+dnl The variable LIBM (which is not an output variable by default) is
+dnl set to a value which is suitable for use in a Makefile (for example,
+dnl in make's LOADLIBES macro) provided you AC_SUBST it first.
+dnl
+dnl @author Matthew D. Langston <langston@SLAC.Stanford.EDU>
+
+# FPTOOLS_CHECK_LIBM - check for math library
+AC_DEFUN(FPTOOLS_CHECK_LIBM,
+[AC_REQUIRE([AC_CANONICAL_HOST])dnl
+LIBM=
+case "$host" in
+*-*-beos*)
+ # These system don't have libm
+ ;;
+*-ncr-sysv4.3*)
+ AC_CHECK_LIB(mw, _mwvalidcheckl, LIBM="-lmw")
+ AC_CHECK_LIB(m, main, LIBM="$LIBM -lm")
+ ;;
+*)
+ AC_CHECK_LIB(m, main, LIBM="-lm")
+ ;;
+esac
+])
+
+dnl ######################################################################
+dnl Note: Caching has been completely rewritten, but is still no perfect yet.
+dnl ######################################################################
+
+dnl ########################### -*- Mode: M4 -*- #######################
+dnl Copyright (C) 98, 1999 Matthew D. Langston <langston@SLAC.Stanford.EDU>
+dnl
+dnl This file is free software; you can redistribute it and/or modify it
+dnl 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 file is distributed in the hope that it will be useful, but
+dnl WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+dnl General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU General Public License
+dnl along with this file; if not, write to:
+dnl
+dnl Free Software Foundation, Inc.
+dnl Suite 330
+dnl 59 Temple Place
+dnl Boston, MA 02111-1307, USA.
+dnl ####################################################################
+
+dnl @synopsis FPTOOLS_HAVE_OPENGL
+dnl
+dnl Search for OpenGL. We search first for Mesa (a GPL'ed version of
+dnl OpenGL) before a vendor's version of OpenGL if we were specifically
+dnl asked to with `--with-Mesa=yes' or `--with-Mesa'.
+dnl
+dnl The four "standard" OpenGL libraries are searched for: "-lGL",
+dnl "-lGLU", "-lGLX" (or "-lMesaGL", "-lMesaGLU" as the case may be) and
+dnl "-lglut".
+dnl
+dnl All of the libraries that are found (since "-lglut" or "-lGLX" might
+dnl be missing) are added to the shell output variable "GL_LIBS", along
+dnl with any other libraries that are necessary to successfully link an
+dnl OpenGL application (e.g. the X11 libraries). Care has been taken to
+dnl make sure that all of the libraries in "GL_LIBS" are listed in the
+dnl proper order.
+dnl
+dnl Additionally, the shell output variable "GL_CFLAGS" is set to any
+dnl flags (e.g. "-I" flags) that are necessary to successfully compile
+dnl an OpenGL application.
+dnl
+dnl The following shell variable (which are not output variables) are
+dnl also set to either "yes" or "no" (depending on which libraries were
+dnl found) to help you determine exactly what was found.
+dnl
+dnl have_GL
+dnl have_GLU
+dnl have_GLX
+dnl have_glut
+dnl
+dnl A complete little toy "Automake `make distcheck'" package of how to
+dnl use this macro is available at:
+dnl
+dnl ftp://ftp.slac.stanford.edu/users/langston/autoconf/ac_opengl-0.01.tar.gz
+dnl
+dnl Please note that as the ac_opengl macro and the toy example evolves,
+dnl the version number increases, so you may have to adjust the above
+dnl URL accordingly.
+dnl
+dnl @author Matthew D. Langston <langston@SLAC.Stanford.EDU>
+
+AC_DEFUN(FPTOOLS_HAVE_OPENGL,