Method GetParticlesCount

Source/Engine/Particles/ParticlesSimulation.cpp:91–134

}

int32 ParticleSystemInstance::GetParticlesCount() const
{
    int32 result = 0;

    // CPU particles
    for (const auto& emitter : Emitters)
    {
        if (emitter.Buffer && emitter.Buffer->Mode == ParticlesSimulationMode::CPU)
        {
            result += emitter.Buffer->CPU.Count;
        }
    }

    // GPU particles
    if (GPUParticlesCountReadback && GPUParticlesCountReadback->IsAllocated())
    {
        auto data = static_cast<uint32*>(GPUParticlesCountReadback->Map(GPUResourceMapMode::Read));
        if (data)
        {
            for (const auto& emitter : Emitters)
            {
                if (emitter.Buffer && emitter.Buffer->Mode == ParticlesSimulationMode::GPU && emitter.Buffer->GPU.HasValidCount)
                {
                    result += *data;
                }
                ++data;
            }
            GPUParticlesCountReadback->Unmap();
        }
    }
    else if (Emitters.HasItems())
    {
        // Initialize readback buffer (next GPU particles simulation update will copy the particle counters)
        if (!GPUParticlesCountReadback)
            GPUParticlesCountReadback = GPUDevice::Instance->CreateBuffer(TEXT("GPUParticlesCountReadback"));
        const auto desc = GPUBufferDescription::Buffer(Emitters.Count() * sizeof(uint32), GPUBufferFlags::None, PixelFormat::Unknown, nullptr, sizeof(uint32), GPUResourceUsage::StagingReadback);
        if (GPUParticlesCountReadback->Init(desc))
        {
            LOG(Error, "Failed to create GPU particles count readback buffer.");
        }
    }

    return result;
}

void ParticleSystemInstance::ClearState()
{