[mkgmap-dev] Filters for overview map

Tue Jun 16 22:33:38 BST 2009

Hi,

On Tue, Jun 16, 2009 at 10:49:45PM +0200, Thilo Hannemann wrote:
> Hi,
> 
> Am 16.06.2009 um 20:39 schrieb Elrond:
> 
> >My current conclusions from both thread parts:
> >
> >1) I should only disable the SizeFilter (we really, really
> >  don't want to drop any polygon).
> 
> For the overview map obviously not.
> 
> >2) We should fix DP.
> 
> From what you explained about the overview map (I was always  
> wondering what it is for...) also DP for the overview map makes no  
> sense.

I read that as "You can commit this". I'll wait for a
little for possible other input. :)

> What would make sense though would be to split the tiles in a  
> way that the polygons in the overview map need no rounding. Or is that  
> already the case?

Hmmm, maybe my naming was bad.

With "tile" I meant a region as defined by the boundaries
in the foo.osm you're using to create one map. So the
boundaries are really set by the user.

And getting those boundaries close to the
overviewmap-alignment is not easy (for the user). The
alignment edges change with the center of the "world" (the
overview map).

So in short: I don't see a simple way for doing it.

Splitting at the map level would require mkgmap to
auto-select new (eight digit) map names for the newly
created maps.
And this splitting can only happen, when/if the "world" is
known, so quite too late. We'd need two-pass handling or
so.

> And yes, we should fix DP (if it is actually broken).

I only noticed it for the overview map. So I can't really
tell, if it is broken or not. I just have speculated on its
cause in the other thread part.

> Regards
> Thilo

    Elrond