setup triangle, mesh, and advancing front classes

src/org/poly2tri/Poly2Tri.scala

@@ -69,6 +69,7 @@ class Poly2TriDemo extends BasicGame("Poly2Tri") {
   var drawSegs = true
   var hiLighter = 0
   var drawEarClip = false
+  var hertelMehlhorn = false
   
   val nazcaMonkey = "data/nazca_monkey.dat"
   val bird = "data/bird.dat"
@@ -114,11 +115,11 @@ class Poly2TriDemo extends BasicGame("Poly2Tri") {
    
    if(!debug && !drawEarClip) {
     var i = 0
-    for(t <- tesselator.triangles) {
+    for(t <- tesselator.polygons) {
-        val triangle = new Polygon
+        val poly = new Polygon
-        t.foreach(p => triangle.addPoint(p.x, p.y))
+        t.foreach(p => poly.addPoint(p.x, p.y))
         g.setColor(red)
-        g.draw(triangle)
+        g.draw(poly)
       }
    } else if (debug && drawMap && !drawEarClip){
     for(mp <- tesselator.monoPolies) {
@@ -158,14 +159,14 @@ class Poly2TriDemo extends BasicGame("Poly2Tri") {
     // UP
     if(key == 200) {
       hiLighter += 1
-      if (hiLighter == tesselator.triangles.size)
+      if (hiLighter == tesselator.polygons.size)
         hiLighter = 0
     }
     // DOWN
     if(key == 208) {
       hiLighter -= 1
       if (hiLighter == -1)
-        hiLighter = tesselator.triangles.size-1
+        hiLighter = tesselator.polygons.size-1
     }
     if(c == 'm') drawMap = !drawMap 
     if(c == '1') {currentModel = nazcaMonkey; selectModel}
@@ -175,6 +176,7 @@ class Poly2TriDemo extends BasicGame("Poly2Tri") {
     if(c == '5') star
     if(c == 's') drawSegs = !drawSegs
     if(c == 'e') {drawEarClip = !drawEarClip; selectModel}
+    if(c == 'h') {hertelMehlhorn = !hertelMehlhorn; selectModel} 
   }
     
   def selectModel {
@@ -227,6 +229,8 @@ class Poly2TriDemo extends BasicGame("Poly2Tri") {
     segments += new Segment(p6, p7)
     
     tesselator = new Triangulator(segments)
+    tesselator.buildTriangles = hertelMehlhorn
+    
     val t1 = System.nanoTime
     tesselator process
     val t2 = System.nanoTime
@@ -260,7 +264,9 @@ class Poly2TriDemo extends BasicGame("Poly2Tri") {
     segments += new Segment(p8, p9)
     segments += new Segment(p9, p10)
     segments += new Segment(p10, p1)
+    
     tesselator = new Triangulator(segments)
+    tesselator.buildTriangles = hertelMehlhorn
     
     val t1 = System.nanoTime
     tesselator process
@@ -301,7 +307,9 @@ class Poly2TriDemo extends BasicGame("Poly2Tri") {
     segments += new Segment(p10, p11)
     segments += new Segment(p11, p12)
     segments += new Segment(p12, p1)
+    
     tesselator = new Triangulator(segments)
+    tesselator.buildTriangles = hertelMehlhorn
     
     val t1 = System.nanoTime
     tesselator process
@@ -355,12 +363,14 @@ class Poly2TriDemo extends BasicGame("Poly2Tri") {
       
 	    // Sediel triangulation
 	    tesselator = new Triangulator(segments)
+        tesselator.buildTriangles = hertelMehlhorn
+        
 	    val t1 = System.nanoTime
 	    tesselator.process
 	    val runTime = System.nanoTime - t1
 	
 	    println("Poly2Tri average (ms) =  " + runTime*1e-6)
-	    println("Number of triangles = " + tesselator.triangles.size)
+	    println("Number of triangles = " + tesselator.polygons.size)
      
     } else {
       

src/org/poly2tri/cdt/AFront.scala

@@ -0,0 +1,36 @@
+/* Poly2Tri
+ * Copyright (c) 2009, Mason Green
+ * http://code.google.com/p/poly2tri/
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * * Neither the name of Poly2Tri nor the names of its contributors may be
+ *   used to endorse or promote products derived from this software without specific
+ *   prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.poly2tri.cdt
+
+// Advancing front
+class AFront {
+
+}

src/org/poly2tri/cdt/Mesh.scala

@@ -0,0 +1,39 @@
+/* Poly2Tri
+ * Copyright (c) 2009, Mason Green
+ * http://code.google.com/p/poly2tri/
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * * Neither the name of Poly2Tri nor the names of its contributors may be
+ *   used to endorse or promote products derived from this software without specific
+ *   prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.poly2tri.cdt
+
+import scala.collection.mutable.HashSet
+                                 
+class Mesh {
+
+  val map = HashSet.empty[Triangle]
+  
+}

