You are going to have to look in the code. Start with
<grass source>/src/include/vect/dig_structs.h
which gives the definitions of all the structures used to store topology
information.
Then start looking through some vector programs to see how topology
is used. I have enclosed a simple program I worked on with another user
to give an area adjacency list. It shows how to use the structures
to get area information. I started this program
by looking at v.rm.dangles.
I never looked at the file structure because I didn't care. I assume
that the contents of all the structures are written to the dig_plus file.
Note that this is 5.03 (or 5.3) information. For 5.7 the vector
format has changed, although I would guess that a lot of information
is at least similar.
I hope that helps. I wish it was documented as it is fundamental to
how vectors work.
thanks a lot for help... that is a really good start.
I also wish there were more documentation regarding topology.
but anyway, thanks....
flavio
Em Terça 10 Fevereiro 2004 20:23, John Gillette escreveu:
You are going to have to look in the code. Start with
<grass source>/src/include/vect/dig_structs.h
which gives the definitions of all the structures used to store topology
information.
Then start looking through some vector programs to see how topology
is used. I have enclosed a simple program I worked on with another user
to give an area adjacency list. It shows how to use the structures
to get area information. I started this program
by looking at v.rm.dangles.
I never looked at the file structure because I didn't care. I assume
that the contents of all the structures are written to the dig_plus file.
Note that this is 5.03 (or 5.3) information. For 5.7 the vector
format has changed, although I would guess that a lot of information
is at least similar.
I hope that helps. I wish it was documented as it is fundamental to
how vectors work.