axmol/extensions/Particle3D/PU/CCPUOnTimeObserver.cpp

/****************************************************************************
 Copyright (C) 2013 Henry van Merode. All rights reserved.
 Copyright (c) 2015-2016 Chukong Technologies Inc.
 Copyright (c) 2017-2018 Xiamen Yaji Software Co., Ltd.

 https://adxeproject.github.io/

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 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

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 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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#include "extensions/Particle3D/PU/CCPUOnTimeObserver.h"
#include "extensions/Particle3D/PU/CCPUParticleSystem3D.h"

NS_CC_BEGIN

// Constants
const float PUOnTimeObserver::DEFAULT_THRESHOLD         = 0.0f;
const bool PUOnTimeObserver::DEFAULT_SINCE_START_SYSTEM = false;

static bool almostEquals(float a, float b, float epsilon = std::numeric_limits<float>::epsilon())
{
    return fabs(a - b) <= ((fabs(a) < fabs(b) ? fabs(b) : fabs(a)) * epsilon);
};

//-----------------------------------------------------------------------
PUOnTimeObserver::PUOnTimeObserver()
    : PUObserver()
    , _threshold(DEFAULT_THRESHOLD)
    , _compare(CO_GREATER_THAN)
    , _sinceStartSystem(DEFAULT_SINCE_START_SYSTEM){};
//-----------------------------------------------------------------------
void PUOnTimeObserver::preUpdateObserver(float deltaTime)
{
    // Call parent
    PUObserver::preUpdateObserver(deltaTime);

    // Also observe if there are no particles emitted, because some of the event handlers do not only
    // perform an action on a particle.
    if (static_cast<PUParticleSystem3D*>(_particleSystem)->getAliveParticleCount() <= 0)
    {
        handleObserve(0, deltaTime);
    }
}
//-----------------------------------------------------------------------
bool PUOnTimeObserver::observe(PUParticle3D* particle, float /*timeElapsed*/)
{
    if (_compare == CO_GREATER_THAN)
    {
        if (_sinceStartSystem)
        {
            // Validate whether time since start of the particle system > threshold
            return (_particleSystem->getTimeElapsedSinceStart() > _threshold);
        }
        else
        {
            // Validate whether time since start of the particle emission > threshold
            return (particle && (particle->totalTimeToLive - particle->timeToLive) > _threshold);
        }
    }
    else if (_compare == CO_LESS_THAN)
    {
        if (_sinceStartSystem)
        {
            // Validate whether time since start of the particle system < threshold
            return (_particleSystem->getTimeElapsedSinceStart() < _threshold);
        }
        else
        {
            // Validate whether time since start of the particle emission < threshold
            return (particle && (particle->totalTimeToLive - particle->timeToLive) < _threshold);
        }
    }
    else
    {
        // Equals
        if (_sinceStartSystem)
        {
            // Validate whether time since start of the particle system == threshold
            return almostEquals(_particleSystem->getTimeElapsedSinceStart(), _threshold, 0.01f);
        }
        else
        {
            // Validate whether time since start of the particle emission == threshold
            return particle && almostEquals((particle->totalTimeToLive - particle->timeToLive), _threshold, 0.01f);
        }
    }

    return false;
}

PUOnTimeObserver* PUOnTimeObserver::create()
{
    auto pto = new PUOnTimeObserver();
    pto->autorelease();
    return pto;
}

void PUOnTimeObserver::copyAttributesTo(PUObserver* observer)
{
    PUObserver::copyAttributesTo(observer);

    PUOnTimeObserver* onTimeObserver  = static_cast<PUOnTimeObserver*>(observer);
    onTimeObserver->_threshold        = _threshold;
    onTimeObserver->_compare          = _compare;
    onTimeObserver->_sinceStartSystem = _sinceStartSystem;
}

NS_CC_END