Index: source/graphics/Camera.h
===================================================================
--- source/graphics/Camera.h
+++ source/graphics/Camera.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2013 Wildfire Games.
+/* Copyright (C) 2017 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -95,7 +95,7 @@
 		void LookAt(const CVector3D& camera, const CVector3D& orientation, const CVector3D& up);
 
 		// Build an orientation matrix from camera position, camera orientation, and up-vector
-		void LookAlong(CVector3D camera, CVector3D focus, CVector3D up);
+		void LookAlong(const CVector3D& camera, CVector3D focus, CVector3D up);
 
 		/**
 		 * Render: Renders the camera's frustum in world space.
Index: source/graphics/Camera.cpp
===================================================================
--- source/graphics/Camera.cpp
+++ source/graphics/Camera.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2010 Wildfire Games.
+/* Copyright (C) 2017 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -357,7 +357,7 @@
 	LookAlong(camera, delta, up);
 }
 
-void CCamera::LookAlong(CVector3D camera, CVector3D orientation, CVector3D up)
+void CCamera::LookAlong(const CVector3D& camera, CVector3D orientation, CVector3D up)
 {
 	orientation.Normalize();
 	up.Normalize();
Index: source/soundmanager/ISoundManager.h
===================================================================
--- source/soundmanager/ISoundManager.h
+++ source/soundmanager/ISoundManager.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2014 Wildfire Games.
+/* Copyright (C) 2017 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -47,7 +47,7 @@
 	virtual void PlayAsUI(const VfsPath& itemPath, bool looping) = 0;
 	virtual void PlayAsMusic(const VfsPath& itemPath, bool looping) = 0;
 	virtual void PlayAsAmbient(const VfsPath& itemPath, bool looping) = 0;
-	virtual void PlayAsGroup(const VfsPath& groupPath, CVector3D sourcePos, entity_id_t source, bool ownedSound) = 0;
+	virtual void PlayAsGroup(const VfsPath& groupPath, const CVector3D& sourcePos, entity_id_t source, bool ownedSound) = 0;
 
 	virtual bool InDistress() = 0;
 };
Index: source/soundmanager/SoundManager.h
===================================================================
--- source/soundmanager/SoundManager.h
+++ source/soundmanager/SoundManager.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2017 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -137,7 +137,7 @@
 	void PlayAsMusic(const VfsPath& itemPath, bool looping);
 	void PlayAsAmbient(const VfsPath& itemPath, bool looping);
 	void PlayAsUI(const VfsPath& itemPath, bool looping);
-	void PlayAsGroup(const VfsPath& groupPath, CVector3D sourcePos, entity_id_t source, bool ownedSound);
+	void PlayAsGroup(const VfsPath& groupPath, const CVector3D& sourcePos, entity_id_t source, bool ownedSound);
 
 	void PlayGroupItem(ISoundItem* anItem, ALfloat groupGain);
 
Index: source/soundmanager/SoundManager.cpp
===================================================================
--- source/soundmanager/SoundManager.cpp
+++ source/soundmanager/SoundManager.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2015 Wildfire Games.
+/* Copyright (C) 2017 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -639,7 +639,7 @@
 	m_MusicEnabled = isEnabled;
 }
 
-void CSoundManager::PlayAsGroup(const VfsPath& groupPath, CVector3D sourcePos, entity_id_t source, bool ownedSound)
+void CSoundManager::PlayAsGroup(const VfsPath& groupPath, const CVector3D& sourcePos, entity_id_t source, bool ownedSound)
 {
 	// Make sure the sound group is loaded
 	CSoundGroup* group;