How to know if a line intersects a rectangle

Question

I have checked out this question, but the answer is very large for me:

How to know if a line intersects a plane in C#? - Basic 2D geometry

Is there any .NET

Answer 1

Unfortunately the wrong answer has been voted up. It is much to expensive to compute the actual intersection points, you only need comparisons. The keyword to look for is "Line Clipping" (http://en.wikipedia.org/wiki/Line_clipping). Wikipedia recommends the Cohen-Sutherland algorithm (http://en.wikipedia.org/wiki/Cohen%E2%80%93Sutherland) when you want fast rejects, which is probably the most common scenario. There is a C++-implementation on the wikipedia page. If you are not interested in actually clipping the line, you can skip most of it. The answer of @Johann looks very similar to that algorithm, but I didn't look at it in detail.