// Filename: baseIntegrator.h
// Created by:  charles (11Aug00)
//
////////////////////////////////////////////////////////////////////
//
// 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 BASEINTEGRATOR_H
#define BASEINTEGRATOR_H

#include "pandabase.h"
#include "pointerTo.h"
#include "referenceCount.h"
#include "luse.h"

#include "linearForce.h"
#include "angularForce.h"

#include "pvector.h"

class Physical;

////////////////////////////////////////////////////////////////////
//       Class : BaseIntegrator
// Description : pure virtual integrator class that holds cached
//               matrix information that really should be common to
//               any possible child implementation.
////////////////////////////////////////////////////////////////////
class EXPCL_PANDAPHYSICS BaseIntegrator : public ReferenceCount {
public:
  typedef pvector<LMatrix4f> MatrixVector;
  typedef pvector<PT(LinearForce)> LinearForceVector;
  typedef pvector<PT(AngularForce)> AngularForceVector;

  virtual ~BaseIntegrator();
  
  virtual void output(ostream &out) const;
  virtual void write_precomputed_linear_matrices(ostream &out,
                                                 unsigned int indent=0) const;
  virtual void write_precomputed_angular_matrices(ostream &out,
                                                  unsigned int indent=0) const;
  virtual void write(ostream &out, unsigned int indent=0) const;

protected:
  BaseIntegrator();

  INLINE const MatrixVector &get_precomputed_linear_matrices() const;
  INLINE const MatrixVector &get_precomputed_angular_matrices() const;

  void precompute_linear_matrices(Physical *physical,
                                  const LinearForceVector &forces);
  void precompute_angular_matrices(Physical *physical,
                                   const AngularForceVector &forces);

private:
  // since the wrt for each physicsobject between its physicalnode
  // and however many forces will be the same among one physical,
  // the transformation matrices can be pulled out of the inner loop
  // and precomputed.
  MatrixVector _precomputed_linear_matrices;
  MatrixVector _precomputed_angular_matrices;
};

#include "baseIntegrator.I"

#endif // BASEINTEGRATOR_H