Hi Clinton,
On Tue, Aug 4, 2009 at 10:40 PM, Mark Burton<markb@ordern.com> wrote:
Ahoy there shipmates,
This patch is a first stab at providing support for the 3-byte extended types that are used on marine maps.
I tested this, and found that it works fine, both on my eTrex and in Roadtrip for Mac OS X.
Excellent.
FYI, I did not have to switch to marine mode or anything else to get the symbols to display. (Although some of the symbols didn't look that nice, but I assume they're there for utility and not aesthetics.) So far, I have just tried this with a few types: a lateral buoy symbol and a pier line type.
On my eTrex, you can choose between various marine icon sets (Garmin, NOAA, International) and there is also an option to have "marine colors".
It would probably be nice to get this committed, so more people can experiment with the additional possibilities this can offer.
As it's fairly unlikely to break maps that don't use any extended types it's probably safe to commit.
At this time, the various extra attributes that can be assigned to the marine entities (depth, colour, light colour/flash, etc.) are not handled but I have made some progress in understanding their encoding so at least some of these could be supported in the future. Obviously, the OSM data would need to be enriched to specify the required attributes.
There appears to be significant progress in adding this type of data to OSM. Since the proposed tags attempt to conform to international standards, it should be fairly easy to match these to Garmin types:
http://wiki.openstreetmap.org/wiki/Proposed_features/marine-tagging
The author of the OpenSeaMap effort says that there are now two proposed schemes for tagging marine entities. As far as mkgmap is concerned it doesn't really make much difference what the tags are but it would be nice if there was just one tag set to transform rather than 2. However, I do intend to continue work on this soon. Cheers, Mark