哈希，相对于x，y位置的多边形形状

Question

I am trying to build a polygonal shape tool and have it calculate against its area to find if a point exists inside or out side the area.

These examples work well you you want to calculate on every object every time, but I am looking for a way to "HASH" the shape/area of a polygon relative to a spacial location, then The math becomes a simple "HASH" check to find if a value exists inside or outside of the defined "HASH".

I have found some decent basic examples:
http://jsfromhell.com/math/is-point-in-poly ,
http://en.wikipedia.org/wiki/Point_in_polygon (Ray casting algorithm)

Answer 1

http://en.wikipedia.org/wiki/Geometric_hashing

I think this explains everything nicely.

Given that it can really only be used to determine if two objects are similar (given that the difference is a simple set of transformations), it can be shown that actual spatial information is lost.

Therefore the answer to your question is no.

To my knowledge you can't use a geometrical hash to determine if a point is in a shape.