void foundPositionedItem(FGPositioned* pos);
void computePositionedPropsAndHeading(FGPositioned* pos, SGPropertyNode* nd, double& heading);
void computePositionedState(FGPositioned* pos, string_set& states);
void foundPositionedItem(FGPositioned* pos);
void computePositionedPropsAndHeading(FGPositioned* pos, SGPropertyNode* nd, double& heading);
void computePositionedState(FGPositioned* pos, string_set& states);
void findRules(const std::string& type, const string_set& states, SymbolRuleVector& rules);
SymbolInstance* addSymbolInstance(const osg::Vec2& proj, double heading, SymbolDef* def, SGPropertyNode* vars);
void findRules(const std::string& type, const string_set& states, SymbolRuleVector& rules);
SymbolInstance* addSymbolInstance(const osg::Vec2& proj, double heading, SymbolDef* def, SGPropertyNode* vars);