/**
 * 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 ringEmitter.h
 * @author charles
 * @date 2000-06-22
 */

#ifndef RINGEMITTER_H
#define RINGEMITTER_H

#include "baseParticleEmitter.h"

/**
 * Describes a planar ring region in which particles are generated.
 */
class EXPCL_PANDA_PARTICLESYSTEM RingEmitter : public BaseParticleEmitter {
PUBLISHED:
  RingEmitter();
  RingEmitter(const RingEmitter &copy);
  virtual ~RingEmitter();

  virtual BaseParticleEmitter *make_copy();

  INLINE void set_radius(PN_stdfloat r);
  INLINE void set_angle(PN_stdfloat angle);
  INLINE void set_radius_spread(PN_stdfloat spread);
  INLINE void set_uniform_emission(int uniform_emission);

  INLINE PN_stdfloat get_radius() const;
  INLINE PN_stdfloat get_angle() const;
  INLINE PN_stdfloat get_radius_spread() const;
  INLINE int get_uniform_emission() const;

  virtual void output(std::ostream &out) const;
  virtual void write(std::ostream &out, int indent=0) const;

protected:
  PN_stdfloat _radius;
  PN_stdfloat _radius_spread;

  // CUSTOM EMISSION PARAMETERS
  PN_stdfloat _aoe;  // angle of elevation

  // viariables used for uniform particle emission
  int _uniform_emission;
  PN_stdfloat _theta;

  // scratch variables that carry over from position calc to velocity calc
  PN_stdfloat _sin_theta;
  PN_stdfloat _cos_theta;

private:
  virtual void assign_initial_position(LPoint3& pos);
  virtual void assign_initial_velocity(LVector3& vel);
};

#include "ringEmitter.I"

#endif // RINGEMITTER_H