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panda/src/express/typeHandle.I

Go to the documentation of this file.

// Filename: typeHandle.I
// Created by:  drose (22Feb00)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001, Disney Enterprises, Inc.  All rights reserved
//
// All use of this software is subject to the terms of the Panda 3d
// Software license.  You should have received a copy of this license
// along with this source code; you will also find a current copy of
// the license at http://www.panda3d.org/license.txt .
//
// To contact the maintainers of this program write to
// panda3d@yahoogroups.com .
//
////////////////////////////////////////////////////////////////////


// In general, we use the express_cat->info() syntax in this file
// (instead of express_cat.info()), because much of this work is done at
// static init time, and we must use the arrow syntax to force
// initialization of the express_cat category.

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::Constructor
//       Access: Published
//  Description: The default constructor must do nothing, because we
//               can't guarantee ordering of static initializers.  If
//               the constructor tried to initialize its value, it
//               might happen after the value had already been set
//               previously by another static initializer!
////////////////////////////////////////////////////////////////////
INLINE TypeHandle::
TypeHandle() {
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::Copy Constructor
//       Access: Published
//  Description:
////////////////////////////////////////////////////////////////////
INLINE TypeHandle::
TypeHandle(const TypeHandle &copy) : _index(copy._index) {
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::Equality Operator
//       Access: Published
//  Description:
////////////////////////////////////////////////////////////////////
INLINE bool TypeHandle::
operator == (const TypeHandle &other) const {
  return (_index == other._index);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::Inequality Operator
//       Access: Published
//  Description:
////////////////////////////////////////////////////////////////////
INLINE bool TypeHandle::
operator != (const TypeHandle &other) const {
  return (_index != other._index);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::Ordering Operator
//       Access: Published
//  Description:
////////////////////////////////////////////////////////////////////
INLINE bool TypeHandle::
operator < (const TypeHandle &other) const {
  return (_index < other._index);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::Ordering Operator
//       Access: Published
//  Description:
////////////////////////////////////////////////////////////////////
INLINE bool TypeHandle::
operator <= (const TypeHandle &other) const {
  return (_index <= other._index);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::Ordering Operator
//       Access: Published
//  Description:
////////////////////////////////////////////////////////////////////
INLINE bool TypeHandle::
operator > (const TypeHandle &other) const {
  return (_index > other._index);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::Ordering Operator
//       Access: Published
//  Description:
////////////////////////////////////////////////////////////////////
INLINE bool TypeHandle::
operator >= (const TypeHandle &other) const {
  return (_index >= other._index);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::compare_to
//       Access: Published
//  Description: Sorts TypeHandles arbitrarily (according to <, >,
//               etc.).  Returns a number less than 0 if this type
//               sorts before the other one, greater than zero if it
//               sorts after, 0 if they are equivalent.
////////////////////////////////////////////////////////////////////
INLINE int TypeHandle::
compare_to(const TypeHandle &other) const {
  return _index - other._index;
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::get_name
//       Access: Published
//  Description: Returns the name of the type.
//
//               The "object" pointer is an optional pointer to the
//               TypedObject class that owns this TypeHandle.  It is
//               only used in case the TypeHandle is inadvertantly
//               undefined.
////////////////////////////////////////////////////////////////////
INLINE string TypeHandle::
get_name(TypedObject *object) const {
  if ((*this) == TypeHandle::none()) {
    return "none";
  } else {
    return TypeRegistry::ptr()->get_name(*this, object);
  }
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::is_derived_from
//       Access: Published
//  Description: Returns true if this type is derived from the
//               indicated type, false otherwise.
//
//               The "object" pointer is an optional pointer to the
//               TypedObject class that owns this TypeHandle.  It is
//               only used in case the TypeHandle is inadvertantly
//               undefined.
////////////////////////////////////////////////////////////////////
INLINE bool TypeHandle::
