(svn r26085) -Codechange: Pass ResolverObjects as reference instead of pointer since they are never NULL.

27 files changed, 155 insertions, 156 deletions

diff --git a/src/base_station_base.h b/src/base_station_base.h
index 812692bb1..53e104a82 100644
--- a/src/base_station_base.h
+++ b/src/base_station_base.h
@@ -103,7 +103,7 @@ struct BaseStation : StationPool::PoolItem<&_station_pool> {
 	 * @param available will return false if ever the variable asked for does not exist
 	 * @return the value stored in the corresponding variable
 	 */
-	virtual uint32 GetNewGRFVariable(const struct ResolverObject *object, byte variable, byte parameter, bool *available) const = 0;
+	virtual uint32 GetNewGRFVariable(const struct ResolverObject &object, byte variable, byte parameter, bool *available) const = 0;
 
 	/**
 	 * Update the coordinated of the sign (as shown in the viewport).
diff --git a/src/newgrf_airport.cpp b/src/newgrf_airport.cpp
index 4b43af483..c03eb2465 100644
--- a/src/newgrf_airport.cpp
+++ b/src/newgrf_airport.cpp
@@ -24,7 +24,7 @@ struct AirportScopeResolver : public ScopeResolver {
 	byte layout;        ///< Layout of the airport to build.
 	TileIndex tile;     ///< Tile for the callback, only valid for airporttile callbacks.
 
-	AirportScopeResolver(ResolverObject *ro, TileIndex tile, Station *st, byte airport_id, byte layout);
+	AirportScopeResolver(ResolverObject &ro, TileIndex tile, Station *st, byte airport_id, byte layout);
 
 	/* virtual */ uint32 GetRandomBits() const;
 	/* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
@@ -216,7 +216,7 @@ void AirportOverrideManager::SetEntitySpec(AirportSpec *as)
 		if (value == 0) return;
 
 		/* Create storage on first modification. */
-		uint32 grfid = (this->ro->grffile != NULL) ? this->ro->grffile->grfid : 0;
+		uint32 grfid = (this->ro.grffile != NULL) ? this->ro.grffile->grfid : 0;
 		assert(PersistentStorage::CanAllocateItem());
 		this->st->airport.psa = new PersistentStorage(grfid);
 	}
@@ -235,7 +235,7 @@ void AirportOverrideManager::SetEntitySpec(AirportSpec *as)
  */
 AirportResolverObject::AirportResolverObject(TileIndex tile, Station *st, byte airport_id, byte layout,
 		CallbackID callback, uint32 param1, uint32 param2)
-	: ResolverObject(AirportSpec::Get(airport_id)->grf_prop.grffile, callback, param1, param2), airport_scope(this, tile, st, airport_id, layout)
+	: ResolverObject(AirportSpec::Get(airport_id)->grf_prop.grffile, callback, param1, param2), airport_scope(*this, tile, st, airport_id, layout)
 {
 }
 
@@ -247,7 +247,7 @@ AirportResolverObject::AirportResolverObject(TileIndex tile, Station *st, byte a
  * @param airport_id Type of airport for which the callback is run.
  * @param layout Layout of the airport to build.
  */
-AirportScopeResolver::AirportScopeResolver(ResolverObject *ro, TileIndex tile, Station *st, byte airport_id, byte layout) : ScopeResolver(ro)
+AirportScopeResolver::AirportScopeResolver(ResolverObject &ro, TileIndex tile, Station *st, byte airport_id, byte layout) : ScopeResolver(ro)
 {
 	this->st = st;
 	this->airport_id = airport_id;
@@ -258,7 +258,7 @@ AirportScopeResolver::AirportScopeResolver(ResolverObject *ro, TileIndex tile, S
 SpriteID GetCustomAirportSprite(const AirportSpec *as, byte layout)
 {
 	AirportResolverObject object(INVALID_TILE, NULL, as->GetIndex(), layout);
-	const SpriteGroup *group = SpriteGroup::Resolve(as->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(as->grf_prop.spritegroup[0], object);
 	if (group == NULL) return as->preview_sprite;
 
 	return group->GetResult();
@@ -267,7 +267,7 @@ SpriteID GetCustomAirportSprite(const AirportSpec *as, byte layout)
 uint16 GetAirportCallback(CallbackID callback, uint32 param1, uint32 param2, Station *st, TileIndex tile)
 {
 	AirportResolverObject object(tile, st, st->airport.type, st->airport.layout, callback, param1, param2);
-	const SpriteGroup *group = SpriteGroup::Resolve(st->airport.GetSpec()->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(st->airport.GetSpec()->grf_prop.spritegroup[0], object);
 	if (group == NULL) return CALLBACK_FAILED;
 
