OpenSceneGraph/include/osgParticle/ConstantRateCounter
2006-07-18 15:21:48 +00:00

78 lines
2.7 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* 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
* OpenSceneGraph Public License for more details.
*/
#ifndef OSGPARTICLE_CONSTANTRATECOUNTER
#define OSGPARTICLE_CONSTANTRATECOUNTER 1
#include <osgParticle/Counter>
#include <osg/Object>
#include <osg/Math>
namespace osgParticle
{
class ConstantRateCounter: public Counter {
public:
ConstantRateCounter():
Counter(),
_minimumNumberOfParticlesToCreate(0),
_numberOfParticlesPerSecondToCreate(0),
_carryOver(0)
{
}
ConstantRateCounter(const ConstantRateCounter& copy, const osg::CopyOp& copyop = osg::CopyOp::SHALLOW_COPY):
Counter(copy, copyop),
_minimumNumberOfParticlesToCreate(copy._minimumNumberOfParticlesToCreate),
_numberOfParticlesPerSecondToCreate(copy._numberOfParticlesPerSecondToCreate),
_carryOver(copy._carryOver)
{
}
META_Object(osgParticle, ConstantRateCounter);
void setMinimumNumberOfParticlesToCreate(int minNumToCreate) { _minimumNumberOfParticlesToCreate = minNumToCreate; }
int getMinimumNumberOfParticlesToCreate() const { return _minimumNumberOfParticlesToCreate; }
void setNumberOfParticlesPerSecondToCreate(double numPerSecond) { _numberOfParticlesPerSecondToCreate = numPerSecond; }
double getNumberOfParticlesPerSecondToCreate() const { return _numberOfParticlesPerSecondToCreate; }
/// Return the number of particles to be created in this frame
virtual int numParticlesToCreate(double dt) const
{
double v = (dt*_numberOfParticlesPerSecondToCreate);
int i = (int)(v);
_carryOver += (v-(double)i);
if (_carryOver>1.0)
{
++i;
_carryOver -= 1.0;
}
return osg::maximum(_minimumNumberOfParticlesToCreate, i);
}
protected:
virtual ~ConstantRateCounter() {}
int _minimumNumberOfParticlesToCreate;
double _numberOfParticlesPerSecondToCreate;
mutable double _carryOver;
};
}
#endif