peteru@tekig5.PEN.TEK.COM (Peter Uchytil) (08/15/89)
Hi, I need an algorithm that will do vector clipping. Ideally it would work like this: give it the clipping window and the endpoints of the vector and it gives you the new endpoints back. There must be an algorithm of this type somewhere out there. Can someone point me in the right direction? Thanks! Pete peteru@icarus.pen.tek.com
lhf@aries5.uucp (Luiz H. deFigueiredo) (08/15/89)
In article <4670@tekig5.PEN.TEK.COM> peteru@tekig5.PEN.TEK.COM (Peter Uchytil) writes: >Hi, I need an algorithm that will do vector clipping. Ideally it would >work like this: give it the clipping window and the endpoints of the >vector and it gives you the new endpoints back. There must be an >algorithm of this type somewhere out there. Can someone point me in the >right direction? Thanks! How about one of the text books like Newman & Sproll, Foley & van Dan, Baker, Harrison, etc... They all explain the Choen-Sutherland algorithm for vector clipping. ------------------------------------------------------------------------------- Luiz Henrique de Figueiredo internet: lhf@aries5.waterloo.edu Computer Systems Group bitnet: lhf@watcsg University of Waterloo (possible domains are waterloo.edu and uwaterloo.ca) -------------------------------------------------------------------------------
jfh@brunix (John Forbes Hughes) (08/22/89)
In article <378@maytag.waterloo.edu> lhf@Self.UUCP (Luiz H. deFigueiredo) writes: >In article <4670@tekig5.PEN.TEK.COM> peteru@tekig5.PEN.TEK.COM (Peter Uchytil) writes: >>Hi, I need an algorithm that will do vector clipping. Ideally it would >>work like this: give it the clipping window and the endpoints of the >>vector and it gives you the new endpoints back. There must be an >>algorithm of this type somewhere out there. Can someone point me in the >>right direction? Thanks! > >How about one of the text books like > Newman & Sproll, Foley & van Dan, Baker, Harrison, etc... >They all explain the Choen-Sutherland algorithm for vector clipping. The new edition of Foley and van Dam (now 'Foley, van Dam, Feiner, and Hughes') contains not only Cohen-Sutherland, but also the Cyrus-Beck/Liang- Barsky algorithms, which are more efficient, in that the average number of intersections computed is smaller than that for C-S. We also describe the Nicholl-Lee-Nicholl algorithm, which is the most efficient, but involves a great deal of code, because of its case-by-case analysis. If you are truly fascinated by these, let me know and I can fax you the relevant pages of the text (or send you the words, but not the pictures, via e-mail). One interesting question: only C-S does 3D clipping. How hard is it to generalize NLN-clipping to 3D? -John Hughes, Mathematics and Computer Science Dept's., Brown University CSnet: jfh@cs.brown.edu@relay.cs.net ARPAnet: jfh@CS.BROWN.EDU BITNET: jfh@browncs UUCP: ...!{decvax,allegra}!brunix!jfh "I was in this prematurely air-conditioned supermarket and there were all these aisles..." -L. Childs