 	return group->GetCallbackResult();
@@ -283,7 +283,7 @@ uint16 GetAirportCallback(CallbackID callback, uint32 param1, uint32 param2, Sta
 StringID GetAirportTextCallback(const AirportSpec *as, byte layout, uint16 callback)
 {
 	AirportResolverObject object(INVALID_TILE, NULL, as->GetIndex(), layout, (CallbackID)callback);
-	const SpriteGroup *group = SpriteGroup::Resolve(as->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(as->grf_prop.spritegroup[0], object);
 	uint16 cb_res = (group != NULL) ? group->GetCallbackResult() : CALLBACK_FAILED;
 	if (cb_res == CALLBACK_FAILED || cb_res == 0x400) return STR_UNDEFINED;
 	if (cb_res > 0x400) {
diff --git a/src/newgrf_airporttiles.cpp b/src/newgrf_airporttiles.cpp
index 78773608f..cc9471c80 100644
--- a/src/newgrf_airporttiles.cpp
+++ b/src/newgrf_airporttiles.cpp
@@ -178,7 +178,7 @@ static uint32 GetAirportTileIDAtOffset(TileIndex tile, const Station *st, uint32
 		case 0x44: return GetAnimationFrame(this->tile);
 
 		/* Land info of nearby tiles */
-		case 0x60: return GetNearbyAirportTileInformation(parameter, this->tile, this->st->index, this->ro->grffile->grf_version >= 8);
+		case 0x60: return GetNearbyAirportTileInformation(parameter, this->tile, this->st->index, this->ro.grffile->grf_version >= 8);
 
 		/* Animation stage of nearby tiles */
 		case 0x61: {
@@ -190,7 +190,7 @@ static uint32 GetAirportTileIDAtOffset(TileIndex tile, const Station *st, uint32
 		}
 
 		/* Get airport tile ID at offset */
-		case 0x62: return GetAirportTileIDAtOffset(GetNearbyTile(parameter, this->tile), this->st, this->ro->grffile->grfid);
+		case 0x62: return GetAirportTileIDAtOffset(GetNearbyTile(parameter, this->tile), this->st, this->ro.grffile->grfid);
 	}
 
 	DEBUG(grf, 1, "Unhandled airport tile variable 0x%X", variable);
@@ -215,7 +215,7 @@ static uint32 GetAirportTileIDAtOffset(TileIndex tile, const Station *st, uint32
  */
 AirportTileResolverObject::AirportTileResolverObject(const AirportTileSpec *ats, TileIndex tile, Station *st,
 		CallbackID callback, uint32 callback_param1, uint32 callback_param2)
-	: ResolverObject(ats->grf_prop.grffile, callback, callback_param1, callback_param2), tiles_scope(this, ats, tile, st)
+	: ResolverObject(ats->grf_prop.grffile, callback, callback_param1, callback_param2), tiles_scope(*this, ats, tile, st)
 {
 }
 
@@ -225,7 +225,7 @@ AirportTileResolverObject::AirportTileResolverObject(const AirportTileSpec *ats,
  * @param tile %Tile for the callback, only valid for airporttile callbacks.
  * @param st Station of the airport for which the callback is run, or \c NULL for build gui.
  */
-AirportTileScopeResolver::AirportTileScopeResolver(ResolverObject *ro, const AirportTileSpec *ats, TileIndex tile, Station *st) : ScopeResolver(ro)
+AirportTileScopeResolver::AirportTileScopeResolver(ResolverObject &ro, const AirportTileSpec *ats, TileIndex tile, Station *st) : ScopeResolver(ro)
 {
 	assert(st != NULL);
 
@@ -237,7 +237,7 @@ AirportTileScopeResolver::AirportTileScopeResolver(ResolverObject *ro, const Air
 uint16 GetAirportTileCallback(CallbackID callback, uint32 param1, uint32 param2, const AirportTileSpec *ats, Station *st, TileIndex tile, int extra_data = 0)
 {
 	AirportTileResolverObject object(ats, tile, st, callback, param1, param2);
-	const SpriteGroup *group = SpriteGroup::Resolve(ats->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(ats->grf_prop.spritegroup[0], object);
 	if (group == NULL) return CALLBACK_FAILED;
 
 	return group->GetCallbackResult();
@@ -275,7 +275,7 @@ bool DrawNewAirportTile(TileInfo *ti, Station *st, StationGfx gfx, const Airport
 	}
 
 	AirportTileResolverObject object(airts, ti->tile, st);
-	const SpriteGroup *group = SpriteGroup::Resolve(airts->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(airts->grf_prop.spritegroup[0], object);
 	if (group == NULL || group->type != SGT_TILELAYOUT) {
 		return false;
 	}
diff --git a/src/newgrf_airporttiles.h b/src/newgrf_airporttiles.h
index 6c68682d4..4d25aa924 100644
--- a/src/newgrf_airporttiles.h
+++ b/src/newgrf_airporttiles.h
@@ -24,7 +24,7 @@ struct AirportTileScopeResolver : public ScopeResolver {
 	byte airport_id;     ///< Type of airport for which the callback is run.
 	TileIndex tile;      ///< Tile for the callback, only valid for airporttile callbacks.
 
