[quake2] Quake 0.16 rc2...

[Brendan Burns]

Cool,
thanks for the info...  I'll make the appropriate changes in the libGL 
loading code.

--brendan

On Sep 25, 2004, at 12:01 PM, Ludwig Nussel wrote:

> Brendan Burns wrote:
>> Hmm is that true?
>> I have to admit to a certain amount of ignorance when it comes to this
>> stuff, but my understanding was:
>>
>> 	libFoo.so = most generic shared (eg dynamically linked) library
>> 	libFoo.so.1 = version 1 of said library
>> 	libFoo.a = the version of the library for static linking.
>>
>> In fact on most systems libGL.so is a symbolic pointer to a specific
>> libGL.so.x.y.
>
> In theory it should only be there if OpenGL development stuff is
> installed. In practice it's probably there because everyone gets it
> wrong.
>
> Example of correct library usage:
>
> $ ls -l /usr/lib/libhd.so*
> lrwxrwxrwx  1 root root      10 2004-09-25 17:43 /usr/lib/libhd.so -> 
> libhd.so.8
> lrwxrwxrwx  1 root root      13 2004-08-28 14:13 /usr/lib/libhd.so.8 
> -> libhd.so.8.62
> -rwxr-xr-x  1 root root 1104680 2004-08-25 22:04 /usr/lib/libhd.so.8.62
> $ rpm -qf /usr/lib/libhd.so
> hwinfo-devel-8.62-0.2
> $ rpm -qf /usr/lib/libhd.so.*
> hwinfo-8.62-0.2
> hwinfo-8.62-0.2
>
> If you compile something and link against -lhd the linker searches
> for libhd.so, looks at the SONAME and puts that into the
> requirements of the program:
>
> $ objdump -p /usr/lib/libhd.so|grep SONAME
>   SONAME      libhd.so.8
> $ objdump -p /usr/sbin/hwinfo|grep libhd
>   NEEDED      libhd.so.8
>
> If some binary incompatible changes are made to libhd, the version
> changes from 8 to 9. Since you probably want to always link newly
> compiled programs against the most recent version, libhd.so would
> point to libhd.so.9. If you still have programs around that need the
> old interface you can have libhd.so.8 and libhd.so.9 installed in
> parallel and it will just work because the SONAME is used. Old
> programs would would segfault if they had libhd.so in NEEDED.
>
> Since the SONAME of the library you want to use is libGL.so.1 you
> also have to dlopen libGL.so.1. Another possibility would be to get
> rid of dlopen and directly link against -lGL.
>
> cu
> Ludwig
>
> -- 
> (o_  Ludwig.Nussel at gmx.de
> //\  PGP Key ID: FF8135CE
> V_/_ ICQ:        52166811
>