UnrealEngineUWP/Engine/Plugins/Runtime/Metasound/Source/MetasoundEngine/Public/MetasoundOperatorCacheSubsystem.h

// Copyright Epic Games, Inc. All Rights Reserved.

#pragma once

#include "Containers/Array.h"
#include "Containers/Map.h"
#include "MetasoundOperatorInterface.h"
#include "Misc/Guid.h"
#include "HAL/CriticalSection.h"
#include "Templates/UniquePtr.h"
#include "Sound/SoundGenerator.h"
#include "Subsystems/AudioEngineSubsystem.h"

#include "MetasoundSource.h"

#include "MetasoundOperatorCacheSubsystem.generated.h"


/**
* 	UMetaSoundCacheSubsystem
*/
UCLASS()
class METASOUNDENGINE_API UMetaSoundCacheSubsystem : public UAudioEngineSubsystem
{
	GENERATED_BODY()

public: 
	//~ Begin USubsystem interface
	virtual bool ShouldCreateSubsystem(UObject* Outer) const override;
	virtual void Initialize(FSubsystemCollectionBase& Collection) override;
	virtual void Update() override;
	//~ End USubsystem interface
	 
	/* Builds the requested number of MetaSound operators (asynchronously) and puts them in the pool for playback.
	(If these operators are not yet available when the MetaSound attempts to play, one will be created Independent of this request.) */
	UFUNCTION(BlueprintCallable, Category = "MetaSound", meta = (DisplayName = "Precache MetaSound"))
	void PrecacheMetaSound(UPARAM(DisplayName = "MetaSound Source") UMetaSoundSource* InMetaSound, UPARAM(DisplayName = "Num Instances") int32 InNumInstances = 1);

	/* same as PrecacheMetaSound except cached operator that already exists in the cache will be moved to the top instead of building,
	any operators that we couldn't move to the top, will be built.
	(i.e. if 2 operators are already cached and Num Instances is 4, it will construct 2 and move the existing 2 to the top of the cache) */
	UFUNCTION(BlueprintCallable, Category = "MetaSound", meta = (DisplayName = "Touch or Precache MetaSound"))
	void TouchOrPrecacheMetaSound(UPARAM(DisplayName = "MetaSound Source") UMetaSoundSource* InMetaSound, UPARAM(DisplayName = "Num Instances") int32 InNumInstances = 1);

	/* Clear the operator pool of any operators associated with the given MetaSound */
	UFUNCTION(BlueprintCallable, Category = "MetaSound", meta = (DisplayName = "RemoveCached Operators for MetaSound"))
	void RemoveCachedOperatorsForMetaSound(UPARAM(DisplayName = "MetaSound Source") UMetaSoundSource* InMetaSound);

private:
	FSoundGeneratorInitParams BuildParams;
}; //UMetaSoundCacheSubsystem