check for the composite library

configure.ac

@@ -136,6 +136,31 @@ else
   xcursor_found=no
 fi
 
+AC_ARG_ENABLE(xcomposite,
+  AC_HELP_STRING(
+    [--disable-xcomposite],
+    [disable use of the X Composite library. [[default=enabled]]]
+  ),
+  [enable_xcomposite=$enableval],
+  [enable_xcomposite=yes]
+)
+
+if test "$enable_xcomposite" = yes; then
+PKG_CHECK_MODULES(XCOMPOSITE, [xcomposite],
+  [
+    AC_DEFINE(USE_XCOMPOSITE, [1], [Use X Composite library])
+    AC_SUBST(XCOMPOSITE_CFLAGS)
+    AC_SUBST(XCOMPOSITE_LIBS)
+    xcomposite_found=yes
+  ],
+  [
+    xcomposite_found=no
+  ]
+)
+else
+  xcomposite_found=no
+fi
+
 dnl Check for session management
 X11_SM
 
@@ -170,6 +195,7 @@ AC_MSG_RESULT
 AC_MSG_RESULT([Compiling with these options:
                Startup Notification... $sn_found
                X Cursor Library... $xcursor_found
+               X Composite Library... $xcomposite_found
                Session Management... $SM
                ])
 AC_MSG_RESULT([configure complete, now type "make"])