using System.Collections;
using System.Collections.Generic;using UnityEngine;public class BorderTest : MonoBehaviour { List<Line> lineList = new List<Line>(); Transform[] transTmp; List<Vector2> vList = new List<Vector2>(); List<Line> nLine = new List<Line>(); int number; int count = 0; Vector2 vec = new Vector2(1, 2); void Start () { number = GameObject.Find("ListPoints").transform.childCount; getChildren(number); // 点都放这个子物体下了， // print(vList.Count); getPointPairs(); // 获取组成线的两个点 test(new Vector2(6, 0)); // 拿这个点来进行测试 } private void test(Vector2 vec1) { foreach (var item in nLine) { if (item.hasCommomPoint(vec1, 0)) { count = count + 1; } } print(count); if ((count % 2) == 1) { print("在里面"); GameObject obj = new GameObject(); obj.transform.position = vec1; } else { print("不在里面"); GameObject obj = new GameObject(); obj.transform.position = vec1; } } private void getChildren(int num) { for (int i = 0; i < num; i++) { Vector2 vec = GameObject.Find("ListPoints").transform.GetChild(i).position; // Debug.Log(vec.ToString() + " " + GameObject.Find("ListPoints").transform.GetChild(i).gameObject.name); vList.Add(vec); } } private void getPointPairs() { for (int i = 0, j = 0; i < vList.Count; j = ++i) { // print(i +" "+ (j + 1) % vList.Count); Line line = new Line(vList[i], vList[(j + 1) % vList.Count]); nLine.Add(line); } } // Update is called once per frame void Update () { }}public class Line{ public Vector2 pointLeft; public Vector2 pointRight; public double k; public double b; public Line(Vector2 vec1, Vector2 vec2) { // Debug.Log(vec1 + " " + vec2); if(vec1.x < vec2.x) { pointLeft = vec1; pointRight = vec2; } else { pointLeft = vec2; pointRight = vec1; } if ((vec1.x == vec2.x)) { Debug.Log("???"); Debug.Log(vec1.ToString() + " " + vec2.ToString()); } else { this.k = (double)(pointRight.y - pointLeft.y) / (pointRight.x - pointLeft.x); this.b = vec1.y - k * vec1.x; Debug.Log(this.k); // Debug.Log((pointRight.y - pointLeft.y) / (pointRight.x - pointRight.x)); } } public bool hasCommomPoint(Vector2 vec, float k1) { float y = vec.y; double x; // Debug.Log(this.k + " " + this.b); if (this.k != null) { if (this.k == 0) { if (pointLeft.y == vec.y) { if (pointLeft.x <= vec.x && pointRight.x > vec.x) { return true; } else{ return false; } } else { Debug.Log("K = 0 没有交点"); return false; } } else { x = (y - this.b) / this.k; if (pointLeft.x < x && x < pointRight.x) { return true; } else { Debug.Log("K ！= 0 交点 超限"); return false; } } } else { Debug.Log("没有K"); if ((pointLeft.y <= y && y <= pointRight.y) || (pointLeft.y >= y && y >= pointRight.y)) { if (vec.x >= pointLeft.x) { return true; } else { return false; } } else { return false; } } }}利用的理论基础：
从目标点向一个方向发一条线，若与目标图形的焦点个数为基数，则在内部，否则不在
但是有一下几个条件：
1.凹多边形：以上基础不适用，建议拆成突多边形来做
2.还有一种情况：
看图
注意：本例使用了Unity，只是为了取点数据。