Nielsen, Hans Peter2014-10-212014-10-2119951467-8659https://doi.org/10.1111/1467-8659.1410003The dual intersection test is described. It is a new method for deciding whether a line intersects a window. The concept of semi-homogeneous coordinates is introduced. It allows us to define line segments in projective space, and to derive a generalized Cohen-Sutherland end-point test for such segments. When this is combined with the dual intersection test, we obtain new clipping algorithms for 2D and 3D projective space.10.1111/1467-8659.14100033-16