3D and 2D homogeneous space line clipping using cohen sudherland algorithm

line clipping using cohen sudherland algorithm

In graphics pipeline, clipping is performed after multiplication of points with perspective matrix. This is known as clip space. The input to algorithm is endpoints of line in homogeneous co-ordinates (x, y, z, w) in clip space. The outputs is clipped line (modified endpoints of line) if line is clipped. If line is removed, is_removed is set to 1. There are three cases:
1. line is unmodified (when it is inside view frustrum) (is_clipped = 0, is_removed =0)
2. line is clipped by one or more planes of view frustrum (is_clipped = 1, is_removed = 0)
3. line is outside the view frustrum (is_removed = 1)