// Filename: rigidBodyCombiner.h
// Created by:  drose (22Feb07)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001 - 2004, 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://etc.cmu.edu/panda3d/docs/license/ .
//
// To contact the maintainers of this program write to
// panda3d-general@lists.sourceforge.net .
//
////////////////////////////////////////////////////////////////////

#ifndef RIGIDBODYCOMBINER_H
#define RIGIDBODYCOMBINER_H

#include "pandabase.h"

#include "pandaNode.h"
#include "nodeVertexTransform.h"
#include "pvector.h"

class NodePath;

////////////////////////////////////////////////////////////////////
//       Class : RigidBodyCombiner
// Description : This is a special node that combines multiple
//               independently-moving rigid nodes into one Geom
//               internally (or as few Geoms as possible), for the
//               purposes of improving rendering performance.
//
//               To use it, parent a number of moving objects to this
//               node and call collect().  A child node is identified
//               as "moving" if (a) it has a non-identity transform
//               initially, or (b) it is a ModelNode with the
//               preserve_transform flag set.  Any other nodes will be
//               considered static, and later transforms applied to
//               them will not be identified.
//
//               You should call collect() only at startup or if you
//               change the set of children; it is a relatively
//               expensive call.
//
//               Once you call collect(), you may change the
//               transforms on the child nodes freely without having
//               to call collect() again.
//
//               RenderEffects such as Billboards are not supported
//               below this node.
////////////////////////////////////////////////////////////////////
class EXPCL_PANDA_GRUTIL RigidBodyCombiner : public PandaNode {
PUBLISHED:
  RigidBodyCombiner(const string &name);
protected:
  RigidBodyCombiner(const RigidBodyCombiner &copy);
  virtual PandaNode *make_copy() const;

PUBLISHED:
  void collect();

  NodePath get_internal_scene();

public:
  // From parent class PandaNode
  virtual bool cull_callback(CullTraverser *trav, CullTraverserData &data);

private:
  void r_collect(PandaNode *node, const RenderState *state, 
                 const VertexTransform *transform);
  PT(GeomVertexData) convert_vd(const VertexTransform *transform, 
                                const GeomVertexData *orig);

  PT(PandaNode) _internal_root;

  typedef pvector< PT(NodeVertexTransform) > Transforms;
  Transforms _internal_transforms;

  class VDUnifier {
  public:
    INLINE VDUnifier(const VertexTransform *transform, 
                     const GeomVertexData *orig);
    INLINE bool operator < (const VDUnifier &other) const;

    const VertexTransform *_transform;
    const GeomVertexData *_orig;
  };

  typedef pmap<VDUnifier, PT(GeomVertexData) > VDTable;
  VDTable _vd_table;


public:
  static TypeHandle get_class_type() {
    return _type_handle;
  }
  static void init_type() {
    PandaNode::init_type();
    register_type(_type_handle, "RigidBodyCombiner",
                  PandaNode::get_class_type());
  }
  virtual TypeHandle get_type() const {
    return get_class_type();
  }
  virtual TypeHandle force_init_type() {init_type(); return get_class_type();}

private:
  static TypeHandle _type_handle;
};

#include "rigidBodyCombiner.I"

#endif
