pointIsInside static method
Returns true iff the point is inside the rectangle given by the Quad, inclusively. Algorithm from https://math.stackexchange.com/a/190373.
Implementation
@visibleForTesting
static bool pointIsInside(Vector3 point, Quad quad) {
final Vector3 aM = point - quad.point0;
final Vector3 aB = quad.point1 - quad.point0;
final Vector3 aD = quad.point3 - quad.point0;
final double aMAB = aM.dot(aB);
final double aBAB = aB.dot(aB);
final double aMAD = aM.dot(aD);
final double aDAD = aD.dot(aD);
return 0 <= aMAB && aMAB <= aBAB && 0 <= aMAD && aMAD <= aDAD;
}