[mkgmap-dev] Configurable flood blocker

Wed Dec 8 20:15:49 GMT 2010


On 08.12.2010 20:50, WanMil wrote:
>>
>> On 05.12.2010 15:48, WanMil wrote:
>>> 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 used it without problems, however currently all geofabrik
>> extracts I had used (even Australia/Oceania or Lower Saxony) worked on
>> the old version without problems too, while often these extracts caused
>> severe flooding (haven't got any broken extracts saved however)...
>> Also not really sure if my command line makes sense:
>> /generate-sea=--generate-sea=extend-sea-sectors,close-gaps=6000,floodblocker,fbgap=50,fbthres=500,fbratio=5/ 
>>
>>
>> (until now I have been using:
>> /generate-sea=--generate-sea=polygons,extend-sea-sectors,close-gaps=6000/ 
>> )
>>
>> I think it is safe to commit the coast branch to trunk (and maybe
>> include some defaults in the help file, especially I have no clue about
>> a sensible fbration value), I could not note any problems.....
>>
>
> Felix,
>
> thanks for testing!
>
> Yesterday I have committed that the multipolygon sea generation also 
> creates land polygons. This should fix a shortcoming which prevented 
> some users from using the mulitpolygon sea generation.
>
okay great, I prefer multipolygon mode (makes maps without land/sea 
overlap if --transparent is used).

> What I am interested in at the moment:
> Does the external coastline file loading fit your needs? I am a bit 
> concerned about memory requirements and would like to decrease its 
> memory footprint.
I have not tried that out yet - I usually only compile single geofabrik 
country extracts (and Africa, South-America and Australia-Oceania 
Extracts). For external coastlines to be useful, I'ld need them handy to 
mix with the geofabrik extracts...
Suppose if coastlines for the extracts were available, that would be the 
best thing... -- Where can one get coastline extracts - anyone providing 
them?
>
>
> The following things should be done before merging back the branch to 
> trunk:
> * Improve multipolygon processing performance for sea polygons. The mp 
> algorithm can count on the "outer" and "inner" tags so the matrix 
> which polygon is contained by which polygon should be less complex to 
> create
> * @Steve: Can you check if my changes to the ElementSaver class and my 
> coastfile loading mechanism feels good for you? Maybe you want to 
> simplify some things?
> * Decrease memory footprint of the coastline file loading. (Maybe this 
> could also be done after merging back).
>
>
> Have fun!
> WanMil