-	AirportTileScopeResolver(ResolverObject *ro, const AirportTileSpec *ats, TileIndex tile, Station *st);
+	AirportTileScopeResolver(ResolverObject &ro, const AirportTileSpec *ats, TileIndex tile, Station *st);
 
 	/* virtual */ uint32 GetRandomBits() const;
 	/* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
diff --git a/src/newgrf_canal.cpp b/src/newgrf_canal.cpp
index ef678a0cc..7310186c0 100644
--- a/src/newgrf_canal.cpp
+++ b/src/newgrf_canal.cpp
@@ -23,7 +23,7 @@ WaterFeature _water_feature[CF_END];
 struct CanalScopeResolver : public ScopeResolver {
 	TileIndex tile; ///< Tile containing the canal.
 
-	CanalScopeResolver(ResolverObject *ro, TileIndex tile);
+	CanalScopeResolver(ResolverObject &ro, TileIndex tile);
 
 	/* virtual */ uint32 GetRandomBits() const;
 	/* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
@@ -108,7 +108,7 @@ struct CanalResolverObject : public ResolverObject {
 	return group->loaded[0];
 }
 
-CanalScopeResolver::CanalScopeResolver(ResolverObject *ro, TileIndex tile) : ScopeResolver(ro)
+CanalScopeResolver::CanalScopeResolver(ResolverObject &ro, TileIndex tile) : ScopeResolver(ro)
 {
 	this->tile = tile;
 }
@@ -123,7 +123,7 @@ CanalScopeResolver::CanalScopeResolver(ResolverObject *ro, TileIndex tile) : Sco
  */
 CanalResolverObject::CanalResolverObject(const GRFFile *grffile, TileIndex tile,
 		CallbackID callback, uint32 callback_param1, uint32 callback_param2)
-		: ResolverObject(grffile, callback, callback_param1, callback_param2), canal_scope(this, tile)
+		: ResolverObject(grffile, callback, callback_param1, callback_param2), canal_scope(*this, tile)
 {
 }
 
@@ -136,7 +136,7 @@ CanalResolverObject::CanalResolverObject(const GRFFile *grffile, TileIndex tile,
 SpriteID GetCanalSprite(CanalFeature feature, TileIndex tile)
 {
 	CanalResolverObject object(_water_feature[feature].grffile, tile);
-	const SpriteGroup *group = SpriteGroup::Resolve(_water_feature[feature].group, &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(_water_feature[feature].group, object);
 	if (group == NULL) return 0;
 
 	return group->GetResult();
@@ -154,7 +154,7 @@ SpriteID GetCanalSprite(CanalFeature feature, TileIndex tile)
 static uint16 GetCanalCallback(CallbackID callback, uint32 param1, uint32 param2, CanalFeature feature, TileIndex tile)
 {
 	CanalResolverObject object(_water_feature[feature].grffile, tile, callback, param1, param2);
-	const SpriteGroup *group = SpriteGroup::Resolve(_water_feature[feature].group, &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(_water_feature[feature].group, object);
 	if (group == NULL) return CALLBACK_FAILED;
 
 	return group->GetCallbackResult();
diff --git a/src/newgrf_cargo.cpp b/src/newgrf_cargo.cpp
index d6227b801..4186b53f6 100644
--- a/src/newgrf_cargo.cpp
+++ b/src/newgrf_cargo.cpp
@@ -50,7 +50,7 @@ CargoResolverObject::CargoResolverObject(const CargoSpec *cs, CallbackID callbac
 SpriteID GetCustomCargoSprite(const CargoSpec *cs)
 {
 	CargoResolverObject object(cs);
-	const SpriteGroup *group = SpriteGroup::Resolve(cs->group, &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(cs->group, object);
 	if (group == NULL) return 0;
 
