+/**
+ * Get a property node.
+ *
+ * @param path The path of the node, relative to root.
+ * @param create true to create the node if it doesn't exist.
+ * @return The node, or 0 if none exists and none was created.
+ */
+extern SGPropertyNode * fgGetNode (const char * path, bool create = false);
+
+
+/**
+ * Get a property node with separate index.
+ *
+ * This method separates the index from the path string, to make it
+ * easier to iterate through multiple components without using sprintf
+ * to add indices. For example, fgGetNode("foo[1]/bar", 3) will
+ * return the same result as fgGetNode("foo[1]/bar[3]").
+ *
+ * @param path The path of the node, relative to root.
+ * @param index The index for the last member of the path (overrides
+ * any given in the string).
+ * @param create true to create the node if it doesn't exist.
+ * @return The node, or 0 if none exists and none was created.
+ */
+extern SGPropertyNode * fgGetNode (const char * path,
+ int index, bool create = false);
+
+
+/**
+ * Test whether a given node exists.
+ *
+ * @param path The path of the node, relative to root.
+ * @return true if the node exists, false otherwise.
+ */
+extern bool fgHasNode (const char * path);
+
+
+/**
+ * Add a listener to a node.
+ *
+ * @param listener The listener to add to the node.
+ * @param path The path of the node, relative to root.
+ * @param index The index for the last member of the path (overrides
+ * any given in the string).
+ */
+extern void fgAddChangeListener (SGPropertyChangeListener * listener,
+ const char * path);
+
+
+/**
+ * Add a listener to a node.
+ *
+ * @param listener The listener to add to the node.
+ * @param path The path of the node, relative to root.
+ * @param index The index for the last member of the path (overrides
+ * any given in the string).
+ */
+extern void fgAddChangeListener (SGPropertyChangeListener * listener,
+ const char * path, int index);
+
+
+/**
+ * Get a bool value for a property.
+ *
+ * This method is convenient but inefficient. It should be used
+ * infrequently (i.e. for initializing, loading, saving, etc.),
+ * not in the main loop. If you need to get a value frequently,
+ * it is better to look up the node itself using fgGetNode and then
+ * use the node's getBoolValue() method, to avoid the lookup overhead.
+ *
+ * @param name The property name.
+ * @param defaultValue The default value to return if the property
+ * does not exist.
+ * @return The property's value as a bool, or the default value provided.
+ */
+extern bool fgGetBool (const char * name, bool defaultValue = false);
+
+
+/**
+ * Get an int value for a property.
+ *
+ * This method is convenient but inefficient. It should be used
+ * infrequently (i.e. for initializing, loading, saving, etc.),
+ * not in the main loop. If you need to get a value frequently,
+ * it is better to look up the node itself using fgGetNode and then
+ * use the node's getIntValue() method, to avoid the lookup overhead.
+ *
+ * @param name The property name.
+ * @param defaultValue The default value to return if the property
+ * does not exist.
+ * @return The property's value as an int, or the default value provided.
+ */
+extern int fgGetInt (const char * name, int defaultValue = 0);
+
+
+/**
+ * Get a long value for a property.
+ *
+ * This method is convenient but inefficient. It should be used
+ * infrequently (i.e. for initializing, loading, saving, etc.),
+ * not in the main loop. If you need to get a value frequently,
+ * it is better to look up the node itself using fgGetNode and then
+ * use the node's getLongValue() method, to avoid the lookup overhead.
+ *
+ * @param name The property name.
+ * @param defaultValue The default value to return if the property
+ * does not exist.
+ * @return The property's value as a long, or the default value provided.
+ */
+extern int fgGetLong (const char * name, long defaultValue = 0L);
+
+
+/**
+ * Get a float value for a property.
+ *
+ * This method is convenient but inefficient. It should be used
+ * infrequently (i.e. for initializing, loading, saving, etc.),
+ * not in the main loop. If you need to get a value frequently,
+ * it is better to look up the node itself using fgGetNode and then
+ * use the node's getFloatValue() method, to avoid the lookup overhead.
+ *
+ * @param name The property name.
+ * @param defaultValue The default value to return if the property
+ * does not exist.
+ * @return The property's value as a float, or the default value provided.
+ */
+extern float fgGetFloat (const char * name, float defaultValue = 0.0);
+
+
+/**
+ * Get a double value for a property.
