PlayerSettings struct for player movement code (#7243)

Instead of calling g_settings->getBool("flag") multiple times
during each movement step, the current settings are cached
in a new player object member. Updated via registered callbacks.

src/player.h

@@ -84,6 +84,18 @@ struct PlayerControl
 	float forw_move_joystick_axis = 0.0f;
 };
 
+struct PlayerSettings
+{
+	bool free_move = false;
+	bool fast_move = false;
+	bool continuous_forward = false;
+	bool always_fly_fast = false;
+	bool aux1_descends = false;
+	bool noclip = false;
+
+	void readGlobalSettings();
+};
+
 class Map;
 struct CollisionInfo;
 struct HudElement;
@@ -152,6 +164,8 @@ public:
 
 	PlayerControl control;
 	const PlayerControl& getPlayerControl() { return control; }
+	PlayerSettings &getPlayerSettings() { return m_player_settings; }
+	static void settingsChangedCallback(const std::string &name, void *data);
 
 	u32 keyPressed = 0;
 
@@ -172,4 +186,5 @@ private:
 	// hud for example can be modified by EmergeThread
 	// and ServerThread
 	std::mutex m_mutex;
+	PlayerSettings m_player_settings;
 };