Hi all,

my findings so far which are not used / needed in GPXSee. Maybe it helps 
someone else:
- method linkLabel() could extract further road labels, bit 0x800000 flags the 
last of up to 4 labels. 
- method linkLabel()  extracts a flag, the bit 0x08 in this flag seems to 
signal a tunnel. No idea yet what the other bits mean.
- the flags field in struct LinkInfo is used like this (netfile.cpp)
        bool firstIsShape = (linkInfo.flags >> 10) & 1;
        bool singleTopology = (linkInfo.flags >> 9) & 1;
        bool hasLevels = (linkInfo.flags >> 11) & 1;
My guesses about the meaning of the lower bits:
        //      int     road_speed = linkInfo.flags  & 7;   
        //      bool oneway = (linkInfo.flags >> 3) & 1; 
        //      int     road_class = (linkInfo.flags >> 4) & 7;  

- The NET header can have two more sections, e.g. I see
00000684 | f6 cb 13 00             | NET5 ???, offset 13cbf6
00000688 | 96 0a 01 00             | NET5 ???, length 68246
0000068c | 23 00                   | ???
0000068e | 8c d6 14 00             | NET6 ???, offset 14d68c
00000692 | 28 05 00 00             | NET6 ???, length 1320
00000696 | 03 00                   | NET6 ??? record size 3
00000698 | 02 00 00 00             | ???

NET6 contains a list of offsets into NET4, they are in sorted order
and each offset points to the byte following the flag byte that is read in  
linkLabel() 
I see 440 recrods here, and 441 NOD6 records in the corresponding NOD file,
so they are obviously related (field blockIndexId).

I've not yet found where the address info like city name, zip name, and house 
numbers are
stored. Maybe that's in NET5.

I think in the old non-NT format there is no need to know NOD data to be able 
to read NET, so
I woulld expect that this is also possible with NT maps.

Gerd
_______________________________________________
mkgmap-dev mailing list
mkgmap-dev@lists.mkgmap.org.uk
https://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev

Reply via email to