dnl Copyright (C) 2006-2020  CEA/DEN, EDF R&D
dnl
dnl This library is free software; you can redistribute it and/or
dnl modify it under the terms of the GNU Lesser General Public
dnl License as published by the Free Software Foundation; either
dnl version 2.1 of the License, or (at your option) any later version.
dnl
dnl This library 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 GNU
dnl Lesser General Public License for more details.
dnl
dnl You should have received a copy of the GNU Lesser General Public
dnl License along with this library; if not, write to the Free Software
dnl Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
dnl
dnl See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
dnl

AC_DEFUN([CHECK_OPENGL],[
AC_REQUIRE([AC_PROG_CC])dnl
AC_REQUIRE([AC_PROG_CPP])dnl
AC_REQUIRE([AC_LINKER_OPTIONS])dnl

AC_LANG_SAVE
AC_LANG_CPLUSPLUS

AC_ARG_WITH(opengl,
  [AC_HELP_STRING([--with-opengl=DIR],[root directory path of OpenGL installation])],
  [opengl_dir="$withval"], 
  [dirs="/usr/lib${LIB_LOCATION_SUFFIX} /usr/local/lib${LIB_LOCATION_SUFFIX} /opt/graphics/OpenGL/lib${LIB_LOCATION_SUFFIX} /usr/openwin/lib${LIB_LOCATION_SUFFIX} /usr/X11R6/lib${LIB_LOCATION_SUFFIX}"])dnl

AC_CHECKING(for OpenGL)
AC_CHECKING(for OpenGL headers)

OGL_INCLUDES=""
OGL_LIBS=""

GL_LIB_PATH=""
GLU_LIB_PATH=""

OpenGL_ok=no
OpenGL_libs_ok=no
OpenGL_headers_ok=no

dnl openGL headers
# by default
if test "x${opengl_dir}" != "x" ; then
  AC_MSG_RESULT(for opengl_dir: $opengl_dir)
  AC_CHECK_HEADER([${opengl_dir}/include/GL/gl.h],
                  [OpenGL_headers_ok=yes; OGL_INCLUDES="-I${opengl_dir}/include"],
                  [OpenGL_headers_ok=no])
  if test "x${OpenGL_headers_ok}" = "xyes" ; then
    AC_CHECKING(for default OpenGL library)
    if test "x${opengl_dir}" = "x/usr" ; then
      OGL_LIBS=""
    else
      OGL_LIBS="-L${opengl_dir}/lib"
    fi
    LDFLAGS_old="$LDFLAGS"
    LDFLAGS="$LDFLAGS $OGL_LIBS"
    AC_CHECK_LIB([GL],
                 [glBegin],
                 [OpenGL_libs_ok=yes],
                 [OpenGL_libs_ok=no])
    if test "x${OpenGL_libs_ok}" = "xyes" ; then
      AC_TRY_LINK([],
                  [],
                  [OpenGL_libs_ok=yes ; OpenGL_ok=yes; OGL_LIBS="$OGL_LIBS -lGL"],
                  [OpenGL_libs_ok=no])
    fi
    LDFLAGS="$LDFLAGS_old"
  fi
fi

if test "x${OpenGL_headers_ok}" = "xno" ; then
  AC_CHECK_HEADER(GL/gl.h,
                  [OpenGL_headers_ok=yes],
                  [OpenGL_headers_ok=no])
fi

# under SunOS ?
if test "x${OpenGL_headers_ok}" = "xno" ; then
  AC_CHECK_HEADERS(/usr/openwin/share/include/GL/glxmd.h,
                  [OpenGL_headers_ok=yes; OGL_INCLUDES="-I/usr/openwin/share/include/"],
                  [OpenGL_headers_ok=no])
fi

# under IRIX ?
if test "x${OpenGL_headers_ok}" = "xno" ; then
  AC_CHECK_HEADERS(/opt/graphics/OpenGL/include/GL/glxmd.h,
                  [OpenGL_headers_ok=yes; OGL_INCLUDES="-I/opt/graphics/OpenGL/include"],
                  [OpenGL_headers_ok=no])
fi

