Aegisub/m4macros/ax_check_gl.m4
2015-07-27 18:19:57 -07:00

559 lines
19 KiB
Text

# ===========================================================================
# http://www.gnu.org/software/autoconf-archive/ax_check_gl.html
# ===========================================================================
#
# SYNOPSIS
#
# AX_CHECK_GL
#
# DESCRIPTION
#
# Check for an OpenGL implementation. If GL is found, the required
# compiler and linker flags are included in the output variables
# "GL_CFLAGS", "GL_LIBS", "GL_LDFLAGS", respectively. If no usable GL
# implementation is found, "no_gl" is set to "yes".
#
# You could disable OpenGL using --with-gl=no
#
# You could choose a specific OpenGL libs using --with-gl=lib_name
#
# Under darwin, cygwin and mingw target you could prefer the OpenGL
# implementation that link with X setting --with-gl=x or without X support
# with --with-gl=nox. Notes that this script try to guess the right
# implementation.
#
# If the header "GL/gl.h" is found, "HAVE_GL_GL_H" is defined. If the
# header "OpenGL/gl.h" is found, HAVE_OPENGL_GL_H is defined. These
# preprocessor definitions may not be mutually exclusive.
#
# You should use something like this in your headers:
#
# #if defined(HAVE_WINDOWS_H) && defined(_WIN32)
# # include <windows.h>
# #endif
# #ifdef HAVE_GL_GL_H
# # include <GL/gl.h>
# #elif defined(HAVE_OPENGL_GL_H)
# # include <OpenGL/gl.h>
# #else
# # error no gl.h
# #endif
#
# LICENSE
#
# Copyright (c) 2009 Braden McDaniel <braden@endoframe.com>
# Copyright (c) 2012 Bastien Roucaries <roucaries.bastien+autoconf@gmail.com>
#
# This program is free software; you can redistribute it and/or modify it
# under the terms of the GNU General Public License as published by the
# Free Software Foundation; either version 2 of the License, or (at your
# option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
# Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program. If not, see <http://www.gnu.org/licenses/>.
#
# As a special exception, the respective Autoconf Macro's copyright owner
# gives unlimited permission to copy, distribute and modify the configure
# scripts that are the output of Autoconf when processing the Macro. You
# need not follow the terms of the GNU General Public License when using
# or distributing such scripts, even though portions of the text of the
# Macro appear in them. The GNU General Public License (GPL) does govern
# all other use of the material that constitutes the Autoconf Macro.
#
# This special exception to the GPL applies to versions of the Autoconf
# Macro released by the Autoconf Archive. When you make and distribute a
# modified version of the Autoconf Macro, you may extend this special
# exception to the GPL to apply to your modified version as well.
#serial 17
m4_define([_AX_CHECK_GL_PROGRAM],
[AC_LANG_PROGRAM([[
