[GRASS5] NVIZ updates

[Markus Neteler]

On Tue, Nov 18, 2003 at 05:49:21PM +0000, Glynn Clements wrote:
> 
> Paul Kelly wrote:
> 
> > Before the 5.3.0 release it will be good to get NVIZ back so that it
> > compiles under Cygwin. There are some glX functions used that appear to be
> > non-standard. I mentioned this before I think but here are the actual
> > compile errors:
> 
> > OBJ.i686-pc-cygwin/do_zoom.o: In function `Create_OS_Ctx':
> > /cygdrive/g/release/530/grass/src.contrib/GMSL/NVIZ2.2/src/do_zoom.c:275: undefined reference to `glXChooseFBConfig'
> > /cygdrive/g/release/530/grass/src.contrib/GMSL/NVIZ2.2/src/do_zoom.c:287: undefined reference to `glXCreatePbuffer'
> > /cygdrive/g/release/530/grass/src.contrib/GMSL/NVIZ2.2/src/do_zoom.c:288: undefined reference to `glXMakeContextCurrent'
> > OBJ.i686-pc-cygwin/do_zoom.o: In function `Destroy_OS_Ctx':
> > /cygdrive/g/release/530/grass/src.contrib/GMSL/NVIZ2.2/src/do_zoom.c:351: undefined reference to `glXDestroyPbuffer'
> 
> In my copy of GL/glx.h, those functions are preceded by the comment:
> 
> 	/* New for GLX 1.3 */
> 
> So, any code which uses those functions should probably be
> conditionalised upon GLX_VERSION_1_3.
> 
> However, all of the lines which produce errors *are* conditionalised
> upon GLX_PBUFFER_WIDTH. That macro is also specific to GLX 1.3.
> 
> This suggests that the GL headers don't match the GL libraries (GLX
> 1.3 headers with pre-1.3 libraries). In which case, even if the code
> was conditionalised upon the correct macro, it would probably still
> fail for you.

Instead of checking the GL version, couldn't we check if
 glXDestroyPbuffer()
exists in the library with 'configure' (no idea how to do that, though)?

Markus