# some linux OpenGL servers hide the includes in /usr/X11R6/include/GL
if test "x${OpenGL_headers_ok}" = "xno" ; then
  AC_CHECK_HEADERS(/usr/X11R6/include/GL/gl.h,
                  [OpenGL_headers_ok=yes; OGL_INCLUDES="-I/usr/X11R6/include"],
                  [OpenGL_headers_ok=no])
fi

if test "x${OpenGL_headers_ok}" = "xyes" ; then
  AC_CHECKING(for OpenGL library)
  for idir in $dirs; do
    if test -r "${idir}/libGL.so"; then
      AC_MSG_RESULT(in ${idir})
      if test "x${idir}" = "x/usr/lib${LIB_LOCATION_SUFFIX}" ; then
        GL_LIB_PATH=""
      else
        GL_LIB_PATH="-L${idir}"
      fi
      break
    fi
    # under IRIX ?
    if test -r "${idir}/libGL.sl"; then
      AC_MSG_RESULT(in ${idir})
      if test "x${idir}" = "x/usr/lib${LIB_LOCATION_SUFFIX}" ; then
        GL_LIB_PATH=""
      else
        GL_LIB_PATH="-L${idir}"
      fi
      break
    fi
  done
  LDFLAGS_old="${LDFLAGS}"
  LDFLAGS="${LDFLAGS} ${GL_LIB_PATH}"
  AC_CHECK_LIB([GL],
               [glBegin],
               [OpenGL_libs_ok=yes],
               [OpenGL_libs_ok=no])
  if test "x${OpenGL_libs_ok}" = "xyes" ; then
    AC_TRY_LINK([],
                [],
                [OpenGL_libs_ok=yes ; OGL_LIBS="${OGL_LIBS} ${GL_LIB_PATH} -lGL"],
                [OpenGL_libs_ok=no])
  fi
  LDFLAGS="$LDFLAGS_old"
fi

if test "x${OpenGL_libs_ok}" = "xyes" ; then
  for idir in $dirs; do
    if test -r "${idir}/libGLU.so"; then
      AC_MSG_RESULT(in ${idir})
      if test "x${idir}" = "x/usr/lib${LIB_LOCATION_SUFFIX}" ; then
        GLU_LIB_PATH=""
      else
        GLU_LIB_PATH="-L${idir}"
      fi
      break
    fi
    # under IRIX ?
    if test -r "${idir}/libGLU.sl"; then
      AC_MSG_RESULT(in ${idir})
      if test "x${idir}" = "x/usr/lib${LIB_LOCATION_SUFFIX}" ; then
        GLU_LIB_PATH=""
      else
        GLU_LIB_PATH="-L${idir}"
      fi
      break
    fi
  done
  LDFLAGS_old="${LDFLAGS}"
  LDFLAGS="${LDFLAGS} ${OGL_LIBS} ${GLU_LIB_PATH}"
  AC_CHECK_LIB([GLU],
               [gluBeginSurface],
               [OpenGL_libs_ok=yes],
               [OpenGL_libs_ok=no])
  if test "x${OpenGL_libs_ok}" = "xyes" ; then
    AC_TRY_LINK([],
                [],
                [OpenGL_libs_ok=yes ; OGL_LIBS="${OGL_LIBS} ${GLU_LIB_PATH} -lGLU"],
                [OpenGL_libs_ok=no])
  fi
  LDFLAGS="$LDFLAGS_old"
fi

if test "x${OpenGL_headers_ok}" = "xyes" ; then
  if test "x${OpenGL_libs_ok}" = "xyes" ; then
    OpenGL_ok=yes
  fi
fi

AC_MSG_RESULT(for OpenGL_headers_ok: $OpenGL_headers_ok)
AC_MSG_RESULT(for OpenGL_libs_ok: $OpenGL_libs_ok)
AC_MSG_RESULT(for OpenGL_ok: $OpenGL_ok)

AC_SUBST(OGL_INCLUDES)
AC_SUBST(OGL_LIBS)

AC_LANG_RESTORE

])dnl