Angle snapping: show 30 instead of 330

[simon04]

At the moment, the angle snapping mode shows possibly values from 0–360°. It may be more intuitive to restrict to 0–180°, e.g., show 30 instead of 330. What do you think?

[akks]

I am ready to implement this, waiting for comments. Only possible problem is different values on screen and in angle panel.

Should we leave current showing method as an option?

[Don-vip]

It's a good idea to change it to 0-180° :) I don't think it's necessary to keep the old method as an option.

[akks]

What about +180/-180 and no old method?

[skyper]

Replying to akks:

What about +180/-180 and no old method?

+1

Personally I have nothing about the correct mathematical values but +180/-180 is probably cleaner for the average of users.

[akks]

Only drawback is that it will not coincide with 'heading', but it does not matter.

[akks]

In 5191/josm:

fix #7566: Angle snapping: show 30 instead of 330