How can I determine whether a 2D Point is within a Polygon?

Question

I\'m trying to create a fast 2D point inside polygon algorithm, for use in hit-testing (e.g. Polygon.contains(p:Point)). Suggestions for effective tech

Answer 1

To deal with the following special cases in Ray casting algorithm:

1. The ray overlaps one of the polygon's side.
2. The point is inside of the polygon and the ray passes through a vertex of the polygon.
3. The point is outside of the polygon and the ray just touches one of the polygon's angle.

Check Determining Whether A Point Is Inside A Complex Polygon. The article provides an easy way to resolve them so there will be no special treatment required for the above cases.