A UE4 Static library for common quaternion operations

QuatStaticLibary.h

#pragma once

#include "CoreMinimal.h"

/**
 * Library of commonly used custom functions
 */
class QuatStaticLibrary
{
public:
	// Finds the difference between two quats
	static FORCEINLINE FQuat FindDeltaQuat(const FQuat& OldQuat, const FQuat& NewQuat)
	{
		return NewQuat * OldQuat.Inverse();
	}

	// Converts Quat from Local Rotation to World rotation (applies delta rotation in local space)
	static FORCEINLINE FQuat QuatLocalToWorld(const FQuat& LocalQuat, const FQuat& ComponentQuat)
	{
		return ComponentQuat * LocalQuat;
	}

	// Converts Quat from World Rotation to Local rotation
	static FORCEINLINE FQuat QuatWorldToLocal(const FQuat& WorldQuat, const FQuat& ComponentQuat)
	{
		return ComponentQuat.Inverse() * WorldQuat;
	}

	static FORCEINLINE FQuat ApplyDeltaQuatInWorldSpace(const FQuat& DeltaQuat, const FQuat& ComponentQuat)
	{
		return DeltaQuat * ComponentQuat;
	}

	static FORCEINLINE FQuat ApplyDeltaQuatInLocalSpace(const FQuat& DeltaQuat, const FQuat& ComponentQuat)
	{
		return QuatLocalToWorld(DeltaQuat, ComponentQuat);
	}
	
	static FORCEINLINE FRotator RotatorLocalToWorld(const FRotator& LocalRot, const FQuat& ComponentQuat)
	{
		return QuatStaticLibrary::QuatLocalToWorld(LocalRot.Quaternion(), ComponentQuat).Rotator();
	}
	
	static FORCEINLINE FRotator RotatorWorldToLocal(const FRotator& WorldRot, const FQuat& ComponentQuat)
	{
		return QuatStaticLibrary::QuatWorldToLocal(WorldRot.Quaternion(), ComponentQuat).Rotator();
	}
}