The IDLgrTessellator class is a helper class that converts a
simple concave polygon (or a simple polygon with holes) into a
number of simple convex polygons (general triangles). A polygon
is simple if it includes no duplicate vertices, if the edges
intersect only at vertices, and exactly two edges meet at any
vertex. Tessellation is useful because the IDLgrPolygon object
accepts only convex polygons. Using the IDLgrTessellator object,
you can convert a concave polygon into a group of convex
polygons. The IDLgrTessellator::Init method takes no arguments.
Use the following statement to create a tessellator object:
myTess = OBJ_NEW('IDLgrTessellator') See IDLgrTessellator for
details on creating tessellator objects. The procedure file
obj_tess.pro, located in the examples/visual subdirectory of the
IDL distribution, provides an example of the use of the
IDLgrTessellator object. To run the example, enter OBJ_TESS at
the IDL prompt. The procedure creates a concave polygon,
attempts to draw it, and then tessellates