Check if polygon is inside a polygon
Yesterday I was looking to check if a point was inside a polygon and found this great script: https://github.com/tparkin/Google-Maps-Point-in-Polygon
But today at work I was told that our client needs to check if one polygon is inside another polygon. I am wondering if is there a formula where I can take, let's say, two coordinates (instead of one to check a point), and from those two coordinates generate a rectangle and check if that rectangle is inside a polygon.
I don't know if I'm asking a stupid question (a teacher in highschool used to say "there are no stupid questions, there is only fools who don't ask"), but if you don't understand me totally but just a bit, I'd be grateful if you just tell me where to start.
Answer
Perform line intersection tests for each pair of lines, one from each polygon. If no pairs of lines intersect and one of the line end-points of polygon A is inside polygon B, then A is entirely inside B.
The above works for any type of polygon. If the polygons are convex, you can skip the line intersection tests and just test that all line end-points of A are inside B.
If really necessary, you can speed up the line intersection tests using the sweep line algorithm.