particle_emitter.h

Go to the documentation of this file.

//            Copyright (C) 2004-2007 by The Allacrost Project
//                         All Rights Reserved
//
// This code is licensed under the GNU GPL version 2. It is free software 
// and you may modify it and/or redistribute it under the terms of this license.
// See http://www.gnu.org/copyleft/gpl.html for details.

/*!****************************************************************************
 * \file    particle_emitter.h
 * \author  Raj Sharma, roos@allacrost.org
 * \brief   Header file for particle emitter
 *
 * This file contains the ParticleEmitter class, and some enumerations for
 * emitter properties.
 *
 * ParticleEmitter stores info about how a system emits particles. This is made
 * up of two things:
 *
 *  1) Where are particles emitted?
 *      -For example, you could create a circle-shaped emitter, and then every
 *         time a particle is emitted, a random spot in that circle is chosen.
 *
 *  2) When are particles emitted?
 *      -For example, you could emit them all at once, or slowly through the
 *         life of the system.
 *****************************************************************************/

#ifndef __PARTICLE_EMITTER_HEADER__
#define __PARTICLE_EMITTER_HEADER__

#include "defs.h"
#include "utils.h"

namespace hoa_video {

/*!***************************************************************************
 *  \brief Specifies whether the orientation for particle rotations should be
 *         counterclockwise, clockwise, or random.
 *****************************************************************************/

enum EMITTER_SPIN
{
  EMITTER_SPIN_INVALID          = -1,
  
  EMITTER_SPIN_CLOCKWISE        = 0,   
  EMITTER_SPIN_COUNTERCLOCKWISE = 1,   
  EMITTER_SPIN_RANDOM           = 2,   
  
  EMITTER_SPIN_TOTAL = 3
};


/*!***************************************************************************
 *  \brief Shape of the emitter. A point emitter is the most simple- all
 *         particles come out from a point. Another example is a line emitter.
 *         This may be useful for a snow effect- you place the line at the top
 *         of the screen, and particles will be generated anywhere along that line.
 *****************************************************************************/

enum EMITTER_SHAPE
{
  EMITTER_SHAPE_INVALID          = -1,
  
  EMITTER_SHAPE_POINT            =  0,   
  EMITTER_SHAPE_LINE             =  1,   
  EMITTER_SHAPE_CIRCLE           =  2,   
  EMITTER_SHAPE_FILLED_CIRCLE    =  3,   
  EMITTER_SHAPE_FILLED_RECTANGLE =  4,   
  
  EMITTER_SHAPE_TOTAL = 5
};

/*!***************************************************************************
 *  \brief An enumeration of EMITTER modes for particles
 *****************************************************************************/

enum EMITTER_MODE
{
  EMITTER_MODE_INVALID = -1, 
  
  EMITTER_MODE_LOOPING  = 0,   
  EMITTER_MODE_ONE_SHOT = 1,   
  EMITTER_MODE_BURST    = 2,   
  EMITTER_MODE_ALWAYS   = 3,   
  
  EMITTER_MODE_TOTAL = 4
};


class ParticleEmitter
{
public:

  float _x; 
  float _y;
  
  float _x2;
  float _y2;

  float _center_x;
  float _center_y;

  float _x_variation;
  float _y_variation;

  float _radius;  
  
  EMITTER_SHAPE _shape;

  bool _omnidirectional;
  
  float _orientation;
  
  float _outer_cone;
  
  float _inner_cone;
  
  float _initial_speed;
  
  float _initial_speed_variation;
    
  float _emission_rate;
  
  float _start_time;
  
  EMITTER_MODE _emitter_mode;
  
  EMITTER_SPIN _spin;
};

} // namespace hoa_video

#endif  // __PARTICLE_EMITTER_HEADER__

---