判断一个坐标点是否在封闭曲线内的方法(swift)

 1 //用playground运行即可
 2 import UIKit
 3 
 4 var str = "Hello, playground"
 5 
 6 let lTestPointsOne : [(Double, Double)]  = [(0,0)]
 7 let lTestPoints : [(Double, Double)]  = [(0,0),(0,1),(1,1)]
 8 let lPoints : [(Double, Double)]  = [(0,0),(0,1),(1,2),(2,1),(3,2),(3,0)]
 9 
10 func judgeIf(point:(Double,Double), isIn pointArr:[(Double, Double)])->Bool{
11     if 0 == pointArr.count {
12         return false
13     }
14     let lPath = UIBezierPath.init()
15     let l1stPoint = pointArr.first
16     lPath.move(to: CGPoint.init(x: l1stPoint!.0, y: l1stPoint!.1))
17     
18     for i in 1..<pointArr.count {
19         let lP = pointArr[i]
20         lPath.addLine(to: CGPoint.init(x: lP.0, y: lP.1))
21     }
22     
23     lPath.close()
24     return lPath.contains(CGPoint.init(x: point.0, y: point.1))
25 }
26 
27 print(lPoints)
28 judgeIf(point: (0,0), isIn: lPoints)
29 judgeIf(point: (1,0), isIn: lPoints)
30 judgeIf(point: (3,-1), isIn: lPoints)
31 judgeIf(point: (0.5,2), isIn: lPoints)
32 judgeIf(point: (1,1), isIn: lPoints)
33 judgeIf(point: (2,1), isIn: lPoints)
34 judgeIf(point: (2,0.5), isIn: lPoints)
35 judgeIf(point: (2,1.5), isIn: lPoints)
36 judgeIf(point: (3,1), isIn: lPoints)
37 judgeIf(point: (3.3,8.1), isIn: lPoints)
38 
39 judgeIf(point: (0,0), isIn: lTestPoints)
40 judgeIf(point: (0,1), isIn: lTestPoints)
41 judgeIf(point: (0.5,0.5), isIn: lTestPoints)
42 judgeIf(point: (0.5,0.7), isIn: lTestPoints)
43 judgeIf(point: (0.5,0.1), isIn: lTestPoints)
44 judgeIf(point: (0,8), isIn: lTestPoints)
45 judgeIf(point: (1,0), isIn: lTestPoints)
46 
47 judgeIf(point: (1,0), isIn: lTestPointsOne)
48 judgeIf(point: (0,0), isIn: lTestPointsOne)