dnl $Id: configure.in,v 1.127 2007-07-09 13:54:36 geuzaine Exp $
dnl
dnl Copyright (C) 1997-2007 C. Geuzaine, J.-F. Remacle
dnl
dnl This program is free software; you can redistribute it and/or modify
dnl it under the terms of the GNU General Public License as published by
dnl the Free Software Foundation; either version 2 of the License, or
dnl (at your option) any later version.
dnl
dnl This program is distributed in the hope that it will be useful,
dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
dnl GNU General Public License for more details.
dnl
dnl You should have received a copy of the GNU General Public License
dnl along with this program; if not, write to the Free Software
dnl Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
dnl USA.
dnl 
dnl Please report all bugs and problems to <gmsh@geuz.org>.

dnl Process this file with autoconf to produce the configure script.

dnl Note: each CHECK_LIB adds the found library to LIBS, which serves
dnl implicitly when checking for the next one. So one should check
dnl in reverse order! (start with -lm, ...)

dnl Check that this is the gmsh source tree
AC_INIT(Parser/Gmsh.y)

dnl Parse '--with' command-line options
AC_ARG_WITH(fltk-prefix,
            AC_HELP_STRING([--with-fltk-prefix=PFX],
                           [prefix where FLTK is installed]),
            [FLTK_PREFIX=$withval])
AC_ARG_WITH(gsl-prefix,
            AC_HELP_STRING([--with-gsl-prefix=PFX],
                           [prefix where GSL is installed]),
            [GSL_PREFIX=$withval])
AC_ARG_WITH(jpeg-prefix,
            AC_HELP_STRING([--with-jpeg-prefix=PFX],
                           [prefix where the JPEG library and includes are installed]),
            [JPEG_PREFIX=$withval])
AC_ARG_WITH(png-prefix,
            AC_HELP_STRING([--with-png-prefix=PFX],
                           [prefix where the PNG library and includes are installed]),
            [PNG_PREFIX=$withval])
AC_ARG_WITH(zlib-prefix,
            AC_HELP_STRING([--with-zlib-prefix=PFX],
                           [prefix where the ZLIB library and includes are installed]),
            [ZLIB_PREFIX=$withval])
AC_ARG_WITH(osmesa-prefix,
            AC_HELP_STRING([--with-osmesa-prefix=PFX],
                           [prefix where OSMesa is installed]),
            [OSMESA_PREFIX=$withval])
AC_ARG_WITH(cgns-prefix,
            AC_HELP_STRING([--with-cgns-prefix=PFX],
                           [prefix where CGNS is installed]),
            [CGNS_PREFIX=$withval])
AC_ARG_WITH(occ-prefix,
            AC_HELP_STRING([--with-occ-prefix=PFX],
                           [prefix where OpenCascade is installed]),
            [OCC_PREFIX=$withval])
AC_ARG_WITH(hdf5-prefix,
            AC_HELP_STRING([--with-hdf5-prefix=PFX],
                           [prefix where OpenCascade is installed]),
            [HDF5_PREFIX=$withval])
AC_ARG_WITH(med-prefix,
            AC_HELP_STRING([--with-med-prefix=PFX],
                           [prefix where OpenCascade is installed]),
            [MED_PREFIX=$withval])