# if defined(HAVE_WINDOWS_H) && defined(_WIN32)
# include <windows.h>
# endif
# ifdef HAVE_GL_GL_H
# include <GL/gl.h>
# elif defined(HAVE_OPENGL_GL_H)
# include <OpenGL/gl.h>
# else
# error no gl.h
# endif
]],[[glBegin(0)]])])
dnl Default include : add windows.h
dnl see http://www.opengl.org/wiki/Platform_specifics:_Windows
dnl (acceded 20120801)
AC_DEFUN([_AX_CHECK_GL_INCLUDES_DEFAULT],dnl
[
AC_INCLUDES_DEFAULT
[
# if defined(HAVE_WINDOWS_H) && defined(_WIN32)
# include <windows.h>
# endif
]
])
dnl local save flags
AC_DEFUN([_AX_CHECK_GL_SAVE_FLAGS],
[dnl
ax_check_gl_saved_libs="${LIBS}"
ax_check_gl_saved_cflags="${CFLAGS}"
ax_check_gl_saved_cppflags="${CPPFLAGS}"
ax_check_gl_saved_ldflags="${LDFLAGS}"
])
dnl local restore flags
AC_DEFUN([_AX_CHECK_GL_RESTORE_FLAGS],
[dnl
LIBS="${ax_check_gl_saved_libs}"
CFLAGS="${ax_check_gl_saved_cflags}"
CPPFLAGS="${ax_check_gl_saved_cppflags}"
LDFLAGS="${ax_check_gl_saved_ldflags}"
])
dnl default switch case failure
AC_DEFUN([_AX_CHECK_MSG_FAILURE_ORDER],
[dnl
AC_MSG_FAILURE([Order logic in ax_check_gl is buggy])
])
# set the varible ax_check_gl_need_x
# this variable determine if we need opengl that link with X
# value are default aka try the first library wether if it link or not with x
# yes that means we need a opengl with x
# no that means we do not need an opengl with x
AC_DEFUN([_AX_CHECK_GL_NEED_X],
[dnl
# do not check if empty : allow a subroutine to modify the choice
AS_IF([test "X$ax_check_gl_need_x" = "X"],
[ax_check_gl_need_x="default"
AS_IF([test "X$no_x" = "Xyes"],[ax_check_gl_need_x="no"])
AS_IF([test "X$ax_check_gl_want_gl" = "Xnox"],[ax_check_gl_need_x="no"])
AS_IF([test "X$ax_check_gl_want_gl" = "Xx"],[ax_check_gl_need_x="yes"])])
])
# compile the example program
AC_DEFUN([_AX_CHECK_GL_COMPILE],
[dnl
AC_LANG_PUSH([C])
_AX_CHECK_GL_SAVE_FLAGS()
CFLAGS="${GL_CFLAGS} ${CFLAGS}"
AC_COMPILE_IFELSE([_AX_CHECK_GL_PROGRAM],
[ax_check_gl_compile_opengl="yes"],
[ax_check_gl_compile_opengl="no"])
_AX_CHECK_GL_RESTORE_FLAGS()
AC_LANG_POP([C])
])
# compile the example program (cache)
AC_DEFUN([_AX_CHECK_GL_COMPILE_CV],
[dnl
AC_CACHE_CHECK([for compiling a minimal OpenGL program],[ax_cv_check_gl_compile_opengl],
[_AX_CHECK_GL_COMPILE()
ax_cv_check_gl_compile_opengl="${ax_check_gl_compile_opengl}"])
ax_check_gl_compile_opengl="${ax_cv_check_gl_compile_opengl}"
])
# link the example program
AC_DEFUN([_AX_CHECK_GL_LINK],
[dnl
AC_LANG_PUSH([C])
_AX_CHECK_GL_SAVE_FLAGS()
CFLAGS="${GL_CFLAGS} ${CFLAGS}"
LIBS="${GL_LIBS} ${LIBS}"
LDFLAGS="${GL_LDFLAGS} ${LDFLAGS}"
AC_LINK_IFELSE([_AX_CHECK_GL_PROGRAM],
[ax_check_gl_link_opengl="yes"],
[ax_check_gl_link_opengl="no"])
_AX_CHECK_GL_RESTORE_FLAGS()
AC_LANG_POP([C])
])
# link the example program (cache)
AC_DEFUN([_AX_CHECK_GL_LINK_CV],
[dnl
AC_CACHE_CHECK([for linking a minimal OpenGL program],[ax_cv_check_gl_link_opengl],
[_AX_CHECK_GL_LINK()
ax_cv_check_gl_link_opengl="${ax_check_gl_link_opengl}"])
ax_check_gl_link_opengl="${ax_cv_check_gl_link_opengl}"
])
