XiJianYCYL/Assets/XDKUnityCloudExamples/Common/Scripts/Tween/TweenPath.cs

using UnityEngine;
using System.Collections;
using System.Collections.Generic;
public class TweenPath : Tweener
{
    public Transform target;
    public Vector3[] path;
    public bool isWorld = false;
    private float from = 0f;
    private float to = 1f;
    private List<Vector3> pathPoints = new List<Vector3>();

    private float mValue;
    public float value {
        get {
            return mValue;
        }
        set {
            mValue = value;
            if (target != null)
            {
                if (isWorld)
                {
                    target.position = GetCRSPoint(mValue);
                }
                else
                {
                    target.localPosition = GetCRSPoint(mValue);
                }
            }
        }
    }

    protected override void Start()
    {
        pathPoints = BuildCRSplinePath(new List<Vector3>(path));
        if (target == null)
        {
            target = transform;
        }
    }

    protected override void OnUpdate(float factor, bool isFinished)
    {
        float t = from + factor * (to - from);
        value = Mathf.Clamp01(t);
    }

    public List<Vector3> BuildCRSplinePath(List<Vector3> pts)
    {
        List<Vector3> path = new List<Vector3>(pts);
        if (pts[0] == pts[pts.Count - 1])
        {
            path.Insert(0, pts[pts.Count - 2]);
            path.Add(pts[1]);
        }
        else
        {
            path.Insert(0, pts[0] + (pts[0] - pts[1]));
            path.Add(pts[pts.Count - 1] + (pts[pts.Count - 1] - pts[pts.Count - 2]));
        }
        return path;
    }

    public Vector3 CRSpline(List<Vector3> pts, float t)
    {
        int numSections = pts.Count - 3;
        int currPt = Mathf.Min(Mathf.FloorToInt(t * (float)numSections), numSections - 1);
        float u = t * (float)numSections - (float)currPt;
        Vector3 a = pts[currPt];
        Vector3 b = pts[currPt + 1];
        Vector3 c = pts[currPt + 2];
        Vector3 d = pts[currPt + 3];

        return 0.5f * (
          (-a + 3f * b - 3f * c + d) * (u * u * u)
          + (2f * a - 5f * b + 4f * c - d) * (u * u)
          + (-a + c) * u
          + 2f * b
          );
    }

    public Vector3 GetCRSPoint(float t)
    {
        return CRSpline(pathPoints, t);
    }

    public void OnDrawGizmos()
    {
        if (path == null || path.Length < 2)
        {
            return;
        }
        int i = 0, count = path.Length;
        Gizmos.color = Color.cyan;
        if (count > 1)
        {
            while (i < count)
            {
                if (i < count - 1)
                {
                    Gizmos.DrawLine(path[i], path[i + 1]);
                }
                i++;
            }
        }
        //Gizmos.color = Color.yellow;
        for (i = 0, count = path.Length; i < path.Length; i++)
        {
            Gizmos.DrawIcon(path[i], "AvatarInspector/DotFrame");
        }
    }
}