dnl Parse '--enable' command line options
AC_ARG_ENABLE(gsl,
              AC_HELP_STRING([--enable-gsl],
                             [use GSL as numerical toolkit (default=yes)]))
AC_ARG_ENABLE(gui,
              AC_HELP_STRING([--enable-gui],
                             [build the graphical user interface (default=yes)]))
AC_ARG_ENABLE(cygwin,
              AC_HELP_STRING([--enable-cygwin],
                             [use the Cygwin library on Windows (default=no)]))
AC_ARG_ENABLE(parallel,
              AC_HELP_STRING([--enable-parallel],
                             [enable parallel version (default=no)]))
AC_ARG_ENABLE(jpeg,
              AC_HELP_STRING([--enable-jpeg],
                             [enable JPEG support (default=yes)]))
AC_ARG_ENABLE(zlib,
              AC_HELP_STRING([--enable-zlib],
                             [enable ZLIB support (default=yes)]))
AC_ARG_ENABLE(png,
              AC_HELP_STRING([--enable-png],
                             [enable PNG support (default=yes)]))
AC_ARG_ENABLE(contrib,
              AC_HELP_STRING([--enable-contrib],
                             [enable contrib packages (default=yes)]))
AC_ARG_ENABLE(triangle,
              AC_HELP_STRING([--enable-triangle],
                             [compile Triangle if available (default=yes)]))
AC_ARG_ENABLE(netgen,
              AC_HELP_STRING([--enable-netgen],
                             [compile Netgen if available (default=yes)]))
AC_ARG_ENABLE(ann,
              AC_HELP_STRING([--enable-ann],
                             [compile ANN if available (default=yes)]))
AC_ARG_ENABLE(metis,
              AC_HELP_STRING([--enable-metis],
                             [compile METIS if available (default=no)]))
AC_ARG_ENABLE(tetgen,
              AC_HELP_STRING([--enable-tetgen],
                             [compile Tetgen if available (default=yes)]))
AC_ARG_ENABLE(matheval,
              AC_HELP_STRING([--enable-matheval],
                             [compile MathEval if available (default=yes)]))
AC_ARG_ENABLE(osmesa,
              AC_HELP_STRING([--enable-osmesa],
                             [use OSMesa for offscreen rendering (default=no)]))
AC_ARG_ENABLE(cgns,
              AC_HELP_STRING([--enable-cgns],
                             [enable CGNS output (default=no)]))
AC_ARG_ENABLE(occ,
              AC_HELP_STRING([--enable-occ],
                             [enable OpenCascade support (default=no)]))
AC_ARG_ENABLE(med,
              AC_HELP_STRING([--enable-med],
                             [enable MED support (default=yes)]))
AC_ARG_ENABLE(fm,
              AC_HELP_STRING([--enable-fm],
                             [enable support for Fourier models (default=yes)]))

dnl Get the operating system name
UNAME=`uname`

dnl Check for default compilers
AC_PROG_CC
AC_PROG_CXX
if test "x${CC}" = "x" -o "x${CXX}" = "x" ; then
  AC_MSG_ERROR([Could not find required compilers, aborting.])
fi
LINKER="${CXX}"
POSTBUILD=""

dnl Use c++ for all compilation tests
AC_LANG(C++)

dnl Take care of no-cygwin option before doing any other tests
case "$UNAME" in
  CYGWIN*)
    if test "x$enable_cygwin" != "xyes"; then
      UNAME="${UNAME}-no-cygwin"
      CC="${CC} -mno-cygwin"
      CXX="${CXX} -mno-cygwin"
      dnl increase stack size to 16Mb to avoid stack overflows in
      dnl recursive tet classification for large 3D Delaunay grids
      LINKER="${LINKER} -mno-cygwin -Wl,--stack,16777216"
    fi
    ;;
esac

dnl Set default flags
FLAGS=""
OPTIM="${CXXFLAGS}"

dnl Check for various programs
AC_PROG_CPP

dnl How to build static libraries?
case "$UNAME" in
  Darwin*)
    RANLIB=true
    AR="libtool -o"
    ;;
  *)
    AC_PROG_RANLIB
    AC_PATH_PROG(AR, ar)
    if test "x${AR}" = "x:"; then
      AC_MSG_ERROR([Could not find the library archiver, aborting.])
    fi
    AR="${AR} ruvs"
    ;;
esac

dnl See if we need a .exe extension on executables
AC_EXEEXT

dnl Set default subdirectories and libraries
GMSH_DIRS="Common DataStr Geo Mesh Post Numeric Parallel Parser Plugin"

dnl Choose blackbox or GUI version
if test "x$enable_gui" != "xno"; then

  GMSH_DIRS="${GMSH_DIRS} Graphics Fltk"
  GMSH_LIBS="-Llib -lGmshFltk -lGmshParser -lGmshGraphics -lGmshMesh -lGmshGeo"
  GMSH_LIBS="${GMSH_LIBS} -lGmshPlugin -lGmshPost -lGmshCommon -lGmshDataStr -lGmshNumeric"
  GMSH_LIBS="${GMSH_LIBS} -lGmshParallel"
  FLAGS="-DHAVE_FLTK ${FLAGS}"

  if test "x${FLTK_PREFIX}" != "x" ; then
    AC_PATH_PROG(FLTKCONFIG,fltk-config,"",[${FLTK_PREFIX}:${FLTK_PREFIX}/bin:$PATH])
    dnl Find the libs/includes even if fltk is _not_ properly installed (ugly hack!)
    GMSH_LIBS="${GMSH_LIBS} -L${FLTK_PREFIX}/lib"
    FLAGS="${FLAGS} -I${FLTK_PREFIX}"
  else
    AC_PATH_PROG(FLTKCONFIG,fltk-config)
  fi
  if test "x$FLTKCONFIG" = "x"; then
    AC_MSG_ERROR([Could not find fltk-config. Try --with-fltk-prefix?])
  fi

