(svn r15306) -Codechange: Deduplicate code by adding Engine::GetDisplayMaxSpeed(), GetPower() and GetDisplayWeight(). (and using them)

6 files changed, 80 insertions, 71 deletions

diff --git a/src/ai/api/ai_engine.cpp b/src/ai/api/ai_engine.cpp
index 564dbc018..762da14b1 100644
--- a/src/ai/api/ai_engine.cpp
+++ b/src/ai/api/ai_engine.cpp
@@ -118,31 +118,10 @@
 {
 	if (!IsValidEngine(engine_id)) return -1;
 
-	switch (::GetEngine(engine_id)->type) {
-		case VEH_ROAD: {
-			const RoadVehicleInfo *vi = ::RoadVehInfo(engine_id);
-			/* Internal speeds are km/h * 2 */
-			return vi->max_speed / 2;
-		} break;
-
-		case VEH_TRAIN: {
-			const RailVehicleInfo *vi = ::RailVehInfo(engine_id);
-			return vi->max_speed;
-		} break;
-
-		case VEH_SHIP: {
-			const ShipVehicleInfo *vi = ::ShipVehInfo(engine_id);
-			/* Internal speeds are km/h * 2 */
-			return vi->max_speed / 2;
-		} break;
-
-		case VEH_AIRCRAFT: {
-			const AircraftVehicleInfo *vi = ::AircraftVehInfo(engine_id);
-			return vi->max_speed / _settings_game.vehicle.plane_speed;
-		} break;
-
-		default: NOT_REACHED();
-	}
+	const Engine *e = ::GetEngine(engine_id);
+	int32 max_speed = e->GetDisplayMaxSpeed() * 16 / 10; // convert mph to km-ish/h
+	if (e->type == VEH_AIRCRAFT) max_speed /= _settings_game.vehicle.plane_speed;
+	return max_speed;
 }
 
 /* static */ Money AIEngine::GetPrice(EngineID engine_id)
diff --git a/src/ai/api/ai_event_types.cpp b/src/ai/api/ai_event_types.cpp
index 1cf14f32d..c495e082e 100644
--- a/src/ai/api/ai_event_types.cpp
+++ b/src/ai/api/ai_event_types.cpp
@@ -79,31 +79,10 @@ int32 AIEventEnginePreview::GetCapacity()
 
 int32 AIEventEnginePreview::GetMaxSpeed()
 {
-	switch (::GetEngine(engine)->type) {
-		case VEH_ROAD: {
-			const RoadVehicleInfo *vi = ::RoadVehInfo(engine);
-			/* Internal speeds are km/h * 2 */
-			return vi->max_speed / 2;
-		} break;
-
-		case VEH_TRAIN: {
-			const RailVehicleInfo *vi = ::RailVehInfo(engine);
-			return vi->max_speed;
-		} break;
-
-		case VEH_SHIP: {
-			const ShipVehicleInfo *vi = ::ShipVehInfo(engine);
-			/* Internal speeds are km/h * 2 */
-			return vi->max_speed / 2;
-		} break;
-
-		case VEH_AIRCRAFT: {
-			const AircraftVehicleInfo *vi = ::AircraftVehInfo(engine);
-			return vi->max_speed / _settings_game.vehicle.plane_speed;
-		} break;
-
-		default: NOT_REACHED();
-	}
+	const Engine *e = ::GetEngine(engine);
+	int32 max_speed = e->GetDisplayMaxSpeed() * 16 / 10; // convert mph to km-ish/h
+	if (e->type == VEH_AIRCRAFT) max_speed /= _settings_game.vehicle.plane_speed;
+	return max_speed;
 }
 
 Money AIEventEnginePreview::GetPrice()
diff --git a/src/build_vehicle_gui.cpp b/src/build_vehicle_gui.cpp
index a3e104a0c..a67ec2eb2 100644
--- a/src/build_vehicle_gui.cpp
+++ b/src/build_vehicle_gui.cpp
@@ -482,7 +482,7 @@ static int DrawRailWagonPurchaseInfo(int x, int y, EngineID engine_number, const
 	y += 10;
 
 	/* Wagon weight - (including cargo) */
-	uint weight = GetEngineProperty(engine_number, 0x16, rvi->weight);
+	uint weight = e->GetDisplayWeight();
 	SetDParam(0, weight);
 	SetDParam(1, (GetCargo(rvi->cargo_type)->weight * GetEngineProperty(engine_number, 0x14, rvi->capacity) >> 4) + weight);
 	DrawString(x, y, STR_PURCHASE_INFO_WEIGHT_CWEIGHT, TC_FROMSTRING);
@@ -490,9 +490,9 @@ static int DrawRailWagonPurchaseInfo(int x, int y, EngineID engine_number, const
 
