/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file eggNode.I
 * @author drose
 * @date 1999-02-10
 */

/**
 *
 */
INLINE EggNode::
EggNode(const std::string &name) : EggNamedObject(name) {
  _parent = nullptr;
  _depth = 0;
  _under_flags = 0;
}

/**
 *
 */
INLINE EggNode::
EggNode(const EggNode &copy) : EggNamedObject(copy) {
  _parent = nullptr;
  _depth = 0;
  _under_flags = 0;
}


/**
 *
 */
INLINE EggNode &EggNode::
operator = (const EggNode &copy) {
  EggNamedObject::operator = (copy);
  update_under(0);
  return *this;
}


/**
 *
 */
INLINE EggGroupNode *EggNode::
get_parent() const {
  return _parent;
}

/**
 * Returns the number of nodes above this node in the egg hierarchy.
 */
INLINE int EggNode::
get_depth() const {
  return _depth;
}


/**
 * Returns true if there is an <Instance> node somewhere in the egg tree at or
 * above this node, false otherwise.
 */
INLINE bool EggNode::
is_under_instance() const {
  return (_under_flags & UF_under_instance) != 0;
}

/**
 * Returns true if there is a <Transform> entry somewhere in the egg tree at
 * or above this node, false otherwise.
 */
INLINE bool EggNode::
is_under_transform() const {
  return (_under_flags & UF_under_transform) != 0;
}

/**
 * Returns true if this node's vertices are not in the global coordinate
 * space.  This will be the case if there was an <Instance> node under a
 * transform at or above this node.
 */
INLINE bool EggNode::
is_local_coord() const {
  return (_under_flags & UF_local_coord) != 0;
}


/**
 * Returns the coordinate frame of the vertices referenced by primitives at or
 * under this node.  This is not the same as get_node_frame().
 *
 * Generally, vertices in an egg file are stored in the global coordinate
 * space, regardless of the transforms defined at each node.  Thus,
 * get_vertex_frame() will usually return the identity transform (global
 * coordinate space).  However, primitives under an <Instance> entry reference
 * their vertices in the coordinate system under effect at the time of the
 * <Instance>.  Thus, nodes under an <Instance> entry may return this non-
 * identity matrix.
 *
 * Specifically, this may return a non-identity matrix only if
 * is_local_coord() is true.
 */
INLINE const LMatrix4d &EggNode::
get_vertex_frame() const {
  if (_vertex_frame == nullptr) {
    return LMatrix4d::ident_mat();
  } else {
    return *_vertex_frame;
  }
}


/**
 * Returns the coordinate frame of the node itself.  This is simply the net
 * product of all transformations up to the root.
 */
INLINE const LMatrix4d &EggNode::
get_node_frame() const {
  if (_node_frame == nullptr) {
    return LMatrix4d::ident_mat();
  } else {
    return *_node_frame;
  }
}

/**
 * Returns the inverse of the matrix returned by get_vertex_frame().  See
 * get_vertex_frame().
 */
INLINE const LMatrix4d &EggNode::
get_vertex_frame_inv() const {
  if (_vertex_frame_inv == nullptr) {
    return LMatrix4d::ident_mat();
  } else {
    return *_vertex_frame_inv;
  }
}


/**
 * Returns the inverse of the matrix returned by get_node_frame().  See
 * get_node_frame().
 */
INLINE const LMatrix4d &EggNode::
get_node_frame_inv() const {
  if (_node_frame_inv == nullptr) {
    return LMatrix4d::ident_mat();
  } else {
    return *_node_frame_inv;
  }
}

/**
 * Returns the transformation matrix suitable for converting the vertices as
 * read from the egg file into the coordinate space of the node.  This is the
 * same thing as:
 *
 * get_vertex_frame() * get_node_frame_inv()
 *
 */
INLINE const LMatrix4d &EggNode::
get_vertex_to_node() const {
  if (_vertex_to_node == nullptr) {
    return LMatrix4d::ident_mat();
  } else {
    return *_vertex_to_node;
  }
}

/**
 * Returns the transformation matrix suitable for converting vertices in the
 * coordinate space of the node to the appropriate coordinate space for
 * storing in the egg file.  This is the same thing as:
 *
 * get_node_frame() * get_vertex_frame_inv()
 *
 */
INLINE const LMatrix4d &EggNode::
get_node_to_vertex() const {
  if (_node_to_vertex == nullptr) {
    return LMatrix4d::ident_mat();
  } else {
    return *_node_to_vertex;
  }
}

/**
 * Returns either a NULL pointer or a unique pointer shared by nodes with the
 * same get_vertex_frame() matrix.
 */
INLINE const LMatrix4d *EggNode::
get_vertex_frame_ptr() const {
  return _vertex_frame;
}


/**
 * Returns either a NULL pointer or a unique pointer shared by nodes with the
 * same get_node_frame() matrix.
 */
INLINE const LMatrix4d *EggNode::
get_node_frame_ptr() const {
  return _node_frame;
}

/**
 * Returns either a NULL pointer or a unique pointer shared by nodes with the
 * same get_vertex_frame_inv() matrix.
 */
INLINE const LMatrix4d *EggNode::
get_vertex_frame_inv_ptr() const {
  return _vertex_frame_inv;
}


/**
 * Returns either a NULL pointer or a unique pointer shared by nodes with the
 * same get_node_frame_inv() matrix.
 */
INLINE const LMatrix4d *EggNode::
get_node_frame_inv_ptr() const {
  return _node_frame_inv;
}

/**
 * Returns either a NULL pointer or a unique pointer shared by nodes with the
 * same get_vertex_to_node() matrix.
 */
INLINE const LMatrix4d *EggNode::
get_vertex_to_node_ptr() const {
  return _vertex_to_node;
}

/**
 * Returns either a NULL pointer or a unique pointer shared by nodes with the
 * same get_node_to_vertex() matrix.
 */
INLINE const LMatrix4d *EggNode::
get_node_to_vertex_ptr() const {
  return _node_to_vertex;
}


/**
 * Applies the indicated transformation to the node and all of its
 * descendants.
 */
INLINE void EggNode::
transform(const LMatrix4d &mat) {
  LMatrix4d inv = invert(mat);

  r_transform(mat, inv, CS_default);
  r_transform_vertices(mat);

  // Now we have to recompute the under_flags to ensure that all the cached
  // relative matrices are correct.
  update_under(0);
}

/**
 * Applies the indicated transformation only to vertices that appear in global
 * space within vertex pools at this node and below.  Joints and other
 * transforms are not affected, nor are local vertices.
 */
INLINE void EggNode::
transform_vertices_only(const LMatrix4d &mat) {
  r_transform_vertices(mat);
}

/**
 * Removes any transform and instance records from this node in the scene
 * graph and below.  If an instance node is encountered, removes the instance
 * and applies the transform to its vertices, duplicating vertices if
 * necessary.
 *
 * Since this function may result in duplicated vertices, it may be a good
 * idea to call remove_unused_vertices() after calling this.
 */
INLINE void EggNode::
flatten_transforms() {
  r_flatten_transforms();
  update_under(0);
}