  dnl Check for offscreen rendering using OSMesa
  if test "x$enable_osmesa" = "xyes"; then
    if test "x${OSMESA_PREFIX}" != "x"; then
      LDFLAGS="-L${OSMESA_PREFIX} -L${OSMESA_PREFIX}/lib ${LDFLAGS}"
    fi
    AC_CHECK_LIB(OSMesa,main,OSMESA="yes",OSMESA="no")
  fi

  if test "x${OSMESA}" = "xyes"; then
    GMSH_LIBS="${GMSH_LIBS} `$FLTKCONFIG --use-images --ldflags` -lfltk_gl"
    FLAGS="${FLAGS} -DHAVE_OSMESA `$FLTKCONFIG --use-images --cxxflags`"
    if test "x${OSMESA_PREFIX}" = "x"; then
      GMSH_LIBS="${GMSH_LIBS} -lOSMesa -lGL -lGLU"
    else
      GMSH_LIBS="${GMSH_LIBS} -L${OSMESA_PREFIX} -L${OSMESA_PREFIX}/lib -lOSMesa -lGL -lGLU"
      FLAGS="${FLAGS} -I${OSMESA_PREFIX} -I${OSMESA_PREFIX}/include"
    fi
  else
    GMSH_LIBS="${GMSH_LIBS} `$FLTKCONFIG --use-gl --use-images --ldflags`"
    FLAGS="${FLAGS} `$FLTKCONFIG --use-gl --use-images --cxxflags`"
  fi

  FL_JPEG=""
  expr "x${GMSH_LIBS}" : 'x.*fltk_jpeg.*' >/dev/null && FL_JPEG="yes"
  FL_PNG=""
  expr "x${GMSH_LIBS}" : 'x.*fltk_png.*' >/dev/null && FL_PNG="yes"
  FL_ZLIB=""
  expr "x${GMSH_LIBS}" : 'x.*fltk_z.*' >/dev/null && FL_ZLIB="yes"

  dnl Check for libjpeg
  if test "x$enable_jpeg" != "xno"; then
    dnl If provided by FLTK, use that one; otherwise, look for it
    if test "x${FL_JPEG}" = "xyes"; then
      FLAGS="-DHAVE_LIBJPEG ${FLAGS}"
    else      
      if test "x${JPEG_PREFIX}" != "x"; then
        LDFLAGS="-L${JPEG_PREFIX} -L${JPEG_PREFIX}/lib ${LDFLAGS}"
      fi
      AC_CHECK_LIB(jpeg,main,JPEG="yes",JPEG="no")
      if test "x${JPEG}" = "xyes"; then
        FLAGS="-DHAVE_LIBJPEG ${FLAGS}"
        if test "x${JPEG_PREFIX}" = "x"; then
          GMSH_LIBS="${GMSH_LIBS} -ljpeg"
        else
          dnl Find the libs/includes even if libjpeg is _not_ properly installed (ugly hack!)
          GMSH_LIBS="${GMSH_LIBS} -L${JPEG_PREFIX} -L${JPEG_PREFIX}/lib -ljpeg"
          FLAGS="${FLAGS} -I${JPEG_PREFIX} -I${JPEG_PREFIX}/include"
        fi
      fi 
    fi
  fi

  dnl Check for libz
  ZLIB=""
  if test "x$enable_zlib" != "xno"; then
    dnl If provided by FLTK, use that one; otherwise, look for it
    if test "x${FL_ZLIB}" = "xyes"; then
      ZLIB="yes"
    else      
      if test "x${ZLIB_PREFIX}" != "x"; then
        LDFLAGS="-L${ZLIB_PREFIX} -L${ZLIB_PREFIX}/lib ${LDFLAGS}"
      fi
      AC_CHECK_LIB(z,main,ZLIB="yes",ZLIB="no")
    fi
  fi

  dnl Check for libpng (only if libz is available)
  if test "x$enable_png" != "xno" -a "x${ZLIB}" = "xyes"; then
    dnl If provided by FLTK, use that one; otherwise, look for it
    if test "x${FL_PNG}" = "xyes"; then
      FLAGS="-DHAVE_LIBPNG ${FLAGS}"
    else
      if test "x${PNG_PREFIX}" != "x"; then
        LDFLAGS="-L${PNG_PREFIX} -L${PNG_PREFIX}/lib ${LDFLAGS}"
      fi
      AC_CHECK_LIB(png,main,PNG="yes",PNG="no")
      if test "x${PNG}" = "xyes"; then
        FLAGS="-DHAVE_LIBPNG ${FLAGS}"
        if test "x${PNG_PREFIX}" = "x"; then
          GMSH_LIBS="${GMSH_LIBS} -lpng"
        else
          dnl Find the libs/includes even if libpng is _not_ properly installed (ugly hack!)
          GMSH_LIBS="${GMSH_LIBS} -L${PNG_PREFIX} -L${PNG_PREFIX}/lib -lpng"
          FLAGS="${FLAGS} -I${PNG_PREFIX} -I${PNG_PREFIX}/include"
        fi
      fi
    fi 
  fi

