Fix some corner case bugs

Author: Oleksandr Glagoliev

Demo/Demo/EdgeCases.swift

@@ -9,6 +9,7 @@
 import Foundation
 
 var edgeCases = [
+    broken0,
     broken,
     testSites_3,
     testSites_4,
@@ -106,3 +107,11 @@ let broken = Set<Site>(
         Site(x: 166.0, y: 153.0),
     ]
 )
+    
+let broken0 = Set<Site>(
+    [
+        Site(x: 241.0, y: 293.0),
+        Site(x: 166.0, y: 192.0),
+    ]
+)
+

Demo/Demo/UIBezierPath+RoundedCorners.swift

@@ -60,7 +60,6 @@ extension UIBezierPath {
         let dy = p.y * 2 - c1.y - c2.y
 
         let p_c = (dx.sqr + dy.sqr).squareRoot()
-
         // Find Circle origin
         let o = CGPoint(
             x: p.x - dx * p_o / p_c,
@@ -72,13 +71,21 @@ extension UIBezierPath {
         let endAngle = (atan2((c2.y - o.y), (c2.x - o.x))).positiveAngle
 
 
-        if isStart {
-            path.move(to: c1)
+        
+        if !radius.isNaN && !o.x.isNaN && !o.y.isNaN {
+            if isStart {
+                path.move(to: c1)
+            } else {
+                path.addLine(to: c1)
+            }
+            path.addArc(withCenter: o, radius: radius, startAngle: startAngle, endAngle: endAngle, clockwise: angle < .pi)
         } else {
-            path.addLine(to: c1)
+            if isStart {
+                path.move(to: p)
+            } else {
+                path.addLine(to: p)
+            }
         }
-        
-        path.addArc(withCenter: o, radius: radius, startAngle: startAngle, endAngle: endAngle, clockwise: angle < .pi)
     }
 
     public static func roundedCornersPath(_ pts: [CGPoint], _ r: CGFloat) -> UIBezierPath? {

Demo/Demo/VoronoiView.swift

@@ -67,12 +67,14 @@ class VoronoiView: UIView {
 //                numberOfAxis: 1
 //            )
 //        )
+        
+        
 //        if axipoints.count > 4 {
 //            axipoints = Array<Site>(axipoints.dropFirst(axipoints.count - 5))
 //        }
 
 
-//        drawRandomSites(100)
+//        drawRandomSites(200)
 
         drawNextEdgeCase()
     }
@@ -87,7 +89,7 @@ class VoronoiView: UIView {
         for i in 0..<numberOfAxis {
             // Dirty hack to prevent points to share coordinate
             // Otherwise it may produce glitches
-            let wiggle = CGFloat(CGFloat.random(in: 0..<10) * 0.2)
+            let wiggle = CGFloat.zero//CGFloat(CGFloat.random(in: 0..<10) * 0.002)
 
             let theta = CGFloat(
                 atan2(seedPoint.y - center.y, seedPoint.x - center.x)
@@ -161,7 +163,7 @@ class VoronoiView: UIView {
             var he = cell.outerComponent
 
             var finish = false
-            while !finish {
+            while !finish  {
 
                 if he!.toSegment()!.length() < 1.0 {
                     he = he?.next

Sources/FortunesAlgorithm/Event.swift

@@ -30,19 +30,6 @@ extension Event: Comparable {
     }
 
     static func < (lhs: Event, rhs: Event) -> Bool {
-        if lhs.point == rhs.point {
-            
-            guard
-                let lp = lhs.arc?.point,
-                let rp = rhs.arc?.point else {
-                    return true
-            }
-            
-            if lp.y == rp.y {
-                return lp.x < rp.x
-            }
-            return lp.y < rp.y
-        }
         if lhs.point.y == rhs.point.y {
             return lhs.point.x < rhs.point.x
         }

Sources/FortunesAlgorithm/FortuneSweep.swift

@@ -79,7 +79,10 @@ public class FortuneSweep {
         if beachline.isEmpty {
             let root = beachline.insertRootArc(point: event.point)
             firstSiteY = event.point.y
-            container = clipper
+            
+            let padding: Double = 20
+            container = .rect(from: clipper, with: padding)
+//            container = clipper
 
             /// Create new **Cell** record in **Voronoi Diagram**
             container.expandToContainPoint(event.point)
@@ -96,7 +99,7 @@ public class FortuneSweep {
         /// We replace *y* with an arbitrary value big enough to cover our case. (`yVal`)
         if firstSiteY == sweepLineY {
             container.expandToContainPoint(event.point)
-            let yVal: Double = .leastNormalMagnitude
+            let yVal: Double = -1000000//.leastNormalMagnitude
             let arc = beachline.handleSpecialArcInsertionCase(event.point)
 
