/**
 * 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 eggMesherStrip.I
 * @author drose
 * @date 2005-03-13
 */

/**
 *
 */
INLINE EggMesherStrip::
EggMesherStrip(const EggMesherStrip &copy) :
  _prims(copy._prims),
  _edges(copy._edges),
  _verts(copy._verts),
  _type(copy._type),
  _index(copy._index),
  _status(copy._status),
  _planar(copy._planar),
  _plane_normal(copy._plane_normal),
  _plane_offset(copy._plane_offset),
  _row_id(copy._row_id),
  _flat_shaded(copy._flat_shaded)
{
}

/**
 * Returns true if the strip and the other strip are coplanar, within the
 * indicated threshold.  See coplanarity().
 */
INLINE bool EggMesherStrip::
is_coplanar_with(const EggMesherStrip &other, PN_stdfloat threshold) const {
  return (coplanarity(other) <= threshold);
}

/**
 * Returns the degree to which the two strips are coplanar.  0.0 is exactly
 * coplanar; numbers somewhat larger than zero indicate less coplanar.  1.0 is
 * at right angles; 2.0 is exactly backfacing.  If either strip is not itself
 * planar, 3.0 is returned.
 */
INLINE PN_stdfloat EggMesherStrip::
coplanarity(const EggMesherStrip &other) const {
  if (_planar && other._planar) {
    return 1.0 - dot(_plane_normal, other._plane_normal);
  }
  return 3.0;
}

/**
 * Returns an integer which gives a heuristic about the similarity of
 * different strip types.  In general, closer numbers are more similar.
 */
INLINE int EggMesherStrip::
type_category() const {
  switch (_type) {
  case PT_tri:
    return 1;

  case PT_tristrip:
    return 2;

  case PT_quad:
  case PT_quadstrip:
    return 5;

  default:
    return 10;
  }
}


/**
 * Rotates a triangle or quad by bringing its first vertex to the back.
 */
INLINE void EggMesherStrip::
rotate_forward() {
  _verts.push_back(_verts.front());
  _verts.pop_front();
}

/**
 * Rotates a triangle or quad by bringing its last vertex to the front.
 */
INLINE void EggMesherStrip::
rotate_back() {
  _verts.push_front(_verts.back());
  _verts.pop_back();
}


/**
 * Returns an EggMesherEdge which represents the leading edge in the quadstrip
 * or tristrip.  This EggMesherEdge will not have pointer equality with any
 * shared EggMesherEdge.
 */
INLINE EggMesherEdge EggMesherStrip::
get_head_edge() const {
  Verts::const_iterator vi = _verts.begin();
  nassertr(vi != _verts.end(), EggMesherEdge(0, 0));
  ++vi;
  return EggMesherEdge(_verts.front(), *vi);
}

/**
 * Returns an EggMesherEdge which represents the trailing edge in the
 * quadstrip or tristrip.  This EggMesherEdge will not have pointer equality
 * with any shared EggMesherEdge.
 */
INLINE EggMesherEdge EggMesherStrip::
get_tail_edge() const {
  Verts::const_reverse_iterator vi = _verts.rbegin();
  nassertr(vi != _verts.rend(), EggMesherEdge(0, 0));
  ++vi;
  return EggMesherEdge(*vi, _verts.back());
}

/**
 * Defines equality for strips.  This actually tests only pointer equality;
 * it's used only when removing a strip from the list.
 */
INLINE bool EggMesherStrip::
operator == (const EggMesherStrip &other) const {
  return this == &other;
}

/**
 *
 */
INLINE bool EggMesherStrip::
operator != (const EggMesherStrip &other) const {
  return !operator == (other);
}