#include #include namespace psemek::audio { namespace { struct volume_control_impl : volume_control { volume_control_impl(stream_ptr stream, float gain, float smoothness) : base_(gain, smoothness) , stream_(std::move(stream)) {} float gain() const override { return base_.gain(); } float gain(float value) override { return base_.gain(value); } float smoothness() const override { return base_.smoothness(); } float smoothness(float value) override { return base_.smoothness(value); } std::optional length() const override { return stream_->length(); } std::size_t read(float * data, std::size_t sample_count) override { auto result = stream_->read(data, sample_count); base_.apply(data, result); return result; } private: volume_base base_; stream_ptr stream_; }; } std::shared_ptr volume(stream_ptr stream, float gain, float smoothness) { return std::make_shared(std::move(stream), gain, smoothness); } }