(svn r12824) -Codechange: Standardise routines for drawing vehicle images, using correct types and less duplication.

9 files changed, 109 insertions, 121 deletions

diff --git a/src/aircraft.h b/src/aircraft.h
index 50611803c..671463b69 100644
--- a/src/aircraft.h
+++ b/src/aircraft.h
@@ -119,7 +119,7 @@ struct Aircraft : public Vehicle {
 	ExpensesType GetExpenseType(bool income) const { return income ? EXPENSES_AIRCRAFT_INC : EXPENSES_AIRCRAFT_RUN; }
 	WindowClass GetVehicleListWindowClass() const { return WC_AIRCRAFT_LIST; }
 	bool IsPrimaryVehicle() const { return IsNormalAircraft(this); }
-	int GetImage(Direction direction) const;
+	SpriteID GetImage(Direction direction) const;
 	int GetDisplaySpeed() const { return this->cur_speed * 10 / 16; }
 	int GetDisplayMaxSpeed() const { return this->max_speed * 10 / 16; }
 	Money GetRunningCost() const { return AircraftVehInfo(this->engine_type)->running_cost * _price.aircraft_running; }
diff --git a/src/aircraft_cmd.cpp b/src/aircraft_cmd.cpp
index a2da629ac..c0795b6fb 100644
--- a/src/aircraft_cmd.cpp
+++ b/src/aircraft_cmd.cpp
@@ -160,16 +160,17 @@ static bool HaveHangarInOrderList(Vehicle *v)
 }
 #endif
 
-int Aircraft::GetImage(Direction direction) const
+SpriteID Aircraft::GetImage(Direction direction) const
 {
-	int spritenum = this->spritenum;
+	uint8 spritenum = this->spritenum;
 
 	if (is_custom_sprite(spritenum)) {
-		int sprite = GetCustomVehicleSprite(this, direction);
-
+		SpriteID sprite = GetCustomVehicleSprite(this, direction);
 		if (sprite != 0) return sprite;
+
 		spritenum = _orig_aircraft_vehicle_info[this->engine_type - AIRCRAFT_ENGINES_INDEX].image_index;
 	}
+
 	return direction + _aircraft_sprite[spritenum];
 }
 
@@ -179,33 +180,33 @@ SpriteID GetRotorImage(const Vehicle *v)
 
 	const Vehicle *w = v->Next()->Next();
 	if (is_custom_sprite(v->spritenum)) {
-		SpriteID spritenum = GetCustomRotorSprite(v, false);
-		if (spritenum != 0) return spritenum;
+		SpriteID sprite = GetCustomRotorSprite(v, false);
+		if (sprite != 0) return sprite;
 	}
 
 	/* Return standard rotor sprites if there are no custom sprites for this helicopter */
 	return SPR_ROTOR_STOPPED + w->u.air.state;
 }
 
-void DrawAircraftEngine(int x, int y, EngineID engine, SpriteID pal)
+static SpriteID GetAircraftIcon(EngineID engine)
 {
-	const AircraftVehicleInfo* avi = AircraftVehInfo(engine);
-	int spritenum = avi->image_index;
-	SpriteID sprite = 0;
+	uint8 spritenum = AircraftVehInfo(engine)->image_index;
 
 	if (is_custom_sprite(spritenum)) {
-		sprite = GetCustomVehicleIcon(engine, DIR_W);
-		if (sprite == 0) {
-			spritenum = _orig_aircraft_vehicle_info[engine - AIRCRAFT_ENGINES_INDEX].image_index;
-		}
-	}
-	if (sprite == 0) {
-		sprite = 6 + _aircraft_sprite[spritenum];
+		SpriteID sprite = GetCustomVehicleIcon(engine, DIR_W);
+		if (sprite != 0) return sprite;
+
+		spritenum = _orig_aircraft_vehicle_info[engine - AIRCRAFT_ENGINES_INDEX].image_index;
 	}
 