else

  GMSH_DIRS="${GMSH_DIRS} Box"
  GMSH_LIBS="-Llib Box/Main.o -lGmshBox -lGmshParser -lGmshMesh -lGmshGeo"
  GMSH_LIBS="${GMSH_LIBS} -lGmshPlugin -lGmshPost -lGmshCommon -lGmshDataStr"
  GMSH_LIBS="${GMSH_LIBS} -lGmshNumeric -lGmshParallel"

  dnl Check for libz
  ZLIB=""
  if test "x$enable_zlib" != "xno"; then
    if test "x${ZLIB_PREFIX}" != "x"; then
      LDFLAGS="-L${ZLIB_PREFIX} -L${ZLIB_PREFIX}/lib ${LDFLAGS}"
    fi
    AC_CHECK_LIB(z,main,ZLIB="yes",ZLIB="no")
  fi

fi

dnl Check for standard math library
AC_CHECK_LIB(m,main)

dnl Check for various functions
AC_CHECK_FUNC(vsnprintf,,FLAGS="-DHAVE_NO_VSNPRINTF ${FLAGS}")
AC_CHECK_FUNC(snprintf,,FLAGS="-DHAVE_NO_SNPRINTF ${FLAGS}")

dnl Check if Unix98 socklen_t type is available
AC_TRY_COMPILE(
 [#include <sys/types.h>
  #include <sys/socket.h>],
 [socklen_t len = 42; return 0;],,FLAGS="-DHAVE_NO_SOCKLEN_T ${FLAGS}")

dnl Check if we should consider the packages in contrib
if test "x$enable_contrib" != "xno"; then

  dnl Check for Triangle
  AC_CHECK_FILE(./contrib/Triangle/triangle.c, TRIANGLE="yes", TRIANGLE="no")
  if test "x${TRIANGLE}" = "xyes"; then
    if test "x$enable_triangle" != "xno"; then
       GMSH_DIRS="${GMSH_DIRS} contrib/Triangle"
       GMSH_LIBS="${GMSH_LIBS} -lGmshTriangle"
       FLAGS="-DHAVE_TRIANGLE ${FLAGS}"
       echo "********************************************************************"
       echo "You are building a version of Gmsh that contains Jonathan"
       echo "Shewchuk's Triangle as an alternative isotropic 2D mesh generator."
       echo "Please note that by doing so, you agree with Triangle's licensing"
       echo "requirements stated in ./contrib/Triangle/README. (Most notably, you"
       echo "may then only redistribute Gmsh for non-commercial purposes.)"
       echo "To disable Triangle, run configure again with the --disable-triangle"
       echo "option."
       echo "********************************************************************"
    fi
  else
    if test "x$enable_triangle" != "xno"; then
       echo "********************************************************************"
       echo "If you want to use Jonathan Shewchuk's Triangle as an alternative"
       echo "isotropic 2D mesh generator, please download Triangle from the"
       echo "author's web site at http://www.cs.cmu.edu/~quake/triangle.html,"
       echo "unpack the archive and copy the two files 'triangle.c' and"
       echo "'triangle.h' in the ./contrib/Triangle subdirectory. Then run"
       echo "./configure again."
       echo "Please note that by doing so, you agree with Triangle's licensing"
       echo "requirements stated in ./contrib/Triangle/README. (Most notably, you"
       echo "may then only redistribute Gmsh if no compensation is received.)"
       echo "********************************************************************"
    fi
  fi

