[mkgmap-dev] Configurable flood blocker

Sun Dec 5 14:48:38 GMT 2010

I committed r1746 to the coast branch.
The floodblocker rules which OSM elements are used to detect land and as 
sea areas can now be configured in the special style 
resources/styles/floodblocker.
If this style marks a ways as garmin type 0x01 the way is on land 
whereas 0x02 is used for sea. Now you can configure your own rules which 
tag combinations should be used for the flood blocking algorithm.

Have fun!
WanMil

> I have committed an improved version of the flood blocker to the coast
> branch.
>
> It is configurable in some parts (please refer to the help file to the
> exact config options).
>
> What are the improvements now ?
> 1. I observed that in many good sea polygons there are some highways
> which are located very close to the edge of the polygon (e.g. a street
> that ends in the sea). It is now possible to set a gap to ignore these
> points during the flood blocking algorithm. (Parameter fbgap=NUM (meter))
>
> 2. Now I count the number of land points and sea points in the sea
> polygon. Given n(bad) = (n(land)-n(sea)) the flood blocker ignores all
> sea polygons where
> n(bad)<  fbthres  (Parameter fbthres=NUM)
>
> 3. At least the number of n(bad)/size of polygon gives a ratio. The
> polygon is removed if the ratio is higher than fbratio. (Default
> fbratio=0.5)
>
>
> Current rules which coords are used for flood blocking evaluation:
> Land:
> highway=* or
> and
> not highway=construction
> not layer!=0
> not man_made=pier
> not man_made=dam
> not bridge=yes/true/1
> not tunnel=yes/true/1
>
> Sea:
> route=ferry or
> boundary=administrative and maritime=yes
>
>
> Next I want to add a configuration file for the flood blocking rules.
>
> Please try the current version and play a little bit with the options
> and tell me what you think and if it fits your needs.
>
> WanMil
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