Look for the awesome CGAL library at configure stage.

git-svn-id: file:///srv/caca.zoy.org/var/lib/svn/libpipi/trunk@3515 92316355-f0b4-4df1-b90c-862c8a59935f

configure.ac

@@ -219,6 +219,18 @@ PKG_CHECK_MODULES([LIBAVFORMAT], [libavformat], [:], [ac_cv_my_have_ffmpeg=no])
 PKG_CHECK_MODULES([LIBSWSCALE], [libswscale], [:], [ac_cv_my_have_ffmpeg=no])
 AM_CONDITIONAL(USE_FFMPEG, test "${ac_cv_my_have_ffmpeg}" = "yes")
 
+# Build CGAL stuff?
+ac_cv_my_have_cgal="no"
+AC_LANG_PUSH(C++)
+AC_CHECK_HEADERS(CGAL/version.h,
+ [ac_cv_my_have_cgal="yes"],
+ [ac_cv_my_have_cgal="no"])
+AC_LANG_POP(C++)
+if test "${ac_cv_my_have_cgal}" != "no"; then
+  AC_DEFINE(USE_CGAL, 1, Define to 1 to use CGAL)
+fi
+AM_CONDITIONAL(USE_CGAL, test "${ac_cv_my_have_cgal}" = "yes")
+
 # Build The Pimp?
 ac_cv_my_have_gtksharp="${ac_cv_my_have_csharp}"
 PKG_CHECK_MODULES([GLIB_SHARP_20], [glib-sharp-2.0], [:], [ac_cv_my_have_gtksharp=no])