When I run cgpsmapper on my map, the output for layer 0 contains this (along with other stuff):
- ****polygons****
Elements to process -->544
100%
Processed -->2304
Split -->297
100%
Successfully imported: 2297 not imported: 7
**** END ****
Maximum error: 1.90085 meter
Mean error: 0.403159 meter
If there any way to determine what polygons aren't being imported? And if I can find them, is there anything I can do to fix whatever is preventing them from being processed?
(I did a search of the manual for the term "imported", which occurs several times, but never in this context. Google didn't provide much better.)
If you can't find them then maybe it is not a problem? ;)
Garmin maps have limited precision, polygons that are too small can't be converted to map format. I think this could be the case.
The whole processing message is rather cryptic and the manual says nothing about the steps. The example above says there are 544 elements to process, but the next line says 2304 were processed. Huh? I was just reading a document describing the .img file layout and my conjecture is that polygons are being split because they are not allowed to cross RGN boundaries, which in turn are influenced by TRE_SIZE. Perhaps that's the 297 split line. By dumb luck, some polygons split across RGN boundaries will be quite small and are thrown out by cgpsmapper.
Of course, all of this is conjecture from the flimsiest of evidence, so perhaps none of it makes any sense at all.
Yes, polygons are split, you can see it, if you read back img to GPSMapEdit. Your explanation is very likely.