[mkgmap-dev] Pending changes

Fri Feb 12 09:37:45 GMT 2021

Hi Carlos

Some bridges are a bit of a strange case. There are a lot of areas
where I walk that are crossed by many small streams and no formal
paths, but, here and there, there are foot bridges over the streams.
These are normally mapped as [highway=path/footway, bridge=yes] and
mostly don't connect to anything, but sometime to another bridge or a
short section of unconnecting path. 

I want to see these on the map, but the little bits of highway will
just cause a routing error if they are picked up as the start or end of
a route; hence my changes.

The only problem I see is if the bridge/highway is connected to the
highway network at one end only and you want to generate a route with
the start or end your of your journey the other side of bridge, then
the routing algo might find another, closer start/end point.

I could change it to be just 'set_unconnected_type' but I considered
the benefits and frequency of fixing paired isolated highway bits
outweighed an incorrect start/end point, which can be overcome by
simply starting the journey in the sensible way and the device will
recalculate or looking at the end-point route and, seeing it is stupid,
choosing a better end-point.

Ticker

On Thu, 2021-02-11 at 18:05 +0100, Carlos Dávila wrote:
> Regarding your extra comment on #3, would it be really the case for 
> bridges? What about any connected highway=* + bridge=yes?
> 
> No objection for new additional changes
> 
> El 11/2/21 a las 15:57, Ticker Berkin escribió:
> > Hi all
> > 
> > I've re-made this set of changes, along with a few improvements
> > that
> > I've gathered over the last 6 months. Following list numbering is
> > the
> > same as original patch, but include some [extra] notes + new items
> > at
> > the end.
> > 
> > Relevant threads:
> > http://www.mkgmap.org.uk/pipermail/mkgmap-dev/2020q3/031375.html
> > http://www.mkgmap.org.uk/pipermail/mkgmap-dev/2020q3/031424.html
> > 
> > 1/ Sometimes charges for using a pedestrian highway are expressed
> > as a
> > fee rather than a toll, so pick this up in mkgmap:toll.
> > 
> > 2/ Show bridges using type 0x10107. With the mapnik addition, these
> > look good for narrow highways, but might not show for wide
> > representations like motorways.
> > 
> > 3/ Where it is likely that bits of highway might not be connected
> > to
> > the road/path system, use mkgmap:set_unconnected_type and
> > mkgmap:set_semi_connected_type to stop the NET/NOD rather than
> > relying
> > on NETnoNOD (now disabled) and --check-routing-island-len=+ve,
> > which is
> > being suspected of causing problems on some devices and BaseCamp.
> > 
> > [extra] In all cases where unconnected/semi-connected changes are
> > mentioned, this only applies to lines not derived from an
> > original/OSM
> > standard highway.
> > 
> > 4/ Quote some filter subst strings that contain spaces - no actual
> > effect but clearer and safer.
> > 
> > 5/ Have line for leisure=track even if area.
> > 
> > 6/ Change the type for tracks/raceways etc from 0x30, which doesn't
> > show on BaseCamp or MapSource, to 0x2a.
> > 
> > 7/ For piers, if 'unconnecting', use marine type 0x1040c
> > (Obstruction:
> > Pier or Jetty) instead of footway.
> > 
> > 8/ Change type for the various barriers from 0x17, which doesn't
> > show
> > on BaseCamp to 0x2b, see:
> > http://www.mkgmap.org.uk/pipermail/mkgmap-dev/2020q1/030348.html
> > 
> > 9/ Consider natural=cliff a barrier.
> > 
> > 10/ Add motorway[_link] roundabouts (yes, some do exist).
> > 
> > 11/ Unquote some numbers - no actual effect.
> > 
> > 12/ Tweak some road speeds.
> > [extra] A few more tweaked.
> > 
> > 13/ Use 0x09 (high-speed ramp) for road class 4 links
> > 
> > 14/ Add footway around car parks if 'connecting'.
> > [extra] This change is disabled.
> > 
> > 15/ Disable coastline. For a long time the tag was suppressed by
> > the
> > Sea processing and it adds little to the map.
> > 
> > 16/ Improve railway platform names and suppress footway if not
> > 'connecting'.
> > 
> > 17/ Show disused:railway in the same way as railway=disused.
> > 
> > 18/ Have cable_car, gondola, funicular as routable, by default with
> > a
> > toll and pedestrian only.
> > 
> > 19/ Show "Course of old Railway", unless a highway has taken over
> > the
> > way (for you Eric, but I like it as well).
> > [extra] This change is disabled
> > 
> > 20/ Speed up car ferries.
> > 
> > 21/ A few other layout/space fixes.
> > 
> > Additional changes:
> > 
> > 22/ motorroad=yes just sets mkgmap:fast_road, which generally
> > increases
> > the speed/class of the highway and decreases the resolution
> > 
> > 23/ natural=landslide like other barriers (eg cliff)
> > 
> > 24/ Don't generate (routable) line for highway=unclassified &
> > area=yes;
> > there are many instances in OSM where this is used to draw a
> > polygon
> > around a complex junction.
> > 
> > 25/ Change the bridleway from 0x07 (Alley) to 0x16 (Trail)
> > 
> > 26/ For ferry/platform/aerialway, blank out address fields to
> > prevent
> > it getting into the Address index
> > 
> > 27/ Add comment about colour pallet to mapnik.txt
> > 
> > Patch attached
> > 
> > Ticker
> > 
> > On Tue, 2021-02-09 at 11:30 +0100, Carlos Dávila wrote:
> > > On [1] Ticker proposed a set of changes to default style lines
> > > file.
> > > There was a long discussion about point #14, which ended without
> > > a
> > > consensus. Other changes didn't get any objection, but they
> > > didn't
> > > get
> > > into trunk. I agree with numbers 1, 6, 8, 10, 15, 17, 18. Also
> > > with 7
> > > and 16, but for unconnected ways only, see #3.
> > > 
> > > 2: more codes could be added for wider highways and their
> > > corresponding
> > > entries in mapnik.txt
> > > 
> > > 3: not sure about this one, specially about semi-connected ways,
> > > which I
> > > think should remain as routable (also applies for 7, 16).
> > > 
> > > [1] 
> > > http://www.mkgmap.org.uk/pipermail/mkgmap-dev/2020q3/031375.html
> > > 
> > > _______________________________________________
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> > > mkgmap-dev at lists.mkgmap.org.uk
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> > > 
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