void ParticleEffectEntityItem::update(const quint64& now) {

    float deltaTime = (float)(now - _lastSimulated) / (float)USECS_PER_SECOND;
    _lastSimulated = now;

    if (isEmittingParticles()) {
        stepSimulation(deltaTime);
    }

    EntityItem::update(now); // let our base class handle it's updates...
}
void ParticleEffectEntityItem::update(const quint64& now) {

    // we check for 'now' in the past in case users set their clock backward
    if (now < _lastSimulated) {
        _lastSimulated = now;
        return;
    }

    float deltaTime = (float)(now - _lastSimulated) / (float)USECS_PER_SECOND;
    _lastSimulated = now;

    if (isEmittingParticles()) {
        stepSimulation(deltaTime);
    }

    EntityItem::update(now); // let our base class handle it's updates...
}