-	DrawSprite(sprite, pal, x, y);
+	return 6 + _aircraft_sprite[spritenum];
+}
 
-	if (!(avi->subtype & AIR_CTOL)) {
+void DrawAircraftEngine(int x, int y, EngineID engine, SpriteID pal)
+{
+	DrawSprite(GetAircraftIcon(engine), pal, x, y);
+
+	if (!(AircraftVehInfo(engine)->subtype & AIR_CTOL)) {
 		SpriteID rotor_sprite = GetCustomRotorIcon(engine);
 		if (rotor_sprite == 0) rotor_sprite = SPR_ROTOR_STOPPED;
 		DrawSprite(rotor_sprite, PAL_NONE, x, y - 5);
@@ -219,21 +220,9 @@ void DrawAircraftEngine(int x, int y, EngineID engine, SpriteID pal)
  */
 void GetAircraftSpriteSize(EngineID engine, uint &width, uint &height)
 {
-	const AircraftVehicleInfo* avi = AircraftVehInfo(engine);
-	int spritenum = avi->image_index;
-	SpriteID sprite = (6 + _aircraft_sprite[spritenum]);
-
-	if (is_custom_sprite(spritenum)) {
-		sprite = GetCustomVehicleIcon(engine, DIR_W);
-		if (sprite == 0) {
-			spritenum = _orig_aircraft_vehicle_info[engine - AIRCRAFT_ENGINES_INDEX].image_index;
-			sprite = (6 + _aircraft_sprite[spritenum]);
-		}
-	}
-
-	const Sprite *spr = GetSprite(sprite);
+	const Sprite *spr = GetSprite(GetAircraftIcon(engine));
 
-	width  = spr->width ;
+	width  = spr->width;
 	height = spr->height;
 }
 
diff --git a/src/roadveh.h b/src/roadveh.h
index 9159a8784..a89b73197 100644
--- a/src/roadveh.h
+++ b/src/roadveh.h
@@ -73,7 +73,7 @@ struct RoadVehicle : public Vehicle {
 	ExpensesType GetExpenseType(bool income) const { return income ? EXPENSES_ROADVEH_INC : EXPENSES_ROADVEH_RUN; }
 	WindowClass GetVehicleListWindowClass() const { return WC_ROADVEH_LIST; }
 	bool IsPrimaryVehicle() const { return IsRoadVehFront(this); }
-	int GetImage(Direction direction) const;
+	SpriteID GetImage(Direction direction) const;
 	int GetDisplaySpeed() const { return this->cur_speed * 10 / 32; }
 	int GetDisplayMaxSpeed() const { return this->max_speed * 10 / 32; }
 	Money GetRunningCost() const { return RoadVehInfo(this->engine_type)->running_cost * GetPriceByIndex(RoadVehInfo(this->engine_type)->running_cost_class); }
diff --git a/src/roadveh_cmd.cpp b/src/roadveh_cmd.cpp
index 19578162f..28d515330 100644
--- a/src/roadveh_cmd.cpp
+++ b/src/roadveh_cmd.cpp
@@ -94,36 +94,42 @@ static const Trackdir _roadveh_depot_exit_trackdir[DIAGDIR_END] = {
 	TRACKDIR_X_NE, TRACKDIR_Y_SE, TRACKDIR_X_SW, TRACKDIR_Y_NW
 };
 
-int RoadVehicle::GetImage(Direction direction) const
+static SpriteID GetRoadVehIcon(EngineID engine)
 {
-	int img = this->spritenum;
-	int image;
+	uint8 spritenum = RoadVehInfo(engine)->image_index;
 
-	if (is_custom_sprite(img)) {
-		image = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(img)));
-		if (image != 0) return image;
-		img = _orig_road_vehicle_info[this->engine_type - ROAD_ENGINES_INDEX].image_index;
+	if (is_custom_sprite(spritenum)) {
+		SpriteID sprite = GetCustomVehicleIcon(engine, DIR_W);
+		if (sprite != 0) return sprite;
+
+		spritenum = _orig_road_vehicle_info[engine - ROAD_ENGINES_INDEX].image_index;
 	}
 
