Added handling for offcurve triangle overlaps.

subdivde overlaping triangles for the case of vertex inside
a off-curve boundary triangle.

added vertex in triangle test (using barycentric coordinates)

1 files changed, 30 insertions, 0 deletions

diff --git a/src/jogl/classes/com/jogamp/graph/math/VectorUtil.java b/src/jogl/classes/com/jogamp/graph/math/VectorUtil.java
index b91969745..2b4a7fd9d 100755
--- a/src/jogl/classes/com/jogamp/graph/math/VectorUtil.java
+++ b/src/jogl/classes/com/jogamp/graph/math/VectorUtil.java
@@ -287,6 +287,36 @@ public class VectorUtil {
     public static float triArea(Vertex a, Vertex b, Vertex c){

         return (b.getX() - a.getX()) * (c.getY() - a.getY()) - (b.getY() - a.getY())*(c.getX() - a.getX());

     }

+    

+    /** Check if a vertex is in triangle using 

+     * barycentric coordinates computation. 

+     * @param a first triangle vertex

+     * @param b second triangle vertex

+     * @param c third triangle vertex

+     * @param p the vertex in question

+     * @return true if p is in triangle (a, b, c), false otherwise.

+     */

+    public static boolean vertexInTriangle(float[] a, float[]  b, float[]  c, float[]  p){

+    	// Compute vectors        

+    	float[] ac = computeVector(a, c); //v0

+    	float[] ab = computeVector(a, b); //v1

+    	float[] ap = computeVector(a, p); //v2

+

+    	// Compute dot products

+    	float dot00 = dot(ac, ac);

+    	float dot01 = dot(ac, ab);

+    	float dot02 = dot(ac, ap);

+    	float dot11 = dot(ab, ab);

+    	float dot12 = dot(ab, ap);

+

+    	// Compute barycentric coordinates

+    	float invDenom = 1 / (dot00 * dot11 - dot01 * dot01);

+    	float u = (dot11 * dot02 - dot01 * dot12) * invDenom;

+    	float v = (dot00 * dot12 - dot01 * dot02) * invDenom;

+

+    	// Check if point is in triangle

+    	return (u > 0) && (v > 0) && (u + v < 1);

+    }

 

     /** Check if points are in ccw order

      * @param a first vertex