ST_AudioIOBase.h

// Copyright (c) 2025 Aaron Trotter (ShaderTech). All Rights Reserved.
 
#pragma once
 
#include "CoreMinimal.h"
#include "Subsystems/EngineSubsystem.h"
#include "Main/ST_AudioProcessingSettings.h"
#include "miniaudio.h"
#if WITH_KISSFFT
#include "kiss_fft.h"
#endif
#include "FFT/ST_FFTThread.h"
 
#include "ST_AudioIOBase.generated.h"
 
// Define the delegates to pass the buffer

DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FOnAudioIOStatusChanged, bool, bIsActive, FIntPoint, IOId);
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FOnRawMagnitudesReady, const TArray<float>&, RawMagnitudes, FIntPoint, IOId);
DECLARE_DYNAMIC_MULTICAST_DELEGATE_ThreeParams(FOnFrequencyBandsReady, const TArray<float>&, FrequencyBands, int32, NumFrequencyBands, FIntPoint, IOId);
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FOnAmplitudesReady, const TArray<float>&, Amplitudes, FIntPoint, IOId);
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FOnPitchesReady, const TArray<float>&, Pitches, FIntPoint, IOId);
DECLARE_DYNAMIC_MULTICAST_DELEGATE_ThreeParams(FOnBeatDetected, const TArray<float>&, Beats, const TArray<bool>&, BeatDetectedForChannel, FIntPoint, IOId);

UCLASS(BlueprintType, Abstract)
class ST_AUDIOPROCESSING_API UST_AudioIOBase : public UEngineSubsystem
{
    GENERATED_BODY()
 
public:
    UST_AudioIOBase();

    ~UST_AudioIOBase();
 
protected:
    //~ Begin USubsystem Interface
    virtual void Initialize(FSubsystemCollectionBase& Collection) override;
    virtual void Deinitialize() override;
    //~ End USubsystem Interface
 
public:
    UFUNCTION(BlueprintCallable, Category = "ShaderTech|AudioProcessing|IO")
    bool Activate();

    UFUNCTION(BlueprintCallable, Category = "ShaderTech|AudioProcessing|IO")
    void Deactivate();

    UFUNCTION(BlueprintPure, Category = "ShaderTech|AudioProcessing|IO")
    virtual EAudioIOType GetAudioIOType() const;

    UFUNCTION(BlueprintPure, Category = "ShaderTech|AudioProcessing|IO")
    FAudioIOConfig GetAudioIOConfig() const;

    UFUNCTION(BlueprintPure, Category = "ShaderTech|AudioProcessing|IO")
    FFFTIOData GetFFTIOData() const;

    UFUNCTION(BlueprintCallable, Category = "ShaderTech|AudioProcessing|IO")
    bool RegisterSampler(UObject* Sampler, bool bSamplerActivates = false);

    UFUNCTION(BlueprintCallable, Category = "ShaderTech|AudioProcessing|IO")
    void DeregisterSampler(UObject* Sampler, bool bZeroSamplersDeactivates = false);

    static void MA_DataOrganiser(ma_device* pDevice, void* pSamples, uint64 PeriodSizeInFrames, ma_format Format, uint32 Channels);

    FCriticalSection AudioBufferLock;

    static constexpr uint32 BufferCount = 2;

    void* SampledAudioBuffers[BufferCount] = { nullptr, nullptr };

    void* CurrentAudioBuffer = nullptr;

    template<typename InterfaceType>
    bool ContainsInterface() const;

    std::atomic<uint32> ReadIndex;

    std::atomic<uint32> WriteIndex;

    UPROPERTY(BlueprintAssignable, Category = "ShaderTech|AudioProcessing|IO")
    FOnAudioIOStatusChanged OnAudioIOStatusChanged;

    UPROPERTY(BlueprintAssignable, Category = "ShaderTech|AudioProcessing|IO")
    FOnRawMagnitudesReady OnRawMagnitudesReady;

    UPROPERTY(BlueprintAssignable, Category = "ShaderTech|AudioProcessing|IO")
    FOnFrequencyBandsReady OnFrequencyBandsReady;

