distancePointLine

Determine the signed distance of the given point <code>(pointX, pointY)</code> to the line specified via its general plane equation <i>a*x + b*y + c = 0</i>. <p> Reference: <a href="http://mathworld.wolfram.com/Point-LineDistance2-Dimensional.html">http://mathworld.wolfram.com</a>

@param pointX the x coordinate of the point @param pointY the y coordinate of the point @param a the x factor in the plane equation @param b the y factor in the plane equation @param c the constant in the plane equation @return the distance between the point and the line