add get_net_tag(), etc.

panda/src/pgraph/nodePath.I

@@ -326,7 +326,9 @@ has_parent() const {
 ////////////////////////////////////////////////////////////////////
 INLINE NodePath NodePath::
 get_parent() const {
-  nassertr(has_parent(), NodePath::fail());
+  if (!has_parent()) {
+    return NodePath::fail();
+  }
   NodePath parent;
   parent._head = _head->get_next();
   return parent;
@@ -1149,11 +1151,15 @@ set_tag(const string &key, const string &value) {
 //  Description: Retrieves the user-defined value that was previously
 //               set on this node for the particular key, if any.  If
 //               no value has been previously set, returns the empty
-//               string.
+//               string.  See also get_net_tag().
 ////////////////////////////////////////////////////////////////////
 INLINE string NodePath::
 get_tag(const string &key) const {
-  nassertr_always(!is_empty(), string());
+  // An empty NodePath quietly returns no tags.  This makes
+  // get_net_tag() easier to implement.
+  if (is_empty()) {
+    return string();
+  }
   return node()->get_tag(key);
 }
 
@@ -1163,10 +1169,15 @@ get_tag(const string &key) const {
 //  Description: Returns true if a value has been defined on this node
 //               for the particular key (even if that value is the
 //               empty string), or false if no value has been set.
+//               See also has_net_tag().
 ////////////////////////////////////////////////////////////////////
 INLINE bool NodePath::
 has_tag(const string &key) const {
-  nassertr_always(!is_empty(), false);
+  // An empty NodePath quietly has no tags.  This makes has_net_tag()
+  // easier to implement.
+  if (is_empty()) {
+    return false;
+  }
   return node()->has_tag(key);
 }
 
@@ -1183,6 +1194,32 @@ clear_tag(const string &key) {
   node()->clear_tag(key);
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: NodePath::get_net_tag
+//       Access: Published
+//  Description: Returns the tag value that has been defined on this
+//               node, or the nearest ancestor node, for the indicated
+//               key.  If no value has been defined for the indicated
+//               key on any ancestor node, returns the empty string.
+//               See also get_tag().
+////////////////////////////////////////////////////////////////////
+INLINE string NodePath::
+get_net_tag(const string &key) const {
+  return find_net_tag(key).get_tag(key);
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: NodePath::has_net_tag
+//       Access: Published
+//  Description: Returns true if the indicated tag value has been
+//               defined on this node or on any ancestor node, or
+//               false otherwise.  See also has_tag().
+////////////////////////////////////////////////////////////////////
+INLINE bool NodePath::
+has_net_tag(const string &key) const {
+  return find_net_tag(key).has_tag(key);
+}
+
 
 INLINE ostream &operator << (ostream &out, const NodePath &node_path) {
   node_path.output(out);

panda/src/pgraph/nodePath.cxx

@@ -2936,6 +2936,25 @@ flatten_strong() {
   return num_removed;
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: NodePath::find_net_tag
+//       Access: Published
+//  Description: Returns the lowest ancestor of this node that
+//               contains a tag definition with the indicated key, if
+//               any, or an empty NodePath if no ancestor of this node
+//               contains this tag definition.  See set_tag().
+////////////////////////////////////////////////////////////////////
+NodePath NodePath::
+find_net_tag(const string &key) const {
+  if (is_empty()) {
+    return NodePath::not_found();
+  }
+  if (has_tag(key)) {
+    return *this;
+  }
+  return get_parent().find_net_tag(key);
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: NodePath::write_bam_file
 //       Access: Published

panda/src/pgraph/nodePath.h

@@ -523,6 +523,9 @@ PUBLISHED:
   INLINE string get_tag(const string &key) const;
   INLINE bool has_tag(const string &key) const;
   INLINE void clear_tag(const string &key);
+  INLINE string get_net_tag(const string &key) const;
+  INLINE bool has_net_tag(const string &key) const;
+  NodePath find_net_tag(const string &key) const;
 
   bool write_bam_file(const string &filename) const;