Reorganize source files into logical subdirectories

Co-authored-by: Hirek193 <23196899+Hirek193@users.noreply.github.com>

vehicle/AirCoupler.h

@@ -0,0 +1,80 @@
+/*
+This Source Code Form is subject to the
+terms of the Mozilla Public License, v.
+2.0. If a copy of the MPL was not
+distributed with this file, You can
+obtain one at
+http://mozilla.org/MPL/2.0/.
+*/
+
+#pragma once
+
+#include "Classes.h"
+
+class AirCoupler
+{
+private:
+    TSubModel *ModelOn, *ModelOff, *ModelxOn;
+    bool On;
+    bool xOn;
+    void Update();
+
+public:
+    AirCoupler();
+    ~AirCoupler();
+    ///Reset members.
+    void Clear();
+    ///Looks for submodels.
+    void Init(std::string const &asName, TModel3d *Model);
+    ///Loads info about coupler.
+    void Load(cParser *Parser, TModel3d *Model);
+    int GetStatus();
+    inline void TurnOn() ///Turns on straight coupler.
+    {
+        On = true;
+        xOn = false;
+        Update();
+    };
+    inline void TurnOff() ///Turns on disconnected coupler.
+    {
+        On = false;
+        xOn = false;
+        Update();
+    };
+    inline void TurnxOn() ///Turns on slanted coupler.
+    {
+        On = false;
+        xOn = true;
+        Update();
+    };
+
+    // if the xOn model is missing, activate plain On instead
+    inline void TurnxOnWithOnAsFallback()
+    {
+        if (ModelxOn != nullptr) {
+            On = false;
+            xOn = true;
+            Update();
+        }
+        else {
+            TurnOn();
+        }
+    };
+    // if the xOn model is missing, activate plain Off instead
+    inline void TurnxOnWithOffAsFallback()
+    {
+        if (ModelxOn != nullptr) {
+            On = false;
+            xOn = true;
+            Update();
+        }
+        else {
+            TurnOff();
+        }
+    };
+    inline bool Active() const
+    {
+        return ( ( ModelOn != nullptr ) || ( ModelxOn != nullptr ) );
+    };
+};
+