 	return group->GetResult();
@@ -60,7 +60,7 @@ SpriteID GetCustomCargoSprite(const CargoSpec *cs)
 uint16 GetCargoCallback(CallbackID callback, uint32 param1, uint32 param2, const CargoSpec *cs)
 {
 	CargoResolverObject object(cs, callback, param1, param2);
-	const SpriteGroup *group = SpriteGroup::Resolve(cs->group, &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(cs->group, object);
 	if (group == NULL) return CALLBACK_FAILED;
 
 	return group->GetCallbackResult();
diff --git a/src/newgrf_engine.cpp b/src/newgrf_engine.cpp
index c48aaad9b..3119524b5 100644
--- a/src/newgrf_engine.cpp
+++ b/src/newgrf_engine.cpp
@@ -360,7 +360,7 @@ static byte MapAircraftMovementAction(const Aircraft *v)
 
 	/* This function must only be called when processing triggers -- any
 	 * other time is an error. */
-	assert(this->ro->trigger != 0);
+	assert(this->ro.trigger != 0);
 
 	if (v != NULL) v->waiting_triggers = triggers;
 }
@@ -546,7 +546,7 @@ static uint32 VehicleGetVariable(Vehicle *v, const VehicleScopeResolver *object,
 			/* Unlike everywhere else the cargo translation table is only used since grf version 8, not 7.
 			 * Note: The grffile == NULL case only happens if this function is called for default vehicles.
 			 *       And this is only done by CheckCaches(). */
-			const GRFFile *grffile = object->ro->grffile;
+			const GRFFile *grffile = object->ro.grffile;
 			uint8 common_bitnum = (common_cargo_type == CT_INVALID) ? 0xFF :
 				(grffile == NULL || grffile->grf_version < 8) ? CargoSpec::Get(common_cargo_type)->bitnum : grffile->cargo_map[common_cargo_type];
 
@@ -617,7 +617,7 @@ static uint32 VehicleGetVariable(Vehicle *v, const VehicleScopeResolver *object,
 		case 0x4A: {
 			if (v->type != VEH_TRAIN) return 0;
 			RailType rt = GetTileRailType(v->tile);
-			return (HasPowerOnRail(Train::From(v)->railtype, rt) ? 0x100 : 0) | GetReverseRailTypeTranslation(rt, object->ro->grffile);
+			return (HasPowerOnRail(Train::From(v)->railtype, rt) ? 0x100 : 0) | GetReverseRailTypeTranslation(rt, object->ro.grffile);
 		}
 
 		case 0x4B: // Long date of last service
@@ -643,8 +643,8 @@ static uint32 VehicleGetVariable(Vehicle *v, const VehicleScopeResolver *object,
 			if (!v->IsGroundVehicle() || parameter == 0x61) return 0;
 
 			/* Only allow callbacks that don't change properties to avoid circular dependencies. */
-			if (object->ro->callback == CBID_NO_CALLBACK || object->ro->callback == CBID_RANDOM_TRIGGER || object->ro->callback == CBID_TRAIN_ALLOW_WAGON_ATTACH ||
-					object->ro->callback == CBID_VEHICLE_START_STOP_CHECK || object->ro->callback == CBID_VEHICLE_32DAY_CALLBACK || object->ro->callback == CBID_VEHICLE_COLOUR_MAPPING) {
+			if (object->ro.callback == CBID_NO_CALLBACK || object->ro.callback == CBID_RANDOM_TRIGGER || object->ro.callback == CBID_TRAIN_ALLOW_WAGON_ATTACH ||
+					object->ro.callback == CBID_VEHICLE_START_STOP_CHECK || object->ro.callback == CBID_VEHICLE_32DAY_CALLBACK || object->ro.callback == CBID_VEHICLE_COLOUR_MAPPING) {
 				Vehicle *u = v->Move((int32)GetRegister(0x10F));
 				if (u == NULL) return 0;
 
