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panda/src/particlesystem/zSpinParticle.cxx

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// Filename: zSpinParticle.cxx
// Created by:  charles (16Aug00)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) 2001, 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://www.panda3d.org/license.txt .
//
// To contact the maintainers of this program write to
// panda3d@yahoogroups.com .
//
////////////////////////////////////////////////////////////////////

#include "zSpinParticle.h"

////////////////////////////////////////////////////////////////////
//    Function : ZSpinParticle
//      Access : public
// Description : constructor
////////////////////////////////////////////////////////////////////
ZSpinParticle::
ZSpinParticle(void) :
  BaseParticle() {
  _initial_angle = 0.0f;
  _final_angle = 0.0f;
  _cur_angle = 0.0f;
  _angular_velocity = 0.0f;
  _bUseAngularVelocity = false;
}

////////////////////////////////////////////////////////////////////
//    Function : ZSpinParticle
//      Access : public
// Description : copy constructor
////////////////////////////////////////////////////////////////////
ZSpinParticle::
ZSpinParticle(const ZSpinParticle &copy) :
  BaseParticle(copy) {
  _initial_angle = copy._initial_angle;
  _final_angle = copy._final_angle;
  _cur_angle = copy._cur_angle;
  _angular_velocity = copy._angular_velocity;
  _bUseAngularVelocity = copy._bUseAngularVelocity;
}

////////////////////////////////////////////////////////////////////
//    Function : ~ZSpinParticle
//      Access : public, virtual
// Description : destructor
////////////////////////////////////////////////////////////////////
ZSpinParticle::
~ZSpinParticle(void) {
}

////////////////////////////////////////////////////////////////////
//    Function : make_copy
//      Access : public, virtual
// Description : dynamic copier
////////////////////////////////////////////////////////////////////
PhysicsObject *ZSpinParticle::
make_copy(void) const {
  return new ZSpinParticle(*this);
}

////////////////////////////////////////////////////////////////////
//    Function : init
//      Access : public, virtual
// Description :
////////////////////////////////////////////////////////////////////
void ZSpinParticle::
init(void) {
}

////////////////////////////////////////////////////////////////////
//    Function : update
//      Access : public, virtual
// Description :
////////////////////////////////////////////////////////////////////
void ZSpinParticle::
update(void) {
  // if using final_angle, want age to range from [0,1] over lifespan, so use parameterized_age
  // for angular velocity, should be allowed to range freely upward, use regular age

  if(_bUseAngularVelocity) {
   // interpolate the current orientation
      _cur_angle = _initial_angle + (get_age() * _angular_velocity);
  } else {
      _cur_angle = _initial_angle + (get_parameterized_age() * (_final_angle - _initial_angle));
  }

  // normalize the result to [0..360)
  _cur_angle = fmod(_cur_angle, 360.0f);

  // if _cur_angle was negative, it is still negative after fmod,
  // wrap it around by adding 360

  // is this really necessary?  should be in range of sin/cos
  if(_cur_angle < 0.0f)
    _cur_angle += 360.0f;
}

////////////////////////////////////////////////////////////////////
//    Function : die
//      Access : public, virtual
// Description :
////////////////////////////////////////////////////////////////////
void ZSpinParticle::
die(void) {
}

////////////////////////////////////////////////////////////////////
//    Function : get_theta
//      Access : public, virtual
// Description :
////////////////////////////////////////////////////////////////////
float ZSpinParticle::
get_theta(void) const {
  return _cur_angle;
}

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