[mkgmap-dev] Another question to the zoom levels

Thu Apr 8 11:51:09 BST 2010

Hello Dani

> In the default style, I find in the options:
> levels = 0:24, 1:22, 2:20, 3:18, 4:16
>
> But in the files (polygons, lines, points) the following resolutions are
> used:
> 10, 12, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24
>
> I think I have read somewhere that just these from the options may be used?

That is not a problem, all features with a lower or equal minimum 
resolution value will show up on a given level.

So for 0:24 everything will be present. (in this example things at: 10, 
12, 14, 16, 17, 18, 19, 20, 21, 22, 23, 24)

for 1:22 everything less than or equal to 22 ( 10, 12, 14, 16, 17, 18, 
19, 20, 21, 22)

So you could say that it is pointless having anything at 23 since it 
will be just the same as having it at 22.  However, you can change the 
levels so that is why it is slightly useful to do so.  If you had
--levels=0:23,1:21,... then there would be a difference for example.

If you were designing your own style though I would always decide on the 
levels first and then just use the ones you have picked. Or perhaps 
better use level instead of resolution.

..Steve