+ *
+ * This method is convenient but inefficient. It should be used
+ * infrequently (i.e. for initializing, loading, saving, etc.),
+ * not in the main loop. If you need to get a value frequently,
+ * it is better to look up the node itself using fgGetNode and then
+ * use the node's getDoubleValue() method, to avoid the lookup overhead.
+ *
+ * @param name The property name.
+ * @param defaultValue The default value to return if the property
+ * does not exist.
+ * @return The property's value as a double, or the default value provided.
+ */
+extern double fgGetDouble (const char * name, double defaultValue = 0.0);
+
+
+/**
+ * Get a string value for a property.
+ *
+ * This method is convenient but inefficient. It should be used
+ * infrequently (i.e. for initializing, loading, saving, etc.),
+ * not in the main loop. If you need to get a value frequently,
+ * it is better to look up the node itself using fgGetNode and then
+ * use the node's getStringValue() method, to avoid the lookup overhead.
+ *
+ * @param name The property name.
+ * @param defaultValue The default value to return if the property
+ * does not exist.
+ * @return The property's value as a string, or the default value provided.
+ */
+extern const char * fgGetString (const char * name,
+ const char * defaultValue = "");
+
+
+/**
+ * Set a bool value for a property.
+ *
+ * Assign a bool value to a property. If the property does not
+ * yet exist, it will be created and its type will be set to
+ * BOOL; if it has a type of UNKNOWN, the type will also be set to
+ * BOOL; otherwise, the bool value will be converted to the property's
+ * type.
+ *
+ * @param name The property name.
+ * @param val The new value for the property.
+ * @return true if the assignment succeeded, false otherwise.
+ */
+extern bool fgSetBool (const char * name, bool val);
+
+
+/**
+ * Set an int value for a property.
+ *
+ * Assign an int value to a property. If the property does not
+ * yet exist, it will be created and its type will be set to
+ * INT; if it has a type of UNKNOWN, the type will also be set to
+ * INT; otherwise, the bool value will be converted to the property's
+ * type.
+ *
+ * @param name The property name.
+ * @param val The new value for the property.
+ * @return true if the assignment succeeded, false otherwise.
+ */
+extern bool fgSetInt (const char * name, int val);
+
+
+/**
+ * Set a long value for a property.
+ *
+ * Assign a long value to a property. If the property does not
+ * yet exist, it will be created and its type will be set to
+ * LONG; if it has a type of UNKNOWN, the type will also be set to
+ * LONG; otherwise, the bool value will be converted to the property's
+ * type.
+ *
+ * @param name The property name.
+ * @param val The new value for the property.
+ * @return true if the assignment succeeded, false otherwise.
+ */
+extern bool fgSetLong (const char * name, long val);
+
+
+/**
+ * Set a float value for a property.
+ *
+ * Assign a float value to a property. If the property does not
+ * yet exist, it will be created and its type will be set to
+ * FLOAT; if it has a type of UNKNOWN, the type will also be set to
+ * FLOAT; otherwise, the bool value will be converted to the property's
+ * type.
+ *
+ * @param name The property name.
+ * @param val The new value for the property.
+ * @return true if the assignment succeeded, false otherwise.
+ */
+extern bool fgSetFloat (const char * name, float val);
+
+
+/**
+ * Set a double value for a property.
+ *
+ * Assign a double value to a property. If the property does not
+ * yet exist, it will be created and its type will be set to
+ * DOUBLE; if it has a type of UNKNOWN, the type will also be set to
+ * DOUBLE; otherwise, the double value will be converted to the property's
+ * type.
+ *
+ * @param name The property name.
+ * @param val The new value for the property.
+ * @return true if the assignment succeeded, false otherwise.
+ */
+extern bool fgSetDouble (const char * name, double val);
+
+
+/**
+ * Set a string value for a property.
+ *
+ * Assign a string value to a property. If the property does not
+ * yet exist, it will be created and its type will be set to
+ * STRING; if it has a type of UNKNOWN, the type will also be set to
+ * STRING; otherwise, the string value will be converted to the property's
+ * type.
+ *
+ * @param name The property name.
+ * @param val The new value for the property.
+ * @return true if the assignment succeeded, false otherwise.
+ */
+extern bool fgSetString (const char * name, const char * val);