Currently I am working on a Javascript program that plots a Voronoi diagram and am trying to find all of the points that form the points that form the region around a point. To make this clearer, here is an example of a potential scenario:
Point D affects the region around point A if the mid-segment of these points intersects rays cast from the intersection of the mid-segments of points B and C. To break this down, here's what I'm saying in relation to the previous diagram:
Using rough approximations of the mid-segments, D does not intersect the Voronoi boundaries of point A. Using A as the current point, B and C as points known to affect the region, and D as the point checked for it's effect on the region; and knowing the angles and distances of B, C, and D relative to the first point, how can I find if D has an effect on the region?