 	/* Wagon speed limit, displayed if above zero */
 	if (_settings_game.vehicle.wagon_speed_limits) {
-		uint max_speed = GetEngineProperty(engine_number, 0x09, rvi->max_speed);
+		uint max_speed = e->GetDisplayMaxSpeed();
 		if (max_speed > 0) {
-			SetDParam(0, max_speed * 10 / 16);
+			SetDParam(0, max_speed);
 			DrawString(x, y, STR_PURCHASE_INFO_SPEED, TC_FROMSTRING);
 			y += 10;
 		}
@@ -511,25 +511,24 @@ static int DrawRailWagonPurchaseInfo(int x, int y, EngineID engine_number, const
 /* Draw locomotive specific details */
 static int DrawRailEnginePurchaseInfo(int x, int y, EngineID engine_number, const RailVehicleInfo *rvi)
 {
-	int multihead = (rvi->railveh_type == RAILVEH_MULTIHEAD ? 1 : 0);
-	uint weight = GetEngineProperty(engine_number, 0x16, rvi->weight);
 	const Engine *e = GetEngine(engine_number);
+	uint weight = e->GetDisplayWeight();
 
 	/* Purchase Cost - Engine weight */
 	SetDParam(0, e->GetCost());
-	SetDParam(1, weight << multihead);
+	SetDParam(1, weight);
 	DrawString(x, y, STR_PURCHASE_INFO_COST_WEIGHT, TC_FROMSTRING);
 	y += 10;
 
 	/* Max speed - Engine power */
-	SetDParam(0, GetEngineProperty(engine_number, 0x09, rvi->max_speed) * 10 / 16);
-	SetDParam(1, GetEngineProperty(engine_number, 0x0B, rvi->power));
+	SetDParam(0, e->GetDisplayMaxSpeed());
+	SetDParam(1, e->GetPower());
 	DrawString(x, y, STR_PURCHASE_INFO_SPEED_POWER, TC_FROMSTRING);
 	y += 10;
 
 	/* Max tractive effort - not applicable if old acceleration or maglev */
 	if (_settings_game.vehicle.train_acceleration_model != TAM_ORIGINAL && rvi->railtype != RAILTYPE_MAGLEV) {
-		SetDParam(0, ((weight << multihead) * 10 * GetEngineProperty(engine_number, 0x1F, rvi->tractive_effort)) / 256);
+		SetDParam(0, (weight * 10 * GetEngineProperty(engine_number, 0x1F, rvi->tractive_effort)) / 256);
 		DrawString(x, y, STR_PURCHASE_INFO_MAX_TE, TC_FROMSTRING);
 		y += 10;
 	}
@@ -553,13 +552,13 @@ static int DrawRailEnginePurchaseInfo(int x, int y, EngineID engine_number, cons
 }
 
 /* Draw road vehicle specific details */
-static int DrawRoadVehPurchaseInfo(int x, int y, EngineID engine_number, const RoadVehicleInfo *rvi)
+static int DrawRoadVehPurchaseInfo(int x, int y, EngineID engine_number)
 {
 	const Engine *e = GetEngine(engine_number);
 
 	/* Purchase cost - Max speed */
 	SetDParam(0, e->GetCost());
-	SetDParam(1, rvi->max_speed * 10 / 32);
+	SetDParam(1, e->GetDisplayMaxSpeed());
 	DrawString(x, y, STR_PURCHASE_INFO_COST_SPEED, TC_FROMSTRING);
 	y += 10;
 
@@ -579,7 +578,7 @@ static int DrawShipPurchaseInfo(int x, int y, EngineID engine_number, const Ship
 
 	/* Purchase cost - Max speed */
 	SetDParam(0, e->GetCost());
-	SetDParam(1, GetEngineProperty(engine_number, 0x0B, svi->max_speed) * 10 / 32);
+	SetDParam(1, e->GetDisplayMaxSpeed());
 	DrawString(x, y, STR_PURCHASE_INFO_COST_SPEED, TC_FROMSTRING);
 	y += 10;
 
@@ -606,7 +605,7 @@ static int DrawAircraftPurchaseInfo(int x, int y, EngineID engine_number, const
 
 	/* Purchase cost - Max speed */
 	SetDParam(0, e->GetCost());
-	SetDParam(1, avi->max_speed * 10 / 16);
+	SetDParam(1, e->GetDisplayMaxSpeed());
 	DrawString(x, y, STR_PURCHASE_INFO_COST_SPEED, TC_FROMSTRING);
 	y += 10;
 
@@ -674,7 +673,7 @@ int DrawVehiclePurchaseInfo(int x, int y, uint w, EngineID engine_number)
 			break;
 		}
 		case VEH_ROAD:
-			y = DrawRoadVehPurchaseInfo(x, y, engine_number, RoadVehInfo(engine_number));
+			y = DrawRoadVehPurchaseInfo(x, y, engine_number);
 			break;
 		case VEH_SHIP:
 			y = DrawShipPurchaseInfo(x, y, engine_number, ShipVehInfo(engine_number));
diff --git a/src/engine.cpp b/src/engine.cpp
index 1e388a3e1..20be6ebd8 100644
--- a/src/engine.cpp
+++ b/src/engine.cpp
@@ -154,6 +154,56 @@ Money Engine::GetCost() const
 	}
 }
 
