[mkgmap-dev] resolution, level & levels

Thu Sep 13 23:41:02 BST 2012

In article <505252F5.3090808 at parabola.me.uk>, steve at parabola.me.uk 
says...
> Yes the documentation could be clearer, but that is not quite what
> is happening.
> 
> The statement "level 2" is the same as "level 0-2" which means
> that the item will appear at levels 0, 1 and 2. It will disappear
> after you zoom out to level 3 or further.
> 
> For resolution the default end point is 24 so "resolution 23" means
> "resolution 23-24". It therefore appears at any level which has a
> resolution of 23 or 24.
> 
> So for
>    levels = 0:24, 1:22, 2:20, 3:18, 4:16
> 
> that just means level 0
> 
> but with
>    levels = 0:24, 1:23, 2:22, 3:20, 4:18, 5:16
> 
> it includes levels 0 and 1, which is what you observed.
> 
> [The wiki also says that you have to write the numbers the wrong way 
> round (resolution 24-23; level 4-2) that was true (a bug) at one time, 
> but now you can write them in any order]

Thank you again. I think the fundamental thing I hadn't grasped was that 
you can't just put a resolution tag on something to cause it to be 
displayed at that resolution or greater, but that you have to in some 
sense "create" the level first with the levels specification before you 
can assign something to that level using either the resolution or level 
tag.

-- 
Cheers,
John