@@ -935,7 +935,7 @@ static uint32 VehicleGetVariable(Vehicle *v, const VehicleScopeResolver *object,
  * @param v %Vehicle being resolved.
  * @param info_view Indicates if the item is being drawn in an info window.
  */
-VehicleScopeResolver::VehicleScopeResolver(ResolverObject *ro, EngineID engine_type, const Vehicle *v, bool info_view)
+VehicleScopeResolver::VehicleScopeResolver(ResolverObject &ro, EngineID engine_type, const Vehicle *v, bool info_view)
 		: ScopeResolver(ro)
 {
 	this->v = v;
@@ -966,9 +966,9 @@ static const GRFFile *GetEngineGrfFile(EngineID engine_type)
 VehicleResolverObject::VehicleResolverObject(EngineID engine_type, const Vehicle *v, bool info_view,
 		CallbackID callback, uint32 callback_param1, uint32 callback_param2)
 	: ResolverObject(GetEngineGrfFile(engine_type), callback, callback_param1, callback_param2),
-	self_scope(this, engine_type, v, info_view),
-	parent_scope(this, engine_type, ((v != NULL) ? v->First() : v), info_view),
-	relative_scope(this, engine_type, v, info_view),
+	self_scope(*this, engine_type, v, info_view),
+	parent_scope(*this, engine_type, ((v != NULL) ? v->First() : v), info_view),
+	relative_scope(*this, engine_type, v, info_view),
 	cached_relative_count(0)
 {
 }
@@ -1019,7 +1019,7 @@ static const SpriteGroup *GetVehicleSpriteGroup(EngineID engine, const Vehicle *
 SpriteID GetCustomEngineSprite(EngineID engine, const Vehicle *v, Direction direction, EngineImageType image_type)
 {
 	VehicleResolverObject object(engine, v, false, CBID_NO_CALLBACK, image_type);
-	const SpriteGroup *group = SpriteGroup::Resolve(GetVehicleSpriteGroup(engine, v), &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(GetVehicleSpriteGroup(engine, v), object);
 	if (group == NULL || group->GetNumResults() == 0) return 0;
 
 	return group->GetResult() + (direction % group->GetNumResults());
@@ -1036,7 +1036,7 @@ SpriteID GetRotorOverrideSprite(EngineID engine, const Aircraft *v, bool info_vi
 
 	VehicleResolverObject object(engine, v, info_view, CBID_NO_CALLBACK, image_type);
 	const SpriteGroup *group = GetWagonOverrideSpriteSet(engine, CT_DEFAULT, engine);
-	group = SpriteGroup::Resolve(group, &object);
+	group = SpriteGroup::Resolve(group, object);
 
 	if (group == NULL || group->GetNumResults() == 0) return 0;
 
@@ -1069,7 +1069,7 @@ bool UsesWagonOverride(const Vehicle *v)
 uint16 GetVehicleCallback(CallbackID callback, uint32 param1, uint32 param2, EngineID engine, const Vehicle *v)
 {
 	VehicleResolverObject object(engine, v, false, callback, param1, param2);
-	const SpriteGroup *group = SpriteGroup::Resolve(GetVehicleSpriteGroup(engine, v, false), &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(GetVehicleSpriteGroup(engine, v, false), object);
 	if (group == NULL) return CALLBACK_FAILED;
 
 	return group->GetCallbackResult();
@@ -1090,7 +1090,7 @@ uint16 GetVehicleCallbackParent(CallbackID callback, uint32 param1, uint32 param
 	VehicleResolverObject object(engine, v, false, callback, param1, param2);
 	object.parent_scope.SetVehicle(parent);
 
-	const SpriteGroup *group = SpriteGroup::Resolve(GetVehicleSpriteGroup(engine, v, false), &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(GetVehicleSpriteGroup(engine, v, false), object);
 	if (group == NULL) return CALLBACK_FAILED;
 
 	return group->GetCallbackResult();
@@ -1121,7 +1121,7 @@ static void DoTriggerVehicle(Vehicle *v, VehicleTrigger trigger, byte base_rando
 	VehicleResolverObject object(v->engine_type, v, false, CBID_RANDOM_TRIGGER);
 	object.trigger = trigger;
 
-	const SpriteGroup *group = SpriteGroup::Resolve(GetVehicleSpriteGroup(v->engine_type, v), &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(GetVehicleSpriteGroup(v->engine_type, v), object);
 	if (group == NULL) return;
 
 	byte new_random_bits = Random();
diff --git a/src/newgrf_engine.h b/src/newgrf_engine.h
index 7eb65f134..5e1661cca 100644
--- a/src/newgrf_engine.h
+++ b/src/newgrf_engine.h
@@ -26,7 +26,7 @@ struct VehicleScopeResolver : public ScopeResolver {
 	EngineID self_type;      ///< Type of the vehicle.
 	bool info_view;          ///< Indicates if the item is being drawn in an info window.
 
