[GRASS5] OpenGL GL/gl.h not found and fftw

Glynn Clements glynn.clements at virgin.net
Tue Aug 17 19:31:37 EDT 2004

DrakeGis wrote:

>   I'm compiling grass 5.7.0 from the sources and I'm unable to find how to
> include OpenGL.
>    I tried "--with-opengl-includes=/usr/X11R6/include/" because gl.h
> "lives" in /usr/X11R6/include/GL/ but I received a message that gl.h is
> not available.
>    I'm using Debian SID, and I also have the xlibmesa packages installed
> on my system.
>    Does anybody knows which are the correct flags ?

You shouldn't need additional switches; the X switches are added
automatically for the OpenGL checks.

If the <GL/gl.h> check fails, it's usually because preprocessing that
file generated either error or warning messages. Look in the
config.log file which configure creates; there should be a couple of
lines like:

configure:9725: checking for GL/gl.h
configure:9733: gcc -E   -I/usr/X11R6/include  conftest.c >/dev/null 2>conftest.out

If any error/warning messages were generated, they will follow.

BTW, if you have installed nVidia's OpenGL package, you need to delete
(or move) the headers, as they are known not to work.

>    By the way I'm very curious about what is for "fftw".

FFTW is a Fast Fourier Transform (FFT) library. It is used by the
programs i.fft, i.zc, i.shape and r.surf.fractal. If you don't need
these programs, you can use --without-fftw. Otherwise, you need FFTW
2.x installed (neither 1.x nor 3.x will work); see www.fftw.org for
more information.

Glynn Clements <glynn.clements at virgin.net>

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