SDK: Add components and system for 2D physics

SDK/include/NDK/Systems/PhysicsSystem2D.inl

@@ -0,0 +1,32 @@
+// Copyright (C) 2015 Jérôme Leclercq
+// This file is part of the "Nazara Development Kit"
+// For conditions of distribution and use, see copyright notice in Prerequesites.hpp
+
+namespace Ndk
+{
+	/*!
+	* \brief Gets the physical world
+	* \return A reference to the physical world
+	*/
+
+	inline Nz::PhysWorld2D& PhysicsSystem2D::GetWorld()
+	{
+		if (!m_world)
+			CreatePhysWorld();
+
+		return *m_world;
+	}
+
+	/*!
+	* \brief Gets the physical world
+	* \return A constant reference to the physical world
+	*/
+
+	inline const Nz::PhysWorld2D& PhysicsSystem2D::GetWorld() const
+	{
+		if (!m_world)
+			CreatePhysWorld();
+
+		return *m_world;
+	}
+}