[mkgmap-dev] I would like a maxways parameter and associated code to limit the number of ways in a tile

Mon May 21 18:27:04 BST 2018

Hi Randolph,

what do you mean by "ways"? Any line, road with an address, road used 
for routing? I don't remember if I ever spotted similar problem.

On the other side, I think splitter can be better tuned for current 
mkgmap. I get impression, that splitter is designed to make a good work 
with simple maps and doesn't account for addresses, routing nodes od DEM 
data. It would be nice, if there were more options, than maxnodes.

For my maps, I split OSM data in two stages. First I prepare artificial 
data, that I believe represent better actual size of compiled tiles.

I extract addresses as points and highways as simple 2-points lines (I 
do it with modified osmfilter). Then I make splitter to calculate all 
tiles using as an input following data:
- OSM source
- 0-2 times extracted addresses
- 6-10 times extracted highways
- 1-2 times contour lines

I believe, that additional points form address account for some NET 
size, points form highways for additional NOD size and duplicated 
contour lines for DEM size. It needs some tuning for different areas, 
but I think I get a bit more uniform sizes of img than with direct 
splitting.

On second stage I use prepared areas.list to split real data.

Basically I do something like this:

osmfilter.exe data.o5m --keep= --keep-ways=highway=* -o=net.o5m
osmfilter.exe data.o5m --keep= --keep-nodes=addr:housenumber=* -o=adr.o5m

splitter.jar --stop-after=split --max-nodes=3000000 data.o5m net.o5m 
net.o5m net.o5m net.o5m net.o5m net.o5m net.o5m net.o5m adr.o5m adr.o5m 
contour.pbf contour.pbf

splitter.jar --split-file=areas.list data.o5m contour.pbf

It would be helpful, if I could do it in a single pass. Maybe splitter 
could filter internally specific nodes - these which would end as 
routing nodes or address information and add some multiplier when 
counting these nodes for splitting? Assuming this is easy to implement, 
otherwise my procedure is good enough.

-- 
Best regards,
Andrzej