From be0112a0a3f287368a645d595c572be81dd0f411 Mon Sep 17 00:00:00 2001
From: masongreen <masongreen@MacBook-Pro.local>
Date: Sat, 1 Aug 2009 10:32:06 -0400
Subject: [PATCH] fixed updateEdge

---
 src/org/poly2tri/Poly2Tri.scala       |  2 +-
 src/org/poly2tri/cdt/CDT.scala        | 27 +++++++++++++++------------
 src/org/poly2tri/cdt/Mesh.scala       |  3 ++-
 src/org/poly2tri/shapes/Point.scala   | 14 ++++++++++++--
 src/org/poly2tri/shapes/Segment.scala |  1 +
 5 files changed, 31 insertions(+), 16 deletions(-)

diff --git a/src/org/poly2tri/Poly2Tri.scala b/src/org/poly2tri/Poly2Tri.scala
index affe53b..ff9006c 100644
--- a/src/org/poly2tri/Poly2Tri.scala
+++ b/src/org/poly2tri/Poly2Tri.scala
@@ -192,7 +192,7 @@ class Poly2TriDemo extends BasicGame("Poly2Tri") {
         hiLighter = seidel.polygons.size-1
     }
     if(c == 'm') drawMap = !drawMap 
-    if(c == 'c') drawCDT = !drawCDT
+    if(c == 'd') drawCDT = !drawCDT
     if(c == '1') selectModel(nazcaMonkey)
     if(c == '2') selectModel(bird)
     if(c == '3') selectModel(strange)
diff --git a/src/org/poly2tri/cdt/CDT.scala b/src/org/poly2tri/cdt/CDT.scala
index a977d7e..9622fdf 100644
--- a/src/org/poly2tri/cdt/CDT.scala
+++ b/src/org/poly2tri/cdt/CDT.scala
@@ -78,17 +78,19 @@ object CDT {
     // Create segments and connect end points; update edge event pointer
   private def initSegments(points: ArrayBuffer[Point]): List[Segment] = {
     var segments = List[Segment]()
-    for(i <- 0 until points.size-1) {
-      val segment = new Segment(points(i), points(i+1))
-      points(i+1).eEvent = segment
-      segments = segment :: segments
-    }
-    val segment = new Segment(points.first, points.last)
-    points.first.eEvent = segment
-    segments =  segment :: segments
+    for(i <- 0 until points.size-1) 
+      segments = segment(points(i), points(i+1)) :: segments
+    segments =  segment(points.first, points.last) :: segments
     segments
   }
   
+  // Create a new segment and updates edge pointer
+  private def segment(p1: Point, p2: Point): Segment = {
+    val seg = new Segment(p1, p2)
+    p1.updateEdges(p2, seg)
+    seg
+  }
+  
   // Insertion sort is one of the fastest algorithms for sorting arrays containing 
   // fewer than ten elements, or for lists that are already mostly sorted.
   // Merge sort: O(n log n)
@@ -145,9 +147,11 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
     val triangle = new Triangle(pts, neighbors)
     mesh.map += triangle
     
+    // Check if edges need to be swapped to preserve CDT
+    // TODO: Make sure AFront pointers are updated correctly
     val oPoint = nTri oppositePoint triangle
     if(illegal(ccwPoint, oPoint, cwPoint, point)) {
-      swapEdges(triangle, nTri, oPoint)
+      legalization(triangle, nTri, oPoint)
     }
     
     nTri.updateNeighbors(ccwPoint, cwPoint, triangle)
@@ -215,9 +219,8 @@ class CDT(val points: List[Point], val segments: List[Segment], iTriangle: Trian
         false
   }
   
-  // Rotate everything clockwise
-  private def swapEdges(t1: Triangle, t2: Triangle, oPoint: Point) {
-    println("swap")
+  // Flip edges and rotate everything clockwise
+  private def legalization(t1: Triangle, t2: Triangle, oPoint: Point) {
     // Rotate points
     val point = t1.points(0)
     t1.points(1) = t1.points(0)
diff --git a/src/org/poly2tri/cdt/Mesh.scala b/src/org/poly2tri/cdt/Mesh.scala
index e901b4f..5914c47 100644
--- a/src/org/poly2tri/cdt/Mesh.scala
+++ b/src/org/poly2tri/cdt/Mesh.scala
@@ -40,10 +40,11 @@ class Mesh(initialTriangle: Triangle) {
   val map = HashSet(initialTriangle)
   
   def addEdge(point:Point, triangle: Triangle) {
+    /*
     val p = point.eEvent.p
     if(!triangle.contains(p)) {
       
     }
-    
+    */
   }
 }
diff --git a/src/org/poly2tri/shapes/Point.scala b/src/org/poly2tri/shapes/Point.scala
index a81c1b0..49ca1ef 100644
--- a/src/org/poly2tri/shapes/Point.scala
+++ b/src/org/poly2tri/shapes/Point.scala
@@ -30,14 +30,16 @@
  */
 package org.poly2tri.shapes
 
+import scala.collection.mutable.ArrayBuffer
+
 case class Point(val x: Float, val y: Float) {
   
   // Pointers to next and previous points in Monontone Mountain
   var next, prev: Point = null
   // The setment this point belongs to
   var segment: Segment = null
-  // Edge event pointer for CDT
-  var eEvent: Segment = null
+  // List of edges this point constitutes an upper ending point (CDT)
+  var edges = new ArrayBuffer[Segment] 
   
   @inline def -(p: Point) = Point(x - p.x, y - p.y) 
   @inline def +(p: Point) = Point(x + p.x, y + p.y)
@@ -55,4 +57,12 @@ case class Point(val x: Float, val y: Float) {
   @inline def >(p: Point) = (y < p.y) 
   @inline def !(p: Point) = !(p.x == x && p.y == y)
   @inline override def clone = Point(x, y)
+  
+  def updateEdges(point: Point, segment: Segment) {
+    if(point.y > y)
+        point.edges += segment
+      else
+        edges += segment
+  }
+  
 }
diff --git a/src/org/poly2tri/shapes/Segment.scala b/src/org/poly2tri/shapes/Segment.scala
index e27444c..22b95af 100644
--- a/src/org/poly2tri/shapes/Segment.scala
+++ b/src/org/poly2tri/shapes/Segment.scala
@@ -33,6 +33,7 @@ package org.poly2tri.shapes
 import scala.collection.mutable.{ArrayBuffer}
 
 // Represents a simple polygon's edge
+// TODO: Rename this class to Edge?
 class Segment(var p: Point, var q: Point) {
  
   // Pointers used for building trapezoidal map