Map charting and drawing interfaces

[xcompwiz]

I would like to know more and do more with map charting. Specifically I'd like to be able to know when a force is actively charting a sector of the world and be able to draw things to the chart either at that time or later.

Suggested features:
An event (ex. on_surface_charted) which informs that a force is about to, currently, or just finished charting a chunk (could be multiple events depending on computation costs, complexity, and options). Vars would be the force, the surface, and the area charted (representation completely up to implementation).

A method to allow "drawing" to the chart, probably per tile though region draw would probably be reasonable to implement.

A method to allow setting custom chart elements to be drawn like the player or vehicle elements are. Could be handled similar to how GUI elements are done (from what I understand of Factorio mod GUI handling).

If there are any questions I would be happy to elaborate. Specific usage info can also be found from the below references.

Thanks, and Cheers!
-XComp

References:
Sharing Vision between Forces (On Charted Event?)
Alternate Map Force (Faction) Colors / Map Drawing