Method Reverb

examples/sound_effects/SoundEffects.cpp:923–965

{
public:
    Reverb() : Processing("Reverb")
    {
        auto& music = getMusic();

        static constexpr auto sustain = 0.7f; // [0.f; 1.f]

        // We use a mutable lambda to tie the lifetime of the state to the lambda itself
        // This is necessary since the Echo object will be destroyed before the Music object
        // While the Music object exists, it is possible that the audio engine will try to call
        // this lambda hence we need to always have a usable state until the Music and the
        // associated lambda are destroyed
        music.setEffectProcessor(
            [sampleRate = sf::PlaybackDevice::getDeviceSampleRate().value_or(44100),
             filters    = std::vector<ReverbFilter<float>>(),
             enabled    = getEnabled()](const float*  inputFrames,
                                     unsigned int& inputFrameCount,
                                     float*        outputFrames,
                                     unsigned int& outputFrameCount,
                                     unsigned int  frameChannelCount) mutable
            {
                // IMPORTANT: The channel count of the audio engine currently sourcing data from this sound
                // will always be provided in frameChannelCount, this can be different from the channel count
                // of the audio source so make sure to size your buffers according to the engine and not the source
                // Ensure we have as many filter objects as the audio engine has channels
                while (filters.size() < frameChannelCount)
                    filters.emplace_back(sampleRate, sustain);

                for (auto frame = 0u; frame < outputFrameCount; ++frame)
                {
                    for (auto channel = 0u; channel < frameChannelCount; ++channel)
                    {
                        const auto input = inputFrames ? inputFrames[channel] : 0.f; // Read silence if no input data available
                        outputFrames[channel] = *enabled ? filters[channel](input) : input;
                    }

                    inputFrames += (inputFrames ? frameChannelCount : 0u);
                    outputFrames += frameChannelCount;
                }

                // We processed data 1:1
                inputFrameCount = outputFrameCount;
            });
    }

private:
    template <typename T>