  dnl Check for ANN
  AC_CHECK_FILE(./contrib/ANN/include/ANN/ANN.h, ANN="yes", ANN="no")
  if test "x${ANN}" != "xno"; then
    if test "x$enable_ann" != "xno"; then
       GMSH_DIRS="${GMSH_DIRS} contrib/ANN"
       GMSH_LIBS="${GMSH_LIBS} -lGmshANN"
       FLAGS="-DHAVE_ANN_ ${FLAGS}"
       echo "********************************************************************"
       echo "You are building a version of Gmsh that contains ANN, the"
       echo "Approximate Nearest Neighbor library."
       echo "Please note that by doing so, you agree with ANN's licensing"
       echo "requirements stated in ./contrib/ANN/Copyright.txt."
       echo "To disable ANN, run configure again with the --disable-ann"
       echo "option."
       echo "********************************************************************"
    fi
  else
    if test "x$enable_ann" != "xno"; then
       echo "********************************************************************"
       echo "If you want to use ANN for doing fast geometrical searchs in the"
       echo "STL mesher, please download ANN from the author's web site at"
       echo "http://www.cs.umd.edu/~mount/ANN/, unpack the archive and copy both"
       echo "src and include directories in the /contrib/ANN subdirectory. Then"
       echo "run ./configure again."
       echo "********************************************************************"
    fi
  fi

  dnl Check for METIS
  AC_CHECK_FILE(./contrib/Metis/metis.h, METIS="yes", METIS="no")
  if test "x${METIS}" = "xyes"; then
    if test "x$enable_metis" = "xyes"; then
       GMSH_DIRS="${GMSH_DIRS} contrib/Metis"
       GMSH_LIBS="${GMSH_LIBS} -lGmshMetis"
       FLAGS="-DHAVE_METIS ${FLAGS}"
       echo "********************************************************************"
       echo "You are building a version of Gmsh that contains METIS, the"
       echo "Serial Graph Partitioner."
       echo "Please note that by doing so, you agree with METIS's licensing"
       echo "requirements stated in ./contrib/Metis/README."
       echo "To disable METIS, run configure again with the --disable-metis"
       echo "option."
       echo "********************************************************************"
    fi
  else
    if test "x$enable-metis" = "xyes"; then
       echo "********************************************************************"
       echo "If you want to use METIS for doing mesh partitioning, please"
       echo "download METIS from the author's web site at"
       echo "http://www-users.cs.umn.edu/~karypis/metis/, unpack the archive and"
       echo "copy the Lib Directory in the ./contrib/Metis subdirectory. Then"
       echo "run ./configure again."
       echo "********************************************************************"
    fi
  fi

  dnl Check for Netgen
  AC_CHECK_FILE(./contrib/Netgen/libsrc/meshing/meshclass.cpp, NETGEN="yes", NETGEN="no")
  if test "x${NETGEN}" = "xyes"; then
    if test "x$enable_netgen" != "xno"; then
       GMSH_DIRS="${GMSH_DIRS} contrib/Netgen"
       GMSH_LIBS="${GMSH_LIBS} -lGmshNetgen"
       FLAGS="-DHAVE_NETGEN ${FLAGS}"
       echo "********************************************************************"
       echo "You are building a version of Gmsh that contains Joachim Schoberl's"
       echo "Netgen as an alternative 3D mesh generator. Netgen is distributed"
       echo "under the GNU LGPL: see ./contrib/Netgen/COPYING.LIB for more info."
       echo "To disable Netgen, run configure again with the --disable-netgen"
       echo "option."
       echo "********************************************************************"
    fi
  else
    if test "x$enable_netgen" != "xno"; then
       echo "********************************************************************"
       echo "If you want to use Joachim Schoberl's Netgen as an alternative"
       echo "3D mesh generator, please download Netgen from the project's"
       echo "web site at http://www.hpfem.jku.at/netgen/, unpack the archive"
       echo "and move the libsrc subdirectory in the ./contrib/Netgen"
       echo "subdirectory. Then run ./configure again."
       echo "Please note that by doing so, you agree with Netgen's licensing"
       echo "requirements stated in ./contrib/Netgen/COPYING.LIB."
       echo "********************************************************************"
    fi
  fi

  dnl Check for Tetgen
  AC_CHECK_FILE(./contrib/Tetgen/tetgen.h, TETGEN="yes", TETGEN="no")
  if test "x${TETGEN}" = "xyes"; then
    if test "x$enable_tetgen" != "xno"; then
       GMSH_DIRS="${GMSH_DIRS} contrib/Tetgen"
       GMSH_LIBS="${GMSH_LIBS} -lGmshTetgen"
       FLAGS="-DHAVE_TETGEN ${FLAGS}"
       echo "********************************************************************"
       echo "You are building a version of Gmsh that contains Hang Si's"
       echo "Tetgen as an alternative 3D mesh generator."
       echo "Please note that by doing so, you agree with Tetgen's licensing"
       echo "requirements stated in ./contrib/Tetgen/LICENSE. (Most notably, you"
       echo "may then only redistribute Gmsh for non-commercial purposes.)"
       echo "To disable Tetgen, run configure again with the --disable-tetgen"
       echo "option."
       echo "********************************************************************"
    fi
  else
    if test "x$enable_tetgen" != "xno"; then
       echo "********************************************************************"
       echo "If you want to use Hang Si's Tetgen as an alternative"
       echo "3D mesh generator, please download Tetgen from the project's"
       echo "web site at http://www.tetgen.berlios.de, unpack the archive"
       echo "and move the files predicates.cxx, tetgen.cxx and tetgen.h in"
       echo "the ./contrib/Tetgen subdirectory. Then run ./configure again."
       echo "Please note that by doing so, you agree with Tetgen's licensing"
       echo "requirements stated in ./contrib/Tetgen/LICENSE. (Most notably, you"
       echo "may then only redistribute Gmsh if no compensation is received.)"
       echo "********************************************************************"
    fi
  fi

