mbuchetics · November 26, 2018 09:25 · Nov 26, 2018
diff --git a/UIBezierPath+Smooth.swift b/UIBezierPath+Smooth.swift
@@ -0,0 +1,44 @@
+import Foundation
+import CoreGraphics
+import UIKit
+
+extension UIBezierPath {
+
+    convenience init?(quadCurve points: [CGPoint]) {
+        guard points.count > 1 else { return nil }
+
+        self.init()
+
+        var p1 = points[0]
+        move(to: p1)
+
+        if points.count == 2 {
+            addLine(to: points[1])
+        }
+
+        for i in 0..<points.count {
+            let mid = midPoint(p1: p1, p2: points[i])
+
+            addQuadCurve(to: mid, controlPoint: controlPoint(p1: mid, p2: p1))
+            addQuadCurve(to: points[i], controlPoint: controlPoint(p1: mid, p2: points[i]))
+
+            p1 = points[i]
+        }
+    }
+
+    private func midPoint(p1: CGPoint, p2: CGPoint) -> CGPoint {
+        return CGPoint(x: (p1.x + p2.x) / 2, y: (p1.y + p2.y) / 2)
+    }
+
+    private func controlPoint(p1: CGPoint, p2: CGPoint) -> CGPoint {
+        var controlPoint = midPoint(p1: p1, p2: p2)
+        let diffY = abs(p2.y - controlPoint.y)
+
+        if p1.y < p2.y {
+            controlPoint.y += diffY
+        } else if p1.y > p2.y {
+            controlPoint.y -= diffY
+        }
+        return controlPoint
+    }
+}