Hi. I'm trying to implement polygon intersection using SAT (Separating Axis Algorithm). There is plenty of nice material on the internet, but there is one particular part of the algorithm that I couldn't understand.
Here are three of the articles I've been reading, just If you wanna take a glance to be sure what I'm talking about:
The part I don't understand, is the projection part. You have a normal vector pointing outwards, perpendicular to each edge, and based on that normal, you have to project the shadow of the polygon. But when I read these articles, this shadow seems to be represented by only two values, a min and a max value. This is the part I don't understand.
To clarify. This is an Image of a projection from the third article:
This magenta line is the line I understand is the projection, or the shadow. But how can It be represented by two values? the min an the max? This is a line, and a line as far as I know can only be represented by two points, that is, four values: x1, y1, x2, y2.
So my question is, how is this projection represented by two values and not two points?
Edited by L i n c k, 29 April 2014 - 01:17 PM.