    UPROPERTY(BlueprintAssignable, Category = "ShaderTech|AudioProcessing|IO")
    FOnAmplitudesReady OnAmplitudesReady;

    UPROPERTY(BlueprintAssignable, Category = "ShaderTech|AudioProcessing|IO")
    FOnPitchesReady OnPitchesReady;

    UPROPERTY(BlueprintAssignable, Category = "ShaderTech|AudioProcessing|IO")
    FOnBeatDetected OnBeatDetected;

    UFUNCTION(BlueprintPure, Category = "ShaderTech|AudioProcessing|IO")
    FIntPoint GetIOId() const;

    UFUNCTION(BlueprintPure, Category = "ShaderTech|AudioProcessing|IO")
    virtual EST_SampleFormat GetAudioFormat() const;
 
protected:
    bool bActivated = false;

    bool bIsProcessingFFT = false;

    virtual bool InitializeAudioIO();

    virtual void DeinitializeAudioIO();

    void BuildFFTIOData(uint32 PeriodSizeInFrames, ma_format Format, uint32 SampleRate, uint32 Channels);

    void DeinitializeFFT();

    virtual ma_decoder* GetPlaybackDecoder() const;

    virtual ma_encoder* GetCaptureEncoder() const;

    FCriticalSection SamplerRegistrationMutex;
    TArray<UObject*> RegisteredSamplers;

    void GetDeviceInfo(EAudioIOType AudioIOType, FString FindDeviceName);

    ma_device_id* pDeviceID = NULL;

    ma_device_info* pPlaybackDeviceInfos = nullptr;

    ma_device_info* pCaptureDeviceInfos = nullptr;

    ma_uint32 playbackDeviceCount = 0;

    ma_uint32 captureDeviceCount = 0;

    FFFTIOData CachedFFTIOData;

    FAudioIOConfig CachedAudioIOConfig;
 
private:
    FST_FFTThread* FFTThreadHandle = nullptr;

    FIntPoint mIOId = FIntPoint::ZeroValue;

    void SwapBuffers();

    UFUNCTION()
    void LOCAL_OnAudioIOStatusChanged(bool bIsActive, FIntPoint IOId);

    UFUNCTION()
    void LOCAL_OnRawMagnitudesReady(const TArray<float>& RawMagnitudes, FIntPoint IOId);

    UFUNCTION()
    void LOCAL_OnFrequencyBandsReady(const TArray<float>& FrequencyBands, int32 NumFrequencyBands, FIntPoint IOId);

    UFUNCTION()
    void LOCAL_OnAmplitudesReady(const TArray<float>& Amplitudes, FIntPoint IOId);

    UFUNCTION()
    void LOCAL_OnPitchesReady(const TArray<float>& Pitches, FIntPoint IOId);

    UFUNCTION()
    void LOCAL_OnBeatDetected(const TArray<float>& Beats, const TArray<bool>& BeatDetectedForChannel, FIntPoint IOId);
};
 
inline EAudioIOType UST_AudioIOBase::GetAudioIOType() const
{
    return EAudioIOType::None;
}
 
inline FAudioIOConfig UST_AudioIOBase::GetAudioIOConfig() const
{
    return CachedAudioIOConfig;
}
 
inline FFFTIOData UST_AudioIOBase::GetFFTIOData() const
{
    return CachedFFTIOData;
}
 
inline ma_decoder* UST_AudioIOBase::GetPlaybackDecoder() const
{
    return nullptr;
}
 
inline ma_encoder* UST_AudioIOBase::GetCaptureEncoder() const
{
    return nullptr;
}
 
template<typename InterfaceType>
inline bool UST_AudioIOBase::ContainsInterface() const
{
    for (UObject* Sampler : RegisteredSamplers)
    {
        if (Sampler && Sampler->Implements<InterfaceType>())
        {
            return true; // Found an object implementing the interface
        }
    }
    return false; // No matching objects found
}
 
inline FIntPoint UST_AudioIOBase::GetIOId() const
{
    return mIOId;
}
 
inline EST_SampleFormat UST_AudioIOBase::GetAudioFormat() const
{
    return EST_SampleFormat::Unknown;
}