Added Source:setRelativePosition and Source:hasRelativePosition, if enabled the Source's position will always be relative to the listener instead of absolute.

src/modules/audio/null/Source.h

@@ -60,6 +60,8 @@ public:
 	virtual void getVelocity(float *v) const;
 	virtual void setDirection(float *v);
 	virtual void getDirection(float *v) const;
+	virtual void setRelativePosition(bool relative);
+	virtual bool hasRelativePosition() const;
 	void setLooping(bool looping);
 	bool isLooping() const;
 	bool isStatic() const;
@@ -78,6 +80,7 @@ private:
 
 	float pitch;
 	float volume;
+	bool relativePosition;
 	bool looping;
 	float minVolume;
 	float maxVolume;