How to find a random point in a quadrangle?

Question

I have to be able to set a random location for a waypoint for a flight sim. The maths challenge is straightforward:

\"To find a single random location within a quadrangl

Answer 1

The "brute force" approach is simply to loop through until you have a valid coordinate. In pseudocode:

left   = min(pa.x, pb.x, pc.x, pd.x)
right  = max(pa.x, pb.x, pc.x, pd.x)
bottom = min(pa.y, pb.y, pc.y, pd.y)
top    = max(pa.y, pb.y, pc.y, pd.y)
do {
    x = left   + fmod(rand, right-left)
    y = bottom + fmod(rand, top-bottom)
} while (!isin(x, y, pa, pb, pc, pd));

You can use a stock function pulled from the net for "isin". I realize that this isn't the fastest-executing thing in the world, but I think it'll work.