dnl Check headers manually (default case)
AC_DEFUN([_AX_CHECK_GL_MANUAL_HEADERS_DEFAULT],
[AC_REQUIRE([AC_PATH_XTRA])
AC_LANG_PUSH([C])
_AX_CHECK_GL_SAVE_FLAGS()
CFLAGS="${GL_CFLAGS} ${CFLAGS}"
# see comment in _AX_CHECK_GL_INCLUDES_DEFAULT
AC_CHECK_HEADERS([windows.h],[],[],[AC_INCLUDES_DEFAULT])
# FIXME: use extra cflags
AC_CHECK_HEADERS([GL/gl.h],[ax_check_gl_have_headers="yes"],
[ax_check_gl_have_headers_headers="no"],
[_AX_CHECK_GL_INCLUDES_DEFAULT()])
# do not try darwin specific OpenGl/gl.h
_AX_CHECK_GL_RESTORE_FLAGS()
AC_LANG_POP([C])
])
# darwin headers without X
AC_DEFUN([_AX_CHECK_GL_MANUAL_HEADERS_DARWIN_NOX],[
AC_LANG_PUSH([C])
_AX_CHECK_GL_SAVE_FLAGS()
# FIXME: use -framework opengl as an extra cflags
CFLAGS="-framework opengl ${GL_CFLAGS} ${CFLAGS}"
AC_CHECK_HEADERS([OpenGL/gl.h],[ax_check_gl_have_headers="yes"],
[ax_check_gl_have_headers_headers="no"],
[_AX_CHECK_GL_INCLUDES_DEFAULT()])
AS_IF([test "X$ax_check_gl_have_headers" = "yes"],
[GL_CFLAGS="-framework opengl ${GL_CFLAGS}"])
_AX_CHECK_GL_SAVE_FLAGS()
AC_LANG_POP([C])
])
# check header for darwin
AC_DEFUN([_AX_CHECK_GL_MANUAL_HEADERS_DARWIN],
[AC_REQUIRE([_AX_CHECK_GL_NEED_X])dnl
AS_CASE(["$ax_check_gl_order"],
# try to use framework
["gl"],[_AX_CHECK_GL_MANUAL_HEADERS_DARWIN_NOX()],
# try to use framework then mesa (X)
["gl mesagl"],[
_AX_CHECK_GL_MANUAL_HEADERS_DARWIN_NOX()
AS_IF([test "X$ax_check_gl_have_headers" = "yes"],
[ax_check_gl_order="gl"
ax_check_gl_need_x="yes"],
[ax_check_gl_order="mesagl gl"
ax_check_gl_need_x="no"]
# retry with general test
_AX_CHECK_GL_MANUAL_HEADERS_DEFAULT()])],
["mesagl gl"],[
_AX_CHECK_GL_MANUAL_HEADERS_DEFAULT()
AS_IF([test "X$ax_check_gl_have_headers" = "yes"],
[ax_check_gl_order="mesagl gl"
ax_check_gl_need_x="no"],
[ax_check_gl_order="gl"
ax_check_gl_need_x="yes"
# retry with framework
_AX_CHECK_GL_MANUAL_HEADERS_DARWIN_NOX()])],
[_AX_CHECK_MSG_FAILURE_ORDER()])
])
dnl Check headers manually: subroutine must set ax_check_gl_have_headers={yes,no}
AC_DEFUN([_AX_CHECK_GL_MANUAL_HEADERS],
[AC_REQUIRE([AC_CANONICAL_HOST])
AS_CASE([${host}],
[*-darwin*],[_AX_CHECK_GL_MANUAL_HEADERS_DARWIN],
[_AX_CHECK_GL_MANUAL_HEADERS_DEFAULT()])
AC_CACHE_CHECK([for OpenGL headers],[ax_cv_check_gl_have_headers],
[ax_cv_check_gl_have_headers="${ax_check_gl_have_headers}"])
])
# dnl try to found library (generic case)
# dnl $1 is set to the library to found
AC_DEFUN([_AX_CHECK_GL_MANUAL_LIBS_GENERIC],
[dnl
ax_check_gl_manual_libs_generic_extra_libs="$1"
AS_IF([test "X$ax_check_gl_manual_libs_generic_extra_libs" = "X"],
[AC_MSG_ERROR([AX_CHECK_GL_MANUAL_LIBS_GENERIC argument must no be empty])])
AC_LANG_PUSH([C])
_AX_CHECK_GL_SAVE_FLAGS()
CFLAGS="${GL_CFLAGS} ${CFLAGS}"
LIBS="${GL_LIBS} ${LIBS}"
AC_SEARCH_LIBS([glBegin],[$ax_check_gl_manual_libs_generic_extra_libs],
[ax_check_gl_lib_opengl="yes"],
[ax_check_gl_lib_opengl="no"])
AS_CASE([$ac_cv_search_glBegin],
["none required"],[],
[no],[],
