[mkgmap-dev] add-pois-to-areas

Sun Mar 23 09:55:34 GMT 2014

On Sun, Mar 23, 2014 at 12:18:16PM +1100, Brett Russell wrote:
>So looks like somewhere on the line the logic in mkgmap was strengthen 
>to pick up what would be a logic error by having POI in polygons.  Or 
>at least that is my feelings.

Many features can be tagged points (nodes) as well as areas (polygons).

The mkgmap option --add-pois-to-areas will introduce POIs for polygons 
at the center of the polygon (or outside, if the polygon contains both 
concave and convex parts). IIRC, this will create a POI if there is a 
covering rule both in the "polygons" and "points" files.  Examples 
include amenity=supermarket and amenity=parking.

On a related note, IMO we should try to not create POIs for areas for 
which a similar POI already exists. For example, a parking facility or a 
building could be tagged both as a point at the entrance, and as an 
area.

How to detect the duplicate POIs? Maybe, flag the auto-generated 
pois-to-areas nodes in some way, and remove the the auto-generated node 
if the same "points" rule(s) would match a boundary node of the polygon.

	Marko