             /// 1. Create new **Cell** record in **Voronoi Diagram**
@@ -397,8 +400,8 @@ public class FortuneSweep {
 
         let clipper = container!.toClipper()
 
-        last.destination = lb_clip(last.toSegment()!, clipper: clipper).resultSegment!.b
-        first.origin = lb_clip(first.toSegment()!, clipper: clipper).resultSegment!.a
+        last.destination = lb_clip(last.toSegment()!, clipper: clipper).resultSegment?.b
+        first.origin = lb_clip(first.toSegment()!, clipper: clipper).resultSegment?.a
 
         guard let start = last.destination, let end = first.origin else {
             return

Sources/FortunesAlgorithm/Geometry/Rectangle.swift

@@ -93,6 +93,13 @@ extension Rectangle {
             getLine(.bottom)
         ]
     }
+    
+    public static func rect(from sourceRect: Rectangle, with padding: Double) -> Rectangle {
+        Rectangle(
+            origin: Site(x: sourceRect.tl.x - padding, y: sourceRect.tl.y - padding),
+            size: Size(width: sourceRect.width + 2 * padding, height: sourceRect.height + 2 * padding)
+        )
+    }
 }
 
 

SpriteKitDemo/SpriteKitDemo/GameScene.swift

@@ -27,7 +27,7 @@ class GameScene: SKScene {
 //        removeAllChildren()
         let totalPath = UIBezierPath()
 
-        DispatchQueue.global(qos: .userInteractive).async { [unowned self] in
+//        DispatchQueue.global(qos: .userInteractive).async { [unowned self] in
             self.diagram.clear()
             self.fs.compute(
                 sites: sites,
@@ -42,11 +42,11 @@ class GameScene: SKScene {
                 var finish = false
                 while !finish {
 
-                    if he!.toSegment()!.length() < 1.0 {
-                        he = he?.next
-                        finish = he === cell.outerComponent
-                        continue
-                    }
+//                    if he!.toSegment()!.length() < 1.0 {
+//                        he = he?.next
+//                        finish = he === cell.outerComponent
+//                        continue
+//                    }
 
                     let o = he!.origin!
                     points.append(o)
@@ -56,21 +56,30 @@ class GameScene: SKScene {
                     finish = he === cell.outerComponent
                 }
 
+//                let hullVertices = points.map { $0.cgPoint }
+//                for i in 0..<hullVertices.count {
+//                    if i == 0 {
+//                        totalPath.move(to: hullVertices[i])
+//                    } else { totalPath.addLine(to: hullVertices[i])}
+//                }
+//                totalPath.close()
+                
                 let hullVertices = points.map { $0.cgPoint }
-                for i in 0..<hullVertices.count {
-                    if i == 0 {
-                        totalPath.move(to: hullVertices[i])
-                    } else { totalPath.addLine(to: hullVertices[i])}
+                
+                for i in 0..<1 {
+                    let paddedHull = paddedPolygon(hullVertices, padding: CGFloat(-i) * 10)
+                    if let path = UIBezierPath.roundedCornersPath(paddedHull, 10) {
+                        totalPath.append(path)
+                    }
                 }
-                totalPath.close()
             }
 
-            DispatchQueue.main.async {
+//            DispatchQueue.main.async {
                 self.diagramNode.path = totalPath.cgPath
                 self.diagramNode.strokeColor = UIColor.black
                 self.diagramNode.fillColor = .clear
-            }
-        }
+//            }
+//        }
     }
 
     override func didMove(to view: SKView) {
@@ -128,17 +137,18 @@ class GameScene: SKScene {
 
 
     var hexLike: [Site] {
-        var num = 5
+        let num = 5
         let step: Double = 50
         var res = [Site]()
         for i in 0..<num {
-            for j in 0..<num {
+            for j in 0..<3 {
                 res.append(
                     Site(
                         x:Double(i) * step + Double(j) * step / 2 + 200,
                         y:Double(j) * step + 200
                     )
                 )
+                print(res.last!)
             }
         }
         return res
@@ -150,8 +160,9 @@ class GameScene: SKScene {
     func touchMoved(toPoint pos : CGPoint) {
         let spriteAtPoint = atPoint(pos)
         if spriteAtPoint != diagramNode {
-            atPoint(pos).position = pos
+            atPoint(pos).position = CGPoint(x: pos.x.rounded(), y: pos.y.rounded())
         }
+        redraw(Set<Site>(balls.map { $0.position.point }))
     }
 
     func touchUp(atPoint pos : CGPoint) {
@@ -179,7 +190,7 @@ class GameScene: SKScene {
     }
 
     override func update(_ currentTime: TimeInterval) {
-        redraw(Set<Site>(balls.map { $0.position.point }))
+//        redraw(Set<Site>(balls.map { $0.position.point }))
     }
 }