[mkgmap-dev] Resurrect adjust-turn-headings

Tue Oct 20 09:46:25 BST 2020

Hi Gerd

Yes, with --x-ignore-sharp-angles, the compactDirs format is disabled.
Some of the example problems I looked at behaved much better when not
using compactDirs, so it seemed reasonable, to avoid more developer "-
-x-" type options, to have it this way.

I thought about having another option to control this when "ignore
-sharp-angles", with options to force on, force off and auto mode that
looks for the cases of 2 roads being in the same sector or where the
road continuation isn't in the opposite sector but some other way is.

I can do something like this if you think it worthwhile.

Ticker

On Tue, 2020-10-20 at 08:10 +0000, Gerd Petermann wrote:
> Hi Ticker,
> 
> sorry for the delay. I've started to compare the results of the
> patched and the original version. I think there might be a problem
> with --x-ignore-sharp-angles.
> I assume that patch disables the compact dirs when this undocument
> option is used?
> 
> Gerd
> 
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Gerd Petermann <gpetermann_muenchen at hotmail.com>
> Gesendet: Mittwoch, 14. Oktober 2020 19:26
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] Resurrect adjust-turn-headings
> 
> Hi Ticker,
> 
> thanks for the patch. I'll have a closer look at the weekend.
> 
> Gerd
> 
> ________________________________________
> Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> von Ticker Berkin <rwb-mkgmap at jagit.co.uk>
> Gesendet: Mittwoch, 14. Oktober 2020 10:24
> An: Development list for mkgmap
> Betreff: Re: [mkgmap-dev] Resurrect adjust-turn-headings
> 
> Hi Gerd
> 
> I've been looking at turn pop-ups and routing decisions and attach a
> patch that makes improvements:
> 
> Move decision about when to use compactDir initialHeadings from
> RouteNode to AngleChecker.
> The current code checks if any headings from a RouteNode share the
> same
> compactDir/4-bit sector and, if so, revert to the full/8-bit value.
> Overlaid roads triggered this, also sharp angles that couldn't be
> widened, probably when many paths converge at a road.
> 
> AngleChecker::fixSharpAngles was coded on the basis that compactDirs
> are used and it tested/increased angles based on this 4-bit step, but
> if these are then represented in 8-bit format, the encode angle could
> be much (up to 22.5 degrees) less that the code was expecting and
> result in turning delays in route calculations.
> 
> Recode fixSharpAngles to work in degrees but choose the thresholds to
> be good for compactDirs. Test the resultant angles and only use
> compactDirs if there are no roads in the same or adjacent 4-bit
> sectors.
> Not allowing Adjacent is necessary because, in compactDirs format, if
> there is a path in the opposite sector to the road and the road
> continuation is the adjacent sector, Garmin gives a "turn to stay on
> road" pop-up, but with 8-bit headings it doesn't. This is slightly
> different from the following case because this concerns an angle that
> doesn't need to be "unsharpened" as it isn't permitted for vehicles
> to
> make this turn.
> 
> When increasing an angle, change the heading of the lower class/speed
> road in preference to the major road.
> This helps prevent the "turn to stay on road" type pop-ups when the
> lead-off road was more straight-on than the main road and one-way
> tagging possibly missing.
> 
> Handle simple (<= 2 RouteArcs) RouteNodes as special cases, giving
> slight efficiency improvements.
> 
> Add some diagnostics for showing RouteNodes and RouteArcs in an area.
> 
> Tidy up normalisation of headings.
> 
> Fix some bugs.
> 
> Ticker
> 
> _______________________________________________
> mkgmap-dev mailing list
> mkgmap-dev at lists.mkgmap.org.uk
> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
> _______________________________________________
> mkgmap-dev mailing list
> mkgmap-dev at lists.mkgmap.org.uk
> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev