Codechange: Move SpriteGroup cast from callers into Resolve.

src/newgrf_airport.cpp

@@ -258,7 +258,7 @@ AirportResolverObject::AirportResolverObject(TileIndex tile, Station *st, const
 SpriteID GetCustomAirportSprite(const AirportSpec *as, uint8_t layout)
 {
 	AirportResolverObject object(INVALID_TILE, nullptr, as, layout);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<ResultSpriteGroup>();
 	if (group == nullptr || group->GetNumResults() == 0) return as->preview_sprite;
 
 	return group->GetResult();

src/newgrf_airporttiles.cpp

@@ -273,13 +273,12 @@ bool DrawNewAirportTile(TileInfo *ti, Station *st, const AirportTileSpec *airts)
 	}
 
 	AirportTileResolverObject object(airts, ti->tile, st);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<TileLayoutSpriteGroup>();
-	if (group == nullptr || group->type != SGT_TILELAYOUT) {
+	if (group == nullptr) {
 		return false;
 	}
 
-	const TileLayoutSpriteGroup *tlgroup = (const TileLayoutSpriteGroup *)group;
+	AirportDrawTileLayout(ti, group, Company::Get(st->owner)->colour);
-	AirportDrawTileLayout(ti, tlgroup, Company::Get(st->owner)->colour);
 	return true;
 }
 

src/newgrf_badge.cpp

@@ -275,7 +275,7 @@ void ApplyBadgeFeaturesToClassBadges()
 PalSpriteID GetBadgeSprite(const Badge &badge, GrfSpecFeature feature, std::optional<TimerGameCalendar::Date> introduction_date, PaletteID remap)
 {
 	BadgeResolverObject object(badge, feature, introduction_date);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<ResultSpriteGroup>();
 	if (group == nullptr || group->GetNumResults() == 0) return {0, PAL_NONE};
 
 	PaletteID pal = badge.flags.Test(BadgeFlag::UseCompanyColour) ? remap : PAL_NONE;

src/newgrf_canal.cpp

@@ -140,7 +140,7 @@ CanalResolverObject::CanalResolverObject(CanalFeature feature, TileIndex tile,
 SpriteID GetCanalSprite(CanalFeature feature, TileIndex tile)
 {
 	CanalResolverObject object(feature, tile);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<ResultSpriteGroup>();
 	if (group == nullptr || group->GetNumResults() == 0) return 0;
 
 	return group->GetResult();

src/newgrf_cargo.cpp

@@ -55,7 +55,7 @@ CargoResolverObject::CargoResolverObject(const CargoSpec *cs, CallbackID callbac
 SpriteID GetCustomCargoSprite(const CargoSpec *cs)
 {
 	CargoResolverObject object(cs);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<ResultSpriteGroup>();
 	if (group == nullptr || group->GetNumResults() == 0) return 0;
 
 	return group->GetResult();

src/newgrf_engine.cpp

@@ -1101,7 +1101,7 @@ static void GetCustomEngineSprite(EngineID engine, const Vehicle *v, Direction d
 	for (uint stack = 0; stack < max_stack; ++stack) {
 		object.ResetState();
 		object.callback_param1 = image_type | (stack << 8);
-		const SpriteGroup *group = object.Resolve();
+		const auto *group = object.Resolve<ResultSpriteGroup>();
 		uint32_t reg100 = sprite_stack ? GetRegister(0x100) : 0;
 		if (group != nullptr && group->GetNumResults() != 0) {
 			result->seq[result->count].sprite = group->GetResult() + (direction % group->GetNumResults());
@@ -1144,7 +1144,7 @@ static void GetRotorOverrideSprite(EngineID engine, const struct Aircraft *v, En
 	for (uint stack = 0; stack < max_stack; ++stack) {
 		object.ResetState();
 		object.callback_param1 = image_type | (stack << 8);
-		const SpriteGroup *group = object.Resolve();
+		const auto *group = object.Resolve<ResultSpriteGroup>();
 		uint32_t reg100 = sprite_stack ? GetRegister(0x100) : 0;
 		if (group != nullptr && group->GetNumResults() != 0) {
 			result->seq[result->count].sprite = group->GetResult() + (rotor_pos % group->GetNumResults());

src/newgrf_house.cpp

@@ -505,12 +505,11 @@ void DrawNewHouseTile(TileInfo *ti, HouseID house_id)
 
