(svn r17898) -Fix: [NoAI] Improve behaviour of (AIEngine|AIEventEnginePreview)::GetCargoType() and AIEngine::CanRefitCargo() wrt. articulated vehicles.

src/ai/api/ai_engine.cpp

@@ -42,10 +42,18 @@
 {
 	if (!IsValidEngine(engine_id)) return CT_INVALID;
 
-	const Engine *e = ::Engine::Get(engine_id);
-	if (!e->CanCarryCargo()) return CT_INVALID;
+	CargoArray cap = ::GetCapacityOfArticulatedParts(engine_id);
+
+	CargoID most_cargo = CT_INVALID;
+	uint amount = 0;
+	for (CargoID cid = 0; cid < NUM_CARGO; cid++) {
+		if (cap[cid] > amount) {
+			amount = cap[cid];
+			most_cargo = cid;
+		}
+	}
 
-	return e->GetDefaultCargoType();
+	return most_cargo;
 }
 
 /* static */ bool AIEngine::CanRefitCargo(EngineID engine_id, CargoID cargo_id)
@@ -53,8 +61,7 @@
 	if (!IsValidEngine(engine_id)) return false;
 	if (!AICargo::IsValidCargo(cargo_id)) return false;
 
-	if (GetCargoType(engine_id) == cargo_id) return true;
-	return ::CanRefitTo(engine_id, cargo_id);
+	return HasBit(::GetUnionOfArticulatedRefitMasks(engine_id, true), cargo_id);
 }
 
 /* static */ bool AIEngine::CanPullCargo(EngineID engine_id, CargoID cargo_id)

src/ai/api/ai_engine.hpp

@@ -41,8 +41,8 @@ public:
 	static char *GetName(EngineID engine_id);
 
 	/**
-	 * Get the cargo-type of an engine. In case it can transport 2 cargos, it
-	 *  returns the first.
+	 * Get the cargo-type of an engine. In case it can transport multiple cargos, it
+	 *  returns the first/main.
 	 * @param engine_id The engine to get the cargo-type of.
 	 * @pre IsValidEngine(engine_id).
 	 * @return The cargo-type of the engine.
@@ -52,6 +52,8 @@ public:
 	/**
 	 * Check if the cargo of an engine can be refitted to your requested. If
 	 *  the engine already allows this cargo, the function also returns true.
+	 *  In case of articulated vehicles the function decides whether at least one
+	 *  part can carry the cargo.
 	 * @param engine_id The engine to check for refitting.
 	 * @param cargo_id The cargo to check for refitting.
 	 * @pre IsValidEngine(engine_id).
@@ -75,8 +77,8 @@ public:
 	static bool CanPullCargo(EngineID engine_id, CargoID cargo_id);
 
 	/**
-	 * Get the capacity of an engine. In case it can transport 2 cargos, it
-	 *  returns the first.
+	 * Get the capacity of an engine. In case it can transport multiple cargos, it
+	 *  returns the first/main.
 	 * @param engine_id The engine to get the capacity of.
 	 * @pre IsValidEngine(engine_id).
 	 * @return The capacity of the engine.

src/ai/api/ai_event_types.cpp

@@ -30,9 +30,18 @@ char *AIEventEnginePreview::GetName()
 
 CargoID AIEventEnginePreview::GetCargoType()
 {
-	const Engine *e = ::Engine::Get(this->engine);
-	if (!e->CanCarryCargo()) return CT_INVALID;
-	return e->GetDefaultCargoType();
+	CargoArray cap = ::GetCapacityOfArticulatedParts(this->engine);
+
+	CargoID most_cargo = CT_INVALID;
+	uint amount = 0;
+	for (CargoID cid = 0; cid < NUM_CARGO; cid++) {
+		if (cap[cid] > amount) {
+			amount = cap[cid];
+			most_cargo = cid;
+		}
+	}
+
+	return most_cargo;
 }
 
 int32 AIEventEnginePreview::GetCapacity()

src/ai/api/ai_event_types.hpp

@@ -238,15 +238,15 @@ public:
 	char *GetName();
 
 	/**
-	 * Get the cargo-type of the offered engine. In case it can transport 2 cargos, it
-	 *  returns the first.
+	 * Get the cargo-type of the offered engine. In case it can transport multiple cargos, it
+	 *  returns the first/main.
 	 * @return The cargo-type of the engine.
 	 */
 	CargoID GetCargoType();
 
 	/**
-	 * Get the capacity of the offered engine. In case it can transport 2 cargos, it
-	 *  returns the first.
+	 * Get the capacity of the offered engine. In case it can transport multiple cargos, it
+	 *  returns the first/main.
 	 * @return The capacity of the engine.
 	 */
 	int32 GetCapacity();