[mkgmap-dev] Line direction flag, merging etc

Mon May 17 18:37:31 BST 2021

Hi Gerd

The ambition was to be able to turn off hasDirection if [oneway=yes/-1]
(roads only) and/or --lines-types-with-direction would have it on.

As I'd never noticed the compass direction on oneway roads, I thought I
might as well turn it off. It also allowed me to test if this
combination causes other problems. When LineMergeFilter does reversals
it might be able to merge more.

This might help some of Felix's problems - has-direction can be turned
off for everything - towards the end of lines: 

<finalise>
...
oneway=* {set mkgmap:has-direction=no}

I presume r4719 was ignore-oneway-for-lines.patch and I took elements
from this, but redid the oneway/road handling slightly so it was all in
the same place.

I've updated the patch to include the unit test change.

Ticker

On Mon, 2021-05-17 at 15:38 +0000, Gerd Petermann wrote:
> Hi Ticker,
> 
> not sure what you want to achive?
> I agree that the evaluation of the --line-types-with-direction option
> should not depend on the --allow-reverse-merge option.
> 
> Seems like an alternative to the solution in r4719 : 
> https://www.mkgmap.org.uk/websvn/revision.php?repname=mkgmap&rev=4719
> but without the correction for the unit test.
> Reg. overlays:
> Yes, first element just gets a different type, the others are forced
> to be MapLine. First element might also be a non-routable line.
> The OpenFietsmap Styles use them, see 
> https://github.com/ligfietser/mkgmap-style-sheets
> 
> Do you see a need for the possibility to have oneway roads which
> don't have the direction flag set?
> In trunk it will not matter reg. merging, in the branch it might
> allow more merging in the overview map.
> 
> Gerd
> 
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> Gesendet: Montag, 17. Mai 2021 17:06
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] Line direction flag, merging etc
> 
> Hi Gerd
> 
> I've rearranged the direction flag setting logic a bit, taking bits
> from ignore-oneway-for-line.patch
> 
> It ignores oneway except for roads and allows direction to be set
> false
> even for routable oneways. I've tested routing when oneway=true,
> hasDirection=false on eTrex HCx and gpsMapEdit and it respected the
> oneway.
> 
> I couldn't find any references to the {style}/overlays file in any
> documentation, but my reading of the code is that first substitution
> element will get the full MapRoad info, including the hasDirection
> flag
> and the MapLine copies will get also get the hasDirection flag.
> 
> Ticker
> 
> On Mon, 2021-05-17 at 11:29 +0100, Ticker Berkin wrote:
> > Hi Gerd and others
> > 
> > I'm starting a dedicated thread as previous posts are split between
> > various svn commits.
> > 
> > Looking at the current trunk code and ignore-oneway-for
> > -lines.patch,
> > there are bits I don't understand or didn't expect.
> > 
> > This is what I hope for:
> > 
> > --line-types-with-direction lists the lineTypes for which the
> > initial
> > state of the hasDirection flag is considered true. It should be
> > independent of --allow-reverse-merge (see later). The purpose of
> > this
> > is to reduce the need to edit styles and clarity as to which
> > lineTypes
> > are displayed with direction.
> > 
> > In the following, road means line with [road_class, road_speed], so
> > includes ferries.
> > 
> > Style processing, having produced a line/road, sets hasDirection,
> > in
> > order of precedence:
> > 1/ value of mkgmap:has-direction if tag exists
> > 2/ true if oneway road
> > 3/ true if in line-types-with-direction list
> > 
> > RoadMerger merges roads with same lineType, names, class, speed,
> > oneway
> > and hasDirection. It must not reverse oneway or hasDirection=true
> > roads
> > when doing this.
> > 
> > I don't think we need --allow-reverse-merge.
> > 
> > LineMergeFilter operates for level > 0. It merges any line/road
> > with
> > the same lineType, names, hasDirection. It must not reverse
> > hasDirection=true.
> > 
> > Ticker
> > 
> > _______________________________________________
> > mkgmap-dev mailing list
> > mkgmap-dev at lists.mkgmap.org.uk
> > https://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
> _______________________________________________
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