 	HouseResolverObject object(house_id, ti->tile, Town::GetByTile(ti->tile));
 
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<TileLayoutSpriteGroup>();
-	if (group != nullptr && group->type == SGT_TILELAYOUT) {
+	if (group != nullptr) {
 		/* Limit the building stage to the number of stages supplied. */
-		const TileLayoutSpriteGroup *tlgroup = (const TileLayoutSpriteGroup *)group;
 		uint8_t stage = GetHouseBuildingStage(ti->tile);
-		DrawTileLayout(ti, tlgroup, stage, house_id);
+		DrawTileLayout(ti, group, stage, house_id);
 	}
 }
 
@@ -525,11 +524,11 @@ void DrawNewHouseTile(TileInfo *ti, HouseID house_id)
 void DrawNewHouseTileInGUI(int x, int y, const HouseSpec *spec, HouseID house_id, int view)
 {
 	HouseResolverObject object(house_id, INVALID_TILE, nullptr, CBID_NO_CALLBACK, 0, 0, true, view);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<TileLayoutSpriteGroup>();
-	if (group == nullptr || group->type != SGT_TILELAYOUT) return;
+	if (group == nullptr) return;
 
 	uint8_t stage = TOWN_HOUSE_COMPLETED;
-	const DrawTileSprites *dts = reinterpret_cast<const TileLayoutSpriteGroup *>(group)->ProcessRegisters(&stage);
+	const DrawTileSprites *dts = group->ProcessRegisters(&stage);
 
 	PaletteID palette = GetColourPalette(spec->random_colour[0]);
 	if (spec->callback_mask.Test(HouseCallbackMask::Colour)) {

src/newgrf_industries.cpp

@@ -629,9 +629,8 @@ void IndustryProductionCallback(Industry *ind, int reason)
 		}
 
 		SB(object.callback_param2, 8, 16, loop);
-		const SpriteGroup *tgroup = object.Resolve();
+		const auto *group = object.Resolve<IndustryProductionSpriteGroup>();
-		if (tgroup == nullptr || tgroup->type != SGT_INDUSTRY_PRODUCTION) break;
+		if (group == nullptr) break;
-		const IndustryProductionSpriteGroup *group = (const IndustryProductionSpriteGroup *)tgroup;
 
 		if (group->version == 0xFF) {
 			/* Result was marked invalid on load, display error message */

src/newgrf_industrytiles.cpp

@@ -205,13 +205,12 @@ bool DrawNewIndustryTile(TileInfo *ti, Industry *i, IndustryGfx gfx, const Indus
 
 	IndustryTileResolverObject object(gfx, ti->tile, i);
 
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<TileLayoutSpriteGroup>();
-	if (group == nullptr || group->type != SGT_TILELAYOUT) return false;
+	if (group == nullptr) return false;
 
 	/* Limit the building stage to the number of stages supplied. */
-	const TileLayoutSpriteGroup *tlgroup = (const TileLayoutSpriteGroup *)group;
 	uint8_t stage = GetIndustryConstructionStage(ti->tile);
-	IndustryDrawTileLayout(ti, tlgroup, i->random_colour, stage);
+	IndustryDrawTileLayout(ti, group, i->random_colour, stage);
 	return true;
 }
 

src/newgrf_object.cpp

@@ -473,10 +473,10 @@ void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec)
 	Object *o = Object::GetByTile(ti->tile);
 	ObjectResolverObject object(spec, o, ti->tile);
 
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<TileLayoutSpriteGroup>();
-	if (group == nullptr || group->type != SGT_TILELAYOUT) return;
+	if (group == nullptr) return;
 
-	DrawTileLayout(ti, (const TileLayoutSpriteGroup *)group, spec);
+	DrawTileLayout(ti, group, spec);
 }
 
 /**
@@ -489,10 +489,10 @@ void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec)
 void DrawNewObjectTileInGUI(int x, int y, const ObjectSpec *spec, uint8_t view)
 {
 	ObjectResolverObject object(spec, nullptr, INVALID_TILE, view);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<TileLayoutSpriteGroup>();
-	if (group == nullptr || group->type != SGT_TILELAYOUT) return;
+	if (group == nullptr) return;
 
-	const DrawTileSprites *dts = ((const TileLayoutSpriteGroup *)group)->ProcessRegisters(nullptr);
+	const DrawTileSprites *dts = group->ProcessRegisters(nullptr);
 
