Why use FALSRotationMode replace EALSRotationMode

[bazhi]

`USTRUCT(BlueprintType)
struct FALSRotationMode
{
GENERATED_BODY()

private:
UPROPERTY(VisibleDefaultsOnly, BlueprintReadOnly, meta = (AllowPrivateAccess = true))
EALSRotationMode RotationMode = EALSRotationMode::VelocityDirection;

UPROPERTY(VisibleDefaultsOnly, BlueprintReadOnly, meta = (AllowPrivateAccess = true))
bool VelocityDirection_ = true;

UPROPERTY(VisibleDefaultsOnly, BlueprintReadOnly, meta = (AllowPrivateAccess = true))
bool LookingDirection_ = false;

UPROPERTY(VisibleDefaultsOnly, BlueprintReadOnly, meta = (AllowPrivateAccess = true))
bool Aiming_ = false;

public:
FALSRotationMode()
{
}

FALSRotationMode(const EALSRotationMode InitialRotationMode) { *this = InitialRotationMode; }

const bool& VelocityDirection() const { return VelocityDirection_; }
const bool& LookingDirection() const { return LookingDirection_; }
const bool& Aiming() const { return Aiming_; }

operator EALSRotationMode() const { return RotationMode; }

void operator=(const EALSRotationMode NewRotationMode)
{
	RotationMode = NewRotationMode;
	VelocityDirection_ = RotationMode == EALSRotationMode::VelocityDirection;
	LookingDirection_ = RotationMode == EALSRotationMode::LookingDirection;
	Aiming_ = RotationMode == EALSRotationMode::Aiming;
}

};`

what's the reason of this design.

[Drakynfly]

The enums are wrapped with structs so that the animation system can treat them as booleans, which is much faster.

[bazhi]

Thanks very much. Got it!

[ameaninglessname]

The enums are wrapped with structs so that the animation system can treat them as booleans, which is much faster.

Isn't the underlying implementation of both boolean and enum is an integer? Why boolean is faster to animation system?
(I am not very familiar to animation system for now.)

[Drakynfly]

I do not know much about animation either, but I'll try to explain as best as a can, what I know. Anyone feel free to correct me.
You are correct that enums are essentially a integer. But the animation nodes to access enums require bytecode to be ran in the animation graph. Booleans and other variables essentially "skip" being compiled to the bytecode, and are accessed somewhat directly, but only if you plug either a variable or a NOT node and a boolean variable, etc.
If you use a enum== node or a enum!= node, or a boolean variable with any other node (like AND or NOR), then it has to compile those nodes to bytecode and run that every time, which can slow things down.
This is called "Fast Path":
https://docs.unrealengine.com/en-US/AnimatingObjects/SkeletalMeshAnimation/Optimization/FastPath/index.html