[mkgmap-dev] Problem in AngleFixer?

Mon Aug 5 07:37:37 BST 2024

Hi all,

in a private email Thorsten Kukuk contacted me about wrong turn instructions a sharp angles.
An example is the node https://www.osm.org/node/27550903

A route coming from South that follows the way https://www.osm.org/way/36138336 at this junction should NOT produce a turn instruction.
A route that turns left SHOULD produce a turn instruction. 
With current mkgmap it's vice versa and thus not OK.

I thnk the current code in AngleFixer.java is too agressive as it tries to enlarge the angles so that a compact format can be used to write the
heading values of the arcs at the mentioned node. It does this by changing the heading values of both arcs with go to the north.

@Ticker: The code was introduced with your arcHeading_v2.patch, but maybe it existed before.
Can you explain why the constant AngleChecker.SHARP_DEGREES is set to 46° instead of maybe 22.5° ?

Gerd