[GRASS5] GRASS extensions build system, r.cva

[Benjamin Ducke]

I am trying to put together a build system
for building GRASS modules and libraries externally and
installing them into the binary installation tree.

As the recent discussion thread has shown, the necessary
libs and header files are being installed by recent
GRASS versions, so that this should in principle be possible.

Unfortunately, things seem to be a bit more complicated,
because the build system still has to take into account
some machine and OS dependent compile options,
different C compiler names and options etc.

Thus, I decided to strip down the original GRASS 6 configure
script, retaining only the most important checks and used
that as a starting point. In this way, I can "simulate" a
GRASS source environment with the most important parts
of the configuration system (Grass.make, Platform.make etc.)
intact. The aim is to make it possible to build modules
externally without making changes to the original 
GRASS 6 style Makefiles.

It seems to me, that three path variables in the original
make system control where things take place

Source directory (SRCDIR): this is the starting point for locating include files and libs?
Build directory (DSTDIR): this is where the object files are stored?
Installation directory: this is where the final executable modules are copied to.

Am I right about the meaning of these?


In other news:

A new version of r.cva (cumulative viewsheds) for GRASS 6 is now finished and has been
tested. I have contacted the original author, Mark Lake, about the possibility of
releasing it under a GPL compatible license. I have not got an answer so far, but
I am told that Mark is really busy these days and I am sure he will look into this
and we will find a good solution for making r.cva more accessible to GRASS users.

Benjamin