+/**
+ * Returns max speed for display purposes
+ * @return max speed in mph
+ */
+uint Engine::GetDisplayMaxSpeed() const
+{
+	switch (this->type) {
+		case VEH_TRAIN:
+			return GetEngineProperty(this->index, 0x09, this->u.rail.max_speed) * 10 / 16;
+
+		case VEH_ROAD:
+			return this->u.road.max_speed * 10 / 32;
+
+		case VEH_SHIP:
+			return GetEngineProperty(this->index, 0x0B, this->u.ship.max_speed) * 10 / 32;
+
+		case VEH_AIRCRAFT:
+			return this->u.air.max_speed * 10 / 16;
+
+		default: NOT_REACHED();
+	}
+}
+
+uint Engine::GetPower() const
+{
+	/* Currently only trains have 'power' */
+	switch (this->type) {
+		case VEH_TRAIN:
+			return GetEngineProperty(this->index, 0x0B, this->u.rail.power);
+
+		default: NOT_REACHED();
+	}
+}
+
+/**
+ * Returns the weight for display purposes.
+ * For dual-headed train-engines this is the weight of both heads
+ * @return weight in display units metric tons
+ */
+uint Engine::GetDisplayWeight() const
+{
+	/* Currently only trains have 'weight' */
+	switch (this->type) {
+		case VEH_TRAIN:
+			return GetEngineProperty(this->index, 0x16, this->u.rail.weight) << (this->u.rail.railveh_type == RAILVEH_MULTIHEAD ? 1 : 0);
+
+		default: NOT_REACHED();
+	}
+}
+
 /** Sets cached values in Company::num_vehicles and Group::num_vehicles
  */
 void SetCachedEngineCounts()
diff --git a/src/engine_base.h b/src/engine_base.h
index d5fd93329..787ae804b 100644
--- a/src/engine_base.h
+++ b/src/engine_base.h
@@ -52,6 +52,9 @@ struct Engine : PoolItem<Engine, EngineID, &_Engine_pool> {
 
 	Money GetRunningCost() const;
 	Money GetCost() const;
+	uint GetDisplayMaxSpeed() const;
+	uint GetPower() const;
+	uint GetDisplayWeight() const;
 };
 
 static inline bool IsEngineIndex(uint index)
diff --git a/src/engine_gui.cpp b/src/engine_gui.cpp
index 0cf3d99d3..be6af32ce 100644
--- a/src/engine_gui.cpp
+++ b/src/engine_gui.cpp
@@ -124,13 +124,12 @@ static uint GetTotalCapacityOfArticulatedParts(EngineID engine, VehicleType type
 static void DrawTrainEngineInfo(EngineID engine, int x, int y, int maxw)
 {
 	const RailVehicleInfo *rvi = RailVehInfo(engine);
-	int multihead = (rvi->railveh_type == RAILVEH_MULTIHEAD) ? 1 : 0;
 	const Engine *e = GetEngine(engine);
 
 	SetDParam(0, e->GetCost());
-	SetDParam(2, GetEngineProperty(engine, 0x09, rvi->max_speed) * 10 / 16);
-	SetDParam(3, GetEngineProperty(engine, 0x0B, rvi->power));
-	SetDParam(1, GetEngineProperty(engine, 0x16, rvi->weight) << multihead);
+	SetDParam(2, e->GetDisplayMaxSpeed());
+	SetDParam(3, e->GetPower());
+	SetDParam(1, e->GetDisplayWeight());
 
 	SetDParam(4, e->GetRunningCost());
 
@@ -150,7 +149,7 @@ static void DrawAircraftEngineInfo(EngineID engine, int x, int y, int maxw)
 	const Engine *e = GetEngine(engine);
 
 	SetDParam(0, e->GetCost());
-	SetDParam(1, avi->max_speed * 10 / 16);
+	SetDParam(1, e->GetDisplayMaxSpeed());
 	SetDParam(2, avi->passenger_capacity);
 	SetDParam(3, avi->mail_capacity);
 	SetDParam(4, e->GetRunningCost());
@@ -164,7 +163,7 @@ static void DrawRoadVehEngineInfo(EngineID engine, int x, int y, int maxw)
 	const Engine *e = GetEngine(engine);
 
 	SetDParam(0, e->GetCost());
-	SetDParam(1, rvi->max_speed * 10 / 32);
+	SetDParam(1, e->GetDisplayMaxSpeed());
 	SetDParam(2, e->GetRunningCost());
 	SetDParam(3, rvi->cargo_type);
 	SetDParam(4, GetTotalCapacityOfArticulatedParts(engine, VEH_ROAD));
@@ -178,7 +177,7 @@ static void DrawShipEngineInfo(EngineID engine, int x, int y, int maxw)
 	const Engine *e = GetEngine(engine);
 
 	SetDParam(0, e->GetCost());
-	SetDParam(1, GetEngineProperty(engine, 0x0B, svi->max_speed) * 10 / 32);
+	SetDParam(1, e->GetDisplayMaxSpeed());
 	SetDParam(2, svi->cargo_type);
 	SetDParam(3, GetEngineProperty(engine, 0x0D, svi->capacity));
 	SetDParam(4, e->GetRunningCost());