Making a new filled symbol of > 4 vertices

For a java package to extend the IDV I wish to make a subclass of MetSymbol that draws a symbol in the z=0 plane that is filled and has more than 4 vertices. The existing IDV code shows how to make symbols of (unfilled) lines using VisADLineArray, and filled symbols of of 3 and 4 vertices that using VisADTriangleArray and VisADQuadArray, and specifing the normals to each edge. See for example ucar.visad.ShapeUtility.java. How are filled symbols of N>4 vertices coded?

Stuart Wier