[mkgmap-dev] Elevation data just partially accessable by Basecamp

Fri Jan 10 22:55:57 GMT 2020

Hi,

there are 2 consecutive bytes in TDB file. Let's name them "fist" and 
"second".

Current processing of mkgmap is:
Option --show-profiles=0|1 sets byte "first" to 0 or 1.
Byte "second" is always 0.

Processing of cgpsmapper is:
Byte "first" is always 0.
Option HeightProfile=N|Y sets byte "second" to 0 or 1.
Cgpsmapper doesn't support DEM, so the option is evidently designed for 
contour lines.

Processing of GMapTool:
Byte "first" is set to 1 if all tiles contain DEM, otherwise is set to 0.
Byte "second" is always set to 1.

I don't know, which way is valid or better. I suspect, that BaseCamp and 
Mapsource can somehow deal with all cases.

-- 
Best regards,
Andrzej