-	image = direction + _roadveh_images[img];
-	if (this->cargo.Count() >= this->cargo_cap / 2U) image += _roadveh_full_adder[img];
-	return image;
+	return 6 + _roadveh_images[spritenum];
 }
 
-void DrawRoadVehEngine(int x, int y, EngineID engine, SpriteID pal)
+SpriteID RoadVehicle::GetImage(Direction direction) const
 {
-	int spritenum = RoadVehInfo(engine)->image_index;
+	uint8 spritenum = this->spritenum;
+	SpriteID sprite;
 
 	if (is_custom_sprite(spritenum)) {
-		int sprite = GetCustomVehicleIcon(engine, DIR_W);
+		sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)));
+		if (sprite != 0) return sprite;
 
-		if (sprite != 0) {
-			DrawSprite(sprite, pal, x, y);
-			return;
-		}
-		spritenum = _orig_road_vehicle_info[engine - ROAD_ENGINES_INDEX].image_index;
+		spritenum = _orig_road_vehicle_info[this->engine_type - ROAD_ENGINES_INDEX].image_index;
 	}
-	DrawSprite(6 + _roadveh_images[spritenum], pal, x, y);
+
+	sprite = direction + _roadveh_images[spritenum];
+
+	if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _roadveh_full_adder[spritenum];
+
+	return sprite;
+}
+
+void DrawRoadVehEngine(int x, int y, EngineID engine, SpriteID pal)
+{
+	DrawSprite(GetRoadVehIcon(engine), pal, x, y);
 }
 
 static CommandCost EstimateRoadVehCost(EngineID engine_type)
diff --git a/src/ship.h b/src/ship.h
index b0a0400ba..3d2e3cc02 100644
--- a/src/ship.h
+++ b/src/ship.h
@@ -35,7 +35,7 @@ struct Ship: public Vehicle {
 	WindowClass GetVehicleListWindowClass() const { return WC_SHIPS_LIST; }
 	void PlayLeaveStationSound() const;
 	bool IsPrimaryVehicle() const { return true; }
-	int GetImage(Direction direction) const;
+	SpriteID GetImage(Direction direction) const;
 	int GetDisplaySpeed() const { return this->cur_speed * 10 / 32; }
 	int GetDisplayMaxSpeed() const { return this->max_speed * 10 / 32; }
 	Money GetRunningCost() const { return ShipVehInfo(this->engine_type)->running_cost * _price.ship_running; }
diff --git a/src/ship_cmd.cpp b/src/ship_cmd.cpp
index 2a0e7222b..de4926999 100644
--- a/src/ship_cmd.cpp
+++ b/src/ship_cmd.cpp
@@ -58,20 +58,23 @@ static inline TrackBits GetTileShipTrackStatus(TileIndex tile)
 	return TrackStatusToTrackBits(GetTileTrackStatus(tile, TRANSPORT_WATER, 0));
 }
 
-void DrawShipEngine(int x, int y, EngineID engine, SpriteID pal)
+static SpriteID GetShipIcon(EngineID engine)
 {
-	int spritenum = ShipVehInfo(engine)->image_index;
+	uint8 spritenum = ShipVehInfo(engine)->image_index;
 
 	if (is_custom_sprite(spritenum)) {
-		int sprite = GetCustomVehicleIcon(engine, DIR_W);
+		SpriteID sprite = GetCustomVehicleIcon(engine, DIR_W);
+		if (sprite != 0) return sprite;
 
