/**
 * 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 cullBinBackToFront.h
 * @author drose
 * @date 2002-02-28
 */

#ifndef CULLBINBACKTOFRONT_H
#define CULLBINBACKTOFRONT_H

#include "pandabase.h"

#include "cullBin.h"
#include "geom.h"
#include "transformState.h"
#include "renderState.h"
#include "pointerTo.h"

/**
 * A specific kind of CullBin that sorts geometry in order from furthest to
 * nearest based on the center of its bounding volume.  This is primarily
 * intended for rendering transparent and semi-transparent geometry that must
 * be sorted from back to front.
 */
class EXPCL_PANDA_CULL CullBinBackToFront : public CullBin {
public:
  INLINE CullBinBackToFront(const std::string &name,
                            GraphicsStateGuardianBase *gsg,
                            const PStatCollector &draw_region_pcollector);
  virtual ~CullBinBackToFront();

  static CullBin *make_bin(const std::string &name,
                           GraphicsStateGuardianBase *gsg,
                           const PStatCollector &draw_region_pcollector);


  virtual void add_object(CullableObject *object, Thread *current_thread);
  virtual void finish_cull(SceneSetup *scene_setup, Thread *current_thread);
  virtual void draw(bool force, Thread *current_thread);

protected:
  virtual void fill_result_graph(ResultGraphBuilder &builder);

private:
  class ObjectData {
  public:
    INLINE ObjectData(CullableObject *object, PN_stdfloat dist);
    INLINE bool operator < (const ObjectData &other) const;

    CullableObject *_object;
    PN_stdfloat _dist;
  };

  typedef pvector<ObjectData> Objects;
  Objects _objects;

public:
  static TypeHandle get_class_type() {
    return _type_handle;
  }
  static void init_type() {
    CullBin::init_type();
    register_type(_type_handle, "CullBinBackToFront",
                  CullBin::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 "cullBinBackToFront.I"

#endif