[mkgmap-dev] [PATCH] Creating contour lines from DEM data

Sat Jul 4 12:18:40 BST 2009

Am 04.07.2009 um 13:06 schrieb Christian Gawron:

> Nop schrieb:
>>> And I don't agree that this would be a derived work. OSM does not  
>>> contain any DEM data or contour lines, so by adding them the OSM  
>>> layer remains unchanged and clearly discernible from the contour  
>>> lines, so I would say the result is a collective work.
>>
>> Discernible is not enough. You need to read through the full  
>> legalese. A collective work is defined as a collection of  
>> unmodified entities. This is definitely not true for a gmapsupp.img.
>>
>> Took me a while to understand and believe how bad the current OSM  
>> licence is, too.
> Thank you for the clarification. So maybe I should add an option to  
> put the contours into a separate IMG file.
> Right now you could achieve this by using an input file which  
> contains no data but the bounding box.
>
> I think using one IMG has the advantage that using a TYP file you  
> can specify the drawing order (first the "background" polygons, than  
> the contours, then the streets).

Actually, using different IMG files will allow you to do that, but  
with one IMG file for everything it will be difficult. You cannot  
specify the drawing order of ways in the TYP file, only of polygons.  
And as I understand it, it is not easy to control the drawing order of  
ways in any other way. Nop seems to be able to do it by controlling  
the order the ways are written into the IMG file, but I was largely  
unsucessfull using that method.

Regards
Thilo