* Create and fill a 2D array with 0s

* Check if a coordinate is inside a polygon * @see http://www.ecse.rpi.edu/Homepages/wrf/Research/Short_Notes/pnpoly.html

* Mark dPieces with in transparent areas with the transparency id

* Trace the outer edge of the transparency region to build a polygon around it

* Flood fill values in visited array so we know which tiles are included in the polygon