[mkgmap-dev] mapnik TYP, forest and wetland

Mon Nov 2 19:21:30 GMT 2020

Hi

I have two examples where a larger polygon is drawn over smaller ones -

near start of 'polygons':

leisure=nature_reserve
    {set mkgmap:drawLevel=75} [0x16 resolution 19 continue]
military=danger_area
    {set mkgmap:drawLevel=75} [0x11 resolution 20 continue]
...

mkgmap:drawLevel is used to cause them to be output them after all
naturally-sized polygons (same effect as a higher draworder) and they
are represented in the TYP file with partially-transparent icons.

I agree that there is no guarantee that future Garmin software will
render objects with equal draworder in the order in which they occur in
the map, but so far it has worked without exception.

Ticker

On Mon, 2020-11-02 at 19:49 +0100, Andrzej Popowski wrote:
> Hi Karl,
> 
>  > I tried makling a map using the same draworder
>  > Type=0x050,2
>  > Type=0x051,2
>  > plus using the option --order-by-decreasing-area
> 
> This is some kind of trick, not a general solution. There is no 
> guarantee, that GPS will follow the order of objects in img.
> And I'm sure you can find examples, where bigger polygon should be
> drawn 
> over a smaller one.
> 
> Wetland is semi-transparent, you can set higher draw-order for it and
> forest below still will be visible.
> 