bug hunting

src/org/poly2tri/Poly2Tri.scala

@@ -160,6 +160,14 @@ class Poly2TriDemo extends BasicGame("Poly2Tri") {
 		 g.setColor(red)
 		 g.draw(triangle) 
 	   })
+	   slCDT.debugTriangles.foreach( t => {
+	     val triangle = new Polygon
+		 triangle.addPoint(t.points(0).x, t.points(0).y)
+		 triangle.addPoint(t.points(1).x, t.points(1).y)
+		 triangle.addPoint(t.points(2).x, t.points(2).y)
+		 g.setColor(blue)
+		 g.draw(triangle) 
+	   })
    }
    
    if(drawSegs) {

src/org/poly2tri/cdt/AFront.scala

@@ -47,11 +47,11 @@ class AFront(iTriangle: Triangle) {
   def locate(point: Point): Node = {
     var node = head
     while(node != tail) {
-      if(point.x >= node.point.x && point.x <= node.next.point.x)
+      if(point.x >= node.point.x && point.x < node.next.point.x)
         return node
       node = node.next
     }
-    throw new Exception("Advancing front error")
+    throw new Exception("Advancing front error: point not found")
   }
   
   def insert(tuple: Tuple3[Point, Triangle, Node]) = {

src/org/poly2tri/cdt/CDT.scala

@@ -108,6 +108,8 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
   
   // Triangle list
   def triangles = mesh.map
+  def debugTriangles = mesh.debug
+  
   // The triangle mesh
   private val mesh = new Mesh(iTriangle)
   // Advancing front
@@ -122,13 +124,12 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
   
   // Implement sweep-line 
   private def sweep {
-    for(i <- 1 until points.size) {
+    for(i <- 1 until 10 /*points.size*/) {
       val point = points(i)
       // Process Point event
-      //val triangle = 
-      pointEvent(point)
+      val triangle = pointEvent(point)
       // Process edge events
-      //point.edges.foreach(e => edgeEvent(e, triangle))
+      point.edges.foreach(e => edgeEvent(e, triangle))
     }
   }  
   
@@ -136,6 +137,7 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
   private def pointEvent(point: Point): Triangle = {
     
     val node = aFront.locate(point)
+    
     // Neightbor points (ccw & cw) and triangle(i)
     val cwPoint = node.next.point
     val ccwPoint = node.point
@@ -167,40 +169,76 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
     
     // STEP 1: Locate the first intersected triangle
     val firstTriangle = triangle.locateFirst(edge)
+    
     // STEP 2: Remove intersected triangles
     if(firstTriangle != null && !firstTriangle.contains(edge)) {
        // Collect intersected triangles
        val triangles = new ArrayBuffer[Triangle]
        triangles += firstTriangle
+       val e = edge.p - edge.q
        while(!triangles.last.contains(edge.p)) 
-         triangles += triangles.last.findNeighbor(edge.p - edge.q)
+         triangles += triangles.last.findNeighbor(e)
        // Remove from the mesh
-       triangles.foreach(t => mesh.map -= t)
+       //triangles.foreach(t => mesh.map -= t)
     } else if(firstTriangle == null) {
       
       // Traverse the AFront, and build triangle list
-     
       var node = aFront.locate(edge.q)
+      node = node.next
+      val points = new ArrayBuffer[Point]
       
       if(edge.p.x > edge.q.x) {
         // Search right
         while(node.point != edge.p) {
           // Collect points
+          points += node.point
           node = node.next
         }
       } else {
         // Search left
         while(node.point != edge.p) {
           // Collect points
+          points += node.point
           node = node.prev
         }
       }
       
+      val T = new ArrayBuffer[Triangle]
+      angladaTPD(points.toArray, List(edge.p, edge.q), T)
+      T.foreach(t => mesh.debug += t)
     }
     
     // STEP 3: Triangulate empty areas.
   }
   
+  // Marc Vigo Anglada's triangulatePseudopolygonDelaunay algo 
+  def angladaTPD(P: Array[Point], ab: List[Point], T: ArrayBuffer[Triangle]) {
+    
+    val a = ab.first
+    val b = ab.last
+    var c: Point = null
+    if(P.size > 1) {
+      c = P.first
+      var i = 0
+      for(j <- 1 until P.size) {
+        if(illegal(a, c, b, P(j))) {
+          c = P(j)
+          i = j
+        } 
+      }
+      val PE = P.slice(0, i)
+      val PD = P.slice(i, P.size-1)
+      angladaTPD(PE, List(a, c), T)
+      angladaTPD(PD, List(c, b), T)
+    }
+    if(!P.isEmpty) {
+      c = P.first
+      val points = Array(a, b, c)
+      val neighbors = new Array[Triangle](3)
+      T += new Triangle(points, neighbors)
+    }
+  }
+
   // Scan left and right along AFront to fill holes
   def scan(n: Node) {
     
