Java library for geometric?

[chris]

Hi,

I need to do some 2D computional geometry, like testing a couple of
polygons for intersection. If I understood java.awt.Polygon etc., I
can't test a Polygon for intersection with another Polygon, I just can
check for intersection with a Rectangle.

Is there any free library out there supporting stuff like this? I'd also
need things like changing positions of objects and rotating them.

Thanks in advance,
Chris

 

[ak]

I need to do some 2D computional geometry, like testing a couple of

polygons for intersection. If I understood java.awt.Polygon etc., I
can't test a Polygon for intersection with another Polygon, I just can
check for intersection with a Rectangle.

may be you could test if one of your polygons contains points from another
polygon.

 

[Norman Barker]

Hi,

I need to do some 2D computional geometry, like testing a couple of
polygons for intersection. If I understood java.awt.Polygon etc., I
can't test a Polygon for intersection with another Polygon, I just can
check for intersection with a Rectangle.

Is there any free library out there supporting stuff like this? I'd also
need things like changing positions of objects and rotating them.

Thanks in advance,
Chris

You could try http://www.vividsolutions.com/jts/jtshome.htm,
it is open source and available under LGPL. I have used it
and like it

 

[Carl Howells]

may be you could test if one of your polygons contains points from another
polygon.

Doesn't work. Two polygons can intersect with neither containing
vertices in the other. Consider these two:

(0,5) -> (15, 5) -> (15,10) -> (0,10) -> (0,5)

and

(5,0) -> (10,0) -> (10, 15) -> (5,15) -> (5,0)

And while those are both rectangles to make the example simple, they
clearly don't have to be.