-		if (sprite != 0) {
-			DrawSprite(sprite, pal, x, y);
-			return;
-		}
 		spritenum = _orig_ship_vehicle_info[engine - SHIP_ENGINES_INDEX].image_index;
 	}
-	DrawSprite(6 + _ship_sprites[spritenum], pal, x, y);
+
+	return 6 + _ship_sprites[spritenum];
+}
+
+void DrawShipEngine(int x, int y, EngineID engine, SpriteID pal)
+{
+	DrawSprite(GetShipIcon(engine), pal, x, y);
 }
 
 /** Get the size of the sprite of a ship sprite heading west (used for lists)
@@ -81,35 +84,23 @@ void DrawShipEngine(int x, int y, EngineID engine, SpriteID pal)
  */
 void GetShipSpriteSize(EngineID engine, uint &width, uint &height)
 {
-	SpriteID spritenum = ShipVehInfo(engine)->image_index;
-	SpriteID custom_sprite = 0;
-
-	if (is_custom_sprite(spritenum)) {
-		custom_sprite = GetCustomVehicleIcon(engine, DIR_W);
-		spritenum = _orig_ship_vehicle_info[engine - SHIP_ENGINES_INDEX].image_index;
-	}
-	if (custom_sprite == 0) {
-		spritenum = 6 + _ship_sprites[spritenum];
-	} else {
-		spritenum = custom_sprite;
-	}
-
-	const Sprite *spr = GetSprite(spritenum);
+	const Sprite *spr = GetSprite(GetShipIcon(engine));
 
 	width  = spr->width;
 	height = spr->height;
 }
 
-int Ship::GetImage(Direction direction) const
+SpriteID Ship::GetImage(Direction direction) const
 {
-	int spritenum = this->spritenum;
+	uint8 spritenum = this->spritenum;
 
 	if (is_custom_sprite(spritenum)) {
-		int sprite = GetCustomVehicleSprite(this, direction);
-
+		SpriteID sprite = GetCustomVehicleSprite(this, direction);
 		if (sprite != 0) return sprite;
+
 		spritenum = _orig_ship_vehicle_info[this->engine_type - SHIP_ENGINES_INDEX].image_index;
 	}
+
 	return _ship_sprites[spritenum] + direction;
 }
 
diff --git a/src/train.h b/src/train.h
index 6aa2ad763..cc1882919 100644
--- a/src/train.h
+++ b/src/train.h
@@ -296,7 +296,7 @@ struct Train : public Vehicle {
 	WindowClass GetVehicleListWindowClass() const { return WC_TRAINS_LIST; }
 	void PlayLeaveStationSound() const;
 	bool IsPrimaryVehicle() const { return IsFrontEngine(this); }
-	int GetImage(Direction direction) const;
+	SpriteID GetImage(Direction direction) const;
 	int GetDisplaySpeed() const { return this->u.rail.last_speed * 10 / 16; }
 	int GetDisplayMaxSpeed() const { return this->u.rail.cached_max_speed * 10 / 16; }
 	Money GetRunningCost() const;
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index a1a378602..84ad087c9 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -467,59 +467,61 @@ void UpdateTrainAcceleration(Vehicle *v)
 	v->acceleration = Clamp(power / weight * 4, 1, 255);
 }
 
-int Train::GetImage(Direction direction) const
+SpriteID Train::GetImage(Direction direction) const
 {
-	int img = this->spritenum;
-	int base;
+	uint8 spritenum = this->spritenum;
+	SpriteID sprite;
 
 	if (HasBit(this->u.rail.flags, VRF_REVERSE_DIRECTION)) direction = ReverseDir(direction);
 
-	if (is_custom_sprite(img)) {
-		base = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(img)));
-		if (base != 0) return base;
-		img = _orig_rail_vehicle_info[this->engine_type].image_index;
+	if (is_custom_sprite(spritenum)) {
+		sprite = GetCustomVehicleSprite(this, (Direction)(direction + 4 * IS_CUSTOM_SECONDHEAD_SPRITE(spritenum)));
+		if (sprite != 0) return sprite;
+
+		spritenum = _orig_rail_vehicle_info[this->engine_type].image_index;
 	}
 
