Geometry Boost List: [ggl] Touching polygons and floating-point

Subject: [ggl] Touching polygons and floating-point
From: Barend Gehrels (barend)
Date: 2011-02-11 05:00:14

Hi Denis,

Op 11-2-2011 4:58, Denis Pesotsky schreef:
> Look at attached picture. There are 2 polygons. Side of first polygon
> lies on side of second. What GGL will do if I unite them? Will it
> produce 1 polygon or 2 polygons?

It will produce 1 polygon.

> In other words, does it support fuzzy detection polygons with touching
> side. When touch side is not vertical or horizontal and they don't
> have same corners (e.g. they only touch by sides).
Yes, it unites polygons with touching sides. Horizontal or vertical does 
not matter here, and neither does having the same corners. Actually I 
don't call this "fuzzy detection", I mean, they must really touch. If 
they are just close, the two polygons will stay separate.

Regards, Barend