question: public void computeDepthParity ( ) { while ( true ) { PolygonizeDirectedEdge de = null ; if ( de == null ) return ; computeDepthParity ( de ) ; } }
target:  Traverses the polygonized edge rings in the graph and computes the depth parity (odd or even) relative to the exterior of the graph. If the client has requested that the output be polygonally valid, only odd polygons will be constructed. 