Math question: How to compute the area of polygons

[Geoff Canyon]

If you're looking for collision detection, I think it would be faster 
to check the line segments of polygon A against the line segments of 
polygon B to see if any of them intersect. If they do, there's a 
collision. There may be a faster way than that, but I think at least 
that it would be faster than computing the areas.

But before you even do that, you should come up with a rough, simple 
calculation that will tell you there is no collision, or that you need 
to do the more exact test. So for example, if polygon A has no point 
more than 30 pixels away from its loc, and polygon B has no point more 
than 25 pixels away from its loc, then your first calculation would be 
the distance between the loc of A and the loc of B; if it's more than 
55 pixels, there is no intersection. If it's less, then you do the more 
exact calculation.

On Wednesday, March 19, 2003, at 02:04 AM, Malte Brill wrote:

> -Smaller than both areas summed -> Objects collided.
>
> If I had a neat algorithm for that job, I think it could be quite fast.
>

regards,

Geoff Canyon
gcanyon at inspiredlogic.com