+PKG_PROG_PKG_CONFIG
+
+AC_PATH_PROGS([DOXYGEN], [doxygen])
+AC_SUBST(DOXYGEN)
+
+#
+# Configure platform-specific stuff.
+#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+case "${host}" in
+ *mingw32*)
+ MINGW32=yes
+ WIN32=yes
+ AC_PATH_PROGS([WINDRES], [windres $host_alias-windres $host_os-windres])
+ if test "x$WINDRES" = x
+ then
+ AC_MSG_ERROR([windres could not be found])
+ fi
+ AC_PATH_PROGS([MAKENSIS], [makensis])
+ ;;
+ *cygwin*)
+ CYGWIN=yes
+ WIN32=yes
+ ;;
+ *-apple-darwin*)
+ MACOSX=yes
+ LIBS="$LIBS -Wl,-framework"
+ ;;
+esac
+
+AM_CONDITIONAL([WIN32], test "$WIN32" = "yes")
+
+
+#
+# Checks for configuration arguments.
+#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+AC_ARG_ENABLE([debug],
+ [ --enable-debug include debugging symbols and features],
+ [debug=$enableval],
+ [debug=no])
+
+AC_ARG_ENABLE([double-precision],
+ [ --enable-double-precision use double-precision numbers],
+ [double_precision=$enableval],
+ [double_precision=no])
+
+AC_ARG_ENABLE([profile],
+ [ --enable-profile make a binary for use with gprof profiler],
+ [profile=$enableval],
+ [profile=no])
+
+AC_ARG_ENABLE([extra-warnings],
+ [ --enable-extra-warnings make the gcc compiler give more warnings],
+ [extra_warnings=$enableval],
+ [extra_warnings=no])
+
+AC_ARG_ENABLE([threads],
+ [ --enable-threads use threads for some parallel tasks],
+ [threads=$enableval],
+ [threads=no])
+
+AC_ARG_ENABLE([gtk],
+ [ --enable-gtk enable GTK+ info/warning dialogs],
+ [gtk=$enableval],
+ [gtk=no])
+
+AC_ARG_ENABLE([qt4],
+ [ --enable-qt4 enable QT info/warning dialogs],
+ [qt4=$enableval],
+ [qt4=no])
+
+
+if test x$debug = xyes
+then
+ CFLAGS="$CFLAGS -DDEBUG -Wall -Wno-uninitialized"
+ CXXFLAGS="$CXXFLAGS -DDEBUG -Wall -Wno-uninitialized"
+else
+ CFLAGS="$CFLAGS -DNDEBUG"
+ CXXFLAGS="$CXXFLAGS -DNDEBUG"
+fi
+
+if test x$double_precision = xyes
+then
+ AC_DEFINE([USE_DOUBLE_PRECISION], 1,
+ [Define to 1 if you want to use doubles instead of floats.])
+fi
+
+if test x$profile = xyes
+then
+ CFLAGS="$CFLAGS -pg"
+ CXXFLAGS="$CXXFLAGS -pg"
+ AC_DEFINE([PROFILING_ENABLED], 1,
+ [Define to 1 if profiling is built in.])
+fi
+
+if test x$extra_warnings = xyes
+then
+ CFLAGS="$CFLAGS -Wextra -Wno-unused-parameter"
+ CXXFLAGS="$CXXFLAGS -Wextra -Wno-unused-parameter"
+fi
+
+if test x$threads = xyes
+then
+ AC_DEFINE([USE_THREADS], 1,
+ [Define to 1 if you want to use threads when applicable.])
+fi
+
+if test x$gtk = xyes
+then
+ AC_DEFINE([USE_GTK], 1,
+ [Define to 1 if you want to use GTK+ info/error dialogs.])
+elif test x$qt4 = xyes
+then
+ AC_DEFINE([USE_QT4], 1,
+ [Define to 1 if you want to use QT4 info/error dialogs.])
+fi
+