 	PaletteID palette;
 	if (Company::IsValidID(_local_company)) {

src/newgrf_railtype.cpp

@@ -110,7 +110,7 @@ SpriteID GetCustomRailSprite(const RailTypeInfo *rti, TileIndex tile, RailTypeSp
 	if (rti->group[rtsg] == nullptr) return 0;
 
 	RailTypeResolverObject object(rti, tile, context, rtsg);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<ResultSpriteGroup>();
 	if (group == nullptr || group->GetNumResults() == 0) return 0;
 
 	if (num_results) *num_results = group->GetNumResults();
@@ -136,7 +136,7 @@ SpriteID GetCustomSignalSprite(const RailTypeInfo *rti, TileIndex tile, SignalTy
 	uint32_t param2 = (type << 16) | (var << 8) | state;
 	RailTypeResolverObject object(rti, tile, TCX_NORMAL, RTSG_SIGNALS, param1, param2);
 
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<ResultSpriteGroup>();
 	if (group == nullptr || group->GetNumResults() == 0) return 0;
 
 	return group->GetResult();

src/newgrf_roadstop.cpp

@@ -291,9 +291,9 @@ void DrawRoadStopTile(int x, int y, RoadType roadtype, const RoadStopSpec *spec,
 
 	const RoadTypeInfo *rti = GetRoadTypeInfo(roadtype);
 	RoadStopResolverObject object(spec, nullptr, INVALID_TILE, roadtype, type, view);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<TileLayoutSpriteGroup>();
-	if (group == nullptr || group->type != SGT_TILELAYOUT) return;
+	if (group == nullptr) return;
-	const DrawTileSprites *dts = ((const TileLayoutSpriteGroup *)group)->ProcessRegisters(nullptr);
+	const DrawTileSprites *dts = group->ProcessRegisters(nullptr);
 
 	PaletteID palette = GetCompanyPalette(_local_company);
 
@@ -346,9 +346,7 @@ void DrawRoadStopTile(int x, int y, RoadType roadtype, const RoadStopSpec *spec,
 const TileLayoutSpriteGroup *GetRoadStopLayout(TileInfo *ti, const RoadStopSpec *spec, BaseStation *st, StationType type, int view)
 {
 	RoadStopResolverObject object(spec, st, ti->tile, INVALID_ROADTYPE, type, view);
-	const SpriteGroup *group = object.Resolve();
+	return object.Resolve<TileLayoutSpriteGroup>();
-	if (group == nullptr || group->type != SGT_TILELAYOUT) return nullptr;
-	return static_cast<const TileLayoutSpriteGroup *>(group);
 }
 
 /** Wrapper for animation control, see GetRoadStopCallback. */

src/newgrf_roadtype.cpp

@@ -153,7 +153,7 @@ SpriteID GetCustomRoadSprite(const RoadTypeInfo *rti, TileIndex tile, RoadTypeSp
 	if (rti->group[rtsg] == nullptr) return 0;
 
 	RoadTypeResolverObject object(rti, tile, context, rtsg);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<ResultSpriteGroup>();
 	if (group == nullptr || group->GetNumResults() == 0) return 0;
 
 	if (num_results) *num_results = group->GetNumResults();

src/newgrf_spritegroup.h

@@ -223,6 +223,8 @@ struct CallbackResultSpriteGroup : SpriteGroup {
 /* A result sprite group returns the first SpriteID and the number of
  * sprites in the set */
 struct ResultSpriteGroup : SpriteGroup {
+	static constexpr SpriteGroupType TYPE = SGT_RESULT;
+
 	/**
 	 * Creates a spritegroup representing a sprite number result.
 	 * @param sprite The sprite number.
@@ -230,7 +232,7 @@ struct ResultSpriteGroup : SpriteGroup {
 	 * @return A spritegroup representing the sprite number result.
 	 */
 	ResultSpriteGroup(SpriteID sprite, uint8_t num_sprites) :
-		SpriteGroup(SGT_RESULT),
+		SpriteGroup(TYPE),
 		num_sprites(num_sprites),
 		sprite(sprite)
 	{
@@ -247,7 +249,9 @@ struct ResultSpriteGroup : SpriteGroup {
  * Action 2 sprite layout for houses, industry tiles, objects and airport tiles.
  */
 struct TileLayoutSpriteGroup : SpriteGroup {
-	TileLayoutSpriteGroup() : SpriteGroup(SGT_TILELAYOUT) {}
+	static constexpr SpriteGroupType TYPE = SGT_TILELAYOUT;
+
+	TileLayoutSpriteGroup() : SpriteGroup(TYPE) {}
 	~TileLayoutSpriteGroup() {}
 
