[mkgmap-dev] Understanding the sea

Mon Dec 28 18:54:52 GMT 2009

Hi,

I'm trying to understand how the --generate-sea stuff works. I want to
know how it decides whether an "island" is water or land. The code does
not really contain sufficient comments for me to work out what it's
doing. I would expect it to close coastline segments that reach the
tile boundary in a direction that is consistent with the "water on the
right" convention but I can't see that in the code. Can anyone help
please?

I hesitate to whine about contributions to mkgmap as I don't want to
stop them arriving but if we can't easily work out how the code works
then it doesn't bode well for maintenance and bug fixing when the
original author has moved on.

I have agreed to help produce a marine map of the Baltic so
it would be really nice if the sea was filled in without any really
major problems (flooded land, etc.) I realise that this is dependent on
the performance of the MP stuff but it seems to me that generating the
right polygons in the first place would be a good start.

I guess that the Baltic area is probably rather a challenge for the
current state of the art.

Thanks,

Mark