[mkgmap-dev] splitter maximum tile size

Wed Dec 5 11:18:13 GMT 2012

Henning Scholland wrote
> So there are several cases:
> 
> 1: several distinct areas in oneinput-file (eg Iceland and Germany or 
> France and all there islands)
> -> splitter should stop and ask the user to use al polygon-file or 
> create a polygon-file itself and warn user, that h did so
> 
> 2: Map crossing 180/-180
> -> split bounding-box at 180/-180 and calculate tiles for each of the 
> two bounding-boxes
> 
> 2a: Map crossing 180/-180, but covers hole planet as input
> -> use bounding-box left=-180 right=180

Yes, there are many cases, but it is not always easy for splitter to find
out what
the user did to create the input file. Splitter doesn't "know" that Europe
exists and
how many nodes it should find in that area. 
This could be changed if we always feed splitter with a file containing the
densityMap 
for planet, but that wouldn't make it much easier to find out what tiles the
user wants.

Reg. "create a polygon-file" :
A possible algorithm for that could try to find bounding boxes that are not
too big and have nice aspect ratio. It would prefer areas with few nodes to
areas that are very big.

I am not sure if this is good enough, but I think it's worth trying.
OK?

Gerd
Gerd

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