[mkgmap-dev] New splitter buggy

Mon Mar 2 16:44:39 GMT 2009

On Sun, 1 Mar 2009, Steve Ratcliffe wrote:

> On Thu, Feb 26, 2009 at 11:33:06PM +0100, Wolfgang v. Hansen wrote:
>> The new splitter with the decimal split file (r25) shows some weird
>> behaviour with respect to the tile boundaries.
>
> Anyway I used to see things like what you are seeing and so I just created
> a map to investigate more.  Trouble is, everything worked fine!

I did some further investigation. I should mention as background 
information, that I prefer to use the tile splitter with an area list 
created by hand. Naturally one starts with a basic tile raster that has a 
lot of trailing zeros in the numbers.

The problem with the overlapping tiles started when decimal numbers were 
introduced to areas.list and I recreated that file. Maybe the error is 
connected to "bad" numbers. I created a small dataset and split that 
automatically into two tiles: Everything fine. Then I resplit it using 
areas.list: Still everything fine. Then I moved the border between the two 
tiles by just one mapunit: Significant overlap between tiles occurs!

It seems that tile borders can not be chosen arbitrarly but should be 
multiples of some power of two. Does the tile splitter assume this 
somewhere in the code or does the img-format require this?

-Wolfgang