-	base = _engine_sprite_base[img] + ((direction + _engine_sprite_add[img]) & _engine_sprite_and[img]);
+	sprite = _engine_sprite_base[spritenum] + ((direction + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]);
+
+	if (this->cargo.Count() >= this->cargo_cap / 2U) sprite += _wagon_full_adder[spritenum];
 
-	if (this->cargo.Count() >= this->cargo_cap / 2U) base += _wagon_full_adder[img];
-	return base;
+	return sprite;
 }
 
-void DrawTrainEngine(int x, int y, EngineID engine, SpriteID pal)
+static SpriteID GetRailIcon(EngineID engine, bool rear_head, int &y)
 {
-	const RailVehicleInfo *rvi = RailVehInfo(engine);
-
-	int img = rvi->image_index;
-	SpriteID image = 0;
+	Direction dir = rear_head ? DIR_E : DIR_W;
+	uint8 spritenum = RailVehInfo(engine)->image_index;
 
-	if (is_custom_sprite(img)) {
-		image = GetCustomVehicleIcon(engine, DIR_W);
-		if (image == 0) {
-			img = _orig_rail_vehicle_info[engine].image_index;
-		} else {
-			y += _traininfo_vehicle_pitch;
+	if (is_custom_sprite(spritenum)) {
+		SpriteID sprite = GetCustomVehicleIcon(engine, dir);
+		if (sprite != 0) {
+			y += _traininfo_vehicle_pitch; // TODO Make this per-GRF
+			return sprite;
 		}
-	}
-	if (image == 0) {
-		image = (6 & _engine_sprite_and[img]) + _engine_sprite_base[img];
+
+		spritenum = _orig_rail_vehicle_info[engine].image_index;
 	}
 
-	if (rvi->railveh_type == RAILVEH_MULTIHEAD) {
-		DrawSprite(image, pal, x - 14, y);
-		x += 15;
-		image = 0;
-		if (is_custom_sprite(img)) {
-			image = GetCustomVehicleIcon(engine, DIR_E);
-			if (image == 0) img = _orig_rail_vehicle_info[engine].image_index;
-		}
-		if (image == 0) {
-			image =
-				((6 + _engine_sprite_add[img + 1]) & _engine_sprite_and[img + 1]) +
-				_engine_sprite_base[img + 1];
-		}
+	if (rear_head) spritenum++;
+
+	return ((6 + _engine_sprite_add[spritenum]) & _engine_sprite_and[spritenum]) + _engine_sprite_base[spritenum];
+}
+
+void DrawTrainEngine(int x, int y, EngineID engine, SpriteID pal)
+{
+	if (RailVehInfo(engine)->railveh_type == RAILVEH_MULTIHEAD) {
+		int yf = y;
+		int yr = y;
+
+		SpriteID spritef = GetRailIcon(engine, false, yf);
+		SpriteID spriter = GetRailIcon(engine, true, yr);
+		DrawSprite(spritef, pal, x - 14, yf);
+		DrawSprite(spriter, pal, x + 15, yr);
+	} else {
+		SpriteID sprite = GetRailIcon(engine, false, y);
+		DrawSprite(sprite, pal, x, y);
 	}
-	DrawSprite(image, pal, x, y);
 }
 
 static CommandCost CmdBuildRailWagon(EngineID engine, TileIndex tile, uint32 flags)
diff --git a/src/vehicle_base.h b/src/vehicle_base.h
index c27fd5aaa..283b743c9 100644
--- a/src/vehicle_base.h
+++ b/src/vehicle_base.h
@@ -390,7 +390,7 @@ public:
 	 * @param direction the direction the vehicle is facing
 	 * @return the sprite for the given vehicle in the given direction
 	 */
-	virtual int GetImage(Direction direction) const { return 0; }
+	virtual SpriteID GetImage(Direction direction) const { return 0; }
 
 	/**
 	 * Gets the speed in mph that can be sent into SetDParam for string processing.