Add guile-sdl check when configure

.gitignore

@@ -2,7 +2,6 @@
 .#*
 *.go
 autom4te.cache/
-build-aux/
 Makefile
 Makefile.in
 /configure

Makefile.am

@@ -3,8 +3,11 @@ include guile.am
 moddir=$(prefix)/share/guile/site/2.0
 godir=$(libdir)/guile/2.0/ccache
 
+ACLOCAL_AMFLAGS = -I build-aux
+
 SOURCES = $(wildcard 2d/*.scm  2d/*/*.scm)
 
-EXTRA_DIST += env.in
+EXTRA_DIST += env.in \
+	build-aux/guile-sdl.m4
 
 SUBDIRS = doc

build-aux/guile-sdl.m4

@@ -0,0 +1,63 @@
+## guile-sdl.m4 --- some -*-autoconf-*- macros for Guile-SDL
+
+# Copyright (C) 2007, 2013 Thien-Thi Nguyen
+#
+# 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 3 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, write to the Free
+# Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+# Boston, MA  02110-1301  USA
+
+##----------------------------------------------------------------------------
+
+# GUILE_SDL_OPTLIB --- Handle --disable-FOO for optional libraries
+#
+# $1 is a component, one of: mixer, ttf.
+# $2 is a C-language function name.
+#
+# Arrange for --disable-$1 support.
+# If not disabled, check libSDL_$1 for function $2.
+# If found, do two things w/ var HAVE_$1 (all upcased):
+# - create an AM_CONDITIONAL;
+# - set its value to 1 and AC_SUBST it.
+#
+AC_DEFUN([GUILE_SDL_OPTLIB],[
+m4_pushdef([ENABLE],  [enable_]$1)
+m4_pushdef([ENABLED], [test $[]ENABLE = yes])
+m4_pushdef([COND],    [AS_TR_CPP([HAVE_]$1)])
+
+AC_ARG_ENABLE([$1],[AC_HELP_STRING([--disable-$1],
+[omit bindings for SDL_$1 (default=enabled)])],:,[ENABLE=yes])
+AS_IF([ENABLED],[
+  dnl Use ":" to avoid prepending to $LIBS.
+  AC_CHECK_LIB([SDL_$1], $2, :, ENABLE=no)
+])
+
+AM_CONDITIONAL(COND, ENABLED)
+
+AS_IF([ENABLED],[
+  COND=1
+  AC_SUBST(COND)
+])
+
+m4_popdef([COND])
+m4_popdef([ENABLED])
+m4_popdef([ENABLE])
+])dnl GUILE_SDL_OPTLIB
+
+##----------------------------------------------------------------------------
+
+# Override libtool's attempt to support C++, Fortran, etc.
+AC_DEFUN([_LT_AC_TAGCONFIG],[:])
+
+##----------------------------------------------------------------------------
+## guile-sdl.m4 ends here

configure.ac

@@ -3,6 +3,7 @@ dnl -*- Autoconf -*-
 AC_INIT(guile-2d, 0.1.0)
 AC_CONFIG_SRCDIR(2d)
 AC_CONFIG_AUX_DIR([build-aux])
+AC_CONFIG_MACRO_DIR([build-aux])
 AM_INIT_AUTOMAKE([color-tests -Wall -Wno-portability foreign])
 AM_SILENT_RULES([yes])
 
@@ -23,4 +24,8 @@ PKG_CHECK_MODULES([FTGL], [ftgl >= 2.1])
 # Why doesn't freeimage have a pkg-config file?
 #PKG_CHECK_MODULES([freeimage], [freeimage >= 3.0])
 
+dnl Bindings for optional libs.
+GUILE_SDL_OPTLIB([mixer],[Mix_OpenAudio])
+GUILE_SDL_OPTLIB([ttf],[TTF_Init])
+
 AC_OUTPUT