@@ -231,11 +269,11 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
 	  val b = (node.next.point - node.point)
 	  val angle = Math.abs(Math.atan2(a cross b, a dot b))
 	  if(angle <= PI_2) {
-	    val points = Array(node.prev.point, node.next.point, node.point)
-	    val neighbors = Array(node.prev.triangle, null, node.triangle)
+	    val points = Array(node.prev.point, node.point, node.next.point)
+	    val neighbors = Array(node.triangle, null, node.prev.triangle)
 	    val triangle = new Triangle(points, neighbors)
         // Update neighbor pointers
-        node.prev.triangle.updateNeighbors(triangle.points(1), triangle.points(2), triangle)
+        node.prev.triangle.updateNeighbors(triangle.points(0), triangle.points(1), triangle)
         node.triangle.updateNeighbors(triangle.points(1), triangle.points(2), triangle)
 	    mesh.map += triangle
 	    aFront -= (node.prev, node, triangle)
@@ -250,7 +288,6 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
       val v3 = p1 - p4
       val v4 = p3 - p4
       if((v1 dot v2) < 0 && (v3 dot v4) < 0)
-        // swap the edge
         true 
       else 
         false
@@ -267,8 +304,11 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
     t2.points(1) = point
     t2.points(0) = t2.points(2)
     t2.points(2) = tmp
-    // Rotate neighbors
     
+    t1.updatePoints
+    t2.updatePoints
+    // TODO: Rotate neighbors
+    println("legalize")
   }
  
   private def finalization {

src/org/poly2tri/cdt/Mesh.scala

@@ -38,6 +38,7 @@ class Mesh(initialTriangle: Triangle) {
   
   // Triangles that constitute the mesh
   val map = HashSet(initialTriangle)
+  val debug = HashSet.empty[Triangle]
   
   def addEdge(point:Point, triangle: Triangle) {
     /*

src/org/poly2tri/shapes/Segment.scala

@@ -53,14 +53,13 @@ class Segment(var p: Point, var q: Point) {
   
   // Update point edge list for CDT
   def updateEdge {
-	if(q.y > p.y) {
+	if(p.y > q.y) {
 	  // For CDT we want q to be the point with > y
-     // val tmp = p
-      //p = q
-      //q = tmp
+      val tmp = p
+      p = q
+      q = tmp
+     }
 	q.edges += this
   }
   
 }
-  
-}

src/org/poly2tri/shapes/Triangle.scala

@@ -37,16 +37,21 @@ import scala.collection.mutable.ArrayBuffer
 //      "Triangulations in CGAL"
 class Triangle(val points: Array[Point], val neighbors: Array[Triangle]) {
 
-  val ik = points(2) - points(0)
-  val ij = points(1) - points(0)
-  val jk = points(2) - points(1)
-  val ji = points(0) - points(1)
-  val kj = points(1) - points(2)
-  val ki = points(0) - points(2)
+  var ik, ij , jk, ji, kj, ki: Point = null
+  updatePoints
   
   // Flags to determine if an edge is the final Delauney edge
   val edges = new Array[Boolean](3)
   
+  def updatePoints {
+    ik = points(2) - points(0)
+    ij = points(1) - points(0)
+    jk = points(2) - points(1)
+    ji = points(0) - points(1)
+    kj = points(1) - points(2)
+    ki = points(0) - points(2)
+  }
+  
   // Update neighbor pointers
   def updateNeighbors(ccwPoint: Point, cwPoint: Point, triangle: Triangle) {
     if(ccwPoint == points(2) && cwPoint == points(1)) 
@@ -105,7 +110,7 @@ class Triangle(val points: Array[Point], val neighbors: Array[Triangle]) {
       if(neighbors(1) == null) return null
       return neighbors(1).locateFirst(edge)
     }
-    throw new Exception("location error")
+    null
   }
   
   def findNeighbor(e: Point): Triangle = {
@@ -118,4 +123,9 @@ class Triangle(val points: Array[Point], val neighbors: Array[Triangle]) {
     this
   }
   
+  def printDebug {
+    println("**************")
+    println(points(0) + "," + points(1) + "," + points(2))
+  }
+  
 }