[GL_LIBS="${ac_cv_search_glBegin} ${GL_LIBS}"])
_AX_CHECK_GL_RESTORE_FLAGS()
AC_LANG_PUSH([C])
])
# dnl try to found lib under darwin
# darwin opengl hack
# see http://web.archive.org/web/20090410052741/http://developer.apple.com/qa/qa2007/qa1567.html
# and http://web.eecs.umich.edu/~sugih/courses/eecs487/glut-howto/
AC_DEFUN([_AX_CHECK_GL_MANUAL_LIBS_DARWIN],
[# ldhack list
ldhack1 = "-Wl,-framework,OpenGL"
ldhack2 = "-Wl,-dylib_file,/System/Library/Frameworks/OpenGL.framework/Versions/A/Libraries/libGL.dylib:/System/Library/Frameworks/OpenGL.framework/Versions/A/Libraries/libGL.dylib"
ldhack3 = "$ldhack1,$ldhack2"
# select hack
AS_IF([test "X$ax_check_gl_need_x" = "Xyes"],
[# libs already set by -framework cflag
darwinlibs=""
ldhacks="$ldhack1 $ldhack2 $ldhack3"],
[# do not use framework ldflags in case of x version
darwinlibs="GL gl MesaGL"
ldhack="$ldhack2"])
ax_check_gl_link_opengl="no"
for extralibs in " " $darwinlibs; do
for extraldflags in " " ldhacks; do
AC_LANG_PUSH([C])
_AX_CHECK_GL_SAVE_FLAGS()
CFLAGS="${GL_CFLAGS} ${CFLAGS}"
LIBS="$extralibs ${GL_LIBS} ${LIBS}"
LDFLAGS="$extraldflags ${GL_LDFLAGS} ${LDFLAGS}"
AC_LINK_IFELSE([_AX_CHECK_GL_PROGRAM],
[ax_check_gl_link_opengl="yes"],
[ax_check_gl_link_opengl="no"])
_AX_CHECK_GL_RESTORE_FLAGS()
AC_LANG_POP([C])
AS_IF([test "X$ax_check_gl_link_opengl" = "Xyes"],[break])
done;
AS_IF([test "X$ax_check_gl_link_opengl" = "Xyes"],[break])
done;
GL_LIBS="$extralibs ${GL_LIBS}"
GL_LDFLAGS="$extraldflags ${GL_LDFLAGS}"
])
dnl Check library manually: subroutine must set
dnl $ax_check_gl_lib_opengl={yes,no}
AC_DEFUN([_AX_CHECK_GL_MANUAL_LIBS],
[AC_REQUIRE([AC_CANONICAL_HOST])
AS_CASE([${host}],
[*-darwin*],[_AX_CHECK_GL_MANUAL_LIBS_DARWIN()],
# try first cygwin version
[*-cygwin*|*-mingw*],[
AS_CASE(["$ax_check_gl_order"],
["gl"],[_AX_CHECK_GL_MANUAL_LIBS_GENERIC([opengl32])],
["gl mesagl"],[_AX_CHECK_GL_MANUAL_LIBS_GENERIC([opengl32 GL gl MesaGL])],
["mesagl gl"],[_AX_CHECK_GL_MANUAL_LIBS_GENERIC([GL gl MesaGL opengl32])],
[_AX_CHECK_MSG_FAILURE_ORDER()])],
[AS_CASE(["$ax_check_gl_order"],
["gl"],[_AX_CHECK_GL_MANUAL_LIBS_GENERIC([GL gl])],
["gl mesagl"],[_AX_CHECK_GL_MANUAL_LIBS_GENERIC([GL gl MesaGL])],
["mesagl gl"],[_AX_CHECK_GL_MANUAL_LIBS_GENERIC([MesaGL GL gl])],
[_AX_CHECK_MSG_FAILURE_ORDER()])]
)
AC_CACHE_CHECK([for OpenGL libraries],[ax_cv_check_gl_lib_opengl],
[ax_cv_check_gl_lib_opengl="${ax_check_gl_lib_opengl}"])
ax_check_gl_lib_opengl="${ax_cv_check_gl_lib_opengl}"
])
# manually check aka old way
AC_DEFUN([_AX_CHECK_GL_MANUAL],
[AC_REQUIRE([AC_CANONICAL_HOST])dnl
AC_REQUIRE([AC_PATH_XTRA])dnl
no_gl="yes"
_AX_CHECK_GL_MANUAL_HEADERS()
AS_IF([test "X$ax_check_gl_have_headers" = "Xyes"],
[_AX_CHECK_GL_COMPILE_CV()],
[ax_check_gl_compile_opengl=no])
AS_IF([test "X$ax_check_gl_compile_opengl" = "Xyes"],
[_AX_CHECK_GL_MANUAL_LIBS],
[ax_check_gl_lib_opengl=no])
AS_IF([test "X$ax_check_gl_lib_opengl" = "Xyes"],