-	VehicleScopeResolver(ResolverObject *ro, EngineID engine_type, const Vehicle *v, bool info_view);
+	VehicleScopeResolver(ResolverObject &ro, EngineID engine_type, const Vehicle *v, bool info_view);
 
 	void SetVehicle(const Vehicle *v) { this->v = v; }
 
diff --git a/src/newgrf_generic.cpp b/src/newgrf_generic.cpp
index 75e25c3d4..f1305636d 100644
--- a/src/newgrf_generic.cpp
+++ b/src/newgrf_generic.cpp
@@ -29,7 +29,7 @@ struct GenericScopeResolver : public ScopeResolver {
 	uint8 count;
 	uint8 station_size;
 
-	GenericScopeResolver(ResolverObject *ro, bool ai_callback);
+	GenericScopeResolver(ResolverObject &ro, bool ai_callback);
 
 	/* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
 
@@ -104,7 +104,7 @@ void AddGenericCallback(uint8 feature, const GRFFile *file, const SpriteGroup *g
 {
 	if (this->ai_callback) {
 		switch (variable) {
-			case 0x40: return this->ro->grffile->cargo_map[this->cargo_type];
+			case 0x40: return this->ro.grffile->cargo_map[this->cargo_type];
 
 			case 0x80: return this->cargo_type;
 			case 0x81: return CargoSpec::Get(this->cargo_type)->bitnum;
@@ -139,7 +139,7 @@ void AddGenericCallback(uint8 feature, const GRFFile *file, const SpriteGroup *g
  * @param ai_callback Callback comes from the AI.
  * @param callback Callback ID.
  */
-GenericResolverObject::GenericResolverObject(bool ai_callback, CallbackID callback) : ResolverObject(NULL, callback), generic_scope(this, ai_callback)
+GenericResolverObject::GenericResolverObject(bool ai_callback, CallbackID callback) : ResolverObject(NULL, callback), generic_scope(*this, ai_callback)
 {
 }
 
@@ -148,7 +148,7 @@ GenericResolverObject::GenericResolverObject(bool ai_callback, CallbackID callba
  * @param ro Surrounding resolver.
  * @param ai_callback Callback comes from the AI.
  */
-GenericScopeResolver::GenericScopeResolver(ResolverObject *ro, bool ai_callback) : ScopeResolver(ro)
+GenericScopeResolver::GenericScopeResolver(ResolverObject &ro, bool ai_callback) : ScopeResolver(ro)
 {
 	this->cargo_type = 0;
 	this->default_selection = 0;
@@ -173,16 +173,16 @@ GenericScopeResolver::GenericScopeResolver(ResolverObject *ro, bool ai_callback)
  *                   May be NULL if not required.
  * @return callback value if successful or CALLBACK_FAILED
  */
-static uint16 GetGenericCallbackResult(uint8 feature, ResolverObject *object, uint32 param1_grfv7, uint32 param1_grfv8, const GRFFile **file)
+static uint16 GetGenericCallbackResult(uint8 feature, ResolverObject &object, uint32 param1_grfv7, uint32 param1_grfv8, const GRFFile **file)
 {
 	assert(feature < lengthof(_gcl));
 
 	/* Test each feature callback sprite group. */
 	for (GenericCallbackList::const_iterator it = _gcl[feature].begin(); it != _gcl[feature].end(); ++it) {
 		const SpriteGroup *group = it->group;
-		object->grffile = it->file;
+		object.grffile = it->file;
 		/* Set callback param based on GRF version. */
-		object->callback_param1 = it->file->grf_version >= 8 ? param1_grfv8 : param1_grfv7;
+		object.callback_param1 = it->file->grf_version >= 8 ? param1_grfv8 : param1_grfv7;
 		group = SpriteGroup::Resolve(group, object);
 		if (group == NULL || group->GetCallbackResult() == CALLBACK_FAILED) continue;
 
@@ -238,7 +238,7 @@ uint16 GetAiPurchaseCallbackResult(uint8 feature, CargoID cargo_type, uint8 defa
 	object.generic_scope.count             = count;
 	object.generic_scope.station_size      = station_size;
 
-	uint16 callback = GetGenericCallbackResult(feature, &object, 0, 0, file);
+	uint16 callback = GetGenericCallbackResult(feature, object, 0, 0, file);
 	if (callback != CALLBACK_FAILED) callback = GB(callback, 0, 8);
 	return callback;
 }
@@ -264,7 +264,7 @@ void AmbientSoundEffectCallback(TileIndex tile)
 
