My postscript interpreter currently implements the Hodgeman-Sutherland clipping algorithm but this is limited to simpler shapes and doesn't have a provision for utilizing various winding-number rules. So it doesn't help me to implement even-odd filling or handle complex self-intersecting shapes.
The Weiler-Atherton algorithm promises to offer all these features, but every time I sit down with it, I get hung up on implementing the basic constructs. Specifically it requires making bi-directional associations between nodes which can then be traversed in either direction. But, how do you do that?
If I implement my path lists in Postscript (or any dynamic object-based language) as an array of points, the points themselves implemented as an array of coordinates, do I make a list of index pairs and do a linear search for traversing? Or can I use an associative array to make a mapping, and is it sufficient to add both (node1->node2) and (node2->node1)?
Or what if the paths are in a linked-list in a C like language with pointers to the next vertex and a NULL pointer designating the end, do you just add more links (pointers) to the nodes?
You don't need to address all my questions here, it should be sufficient to describe the strategy for building this data structure for any 1 language (not necessarily Postscript or C), and I should be able to apply it to my specific case which is usually to prototype in Postscript and translate to C if necessary for speed.
