Fishing2/Assets/Scripts/PhysicsTools/Bezier.cs

using System;
using System.Collections.Generic;
using UnityEngine;

namespace PhysicsTools
{
	public class Bezier
	{
		private Vector3[] knots;

		private Vector3[] firstControlPts;

		private Vector3[] secondControlPts;

		private int lastIndex = 1;

		private float lengthCovered;

		private float indexedLength;

		private float totalLength;

		public Bezier(List<PosOri> points)
		{
			Vector3[] array = new Vector3[points.Count];
			for (int i = 0; i < points.Count; i++)
			{
				array[i] = points[i].pos;
			}
			init(array);
		}

		public Bezier(Vector3[] points)
		{
			init(points);
		}

		private void init(Vector3[] points)
		{
			knots = new Vector3[points.Length];
			for (int i = 0; i < points.Length; i++)
			{
				knots[i] = points[i];
				if (i != 0)
				{
					totalLength += (knots[i] - knots[i - 1]).magnitude;
				}
			}
			GetCurveControlPoints(knots, out firstControlPts, out secondControlPts);
			indexedLength = (knots[1] - knots[0]).magnitude;
		}

		public float TotalLength()
		{
			return totalLength;
		}

		public PosOri getNext(float deltaLen)
		{
			return new PosOri(getNextPos(deltaLen), Quaternion.identity);
		}

		public Vector3 getNextPos(float deltaLen)
		{
			bool flag = false;
			float num = indexedLength;
			float num2 = indexedLength;
			while (!flag)
			{
				num = indexedLength;
				num2 = indexedLength - (knots[lastIndex] - knots[lastIndex - 1]).magnitude;
				if (lengthCovered + deltaLen > num)
				{
					lastIndex++;
					if (lastIndex == knots.Length)
					{
						flag = true;
						deltaLen = num - lengthCovered;
						lastIndex = knots.Length - 1;
					}
					else
					{
						indexedLength += (knots[lastIndex] - knots[lastIndex - 1]).magnitude;
					}
					continue;
				}
				break;
			}
			float num3 = (lengthCovered + deltaLen - num2) / (num - num2);
			Vector3 result = (float)Math.Pow(1f - num3, 3.0) * knots[lastIndex - 1] + 3f * (float)Math.Pow(1f - num3, 2.0) * num3 * firstControlPts[lastIndex - 1] + 3f * (1f - num3) * num3 * num3 * secondControlPts[lastIndex - 1] + num3 * num3 * num3 * knots[lastIndex];
			lengthCovered += deltaLen;
			return result;
		}

		private void GetCurveControlPoints(Vector3[] knots, out Vector3[] firstControlPoints, out Vector3[] secondControlPoints)
		{
			if (knots == null)
			{
				throw new ArgumentNullException("knots");
			}
			int num = knots.Length - 1;
			if (num < 1)
			{
				throw new ArgumentException("At least two knot points required", "knots");
			}
			if (num == 1)
			{
				firstControlPoints = new Vector3[1];
				firstControlPoints[0].x = (2f * knots[0].x + knots[1].x) / 3f;
				firstControlPoints[0].y = (2f * knots[0].y + knots[1].y) / 3f;
				firstControlPoints[0].z = (2f * knots[0].z + knots[1].z) / 3f;
				secondControlPoints = new Vector3[1];
				secondControlPoints[0].x = 2f * firstControlPoints[0].x - knots[0].x;
				secondControlPoints[0].y = 2f * firstControlPoints[0].y - knots[0].y;
				secondControlPoints[0].z = 2f * firstControlPoints[0].z - knots[0].z;
				return;
			}
			float[] array = new float[num];
			for (int i = 1; i < num - 1; i++)
			{
				array[i] = 4f * knots[i].x + 2f * knots[i + 1].x;
			}
			array[0] = knots[0].x + 2f * knots[1].x;
			array[num - 1] = (8f * knots[num - 1].x + knots[num].x) / 2f;
			float[] firstControlPoints2 = GetFirstControlPoints(array);
			for (int j = 1; j < num - 1; j++)
			{
				array[j] = 4f * knots[j].y + 2f * knots[j + 1].y;
			}
			array[0] = knots[0].y + 2f * knots[1].y;
			array[num - 1] = (8f * knots[num - 1].y + knots[num].y) / 2f;
			float[] firstControlPoints3 = GetFirstControlPoints(array);
			for (int k = 1; k < num - 1; k++)
			{
				array[k] = 4f * knots[k].z + 2f * knots[k + 1].z;
			}
			array[0] = knots[0].z + 2f * knots[1].z;
			array[num - 1] = (8f * knots[num - 1].z + knots[num].z) / 2f;
			float[] firstControlPoints4 = GetFirstControlPoints(array);
			firstControlPoints = new Vector3[num];
			secondControlPoints = new Vector3[num];
			for (int l = 0; l < num; l++)
			{
				firstControlPoints[l] = new Vector3(firstControlPoints2[l], firstControlPoints3[l], firstControlPoints4[l]);
				if (l < num - 1)
				{
					secondControlPoints[l] = new Vector3(2f * knots[l + 1].x - firstControlPoints2[l + 1], 2f * knots[l + 1].y - firstControlPoints3[l + 1], 2f * knots[l + 1].z - firstControlPoints4[l + 1]);
				}
				else
				{
					secondControlPoints[l] = new Vector3((knots[num].x + firstControlPoints2[num - 1]) / 2f, (knots[num].y + firstControlPoints3[num - 1]) / 2f, (knots[num].z + firstControlPoints4[num - 1]) / 2f);
				}
			}
		}

		private float[] GetFirstControlPoints(float[] rhs)
		{
			int num = rhs.Length;
			float[] array = new float[num];
			float[] array2 = new float[num];
			float num2 = 2f;
			array[0] = rhs[0] / num2;
			for (int i = 1; i < num; i++)
			{
				array2[i] = 1f / num2;
				num2 = ((i >= num - 1) ? 3.5f : 4f) - array2[i];
				array[i] = (rhs[i] - array[i - 1]) / num2;
			}
			for (int j = 1; j < num; j++)
			{
				array[num - j - 1] -= array2[num - j] * array[num - j];
			}
			return array;
		}
	}
}