bug hunting

src/org/poly2tri/cdt/CDT.scala

@@ -157,7 +157,7 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
         mesh.map += lTriangle
         mesh.map += rTriangle
         
-        // No need for legalization here
+        // Skip legalization
         
         // Update neighbors
         node.triangle.updateNeighbors(rTriangle.points(1), rTriangle.points(2), rTriangle, mesh.debug)
@@ -412,10 +412,24 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
     val oPoint = t2 oppositePoint t1
     
     if(illegal(t1.points(1), oPoint, t1.points(2), t1.points(0))) {
+      
         // Flip edges and rotate everything clockwise
         val point = t1.points(0)
 	    t1.legalize(oPoint) 
 	    t2.legalize(oPoint, point)
+
+	    // Update neighbor pointers
+        val ccwNeighbor = t2.neighborCCW(oPoint)
+        
+        if(ccwNeighbor != null) {
+          ccwNeighbor.updateNeighbors(t1.points(2), t1.points(0), t1, mesh.debug)
+          t1.neighbors(1) = ccwNeighbor
+        }
+        
+        t2.rotateNeighborsCW(oPoint, t1)        
+        t1.neighbors(0) = t2
+        t1.neighbors(2) = null
+	    
 	    false
     } else {
       true

src/org/poly2tri/shapes/Triangle.scala

@@ -88,7 +88,6 @@ class Triangle(val points: Array[Point], val neighbors: Array[Triangle]) {
   // Locate first triangle crossed by constrained edge
   def locateFirst(edge: Segment): Triangle = {
     val p = edge.p
-    if(contains(p)) return this
     val q = edge.q
     val e = p - q
     if(q == points(0)) {
@@ -107,16 +106,16 @@ class Triangle(val points: Array[Point], val neighbors: Array[Triangle]) {
       if(neighbors(1) == null) return null
       return neighbors(1).locateFirst(edge)
     }
-    null
+    throw new Exception("Point not found")
   }
   
   // Locate next triangle crossed by edge
   def findNeighbor(e: Point): Triangle = {
     if(orient(points(0), points(1), e) >= 0)
       return neighbors(2)
-    if(orient(points(1), points(2), e) >= 0)
+    else if(orient(points(1), points(2), e) >= 0)
       return neighbors(0)
-    if(orient(points(2), points(0), e) >= 0)
+    else if(orient(points(2), points(0), e) >= 0)
       return neighbors(1)
     else
       // Point must reside inside this triangle
@@ -155,6 +154,16 @@ class Triangle(val points: Array[Point], val neighbors: Array[Triangle]) {
       neighbors(0)
   }
   
+  // The neighbor clockwise to given point
+  def neighborAcross(point: Point): Triangle = {
+    if(point == points(0)) {
+      neighbors(0)
+    }else if(point == points(1)) {
+      neighbors(1)
+    } else 
+      neighbors(2)
+  }
+  
   // The point counter-clockwise to given point
   def pointCCW(point: Point): Point = {
     if(point == points(0)) {
@@ -207,6 +216,25 @@ class Triangle(val points: Array[Point], val neighbors: Array[Triangle]) {
     updateEdges
   }
   
+  // Rotate neighbors clockwise around give point. Share diagnal with triangle
+  def rotateNeighborsCW(oPoint: Point, triangle: Triangle) {
+    if(oPoint == points(0)) {
+      neighbors(2) = neighbors(1)
+      neighbors(1) = null
+      neighbors(0) = triangle
+    } else if (oPoint == points(1)) {
+      neighbors(0) = neighbors(2)
+      neighbors(2) = null
+      neighbors(1) = triangle
+    } else if (oPoint == points(2)) {
+      neighbors(1) = neighbors(0)
+      neighbors(0) = null
+      neighbors(2) = triangle
+    } else {
+      throw new Exception("pointer bug")
+    }
+  }
+  
   def printDebug = println(points(0) + "," + points(1) + "," + points(2))
   
   private var ik, ij , jk, ji, kj, ki: Point = null