is_derived_from(TypeHandle parent, TypedObject *object) const {
  return TypeRegistry::ptr()->is_derived_from(*this, parent, object);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::get_num_parent_classes
//       Access: Published
//  Description: Returns the number of parent classes that this
//               type is known to have.  This may then be used to
//               index into get_parent_class().  The result will be 0
//               if this class does not inherit from any other
//               classes, 1 if normal, single inheritance is in
//               effect, or greater than one if multiple inheritance
//               is in effect.
//
//               The "object" pointer is an optional pointer to the
//               TypedObject class that owns this TypeHandle.  It is
//               only used in case the TypeHandle is inadvertantly
//               undefined.
////////////////////////////////////////////////////////////////////
INLINE int TypeHandle::
get_num_parent_classes(TypedObject *object) const {
  return TypeRegistry::ptr()->get_num_parent_classes(*this, object);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::get_num_parent_classes
//       Access: Published
//  Description: Returns the nth parent class of this type.  The index
//               should be in the range 0 <= index <
//               get_num_parent_classes().
////////////////////////////////////////////////////////////////////
INLINE TypeHandle TypeHandle::
get_parent_class(int index) const {
  return TypeRegistry::ptr()->get_parent_class(*this, index);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::get_num_child_classes
//       Access: Published
//  Description: Returns the number of child classes that this
//               type is known to have.  This may then be used to
//               index into get_child_class().
//
//               The "object" pointer is an optional pointer to the
//               TypedObject class that owns this TypeHandle.  It is
//               only used in case the TypeHandle is inadvertantly
//               undefined.
////////////////////////////////////////////////////////////////////
INLINE int TypeHandle::
get_num_child_classes(TypedObject *object) const {
  return TypeRegistry::ptr()->get_num_child_classes(*this, object);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::get_num_child_classes
//       Access: Published
//  Description: Returns the nth child class of this type.  The index
//               should be in the range 0 <= index <
//               get_num_child_classes().
////////////////////////////////////////////////////////////////////
INLINE TypeHandle TypeHandle::
get_child_class(int index) const {
  return TypeRegistry::ptr()->get_child_class(*this, index);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::get_parent_towards
//       Access: Published
//  Description: Returns the parent class that is in a direct line of
//               inheritance to the indicated ancestor class.  This is
//               useful in the presence of multiple inheritance to try
//               to determine what properties an unknown type may
//               have.
//
//               The return value is TypeHandle::none() if the type
//               does not inherit from the ancestor.  If ancestor is
//               the same as this type, the return value is this type.
//
//               The "object" pointer is an optional pointer to the
//               TypedObject class that owns this TypeHandle.  It is
//               only used in case the TypeHandle is inadvertantly
//               undefined.
////////////////////////////////////////////////////////////////////
INLINE TypeHandle TypeHandle::
get_parent_towards(TypeHandle ancestor, TypedObject *object) const {
  return TypeRegistry::ptr()->get_parent_towards(*this, ancestor, object);
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::get_index
//       Access: Published
//  Description: Returns the integer index associated with this
//               TypeHandle. Each different TypeHandle will have a
//               different index.  However, you probably shouldn't be
//               using this method; you should just treat the
//               TypeHandles as opaque classes.  This is provided for
//               the convenience of non-C++ scripting languages to
//               build a hashtable of TypeHandles.
////////////////////////////////////////////////////////////////////
INLINE int TypeHandle::
get_index() const {
  return _index;
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::output
//       Access: Published
//  Description: 
////////////////////////////////////////////////////////////////////
INLINE void TypeHandle::
output(ostream &out) const {
  out << get_name();
}

////////////////////////////////////////////////////////////////////
//     Function: TypeHandle::none
//       Access: Published, Static
//  Description: Returns a special zero-valued TypeHandle that is used
//               to indicate no type.
////////////////////////////////////////////////////////////////////
INLINE TypeHandle TypeHandle::
none() {
  return _none;
}

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