 	/* Run callback. */
 	const GRFFile *grf_file;
-	uint16 callback = GetGenericCallbackResult(GSF_SOUNDFX, &object, param1_v7, param1_v8, &grf_file);
+	uint16 callback = GetGenericCallbackResult(GSF_SOUNDFX, object, param1_v7, param1_v8, &grf_file);
 
 	if (callback != CALLBACK_FAILED) PlayTileSound(grf_file, callback, tile);
 }
diff --git a/src/newgrf_house.cpp b/src/newgrf_house.cpp
index 9a7ff4444..a31ac4bc4 100644
--- a/src/newgrf_house.cpp
+++ b/src/newgrf_house.cpp
@@ -39,7 +39,7 @@ HouseOverrideManager _house_mngr(NEW_HOUSE_OFFSET, NUM_HOUSES, INVALID_HOUSE_ID)
  * @param initial_random_bits Random bits during construction checks.
  * @param watched_cargo_triggers Cargo types that triggered the watched cargo callback.
  */
-HouseScopeResolver::HouseScopeResolver(ResolverObject *ro, HouseID house_id, TileIndex tile, Town *town,
+HouseScopeResolver::HouseScopeResolver(ResolverObject &ro, HouseID house_id, TileIndex tile, Town *town,
 			bool not_yet_constructed, uint8 initial_random_bits, uint32 watched_cargo_triggers)
 		: ScopeResolver(ro)
 {
@@ -78,8 +78,8 @@ HouseResolverObject::HouseResolverObject(HouseID house_id, TileIndex tile, Town
 		CallbackID callback, uint32 param1, uint32 param2,
 		bool not_yet_constructed, uint8 initial_random_bits, uint32 watched_cargo_triggers)
 	: ResolverObject(GetHouseSpecGrf(house_id), callback, param1, param2),
-	house_scope(this, house_id, tile, town, not_yet_constructed, initial_random_bits, watched_cargo_triggers),
-	town_scope(this, town, not_yet_constructed) // Don't access StorePSA if house is not yet constructed.
+	house_scope(*this, house_id, tile, town, not_yet_constructed, initial_random_bits, watched_cargo_triggers),
+	town_scope(*this, town, not_yet_constructed) // Don't access StorePSA if house is not yet constructed.
 {
 }
 
@@ -352,7 +352,7 @@ static uint32 GetDistanceFromNearbyHouse(uint8 parameter, TileIndex tile, HouseI
 		}
 
 		/* Land info for nearby tiles. */
-		case 0x62: return GetNearbyTileInformation(parameter, this->tile, this->ro->grffile->grf_version >= 8);
+		case 0x62: return GetNearbyTileInformation(parameter, this->tile, this->ro.grffile->grf_version >= 8);
 
 		/* Current animation frame of nearby house tiles */
 		case 0x63: {
@@ -362,7 +362,7 @@ static uint32 GetDistanceFromNearbyHouse(uint8 parameter, TileIndex tile, HouseI
 
 		/* Cargo acceptance history of nearby stations */
 		case 0x64: {
-			CargoID cid = GetCargoTranslation(parameter, this->ro->grffile);
+			CargoID cid = GetCargoTranslation(parameter, this->ro.grffile);
 			if (cid == CT_INVALID) return 0;
 
 			/* Extract tile offset. */
@@ -400,7 +400,7 @@ static uint32 GetDistanceFromNearbyHouse(uint8 parameter, TileIndex tile, HouseI
 			/* Information about the grf local classid if the house has a class */
 			uint houseclass = 0;
 			if (hs->class_id != HOUSE_NO_CLASS) {
-				houseclass = (hs->grf_prop.grffile == this->ro->grffile ? 1 : 2) << 8;
+				houseclass = (hs->grf_prop.grffile == this->ro.grffile ? 1 : 2) << 8;
 				houseclass |= _class_mapping[hs->class_id].class_id;
 			}
 			/* old house type or grf-local houseid */
@@ -408,7 +408,7 @@ static uint32 GetDistanceFromNearbyHouse(uint8 parameter, TileIndex tile, HouseI
 			if (this->house_id < NEW_HOUSE_OFFSET) {
 				local_houseid = this->house_id;
 			} else {
-				local_houseid = (hs->grf_prop.grffile == this->ro->grffile ? 1 : 2) << 8;
+				local_houseid = (hs->grf_prop.grffile == this->ro.grffile ? 1 : 2) << 8;
 				local_houseid |= hs->grf_prop.local_id;
 			}
 			return houseclass << 16 | local_houseid;
@@ -440,7 +440,7 @@ uint16 GetHouseCallback(CallbackID callback, uint32 param1, uint32 param2, House
 	HouseResolverObject object(house_id, tile, town, callback, param1, param2,
 			not_yet_constructed, initial_random_bits, watched_cargo_triggers);
 
-	const SpriteGroup *group = SpriteGroup::Resolve(HouseSpec::Get(house_id)->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(HouseSpec::Get(house_id)->grf_prop.spritegroup[0], object);
 	if (group == NULL) return CALLBACK_FAILED;
 
 	return group->GetCallbackResult();
@@ -490,7 +490,7 @@ void DrawNewHouseTile(TileInfo *ti, HouseID house_id)
 