  dnl Check for MathEval
  if test "x$enable_matheval" != "xno"; then
    AC_CHECK_FILE(./contrib/MathEval/matheval.cpp, MATHEVAL="yes", MATHEVAL="no")
    if test "x${MATHEVAL}" = "xyes"; then
      GMSH_DIRS="${GMSH_DIRS} contrib/MathEval"
      GMSH_LIBS="${GMSH_LIBS} -lGmshMathEval"
      FLAGS="-DHAVE_MATH_EVAL ${FLAGS}"
    fi
  fi

  dnl Check for FourierModel
  if test "x$enable_fm" != "xno"; then
    AC_CHECK_FILE(./contrib/FourierModel/FM_Face.cpp, FOURIER="yes", FOURIER="no")
    if test "x${FOURIER}" = "xyes"; then
      GMSH_DIRS="${GMSH_DIRS} contrib/FourierModel"
      GMSH_LIBS="${GMSH_LIBS} -lGmshFourierModel"
      FLAGS="-DHAVE_FOURIER_MODEL ${FLAGS}"
    fi
  fi
fi

dnl Check for GSL
if test "x$enable_gsl" != "xno"; then
  if test "x${GSL_PREFIX}" != "x"; then
    LDFLAGS="-L${GSL_PREFIX} -L${GSL_PREFIX}/lib ${LDFLAGS}"
  fi
  AC_CHECK_LIB(gslcblas,main)
  AC_CHECK_LIB(gsl,main,GSL="yes",GSL="no")
  if test "x${GSL}" = "xyes"; then
    FLAGS="-DHAVE_GSL ${FLAGS}"
    if test "x${GSL_PREFIX}" = "x"; then
      GMSH_LIBS="${GMSH_LIBS} -lgsl -lgslcblas"
    else
      GMSH_LIBS="${GMSH_LIBS} -L${GSL_PREFIX} -L${GSL_PREFIX}/lib -lgsl -lgslcblas"
      FLAGS="${FLAGS} -I${GSL_PREFIX} -I${GSL_PREFIX}/include"
    fi
  fi
fi
if test "x${GSL}" != "xyes"; then
  dnl Check if non-free numerical recipes routines are in the tree
  AC_CHECK_FILE(./contrib/NR/dsvdcmp.cpp,NR="yes",NR="no")
  if test "x${NR}" = "xyes"; then
    echo "********************************************************************"
    echo "You are building a non-free version of Gmsh, using code copyright"
    echo "(C) 1986-92 Numerical Recipes Software J!0."
    echo "To use the GSL instead, run configure again with the --enable-gsl"
    echo "option."
    echo "********************************************************************"
    GMSH_DIRS="${GMSH_DIRS} contrib/NR"
    GMSH_LIBS="${GMSH_LIBS} -lGmshNR"
  else
    echo "********************************************************************"
    echo "This is the free version of Gmsh and configure could not find"
    echo "the GNU Scientific Library (GSL) on your system:"
    echo "- if it is installed in a non-standard location, please run"
    echo "  configure again with the --with-gsl-prefix option"
    echo "- if it is not installed on your system, you can download it from"
    echo "  http://sources.redhat.com/gsl/"
    echo ""
    echo "IMPORTANT NOTE: You need to install GSL version 1.2 or above. All"
    echo "versions <= 1.1.1 have a bug in the singular value decomposition"
    echo "algorithm that will cause Gmsh to hang during mesh generation."
    echo "********************************************************************"
    AC_MSG_ERROR([Could not find GSL, aborting.])
  fi
fi

