Vehicles - Add Auto-Throttle to Planes (#8275)

* Add auto throttle to planes

* add newline

* clarify things

* Use a better deltaTime value. Takes into account game pause

* add coment

* Add auto throttle cancellation on user input

* misc fixes

addons/vehicles/XEH_PREP.hpp

@@ -1,4 +1,4 @@
-
+PREP(autoThrottle);
 PREP(speedLimiter);
 PREP(startEngine);
 PREP(setVehicleStartDelay);

addons/vehicles/XEH_postInit.sqf

@@ -19,11 +19,16 @@ GVAR(isSpeedLimiter) = false;
         // Conditions: specific
         if !(ACE_player == driver vehicle ACE_player &&
             {vehicle ACE_player isKindOf 'Car' ||
-            {vehicle ACE_player isKindOf 'Tank'}}) exitWith {false};
+            {vehicle ACE_player isKindOf 'Tank'} ||
+            {vehicle ACE_player isKindOf 'Plane'}}) exitWith {false};
 
             GVAR(isUAV) = false;
         // Statement
-        [ACE_player, vehicle ACE_player] call FUNC(speedLimiter);
+        if (vehicle ACE_player isKindOf 'Plane') then {
+            [ACE_player, vehicle ACE_player] call FUNC(autoThrottle);
+        } else {
+            [ACE_player, vehicle ACE_player] call FUNC(speedLimiter);
+        };
         true
     };
 

addons/vehicles/functions/fnc_autoThrottle.sqf

@@ -0,0 +1,98 @@
+#include "script_component.hpp"
+/*
+ * Author: Brandon (TCVM)
+ * Toggle speed limiter for Driver in Plane. Uses a simple PID controller to manage thrust
+ *
+ * Arguments:
+ * 0: Driver <OBJECT>
+ * 1: Vehicle <OBJECT>
+ *
+ * Return Value:
+ * None
+ *
+ * Example:
+ * [player, car] call ace_vehicles_fnc_autoThrottle
+ *
+ * Public: No
+ */
+#define PID_P 1
+#define PID_I 0.3
+#define PID_D 0
+#define EPSILON 0.001
+
+params ["_driver", "_vehicle"];
+
+if (GVAR(isSpeedLimiter)) exitWith {
+    [localize LSTRING(Off)] call EFUNC(common,displayTextStructured);
+    playSound "ACE_Sound_Click";
+    GVAR(isSpeedLimiter) = false;
+};
+
+[localize LSTRING(On)] call EFUNC(common,displayTextStructured);
+playSound "ACE_Sound_Click";
+GVAR(isSpeedLimiter) = true;
+
+// Convert forward speed to KM/H. `speed _vehicle` isnt accurate enough for this controller to work well, so its easier to use M/S. The system assumes it is KM/H so we need the conversion
+GVAR(speedLimit) = (((velocityModelSpace _vehicle) select 1) * 3.6) max 5;
+
+[{
+    params ["_args", "_idPFH"];
+    _args params ["_driver", "_vehicle", "_autothrottleParameters"];
+    _autothrottleParameters params ["_lastVelocity", "_integralValue", "_lastTime", "_lastThrottleValue", "_throttleLogValue"];
+
+    // this will take into account game being pausesd
+    private _deltaTime = CBA_missionTime - _lastTime;
+
+    if (_driver != driver _vehicle) then {
+        GVAR(isSpeedLimiter) = false;
+    };
+
+    if (_throttleLogValue == 0) then {
+        _throttleLogValue = 1;
+    };
+
+    private _currentThrottle = (airplaneThrottle _vehicle) ^ _throttleLogValue;
+    if (_lastThrottleValue != -1 && { EPSILON < abs (_currentThrottle - _lastThrottleValue) }) then {
+        // player/script has moved throttle, stop limiting speed
+        // ARMA will allow an increment of one throttle unit per frame, so if there is a difference between our known throttle value and actual throttle value, the player must of changed it
+        [localize LSTRING(Off)] call EFUNC(common,displayTextStructured);
+        playSound "ACE_Sound_Click";
+        GVAR(isSpeedLimiter) = false;
+    };
+
+    if (!GVAR(isSpeedLimiter)) exitWith {
+        [_idPFH] call CBA_fnc_removePerFrameHandler;
+    };
+
+    if (_deltaTime == 0) exitWith {};
+
+    private _forwardVelocity = (velocityModelSpace _vehicle) select 1;
+    // convert from KM/H to M/S
+    private _velocityError = (GVAR(speedLimit) / 3.6) - _forwardVelocity;
+
+    // strictly speaking this would work better if this error was time to zero acceleration. I can't find the acceleration values in config, however, so this works instead
+    private _errorDiff = _velocityError - _lastVelocity;
+
+    private _p = PID_P * _velocityError;
+    private _i = _integralValue + (PID_I * _errorDiff * _deltaTime);
+    private _d = PID_D * _errorDiff / _deltaTime;
+
+    private _outputBeforeSaturation = _p + _i + _d;
+    private _throttle = 0 max (_outputBeforeSaturation min 1);
+
+    // if we are saturated, we clamp the integral value to avoid integral windup
+    if (_outputBeforeSaturation != _throttle) then {
+        // saturated
+        _i = _integralValue;
+        _throttle = 0 max ((_p + _d) min 1);
+    };
+
+    _vehicle setAirplaneThrottle _throttle;
+
+    _autothrottleParameters set [0, _d];
+    _autothrottleParameters set [1, _i];
+    _autothrottleParameters set [2, CBA_missionTime];
+    _autothrottleParameters set [3, _throttle];
+
+}, 0, [_driver, _vehicle, [0, 0, CBA_missionTime, -1, getNumber (configOf _vehicle >> "throttleToThrustLogFactor")]]] call CBA_fnc_addPerFrameHandler;
+