = this.frames;
			if (time < frames[0]) return; // Time is before first frame.

			PathConstraint constraint = skeleton.pathConstraints.Items[pathConstraintIndex];

			if (time >= frames[frames.Length - ENTRIES]) { // Time is after last frame.
				int i = frames.Length;
				constraint.rotateMix += (frames[i + PREV_ROTATE] - constraint.rotateMix) * alpha;
				constraint.translateMix += (frames[i + PREV_TRANSLATE] - constraint.translateMix) * alpha;
				return;
			}

			// Interpolate between the previous frame and the current frame.
			int frame = Animation.binarySearch(frames, time, ENTRIES);
			float rotate = frames[frame + PREV_ROTATE];
			float translate = frames[frame + PREV_TRANSLATE];
			float frameTime = frames[frame];
			float percent = GetCurvePercent(frame / ENTRIES - 1, 1 - (time - frameTime) / (frames[frame + PREV_TIME] - frameTime));

			constraint.rotateMix += (rotate + (frames[frame + ROTATE] - rotate) * percent - constraint.rotateMix) * alpha;
			constraint.translateMix += (translate + (frames[frame + TRANSLATE] - translate) * percent - constraint.translateMix)
				* alpha;
		}
	}
}
