[mkgmap-dev] Multiple pass cleanup possible with style?

Sat Jul 23 00:48:57 BST 2022

I'm not sure the issue is clear.

The problem is I delete objects that once was fully connected (both ends 
are connected but meets other criteria for deletion) but after deleting 
that object, the remaining objects now have a different status - and these 
now need to be cleaned up based by my rules ... which as I understand 
would require a second pass through the style (which is problematic of 
course, but that's another issue).  This is because a way that used to be 
fully connected is could now only connected on one end, and some ways that 
were only connected on one end is now connected on neither end.

The OSM-ways I want to delete may not have met the requirements on the 
first pass, but now do after the initial pruning.

If this is simply not possible, that's all I need to know.  Sounds like 
this is the case.

On Fri, 22 Jul 2022, Gerd Petermann wrote:

> Date: Fri, 22 Jul 2022 19:24:48 +0000
> From: Gerd Petermann <gpetermann_muenchen at hotmail.com>
> Reply-To: Development list for mkgmap <mkgmap-dev at lists.mkgmap.org.uk>
> To: Development list for mkgmap <mkgmap-dev at lists.mkgmap.org.uk>
> Subject: Re: [mkgmap-dev] Multiple pass cleanup possible with style?
> 
> I am pretty sure that you don't understand the meaning of the special tags.
> Your style tells mkgmap which ways are roads. So, only after passing all
> OSM ways through your style mkgmap can calculate the road network and
> only at this time it is possible to detect unconnected or "semi-connected" roads
> and use the value of the special tags to decide what to do with special cases.
>
> My understanding of your text is that you expect the special tags to contain an
> information like "this OSM way is connected to the road network" but that's not the
> case. The program mkgmap reads the variables, it doesn't set them.
>
> Gerd
>
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag von blc <blc+mkgmap at mail.vanade.com>
> Gesendet: Freitag, 22. Juli 2022 21:00
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] Multiple pass cleanup possible with style?
>
> I've used the mkgmap:set_unconnected_type and
> mkgmap:set_semi_connected_type to delete already one- and no-connnect ways
> in the OSM data, and that has been helpful, but sometimes I delete ways
> that are connected both ends, with the implication that something now
> that used to be connected on both ends is connected only on one end now,
> and something else that was connected on one end may now be not connected
> on either end.
>
> I think a specific use case is that I find a 2-connect low priority way
> (like service=driveway) that passes through a private building or is very
> short.  Ideally I would like to simply delete all of them but this is
> just a heuristic to reduce file sizes.  Anyway, I delete that way, but
> that way continues on connected to something else, but now that way is
> newly 1- or 0-connect, and I want that removed too.  Of course there are
> two halves left when removing a 2-connect way, but it should be easy
> enough to determine the lower class way (another driveway) is the one that
> should also be trimmed.
>
> (One exact issue is that someone has a loop driveway with both ends
> connected to a residential road, and the loop driveway has an offshoot.
> Removing the driveway would leave the offshoot dangling -- originally one
> connect, now zero connect due to deletion of the loop -- and that I would
> also like to remove.)
>
> Is something like this possible?