Hi Gerd,
I call these values TRE parameters. They are 3 bytes at offsets 0x43,
0x44, 0x45. I'm not sure, what is the real meaning of parameters. Same
guesses are that it indicate routable/non routable map, general display
priority, some parameters for navigation, general map type.
Info about faster routing probably comes form cgpsmapper. Table on OSM
wiki looks wrong. Byte 0x40 is priority, I don't know if 3 byte is used,
single byte works for me. Beside this priority, TRE parameters influence
priority too, but differently on different GPS. It is like some GPS
display City Navigator map over topo, regardless of draw priority in
byte 0x40.
On Garmin maps byte 0x43 gets values 0 or 1, Byte 0x44 gets values
3-4-6, byte 0x45 some values in range 1-43. Wiki shows it in reversed
order. Last byte decide if map is visible in chartplotters, so probably
define map type.
My idea is simply to copy values from original Garmin's map. So now
mkgmap is using City Navigator parameters and option sets custom MPC map
( https://developer.garmin.com/map-product-creator/overview/ ). You
could set 3 values in option directly, but I'm not sure if it will help.
Probably anybody who want to manipulate these values is able to use
GMapTool or other patching programs to change it in img.
--
Best regards,
Andrzej
_______________________________________________
mkgmap-dev mailing list
[email protected]
http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
