-##### librt (optional) #####
-AC_SEARCH_LIBS([clock_gettime], [rt],
- [AC_DEFINE([HAVE_CLOCK_GETTIME], 1,
- [Define to 1 if you have the 'clock_gettime' function.])])
+##### libpng #####
+website="http://www.libpng.org/pub/png/libpng.html"
+PKG_CHECK_MODULES([PNG], [libpng],
+ [LIBS="$LIBS $PNG_LIBS"
+ CFLAGS="$CFLAGS $PNG_CFLAGS"
+ CXXFLAGS="$CXXFLAGS $PNG_CFLAGS"],
+ [missing=yes
+ echo "***** Missing libpng ($website) *****"])
+
+##### libvorbis #####
+website="http://www.xiph.org/downloads/"
+PKG_CHECK_MODULES([VORBIS], [vorbisfile],
+ [LIBS="$LIBS $VORBIS_LIBS"
+ CFLAGS="$CFLAGS $VORBIS_CFLAGS"
+ CXXFLAGS="$CXXFLAGS $VORBIS_CFLAGS"],
+ [missing=yes
+ echo "***** Missing libvorbisfile ($website) *****"])
+
+##### GTK+ 2.0 #####
+if test x$gtk = xyes
+then
+ website="http://www.gtk.org/"
+ PKG_CHECK_MODULES([GTK], [gtk+-2.0],
+ [LIBS="$LIBS $GTK_LIBS"
+ CFLAGS="$CFLAGS $GTK_CFLAGS"
+ CXXFLAGS="$CXXFLAGS $GTK_CFLAGS"],
+ [missing=yes
+ echo "***** Missing GTK+-2.0 ($website) *****"])
+fi
+
+##### QT4 #####
+if test x$qt4 = xyes
+then
+ website="http://qt.nokia.com/"
+ PKG_CHECK_MODULES([QT], [QtGui],
+ [LIBS="$LIBS $QT_LIBS"
+ CFLAGS="$CFLAGS $QT_CFLAGS"
+ CXXFLAGS="$CXXFLAGS $QT_CFLAGS"],
+ [missing=yes
+ echo "***** Missing QT ($website) *****"])
+fi