[mkgmap-dev] Error in Africa?

Mon Sep 14 14:17:11 BST 2020

Hi Gerd

I don't understand how splitting the road in addRoadsWithoutLoops()
changes anything - won't the bits (and the other OSM ways with same
typ/names/class/speed) just be joined up again during StyledConverted
end() processing in the call mergeRoads().

For a road with many points, it is going to be LineSplitterFilter that
creates too many road segments. Probably the easiest way to prevent
this many-pointed road causing this problem is to split it before
invoking the filter but after mergeRoads(). However I maintain that a
single OSM way won't cause the problem and so stopping RoadMerger from
creating the problem is a safe solution. RoadMerger.MAX_MERGED_POINTS
should be re-expressed as per StyledConverter.MAX_ROAD_POINTS.

I understand the change to remove the warning in MapSplitter about a
single item being too big.

Ticker

On Sun, 2020-09-06 at 08:56 +0000, Gerd Petermann wrote:
> Hi Ticker,
> 
> I've now found the time to look at the details. The problem was not
> the size of the sub division but the number of Polyline instances
> created for the long road.
> This has to be < 0x80. The corresponding check was only implemented
> with an assert statement and Valentins call doesn't enable
> assertions, so invalid data was written.
> I've attached a patch which implements the splitting in
> StyledConverter and which throws a MapFailedException instead of
> using an assertion.
> Open problem: MapSplitter still
> SCHW: uk.me.parabola.mkgmap.build.MapSplitter 
>  f:\dwnload\temp\63240201.osm.pbf: Single item predicted to exceed
> subdivision 
> http://www.openstreetmap.org/?mlat=10.489948&mlon=-13.065190&zoom=17
> SCHW: uk.me.parabola.mkgmap.build.MapSplitter 
>  f:\dwnload\temp\63240201.osm.pbf: Single item predicted to exceed
> subdivision 
> http://www.openstreetmap.org/?mlat=10.368004&mlon=-12.969704&zoom=17
> while the map seems to be OK. So I think the estimation also needs a
> fix?
> 
> Gerd
> 
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von valentin3151 at gmail.com <valentin3151 at gmail.com>
> Gesendet: Dienstag, 4. August 2020 12:28
> An: mkgmap-dev at lists.mkgmap.org.uk
> Betreff: Re: [mkgmap-dev] Error in Africa?
> 
> Hi, Ticker.
> 
> Thanks for your investigation.
> I am very impressed with how some people are using the wrong tags.
> With --x-no-mergeroads option, my problem was fixed. Great!
> 
> Best regadrs,
> Valrntin
> 
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