[mkgmap-dev] Map display squeezed horizontally

Sun Apr 21 22:18:55 BST 2013

GerdP schrieb:

Hello Gerd,

> Michael Prinzing-3 wrote
>> Although I am creating a map for Germany, there are some huge but almost
>> empty tiles up to N 60°. One of them covers the whole area between
>> Berlin and Helsinki, others are far out on the Atlantic Ocean, west of
>> Scottland. If Mapsource automatically selects an projection angle in the
>> middle between the points with the max. and the min. latitude, this will
>> result in a projectoion angle of more than 50° for my map and so almost
>> the whole area of Germany appears to be squeezed.
>>
>> Is there an easy way to remove these tiles from the map (I think they
>> only contain ferry lines, pipelines etc.) without using
>> --keep-complete=false for the splitter and without causing artifacts by
>> cutting the contour lines (they are merged to the OSM data before
>> splitting)?
>
> Strange. When I create a map for Germany the tiles are not covering much
> more.
> I assume the problem is caused by the SRTM data.

I'll have a deeper look into this, but I cannot imagine the contour data 
being the cause. I've created the contour data for the rectangle

47.15 5.75 55.15 15.15

This is a lot smaller than the areas covered by the almost empty tiles. 
Even more, I am splitting the contour lines into parts, none of them 
consisting of more than 2000 nodes, and then I am using osmosis to cut 
them to the shape of Germany. I have to use osmosis' parameter 
completeWays=yes when I am doing this, but even if 1999 out of the max 
2000 nodes of a contour line are outside the bounding polygon this 
should be no more than a few kilometers.

It's difficult to find the few data inside the huge and almost empty 
tiles without coastlines and cities, but at
N 54° 42,0' E 13° 51,0'
for example there are 3 ferry lines crossing: "Swinoujscie - 
Trelleborg", "Finnlines" and "Klaipeda - Kiel". All these lines leave 
the area my map should cover and seem to be included completely.

> You can use a polygon file with splitter to make sure that you only get
> tiles for the wanted area.

Isn't a line starting inside the bounding polygon and ending outside 
inluded completely if --keep-complete=false is not set?

Thank you,

Michael