[_AX_CHECK_GL_LINK_CV()],
[ax_check_gl_link_opengl=no])
AS_IF([test "X$ax_check_gl_link_opengl" = "Xyes"],
[no_gl="no"],
[no_gl="yes"])
])dnl
# try to test using pkgconfig: set ax_check_gl_pkg_config=no if not found
AC_DEFUN([_AX_CHECK_GL_PKG_CONFIG],dnl
[dnl
AC_REQUIRE([PKG_PROG_PKG_CONFIG])
dnl First try mesagl
AS_CASE(["$ax_check_gl_order"],
["gl"],[PKG_CHECK_MODULES([GL],[mesagl],
[ax_check_gl_pkg_config=yes],
[ax_check_gl_pkg_config=no])],
["gl mesagl"],[PKG_CHECK_MODULES([GL],[gl],
[ax_check_gl_pkg_config=yes],
[PKG_CHECK_MODULES([GL],[mesagl],
[ax_check_gl_pkg_config=yes],
[ax_check_gl_pkg_config=no])])],
["mesagl gl"],[PKG_CHECK_MODULES([GL],[mesagl],
[ax_check_gl_pkg_config=yes],
[PKG_CHECK_MODULES([GL],[gl],
[ax_check_gl_pkg_config=yes],
[ax_check_gl_pkg_config=no])])],
[_AX_CHECK_MSG_FAILURE_ORDER])
AS_IF([test "X$ax_check_gl_pkg_config" = "Xyes"],[
# check headers
AC_LANG_PUSH([C])
_AX_CHECK_GL_SAVE_FLAGS()
CFLAGS="${GL_CFLAGS} ${CFLAGS}"
AC_CHECK_HEADERS([windows.h],[],[],[AC_INCLUDES_DEFAULT])
AC_CHECK_HEADERS([GL/gl.h OpenGL/gl.h],
[ax_check_gl_have_headers="yes";break],
[ax_check_gl_have_headers_headers="no"],
[_AX_CHECK_GL_INCLUDES_DEFAULT()])
_AX_CHECK_GL_RESTORE_FLAGS()
AC_LANG_POP([C])
AC_CACHE_CHECK([for OpenGL headers],[ax_cv_check_gl_have_headers],
[ax_cv_check_gl_have_headers="${ax_check_gl_have_headers}"])
# pkgconfig library are suposed to work ...
AS_IF([test "X$ax_cv_check_gl_have_headers" = "Xno"],
[AC_MSG_ERROR("Pkgconfig detected OpenGL library has no headers!")])
_AX_CHECK_GL_COMPILE_CV()
AS_IF([test "X$ax_cv_check_gl_compile_opengl" = "Xno"],
[AC_MSG_ERROR("Pkgconfig detected opengl library could not be used for compiling minimal program!")])
_AX_CHECK_GL_LINK_CV()
AS_IF([test "X$ax_cv_check_gl_link_opengl" = "Xno"],
[AC_MSG_ERROR("Pkgconfig detected opengl library could not be used for linking minimal program!")])
],[ax_check_gl_pkg_config=no])
])
# test if gl link with X
AC_DEFUN([_AX_CHECK_GL_WITH_X],
[
# try if opengl need X
AC_LANG_PUSH([C])
_AX_CHECK_GL_SAVE_FLAGS()
CFLAGS="${GL_CFLAGS} ${CFLAGS}"
LIBS="${GL_LIBS} ${LIBS}"
LDFLAGS="${GL_LDFLAGS} ${LDFLAGS}"
AC_LINK_IFELSE([AC_LANG_CALL([], [glXQueryVersion])],
[ax_check_gl_link_implicitly_with_x="yes"],
[ax_check_gl_link_implicitly_with_x="no"])
_AX_CHECK_GL_RESTORE_FLAGS()
AC_LANG_POP([C])
])
# internal routine: entry point if gl not disable
AC_DEFUN([_AX_CHECK_GL],[dnl
AC_REQUIRE([PKG_PROG_PKG_CONFIG])
AC_REQUIRE([AC_PATH_X])dnl
# does we need X or not
_AX_CHECK_GL_NEED_X()
# try first pkgconfig
AC_MSG_CHECKING([for a working OpenGL implementation by pkg-config])
AS_IF([test "X${PKG_CONFIG}" = "X"],
[ AC_MSG_RESULT([no])
ax_check_gl_pkg_config=no],
[ AC_MSG_RESULT([yes])
_AX_CHECK_GL_PKG_CONFIG()])
# if no pkgconfig or pkgconfig fail try manual way
AS_IF([test "X$ax_check_gl_pkg_config" = "Xno"],
[_AX_CHECK_GL_MANUAL()],
[no_gl=no])
# test if need to test X compatibility
AS_IF([test $no_gl = no],
