[Bprocessor-commit] model/src/net/sourceforge/bprocessor/model CoordinateSystem.java, 1.65, 1.66

[Michael L. <he...@us...>]

Update of /cvsroot/bprocessor/model/src/net/sourceforge/bprocessor/model
In directory sc8-pr-cvs3.sourceforge.net:/tmp/cvs-serv2837/src/net/sourceforge/bprocessor/model

Modified Files:
	CoordinateSystem.java 
Log Message:
Implemented CoordinateSystem.systemFor(origin, normal) that returns an appropriate coordinate system

Index: CoordinateSystem.java
===================================================================
RCS file: /cvsroot/bprocessor/model/src/net/sourceforge/bprocessor/model/CoordinateSystem.java,v
retrieving revision 1.65
retrieving revision 1.66
diff -C2 -d -r1.65 -r1.66
*** CoordinateSystem.java	21 Nov 2007 13:51:01 -0000	1.65
--- CoordinateSystem.java	22 Nov 2007 10:26:00 -0000	1.66
***************
*** 144,147 ****
--- 144,185 ----
    
    /**
+    * CoordinateSystem for specified origin and z-axis (n), where the orientation
+    * is such that x-axis points right when looking down the negative z-axis.
+    * @param origin Vertex
+    * @param n z-axis
+    * @return coordinate system
+    */
+   public static CoordinateSystem systemFor(Vertex origin, Vertex n) {
+     int index = n.largestCoefficient();
+     Vertex i = null;
+     Vertex j = null;
+     if (index == Vertex.X) {
+       i = new Vertex(0, 1, 0);
+       Vertex z = new Vertex(1, 0, 0);
+       if (n.dot(z) < 0) {
+         i = i.scale(-1);
+       }
+     }
+     if (index == Vertex.Y) {
+       i = new Vertex(-1, 0, 0);
+       Vertex z = new Vertex(0, 1, 0);
+       if (n.dot(z) < 0) {
+         i = i.scale(-1);
+       }
+     }
+     if (index == Vertex.Z) {
+       i = new Vertex(1, 0, 0);
+     }
+ 
+     double t = n.dot(i);
+ 
+     i = i.minus(n.scale(t));
+     i.normalize();
+     j = n.cross(i);
+ 
+     return new CoordinateSystem(i, j, n, origin);
+   }
+ 
+   /**
     * Empty constructor for persistence only
     */