src/org/poly2tri/cdt/Triangle.scala

@@ -0,0 +1,40 @@
+/* Poly2Tri
+ * Copyright (c) 2009, Mason Green
+ * http://code.google.com/p/poly2tri/
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * * Redistributions of source code must retain the above copyright notice,
+ *   this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright notice,
+ *   this list of conditions and the following disclaimer in the documentation
+ *   and/or other materials provided with the distribution.
+ * * Neither the name of Poly2Tri nor the names of its contributors may be
+ *   used to endorse or promote products derived from this software without specific
+ *   prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.poly2tri.cdt
+
+import shapes.Point
+
+// Triangle-based data structures have better performance than quad-edge structures
+// See: Shewchuk, "Triangle: Engineering a 2D Quality Mesh Generator and Delaunay Triangulator"
+//      "Triangulations in CGAL"
+class Triangle(points: Array[Point], neighbors: Array[Triangle]) {
+
+}

src/org/poly2tri/seidel/MonotoneMountain.scala

@@ -35,7 +35,7 @@ import scala.collection.mutable.{ArrayBuffer, Queue}
 import shapes.Point
 
 // Doubly linked list
-class MonotoneMountain {
+class MonotoneMountain(buildTriangles: Boolean) {
 
 	var tail, head: Point = null
 	var size = 0
@@ -45,6 +45,8 @@ class MonotoneMountain {
 	val monoPoly = new ArrayBuffer[Point]
     // Triangles that constitute the mountain
 	val triangles = new ArrayBuffer[Array[Point]]
+	// Convex polygons that constitute the mountain
+	val convexPolies = new ArrayBuffer[Array[Point]]
 	// Used to track which side of the line we are on                                
 	private var positive = false
 	// Almost Pi!
@@ -86,7 +88,7 @@ class MonotoneMountain {
  
 	// Partition a x-monotone mountain into triangles O(n)
 	// See "Computational Geometry in C", 2nd edition, by Joseph O'Rourke, page 52
-	def triangulate {
+	def process {
 	
 	  // Establish the proper sign
 	  positive = angleSign
@@ -106,6 +108,15 @@ class MonotoneMountain {
         p = p.next
       }
       
+      if(buildTriangles) 
+    	triangulate
+       else
+        hertelMehlhorn
+
+    }
+ 
+	private def triangulate {
+	  
       while(!convexPoints.isEmpty) {
 	     
         val ear = convexPoints.remove(0)
@@ -123,7 +134,30 @@ class MonotoneMountain {
       }
       assert(size <= 3, "Triangulation bug, please report")
    
-  }
+	}
+ 
+	private def hertelMehlhorn {
+	  
+		while(!convexPoints.isEmpty) {
+	        val ear = convexPoints.remove(0)
+	        val a = ear.prev
+	        val b = ear
+	        val c = ear.next
+	        val triangle = Array(a, b, c)
+	        convexPolies += triangle
+	        // Remove ear, update angles and convex list
+	        remove(ear)
+        }
+  
+		val polygon = new Array[Point](size)
+		
+		var p = head
+		for(i <- 0 until size) {
+		  polygon(i) = p
+          p = p.next
+		}
+        convexPolies += polygon
+	}
  
 	private def valid(p: Point) = (p != head && p != tail && convex(p))
 	  

src/org/poly2tri/seidel/TrapezoidalMap.scala

@@ -38,7 +38,7 @@ import shapes.{Point, Segment, Trapezoid}
 
 class TrapezoidalMap {
 
-  // Trapezoid associated array
+  // Trapezoid container
   val map = HashSet.empty[Trapezoid]
   // AABB margin
   var margin = 50f

src/org/poly2tri/seidel/Triangulator.scala

@@ -41,9 +41,11 @@ import shapes.{Point, Segment, Trapezoid}
 //           "Computational Geometry in C", 2nd edition, by Joseph O'Rourke
 class Triangulator(segments: ArrayBuffer[Segment]) {
   
-  // Triangle decomposition list
+  // Convex polygon list
-  var triangles = new ArrayBuffer[Array[Point]]
+  var polygons = new ArrayBuffer[Array[Point]]
-  
+  // Generate triangles vs non-convex polygons 
+  // On by default
+  var buildTriangles = true
   // Order and randomize the segments
   val segmentList = orderSegments
   
@@ -147,7 +149,7 @@ class Triangulator(segments: ArrayBuffer[Segment]) {
       
       if(s.mPoints.size > 0) {
         
-         val mountain = new MonotoneMountain
+         val mountain = new MonotoneMountain(buildTriangles)
          var k: List[Point] = null
     
          // Sorting is a perfromance hit. Literature says this can be accomplised in
@@ -169,13 +171,22 @@ class Triangulator(segments: ArrayBuffer[Segment]) {
          }
          
          // Triangulate monotone mountain
-         mountain.triangulate
+         mountain process
          
-         // Extract the triangles into a single list
+         if(buildTriangles) {
-         j = 0
+	         // Extract the triangles into a single list
-         while(j < mountain.triangles.size) {
+	         j = 0
-    	   triangles += mountain.triangles(j)
+	         while(j < mountain.triangles.size) {
-           j += 1
+	    	   polygons += mountain.triangles(j)
+	           j += 1
+	         }
+         } else {
+        	 // Extract the convex polygons into a single list
+	         j = 0
+	         while(j < mountain.convexPolies.size) {
+	    	   polygons += mountain.convexPolies(j)
+	           j += 1
+	         }
          }
          
          xMonoPoly += mountain