/*
     $Id$
     PLIB - A Suite of Portable Game Libraries
     Copyright (C) 1998,2002  Steve Baker
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
     version 2 of the License, or (at your option) any later version.
 
     This library is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Library General Public License for more details.
 
     You should have received a copy of the GNU Library General Public
     License along with this library; if not, write to the Free Software
     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 
     For further information visit http://plib.sourceforge.net                  */

#include <plib/ssg.h>

class Particle
{
public:

  sgVec4 col ;
  sgVec3 pos ;
  sgVec3 vel ;
  sgVec3 acc ;

  float size ;

  float time_to_live ;
  void *userData ;

  void update ( float dt )
  {
    sgAddScaledVec3 ( vel, acc, dt ) ;
    sgAddScaledVec3 ( pos, vel, dt ) ;
    time_to_live -= dt ;
  }

  Particle ()
  {
    sgSetVec4 ( col, 1, 1, 1, 1 ) ;
    sgZeroVec3 ( pos ) ;
    sgZeroVec3 ( vel ) ;
    sgZeroVec3 ( acc ) ;
    time_to_live = 0 ;
    userData = 0 ;
    size = 1.0f ;
  } 

} ;


class ParticleSystem ;

class ParticleSystem : public ssgVtxTable
{
  int num_particles  ;
  int num_verts      ;
  int turn_to_face   ;
  int num_active     ;
  Particle* particles ;

  float create_error ;
  float create_rate ;

  float size ;

public:

  ParticleSystem ( int num, float _create_rate, int _turn_to_face,
                   float sz, float bsphere_size);
  virtual ~ParticleSystem () ;
  virtual void update ( float t ) ;

  virtual void particle_create( int index, Particle *p ) = 0;
  virtual void particle_update( float deltaTime, int index, Particle *p ) = 0;
  virtual void particle_delete( int index, Particle* p ) = 0;

  void init(int initial_num);
  void recalcBSphere();

  void setSize ( float sz ) { size = sz ; }
  float getSize () const { return size ; }

  void draw_geometry () ;

  void  setCreationRate ( float cr ) { create_rate = cr ; }
  float getCreationRate () const { return create_rate ; }

  int getNumParticles       () const { return num_particles ; }
  int getNumActiveParticles () const { return num_active    ; }
} ;

/* EOF */
