Surface covering Google Maps

Question

This is the setting:

I have a car moving inside a specific area on google maps. This area is determined by a Polygon. The car is tracked via GPS and you can see it on the map moving.

I want to know which parts of that polygon area the car covered on its route before leaving the polygon, and show the covered in green color and the uncovered in red color (these will be polygons also, right?).

I don't asking for any code at all, only the idea of how an algorithm would work for that purposes.

If someone can throw me some pointers, I'll apreciate it.

Answer 1

Your better off coloring the polygon Red initially and overlaying a green polygon based on historical locations. The algorithm would end up creating a list of all max/min lats with unique lons, and all min/max lons with unique lats. Let me know if this isn't enough information for you and I can elaborate further.