[mkgmap-dev] type/subtype of points and cities

Tue Oct 22 15:29:37 BST 2019

Hi Gerd

The old reader/osm/Gtype:checkType() didn't diagnose cities (however
they might be defined) with non-zero subtypes - this is where the new
message comes from.

Old general/MapPoint:isCity[Type] defined city as:

        return type >= 0x0100 && type <= 0x1100

ie 0x1100 is city, 0x1101 isn't, which I thought wasn't a good
definition, so I changed it to:

	return type >= 0x0100 && type < 0x1200;

I chose all of 0x11XX to be considered cities so that 0x1100 processing
as a city didn't change (this and 0x1000 were put into RGN indPoints,
but were not indexed as cities by MDR)

Changing it to < 0x1100 would be reasonable, because the device range
seems to be < 0x0e00 and MDR5 city indexing was for points < 0x1000

Ticker

On Tue, 2019-10-22 at 12:32 +0000, Gerd Petermann wrote:
> Hi Ticker,
> 
> I see some new warnings for Minkos popular Openfietsmap styles with
> this patch:
> checking style: Openfietsmap full
> Warning: invalid type 0x1101 for POINT in style file points, line 97
> Warning: invalid type 0x1102 for POINT in style file points, line 263
> Warning: invalid type 0x1102 for POINT in style file points, line 264
> Warning: invalid type 0x1108 for POINT in style file points, line 336
> Warning: invalid type 0x1108 for POINT in style file points, line 348
> Warning: invalid type 0x1108 for POINT in style file points, line 349
> Warning: invalid type 0x1108 for POINT in style file points, line 350
> 
> The corresponding lines in the points file
> amenity=bus_station [0x1101 resolution 24 continue]
> railway=halt [0x1102 resolution 22]
> railway=station [0x1102 resolution 20-23 continue]
> (barrier=bollard | barrier=bus_trap | barrier=block) [0x1108
> resolution 23]
> access:conditional=* & access:conditional ~
> '!(sunset|sunrise|destination)' & bicycle!=no & bicycle!=permissive &
> vehicle!=no { name 'access=${access:conditional}' } [0x1108
> resolution 24]
> bicycle:conditional=* & bicycle:conditional ~
> '!(sunset|sunrise|destination)' { name
> 'bicycle=${bicycle:conditional}' } [0x1108 resolution 24]
> vehicle:conditional=* & vehicle:conditional ~
> '!(sunset|sunrise|destination)' { name
> 'vehicle=${vehicle:conditional}' } [0x1108 resolution 24]
> 
> Can you explain what happened with those POI without the patch?
> 
> Gerd
> 
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> Gesendet: Dienstag, 22. Oktober 2019 13:07
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] type/subtype of points and cities
> 
> Hi Gerd
> 
> Here is the patch based on the current trunk
> 
> Ticker
> On Tue, 2019-04-23 at 11:51 +0100, Ticker Berkin wrote:
> > Hi
> > 
> > I think the mkgmap internal handling of types/subtypes of points is
> > obscure.
> > 
> > In the points style file, the type code is always full, ie type <<
> > 8
> > > 
> > subtype, but when the points are read back from the RGN file for
> > the
> > MDR processing, the representation is the same provided the subtype
> > is
> > not zero, otherwise it is just type! Logic then decides that if the
> > value is <= 0xff it is because the subtype is zero.
> > 
> > It is simpler and much clearer to preserve the original
> > representation.
> > This also allows unambiguous use of type 0 with subtypes, and,
> > possibly, city with subtypes.
> > 
> > It also allows the same function to be used to test a type for
> > being
> > in
> > the 'city' range, regardless of the context. mkgmap wasn't
> > consistent
> > the ranges for the isCity test.
> > 
> > City POI are written in a different manner to the RGN file. The old
> > range for this was:
> >   type >= 0x0100 && type <= 0x1100
> > which I've kept, except changing to: ...& type < 0x1200. A similar
> > range was used for MDR5.
> > 
> > However, city POI are held in group 1 of MDR 9/10. This is used in
> > Find
> > > City 'By Name'. The old range was: type <= 0xf, where, if the
> > > subtype
> > was zero, type is right shifted by 8 (see above), non-zero subtypes
> > messed up the testing. Now it uses the same range as above.
> > 
> > Actually neither of these ranges are correct for my Garmin devices.
> > Find > City show nearby POI with types in the range 0x0100..0x0d1f,
> > regardless of the img RGN or MDR. The eTrex Legend labels POIs in
> > this
> > range as {Large/Medium/Small} City/Town and points in the range
> > 0x0e00..0x111f as "*".
> > 
> > Find > City 'by-name' returns POI if in group 1 of MDR 9/10. I find
> > it
> > a useful feature to have a POI that can be searched for but doesn't
> > flood the list of nearby points.
> > 
> > Generally, non-zero subtypes for cities cause problems in the RGN
> > structure and I've added a test for this to the style validation.
> > 
> > There is also a fix to --make-poi-index, but I can't detect any
> > effect
> > of this option.
> > 
> > This patch won't make any difference to the img output unless the
> > there
> > are points 0x1000, 0x1100.
> > 
> > If this patch is accepted, I'll do the equivalent to the img
> > display
> > system.
> > 
> > Regards
> > Ticker
> > _______________________________________________
> > mkgmap-dev mailing list
> > mkgmap-dev at lists.mkgmap.org.uk
> > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
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