 	NewGRFSpriteLayout dts{};
@@ -256,7 +260,9 @@ struct TileLayoutSpriteGroup : SpriteGroup {
 };
 
 struct IndustryProductionSpriteGroup : SpriteGroup {
-	IndustryProductionSpriteGroup() : SpriteGroup(SGT_INDUSTRY_PRODUCTION) {}
+	static constexpr SpriteGroupType TYPE = SGT_INDUSTRY_PRODUCTION;
+
+	IndustryProductionSpriteGroup() : SpriteGroup(TYPE) {}
 
 	uint8_t version = 0; ///< Production callback version used, or 0xFF if marked invalid
 	uint8_t num_input = 0; ///< How many subtract_input values are valid
@@ -310,6 +316,11 @@ struct ResolverObject {
 
 	virtual ~ResolverObject() = default;
 
+	const SpriteGroup *DoResolve()
+	{
+		return SpriteGroup::Resolve(this->root_spritegroup, *this);
+	}
+
 	ScopeResolver default_scope; ///< Default implementation of the grf scope.
 
 	CallbackID callback{}; ///< Callback being resolved.
@@ -330,10 +341,14 @@ public:
 	/**
 	 * Resolve SpriteGroup.
 	 * @return Result spritegroup.
+	 * @tparam TSpriteGroup Sprite group type
 	 */
-	const SpriteGroup *Resolve()
+	template <class TSpriteGroup>
+	inline const TSpriteGroup *Resolve()
 	{
-		return SpriteGroup::Resolve(this->root_spritegroup, *this);
+		auto result = this->DoResolve();
+		if (result == nullptr || result->type != TSpriteGroup::TYPE) return nullptr;
+		return static_cast<const TSpriteGroup *>(result);
 	}
 
 	/**
@@ -343,20 +358,20 @@ public:
 	 * - GetReseedSum: Bits to rerandomise for SELF scope, for features with broken-by-design PARENT randomisation. (all but industry tiles)
 	 * - GetUsedRandomTriggers: Consumed random triggers to be reset.
 	 */
-	void ResolveRerandomisation()
+	inline void ResolveRerandomisation()
 	{
 		/* The Resolve result has no meaning.
 		 * It can be a SpriteSet, a callback result, or even an invalid SpriteGroup reference (nullptr). */
-		this->Resolve();
+		this->DoResolve();
 	}
 
 	/**
 	 * Resolve callback.
 	 * @return Callback result.
 	 */
-	uint16_t ResolveCallback()
+	inline uint16_t ResolveCallback()
 	{
-		const SpriteGroup *result = this->Resolve();
+		const SpriteGroup *result = this->DoResolve();
 		return result != nullptr ? result->GetCallbackResult() : CALLBACK_FAILED;
 	}
 

src/newgrf_station.cpp

@@ -640,7 +640,7 @@ StationResolverObject::StationResolverObject(const StationSpec *statspec, BaseSt
 SpriteID GetCustomStationRelocation(const StationSpec *statspec, BaseStation *st, TileIndex tile, uint32_t var10)
 {
 	StationResolverObject object(statspec, st, tile, CBID_NO_CALLBACK, var10);
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<ResultSpriteGroup>();
 	if (group == nullptr || group->GetNumResults() == 0) return 0;
 	return group->GetResult() - SPR_RAIL_PLATFORM_Y_FRONT;
 }
@@ -659,7 +659,7 @@ SpriteID GetCustomStationFoundationRelocation(const StationSpec *statspec, BaseS
 	/* callback_param1 == 2 means  we are resolving the foundation sprites. */
 	StationResolverObject object(statspec, st, tile, CBID_NO_CALLBACK, 2, layout | (edge_info << 16));
 
-	const SpriteGroup *group = object.Resolve();
+	const auto *group = object.Resolve<ResultSpriteGroup>();
 	/* Note: SpriteGroup::Resolve zeroes all registers, so register 0x100 is initialised to 0. (compatibility) */
 	auto offset = GetRegister(0x100);
 	if (group == nullptr || group->GetNumResults() <= offset) return 0;