audio_callback.h

// SPDX-FileCopyrightText: © 2025 Alexandros Theodotou <alex@zrythm.org>
// SPDX-License-Identifier: LicenseRef-ZrythmLicense
 
#pragma once
 
#include <functional>
 
#include <juce_wrapper.h>
 
namespace zrythm::dsp
{
class AudioCallback : public juce::AudioIODeviceCallback
{
public:
  using EngineProcessCallback = std::function<void (
    const float * const * inputChannelData,
    int                   numInputChannels,
    float * const *       outputChannelData,
    int                   numOutputChannels,
    int                   numSamples)>;
  using DeviceAboutToStartCallback = std::function<void (juce::AudioIODevice *)>;
  using DeviceStoppedCallback = std::function<void ()>;
 
  AudioCallback (
    EngineProcessCallback      process_cb,
    DeviceAboutToStartCallback device_about_to_start_cb,
    DeviceStoppedCallback      device_stopped_cb);
 
public:
  void audioDeviceIOCallbackWithContext (
    const float * const *                     inputChannelData,
    int                                       numInputChannels,
    float * const *                           outputChannelData,
    int                                       numOutputChannels,
    int                                       numSamples,
    const juce::AudioIODeviceCallbackContext &context) override;
  void audioDeviceAboutToStart (juce::AudioIODevice * device) override;
  void audioDeviceStopped () override;
  void audioDeviceError (const juce::String &errorMessage) override;
 
private:
  EngineProcessCallback                     process_cb_;
  std::optional<DeviceAboutToStartCallback> device_about_to_start_cb_;
  std::optional<DeviceStoppedCallback>      device_stopped_cb_;
};
} // namespace zrythm::engine::device_io