[mkgmap-dev] reduce_peak_mem_v1.patch

Sat Jan 12 16:01:56 GMT 2013

> Hi WanMil,
>
>  > > Are you still working on the mp_cut branch or do you wait for something
>  > > from me?
>  > > I assume that the precomp-sea handling will change when the mp cut algo
>  > > changes?
>  >
>  > Yes. I have found some problems around tagging in mps that need to be
>  > fixed for the mp_cut branch but I am working on it. I am not waiting for
>  > you. Feel free to create you own CutAlgorithm (the interface probably
>  > will change a bit but that will be no big problem).
>  >
>
>
> OK, I am sure this is a complex change.
> Up to now I have no real new algorithm because I am not sure if
> the new algo should just try to avoid thin areas or if it
> should try to avoid small areas at all.
>
> Another point:
> I think you wrote that garmin format doesn't support holes in areas, but
> I can't imagine what
> problem one gets when we just overlay one polygon with
> one or more other polygons.

One little thing is obvious: When selecting a point on the land area 
Garmin shows you all stuff at this point and that's:
Land
Sea

Another thing is that the order of how data is drawn cannot be defined 
(as far as I know...). So if you have overlapping polygons it's a kind 
of luck which polygon is on top of the other.

> I think this is by far the better solution compared to the complex algo in
> cutOutInnerPolygons().
> I wanted to try it with --generate-sea=polygons, but I am not experienced
> regarding styles and TYP files.
> My problem: I did not find out what changes are needed in the style and
> what TYP file one needs to try it.
> It would be great if the wiki could show all needed steps.

I think the only thing you have to do is to add a rule for natural=sea 
and natural=land in your polygons file.

WanMil

>
> Ciao,
> Gerd
>