dnl Check for CGNS
if test "x${CGNS_PREFIX}" != "x"; then
  if test "x$enable_cgns" != "xno"; then
    enable_cgns="yes"
  fi
fi
if test "x$enable_cgns" = "xyes"; then
  if test "x${CGNS_PREFIX}" != "x"; then
    LDFLAGS="-L${CGNS_PREFIX}/lib ${LDFLAGS}"
  fi
  AC_CHECK_LIB(cgns,main,CGNS="yes",CGNS="no")
  if test "x${CGNS}" = "xyes"; then
    if test "x${CGNS_PREFIX}" = "x"; then
      GMSH_LIBS="${GMSH_LIBS} -lcgns"
      FLAGS="${FLAGS} -DHAVE_LIBCGNS"
    else
      GMSH_LIBS="${GMSH_LIBS} -L${CGNS_PREFIX}/lib -lcgns"
      FLAGS="${FLAGS} -DHAVE_LIBCGNS -I${CGNS_PREFIX}/include"
    fi
  fi
fi

dnl Check for OpenCascade
if test "x${OCC_PREFIX}" != "x"; then
  if test "x$enable_occ" != "xno"; then
    enable_occ="yes"
  fi
fi
if test "x$enable_occ" = "xyes"; then
  if test "x${OCC_PREFIX}" != "x"; then
    LDFLAGS="-L${OCC_PREFIX}/lib ${LDFLAGS}"
  fi
  AC_CHECK_LIB(TKernel,main,OCC="yes",OCC="no")
  if test "x${OCC}" = "xyes"; then
    # DataExchange (subset; see occ/ros/adm/make/Makefile for more info)
    OCC_LIBS="-lTKSTEP -lTKSTEP209 -lTKSTEPAttr -lTKSTEPBase -lTKIGES -lTKXSBase"
    # ModelingAlgorithms
    OCC_LIBS="${OCC_LIBS} -lTKOffset -lTKFeat -lTKFillet -lTKBool -lTKShHealing"
    OCC_LIBS="${OCC_LIBS} -lTKMesh -lTKHLR -lTKBO -lTKPrim -lTKTopAlgo -lTKGeomAlgo"
    # ModelingData
    OCC_LIBS="${OCC_LIBS} -lTKBRep -lTKGeomBase -lTKG3d -lTKG2d"
    # FoundationClasses
    OCC_LIBS="${OCC_LIBS} -lTKAdvTools -lTKMath -lTKernel"
    if test "x${OCC_PREFIX}" = "x"; then
      GMSH_LIBS="${GMSH_LIBS} ${OCC_LIBS}"
      FLAGS="${FLAGS} -DHAVE_OCC"
    else
      GMSH_LIBS="${GMSH_LIBS} -L${OCC_PREFIX}/lib ${OCC_LIBS}"
      FLAGS="${FLAGS} -DHAVE_OCC -I${OCC_PREFIX}/inc"
    fi
  fi
fi

dnl Check for HDF5 (required by MED, needs zlib)
if test "x${ZLIB}" = "xyes"; then
  if test "x$enable_med" != "xno"; then
    if test "x${HDF5_PREFIX}" != "x"; then
      LDFLAGS="-L${HDF5_PREFIX}/lib ${LDFLAGS}"
    fi
    AC_CHECK_LIB(hdf5,main,HDF5="yes",HDF5="no")
    if test "x${HDF5}" = "xyes"; then
      if test "x${HDF5_PREFIX}" = "x"; then
        GMSH_LIBS="${GMSH_LIBS} -lhdf5"
      else
        GMSH_LIBS="${GMSH_LIBS} -L${HDF5_PREFIX}/lib -lhdf5"
        FLAGS="${FLAGS} -I${HDF5_PREFIX}/include"
      fi
    fi
  fi
fi

dnl Check for MED (needs hdf5)
if test "x${HDF5}" = "xyes"; then
  if test "x$enable_med" != "xno"; then
    if test "x${MED_PREFIX}" != "x"; then
      LDFLAGS="-L${MED_PREFIX}/lib ${LDFLAGS}"
    fi
    AC_CHECK_LIB(med,main,MED="yes",MED="no")
    if test "x${MED}" = "xyes"; then
      if test "x${MED_PREFIX}" = "x"; then
        GMSH_LIBS="${GMSH_LIBS} -lmed"
        FLAGS="${FLAGS} -DHAVE_MED"
      else
        GMSH_LIBS="${GMSH_LIBS} -L${MED_PREFIX}/lib -lmed"
        FLAGS="${FLAGS} -DHAVE_MED -I${MED_PREFIX}/include"
      fi
    fi
  fi
fi

