[mkgmap-dev] Commit: r1443: Combine any gmapsupp files given as input into the output gmapsupp file correctly preserving family id's etc.

Sat Jan 2 23:50:53 GMT 2010

On 02.01.2010 19:17, Charlie Ferrero wrote:
>
> svn commit wrote:
>    
>> Version 1443 was commited by steve on 2009-12-27 21:12:59 +0000 (Sun, 27 Dec 2009)
>>
>> Combine any gmapsupp files given as input into the output gmapsupp file correctly preserving family id's etc.
>> _______________________________________________
>>      
> I can confirm that this now works (each layer can be enabled/disabled
> and each tile has the correct name), bar one thing...transparency
> information is being incorrectly applied to all layers.  My mapset is as
> follows:
>
> top layer (contours): transparent
> mid layer (OSM map): opaque
> bottom layer (routing): opaque
>
> The transparency from the top layer is being applied to the lower
> layers, meaning that when the GPS draws, it first draws the routing
> layer, then the OSM layer, then the contour layer, which is reeeeaaally
> slow.
>
> This is definitely a mkgmap issue because when I combine the gmapsupp
> files using sendmap only the top layer is transparent.
>    
No this is not an mkgmap issue, but an issue in understanding how DP and 
transparency work. If not disabled ALL enabled maps will be drawn.

1. Opaque maps are drawn, the order depend on the Draw Priority
2. After all opaque maps, the transparent maps are drawn on top, if they 
have polygons those polygons will be drawn above non transparent maps. 
The draw priority of a transparent map does not matter (the behaviour 
what happens if there are several transparent maps is depending on the 
unit and a bit erroneus).

-- A mapset can include transparent as well as opaque maps, and also 
maps of different DP. You can also include several maps (be they 
transparent or not) of the same area into the same mapset.

So if you have three maps you should decide:
a) which maps are transparent, which are opaque
b) which maps to assign which DP
c) decide which maps to put into which mapset (or all into one mapset).

I don't know how the mkgmap --gmapsupp option works, but in the above 
you're writing everything is working correctly.