On Fri, 25 Jul 2003, Tan Ka Ju wrote: > Thanks Bill for your reply. > > However, I currently only using Java-2D to generate graph (2D, planning > to make into 3D after getting 2D done). I was trying to look for the > algorithm, on how to detect a LINE if it is in a POLYGON, where the > LINE's end and start points are given, and the POLYGON Area is obtained. > The polygon is a tilted rectangle or a tilted pentagon. The angle of the > tilted polygon is the same as the line. > > I know this is really unrelated to VisAD. But I do hope if anyone of you > did come across any articles or resources on this matter please kindly > point me to it or guide me. > > Thank you. > Kj > > Ps: Bill, even with the methods you mentioned, it can only detects a > point. If this is the case, that means I need to run trough a loop for > every point in the line in order for me to know if any part of the line > is in a specified polygon. The problem is that I might need to check for > hundreds or even thousands of lines (performance issue). Hence, I was > looking for if there is any geometric or algorithm that can really save > all of this looping, you know, by using some formula. Thanks. Follow Mathias's advice, possibly using the JTS package that Ugo recommended.