Method update

core/2d/ParticleSystem.cpp:1557–1844

ParticleSystem - MainLoop

// ParticleSystem - MainLoop
void ParticleSystem::update(float dt)
{
    // don't process particles nor update gl buffer when this node is invisible.
    if (!_visible)
        return;

    AX_PROFILER_START_CATEGORY(kProfilerCategoryParticles, "CCParticleSystem - update");

    if (_componentContainer && !_componentContainer->isEmpty())
    {
        _componentContainer->visit(dt);
    }

    if (_fixedFPS != 0)
    {
        _fixedFPSDelta += dt;
        if (_fixedFPSDelta < 1.0F / _fixedFPS)
        {
            updateParticleQuads();
            _transformSystemDirty = false;
            AX_PROFILER_STOP_CATEGORY(kProfilerCategoryParticles, "CCParticleSystem - update");
            return;
        }
        dt             = _fixedFPSDelta;
        _fixedFPSDelta = 0.0F;
    }

    float pureDt = dt;
    dt *= _timeScale;

    if (_isActive && _emissionRate)
    {
        float rate         = 1.0f / _emissionRate;
        int totalParticles = static_cast<int>(_totalParticles * __totalParticleCountFactor);

        // issue #1201, prevent bursts of particles, due to too high emitCounter
        if (_particleCount < totalParticles)
        {
            _emitCounter += dt;
            _emitCounter = MAX(0.0F, _emitCounter);
        }

        int emitCount = MIN(totalParticles - _particleCount, _emitCounter / rate);
        addParticles(emitCount);
        _emitCounter -= rate * emitCount;

        _elapsed += dt;
        if (_elapsed < 0.f)
            _elapsed = 0.f;
        if (_duration != static_cast<float>(DURATION_INFINITY) && _duration < _elapsed)
        {
            this->stopSystem();
        }
    }

    // The reason for using for-loops separately for every property is because
    // When the processor needs to read from or write to a location in memory,
    // it first checks whether a copy of that data is in the cpu's cache.