Fuel scooping rework

data/modules/FuelScoop.lua

@@ -12,11 +12,11 @@ local lc = Lang.GetResource("core")
 -- These callbacks are triggered from C++ or Lua and are responsible for
 -- providing UI feedback about the scooping process.
 
-Event.Register("onShipScoopFuel", function(ship, body)
+Event.Register("onShipScoopFuel", function(ship, body, amount)
 	---@type CargoManager
 	local cargoMgr = ship:GetComponent('CargoManager')
 
-	cargoMgr:AddCommodity(Commodities.hydrogen, 1)
+	cargoMgr:AddCommodity(Commodities.hydrogen, amount)
 
 	if ship == Game.player then
 		Game.AddCommsLogLine(lc.FUEL_SCOOP_ACTIVE_N_TONNES_H_COLLECTED:gsub('%%quantity',

src/Ship.cpp

@@ -1256,10 +1256,23 @@ void Ship::StaticUpdate(const float timeStep)
 				const vector3d vdir = GetVelocity().Normalized();
 				const vector3d pdir = -GetOrient().VectorZ();
 				const double dot = vdir.Dot(pdir);
-				if ((m_stats.free_capacity) && (dot > 0.90) && (speed > 100.0) && (density > 0.3)) {
-					const double rate = speed * density * 0.00000333 * double(m_stats.fuel_scoop_cap);
-					if (Pi::rng.Double() < rate) {
-						LuaEvent::Queue("onShipScoopFuel", this, p);
+				const double speed_times_density = speed * density;
+				/*
+				 * speed = m/s, density = g/cm^3 -> T/m^3, pressure = Pa -> N/m^2 -> kg/(m*s^2)
+				 * m    T      kg         m*kg^2           kg^2
+				 * - * --- * ----- = 1000 ------- = 1000 -------
+				 * s   m^3   m*s^2        m^4*s^3        m^3*s^3
+				 *
+				 * fuel_scoop_cap = area, m^2. rate = kg^2/(m*s^3) = (Pa*kg)/s^2
+				 */
+				const double hydrogen_density = 0.0002;
+				if ((m_stats.free_capacity) && (dot > 0.90) && speed_times_density > (100.0 * 0.3)) {
+					const double rate = speed_times_density * hydrogen_density * double(m_stats.fuel_scoop_cap);
+					m_hydrogenScoopedAccumulator += rate * timeStep;
+					if (m_hydrogenScoopedAccumulator > 1) {
+						const double scoopedTons = floor(m_hydrogenScoopedAccumulator);
+						LuaEvent::Queue("onShipScoopFuel", this, p, scoopedTons);
+						m_hydrogenScoopedAccumulator -= scoopedTons;
 					}
 				}
 			}

src/Ship.h

@@ -330,6 +330,8 @@ class Ship : public DynamicBody {
 
 	std::string m_shipName;
 
+	double m_hydrogenScoopedAccumulator = 0;
+
 public:
 	// FIXME: these methods are deprecated; all calls should use the propulsion object directly.
 	void ClearAngThrusterState() { m_propulsion->ClearAngThrusterState(); }