dnl Complete zlib link line (zlib must be linked in after libpng and libhdf5)
if test "x${ZLIB}" = "xyes"; then
  dnl If provided by FLTK, use that one; otherwise, look for it
  if test "x${FL_ZLIB}" = "xyes"; then
    FLAGS="-DHAVE_LIBZ ${FLAGS}"
  else
    FLAGS="-DHAVE_LIBZ ${FLAGS}"
    if test "x${ZLIB_PREFIX}" = "x"; then
      GMSH_LIBS="${GMSH_LIBS} -lz"
    else
      dnl Find the libs/includes even if libz is _not_ properly installed (ugly hack!)
      GMSH_LIBS="${GMSH_LIBS} -L${ZLIB_PREFIX} -L${ZLIB_PREFIX}/lib -lz"
      FLAGS="${FLAGS} -I${ZLIB_PREFIX} -I${ZLIB_PREFIX}/include"
    fi
  fi
fi 

dnl Check if we should build the parallel version
if test "x$enable_parallel" = "xyes"; then
  FLAGS="-DHAVE_PARALLEL ${FLAGS}"
fi

dnl Finish link line
GMSH_LIBS="${GMSH_LIBS} -lm"

dnl Modify defaults according to OS
case "$UNAME" in

  CYGWIN* | MINGW*)
    LINKER="${LINKER} -mwindows"
    if test "x$enable_cygwin" != "xyes"; then
      FLAGS="${FLAGS} -DHAVE_NO_DLL"
    fi
    if test "x${OCC}" = "xyes"; then
      GMSH_LIBS="${GMSH_LIBS} -lwinspool -lws2_32"
    fi
    if test "x$enable_gui" != "xno"; then
      GMSH_LIBS="${GMSH_LIBS} Fltk/Win32Icon.res"
    fi
    ;;

  Darwin*)
    dnl to build a universal binary, add "-arch ppc -arch i686"
    FLAGS="-DHAVE_NO_DLL ${FLAGS}"
    if test "x$enable_gui" = "xno"; then
      GMSH_LIBS="${GMSH_LIBS} -framework ApplicationServices"
    fi
    POSTBUILD="/Developer/Tools/Rez -t APPL -o bin/gmsh Fltk/MacRes.r"
    ;;

  AIX*)
    FLAGS="-D_BSD -DHAVE_NO_DLL ${FLAGS}"
    ;;

  IRIX*)
    dnl options for native SGI compiler
    case "${CXX}" in
      *CC*)
        dnl add "-mips3 -n32" to FLAGS, AR and LINKER for portable 32 bit exe
        dnl "-DOLDCINCLUDE" is for Netgen
        FLAGS="-LANG:std -OPT:Olimit=0 -DOLDCINCLUDE ${FLAGS}"
        AR="${CXX} -ar -o"
        LINKER="${CXX}"
        ;;
    esac
    ;;

  OSF1*)
    FLAGS="-DHAVE_NO_SOCKLEN_T ${FLAGS}"
    dnl options for native DEC compiler
    case "${CXX}" in
      *cxx*)
        FLAGS="-D__USE_STD_IOSTREAM ${FLAGS}"
        ;;
    esac
    ;;

  SunOS*)
    FLAGS="-DHAVE_NO_DLL ${FLAGS}"
    GMSH_LIBS="${GMSH_LIBS} -lsocket -lnsl -ldl"
    ;;

  HP-UX*)
    FLAGS="-DHAVE_NO_DLL ${FLAGS}"
    ;;

esac

dnl Compiler characteristics
dnl Check sizeof size_t (flag as 64 if not 32)
AC_CHECK_SIZEOF([size_t])
if test $ac_cv_sizeof_size_t != 4; then
  if test $ac_cv_sizeof_size_t != 8; then
    AC_MSG_WARN([Unsupported size of size_t - this may affect FNV hashing.])
  else
    FLAGS="$FLAGS -DHAVE_64BIT_SIZE_T"
  fi
fi

dnl Write output
AC_SUBST(UNAME)
AC_SUBST(FLAGS)
AC_SUBST(OPTIM)
AC_SUBST(LINKER)
AC_SUBST(GMSH_DIRS)
AC_SUBST(GMSH_LIBS)
AC_SUBST(POSTBUILD)
AC_SUBST(AR)
AC_OUTPUT(variables)

dnl Print some information
echo "********************************************************************"
echo "Gmsh is configured for"
echo "- OS           : $UNAME"
echo "- C compiler   : $CC"
echo "- C++ compiler : $CXX"
echo "- Linker       : $LINKER"
echo "- Optimization : $OPTIM"
echo "- Options      : $FLAGS"
echo "********************************************************************"
echo "To fine-tune the configuration, edit the 'variables' file"
echo "********************************************************************"