[# test X compatibility
AS_IF([test X$ax_check_gl_need_x != "Xdefault"],
[AC_CACHE_CHECK([wether OpenGL link implictly with X],[ax_cv_check_gl_link_with_x],
[_AX_CHECK_GL_WITH_X()
ax_cv_check_gl_link_with_x="${ax_check_gl_link_implicitly_with_x}"])
AS_IF([test "X${ax_cv_check_gl_link_with_x}" = "X${ax_check_gl_need_x}"],
[no_gl="no"],
[no_gl=yes])])
])
])
# ax_check_gl entry point
AC_DEFUN([AX_CHECK_GL],
[AC_REQUIRE([AC_PATH_X])dnl
AC_REQUIRE([AC_CANONICAL_HOST])
AC_ARG_WITH([gl],
[AS_HELP_STRING([--with-gl@<:@=ARG@:>@],
[use opengl (ARG=yes),
using the specific lib (ARG=<lib>),
using the OpenGL lib that link with X (ARG=x),
using the OpenGL lib that link without X (ARG=nox),
or disable it (ARG=no)
@<:@ARG=yes@:>@ ])],
[
AS_CASE(["$withval"],
["no"|"NO"],[ax_check_gl_want_gl="no"],
["yes"|"YES"],[ax_check_gl_want_gl="yes"],
[ax_check_gl_want_gl="$withval"])
],
[ax_check_gl_want_gl="yes"])
dnl compatibility with AX_HAVE_OPENGL
AC_ARG_WITH([Mesa],
[AS_HELP_STRING([--with-Mesa@<:@=ARG@:>@],
[Prefer the Mesa library over a vendors native OpenGL (ARG=yes except on mingw ARG=no),
@<:@ARG=yes@:>@ ])],
[
AS_CASE(["$withval"],
["no"|"NO"],[ax_check_gl_want_mesa="no"],
["yes"|"YES"],[ax_check_gl_want_mesa="yes"],
[AC_MSG_ERROR([--with-mesa flag is only yes no])])
],
[ax_check_gl_want_mesa="default"])
# check consistency of parameters
AS_IF([test "X$have_x" = "Xdisabled"],
[AS_IF([test X$ax_check_gl_want_gl = "Xx"],
[AC_MSG_ERROR([You prefer OpenGL with X and asked for no X support])])])
AS_IF([test "X$have_x" = "Xdisabled"],
[AS_IF([test X$x_check_gl_want_mesa = "Xyes"],
[AC_MSG_WARN([You prefer mesa but you disable X. Disable mesa because mesa need X])
ax_check_gl_want_mesa="no"])])
# mesa default means yes except on mingw
AC_MSG_CHECKING([wether we should prefer mesa for opengl implementation])
AS_IF([test X$ax_check_gl_want_mesa = "Xdefault"],
[AS_CASE([${host}],
[*-mingw*],[ax_check_gl_want_mesa=no],
[ax_check_gl_want_mesa=yes])])
AC_MSG_RESULT($ax_check_gl_want_mesa)
# set default guess order
AC_MSG_CHECKING([for a working OpenGL order detection])
AS_IF([test "X$no_x" = "Xyes"],
[ax_check_gl_order="gl"],
[AS_IF([test X$ax_check_gl_want_mesa = "Xyes"],
[ax_check_gl_order="mesagl gl"],
[ax_check_gl_order="gl mesagl"])])
AC_MSG_RESULT($ax_check_gl_order)
# set flags
no_gl="yes"
have_GL="no"
# now do the real testing
AS_IF([test X$ax_check_gl_want_gl != "Xno"],
[_AX_CHECK_GL()])
AC_MSG_CHECKING([for a working OpenGL implementation])
AS_IF([test "X$no_gl" = "Xno"],
[have_GL="yes"
AC_MSG_RESULT([yes])
AC_MSG_CHECKING([for CFLAGS needed for OpenGL])
AC_MSG_RESULT(["${GL_CFLAGS}"])
AC_MSG_CHECKING([for LIBS needed for OpenGL])
AC_MSG_RESULT(["${GL_LIBS}"])
AC_MSG_CHECKING([for LDFLAGS needed for OpenGL])
AC_MSG_RESULT(["${GL_LDFLAGS}"])],
[AC_MSG_RESULT([no])
GL_CFLAGS=""
GL_LIBS=""
GL_LDFLAGS=""])
AC_SUBST([GL_CFLAGS])
AC_SUBST([GL_LIBS])
AC_SUBST([GL_LDFLAGS])
])