Re: Qhull include files

[Rik]

On 01/30/2012 09:09 PM, Tatsuro MATSUOKA wrote:
> Hello
>
> One thing I have to tell that directories of the header files of the qhull 2012 are 'libqhull' and 'libqhullcpp' in the include directory.
>
> However, the octave assume that header files in the 'qhull'.
>
> I have copied libqhull to qhull in the build
>
> Regards
>
> Tatsuro
1/31/12

The Qhull include files have drifted around in the file system which is why it is necessary when using Qhull2012 to either specify '--with-qhull-includedir=DIR' or rename the libqhull directory to qhull so that the build system can find them.

From configure.ac, Octave is checking for Qhull in 4 places [qhull/libqhull.h libqhull.h qhull/qhull.h qhull.h].

--- configure.ac ---

OCTAVE_CHECK_LIBRARY(qhull, QHull,
  [Qhull library not found -- this will result in loss of functionality of some geometry functions.],
  [qhull/libqhull.h libqhull.h qhull/qhull.h qhull.h], [qh_qhull], [], [],

--- configure.ac ---

The resulting include file is similarly convoluted.

--- oct-qhull.h ---

#if defined (HAVE_QHULL_LIBQHULL_H) || defined (HAVE_QHULL_QHULL_H)
# if defined (HAVE_QHULL_LIBQHULL_H)
#  include <qhull/libqhull.h>
# else
#  include <qhull/qhull.h>
# endif
# include <qhull/qset.h>
# include <qhull/geom.h>
# include <qhull/poly.h>
# include <qhull/io.h>
#elif defined (HAVE_LIBQHULL_H) || defined (HAVE_QHULL_H)
# if defined (HAVE_LIBQHULL_H)
#  include <libqhull.h>
# else
#  include <qhull.h>
# endif
# include <qset.h>
# include <geom.h>
# include <poly.h>
# include <io.h>
#endif

--- oct-qhull.h ---

Qhull2012, using the cmake build and install instructions in the README, installed the required header file in /usr/local/libqhull/libqhull.h.

One option for Octave would be to add a fifth location [libqhull/libqhull.h] to configure.ac.  In addition oct-qhull.h would then need a third #elif branch to locate the necessary config files.

However, I have a question about how downstream package maintainers intend to treat Qhull.  They may decide to override the source code's default install location and put the files in one of the existing directories.  If they do that then a build on an ordinary system will be fine.  I have CC'ed Jordi, who has experience with Debian packaging, and Jussi, who has experience with Fedora packging, to get their opinion on how the source code default paths and the distribution's default paths interact and what the likely location of a Qhull2012 package would be.

--Rik