unity 绘制Bezier曲线

绘制Bezier曲线

using UnityEngine;using System.Collections.Generic;using System;namespace MyTools{[System.Serializable]/// <summary>/// 贝塞尔曲线/// </summary>public class Bezier :System.Object {private List <Vector3> m_Points;private List <Line> createdLine;/// <summary>/// Initializes a new instance of the <see cref="MyTools.Bezier"/> class./// </summary>/// <param name="points">Points.</param>public Bezier(List<Vector3> points){if (points.Count < 2) {throw(new ArgumentException ("实例化贝塞尔曲线至少需要2个点"));} else {m_Points = new List<Vector3> ();createdLine = new List<Line> ();CreateLine (points);}}#region 修改参数的方法public void AddPoint(Vector3 point){m_Points.Add (point);CreateLine (m_Points);}public void AddPointAt(int index,Vector3 point){m_Points.Add (point);var buf = m_Points [index];m_Points [index] = point;m_Points [m_Points.Count - 1] = buf;CreateLine (m_Points);}public void RemovePoint(Vector3 point){if (m_Points.Count > 2) {for (int i = 0; i < m_Points.Count; i++) {if (m_Points [i] == point) {m_Points.RemoveAt (i);CreateLine (m_Points);} else {continue;}}} else {Exception ex = new Exception ("当前曲线锚点数量已经最低，不能移除锚点");throw(ex);}}public void RemovePointAt(int index){if (m_Points.Count > 2) {m_Points.RemoveAt (index);CreateLine (m_Points);} else {Exception ex = new Exception ("当前曲线锚点数量已经最低，不能移除锚点");throw(ex);}}public void UpdatePoint(int ListIndex, Vector3 point){if (ListIndex < 0) {throw (new ArgumentException ("坐标索引参数错误（取值必须大于0）"));} else if (ListIndex >= m_Points.Count) {throw (new ArgumentException ("坐标索引参数错误（取值必须x小于曲线顶点的个数）"));} else {m_Points [ListIndex] = point;CreateLine (m_Points);}}#endregion/// <summary>/// 根据传入的参数获取曲线上某一点的值/// </summary>/// <returns>The point.</returns>/// <param name="T">取值参数（0-1）.</param>public Vector3 GetPoint(float T){var point = new Vector3 ();if (T < 0) {T = 0;} else if (T > 1) {T = 1;}var bufListLine = createdLine;if (bufListLine == null) {throw(new NullReferenceException ("曲线锚点为空"));}while (bufListLine.Count > 1) {bufListLine = CaculateResoultLine (bufListLine, T);}if (bufListLine.Count == 1) {point = bufListLine [0].GetPoint (T);} else {throw(new Exception("Program Error : Current Line Count is:   " + bufListLine.Count));}return point;}/// <summary>/// 根据当前的线段以及取值参数T，创建新的线段链表（新的链表长度始终等于原始链表长度-1）。/// 使用迭代计算的方式降低程序的复杂性/// </summary>/// <param name="Lines">Lines.</param>/// <param name="T">T.</param>private List<Line> CaculateResoultLine(List<Line> Lines,float T){var ListLine = new List<Line>();for (int i = 0; i < Lines.Count-1; i++) {var j = i + 1;Line bufLine = new Line (Lines [i].GetPoint (T),Lines [j].GetPoint (T));ListLine.Add (bufLine);}return ListLine;}/// <summary>/// 根据已知的锚点依次创建一条连续的折线/// </summary>/// <param name="points">Points.</param>private void CreateLine(List<Vector3> points){createdLine = new List<Line> ();m_Points = points;for (int i = 0; i < points.Count; i++) {var j = i + 1;if (j >= points.Count) {break;} else {Line curLine = new Line (points [i], points [j]);createdLine.Add (curLine);}}}}/// <summary>/// 线段，包含起点和终点/// </summary>public struct Line{public Line(Vector3 start,Vector3 end){StartPoint = start;EndPoint = end;}/// <summary>/// 线段的起点/// </summary>/// <value>The start point.</value>public Vector3 StartPoint {get;set;}/// <summary>/// 线段的终点/// </summary>/// <value>The end point.</value>public Vector3 EndPoint{get;set;}/// <summary>/// 判断一个点是否是自己的起点或者终点/// </summary>/// <returns><c>true</c>, if me was ised, <c>false</c> otherwise.</returns>/// <param name="point">Point.</param>public bool isMe(Vector3 point){if (StartPoint == point || EndPoint == point) {return true;} else {return false;}}/// <summary>/// 根据传入的值获取这条线段上的任意一点，T>=0&&T<=1/// T=0时返回起点/// T=1时返回终点/// </summary>/// <returns>The point.</returns>/// <param name="T">T.</param>public Vector3 GetPoint(float T){var point = new Vector3 ();if (T < 0) {T = 0;} else if (T > 1) {T = 1;}point = (EndPoint - StartPoint) * T + StartPoint;return point;}}}