add framework to add virtual mass to containers

addons/movement/XEH_PREP.hpp

@@ -1,5 +1,7 @@
 
+PREP(addLoadToUnitContainer);
 PREP(getWeight);
 PREP(canClimb);
 PREP(climb);
 PREP(handleClimb);
+PREP(handleVirtualMass);

addons/movement/XEH_postInit.sqf

@@ -3,6 +3,9 @@
 
 if (!hasInterface) exitWith {};
 
+["playerChanged", FUNC(handleVirtualMass)] call FUNC(addEventHandler);
+["playerInventoryChanged", FUNC(handleVirtualMass)] call FUNC(addEventHandler);
+
 ["ACE3 Movement", QGVAR(climb), localize LSTRING(Climb),
 {
     // Conditions: canInteract

addons/movement/functions/fnc_addLoadToUnitContainer.sqf

@@ -0,0 +1,31 @@
+/*
+ * Author: commy2
+ * Add (negative numbers to subtract) a virtual mass to a units container.
+ *
+ * Arguments:
+ * 0: The Unit <OBJECT>
+ * 1: The Container <OBEJCT>
+ * 2: The Virtual Load <NUMBER>
+ *
+ * Return Value:
+ * Success? <BOOLEAN>
+ *
+ * Public: No
+ */
+#include "script_component.hpp"
+
+params [["_unit", objNull, [objNull]], ["_container", objNull, [objNull]], ["_virtualLoadToAdd", 0, [0]]];
+
+if !(_container in [
+    uniformContainer _unit,
+    vestContainer _unit,
+    backpackContainer _unit
+]) exitWith {false};
+
+private _virtualLoad = (_container getVariable [QGVAR(vLoad), 0]) + _virtualLoadToAdd;
+_container setVariable [QGVAR(vLoad), _virtualLoad];
+
+// update
+_unit call FUNC(handleVirtualMass);
+
+true

addons/movement/functions/fnc_handleVirtualMass.sqf

@@ -0,0 +1,42 @@
+/*
+ * Author: commy2
+ * Recalculate the units loadCoef to emulate a mass added to uniform, vest or backpack.
+ *
+ * Arguments:
+ * 0: The Unit (usually the player) <OBJECT>
+ *
+ * Return Value:
+ * Nothing
+ *
+ * Public: No
+ */
+#include "script_component.hpp"
+
+params ["_unit"];
+
+// add sum of virtual loads
+private _virtualLoad = 0;
+
+{
+    _virtualLoad = _virtualLoad + (_x getVariable [QGVAR(vLoad), 0]);
+} forEach [
+    uniformContainer _unit,
+    vestContainer _unit,
+    backpackContainer _unit
+];
+
+// get absolute vanilla load
+private _absLoad = loadAbs _unit / load _unit;
+
+// try to preserve other changes to the "LoadCoef" unitTrait
+private _loadCoef = _unit getVariable QGVAR(loadCoef);
+
+if (isNil "_loadCoef") then {
+    _loadCoef = _unit getUnitTrait "loadCoef";
+    _unit setVariable [QGVAR(loadCoef), _loadCoef, true];
+};
+
+// calc. new "virtual" loadCoef
+private _virtualLoadCoef = (1 + _virtualLoad / _absLoad) * _loadCoef;
+
+_unit setUnitTrait ["loadCoef", _virtualLoadCoef];