Hmm... Firebrand, I see that you totaly misunderstood me.
Well, perhaps I wasn't that clear.
I want to check whether Actor is crossing a polygon. Polygon - is a ...er... polygon
- a plane figure of some shape. In my case it is:
b) does NOT belong to level at all; it is described by some some variables of Trigger thing.
How can I check whether Actor crosses it? I need to have Actor's previous position and current position (after movement). Then, I'll have two points. Thus I can build a line (segment - is right math term) based on these points. If this segment crosses a polygon - then it means that Actor passed thru it.
Then, ofcourse, if I am going to represent Actor as a line, as Janis suggested, I'll need not line, but a plane, based on two lines, 1st is between previous and current Origin points, and another one is from prev. to current (Origin + Height) points, plus some extra calculations, but that is another story, so do not mind.
Well, if it will be too difficult to make it this way, I will limit myself with only 2 possible cases - a vertical and horizontal rectangulars. But in ideal case it should be of any rotation and any shape (still 4-sided).
EDIT: 15 jul 2006
Possibly I have found what I need. If this will fit my needs, I'll post it here so those who now Geometry better check whether it is right.