 	HouseResolverObject object(house_id, ti->tile, Town::GetByTile(ti->tile));
 
-	const SpriteGroup *group = SpriteGroup::Resolve(hs->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(hs->grf_prop.spritegroup[0], object);
 	if (group != NULL && group->type == SGT_TILELAYOUT) {
 		/* Limit the building stage to the number of stages supplied. */
 		const TileLayoutSpriteGroup *tlgroup = (const TileLayoutSpriteGroup *)group;
@@ -615,7 +615,7 @@ static void DoTriggerHouse(TileIndex tile, HouseTrigger trigger, byte base_rando
 	HouseResolverObject object(hid, tile, Town::GetByTile(tile), CBID_RANDOM_TRIGGER);
 	object.trigger = trigger;
 
-	const SpriteGroup *group = SpriteGroup::Resolve(hs->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(hs->grf_prop.spritegroup[0], object);
 	if (group == NULL) return;
 
 	byte new_random_bits = Random();
diff --git a/src/newgrf_house.h b/src/newgrf_house.h
index d6d4beb5d..37c167947 100644
--- a/src/newgrf_house.h
+++ b/src/newgrf_house.h
@@ -27,7 +27,7 @@ struct HouseScopeResolver : public ScopeResolver {
 	uint16 initial_random_bits;    ///< Random bits during construction checks.
 	uint32 watched_cargo_triggers; ///< Cargo types that triggered the watched cargo callback.
 
-	HouseScopeResolver(ResolverObject *ro, HouseID house_id, TileIndex tile, Town *town,
+	HouseScopeResolver(ResolverObject &ro, HouseID house_id, TileIndex tile, Town *town,
 			bool not_yet_constructed, uint8 initial_random_bits, uint32 watched_cargo_triggers);
 
 	/* virtual */ uint32 GetRandomBits() const;
diff --git a/src/newgrf_industries.cpp b/src/newgrf_industries.cpp
index e0953434e..c9ae6168b 100644
--- a/src/newgrf_industries.cpp
+++ b/src/newgrf_industries.cpp
@@ -159,7 +159,7 @@ static uint32 GetCountAndDistanceOfClosestInstance(byte param_setID, byte layout
 
 /* virtual */ uint32 IndustriesScopeResolver::GetVariable(byte variable, uint32 parameter, bool *available) const
 {
-	if (this->ro->callback == CBID_INDUSTRY_LOCATION) {
+	if (this->ro.callback == CBID_INDUSTRY_LOCATION) {
 		/* Variables available during construction check. */
 
 		switch (variable) {
@@ -185,7 +185,7 @@ static uint32 GetCountAndDistanceOfClosestInstance(byte param_setID, byte layout
 			case 0x89: return min(DistanceManhattan(this->industry->town->xy, this->tile), 255);
 
 			/* Lowest height of the tile */
-			case 0x8A: return Clamp(GetTileZ(this->tile) * (this->ro->grffile->grf_version >= 8 ? 1 : TILE_HEIGHT), 0, 0xFF);
+			case 0x8A: return Clamp(GetTileZ(this->tile) * (this->ro.grffile->grf_version >= 8 ? 1 : TILE_HEIGHT), 0, 0xFF);
 
 			/* Distance to the nearest water/land tile */
 			case 0x8B: return GetClosestWaterDistance(this->tile, (GetIndustrySpec(this->industry->type)->behaviour & INDUSTRYBEH_BUILT_ONWATER) == 0);
@@ -201,7 +201,7 @@ static uint32 GetCountAndDistanceOfClosestInstance(byte param_setID, byte layout
 	const IndustrySpec *indspec = GetIndustrySpec(this->type);
 
 	if (this->industry == NULL) {
-		DEBUG(grf, 1, "Unhandled variable 0x%X (no available industry) in callback 0x%x", variable, this->ro->callback);
+		DEBUG(grf, 1, "Unhandled variable 0x%X (no available industry) in callback 0x%x", variable, this->ro.callback);
 
 		*available = false;
 		return UINT_MAX;
@@ -251,7 +251,7 @@ static uint32 GetCountAndDistanceOfClosestInstance(byte param_setID, byte layout
 		case 0x46: return this->industry->construction_date; // Date when built - long format - (in days)
 
 		/* Get industry ID at offset param */
-		case 0x60: return GetIndustryIDAtOffset(GetNearbyTile(parameter, this->industry->location.tile, false), this->industry, this->ro->grffile->grfid);
+		case 0x60: return GetIndustryIDAtOffset(GetNearbyTile(parameter, this->industry->location.tile, false), this->industry, this->ro.grffile->grfid);
 
 		/* Get random tile bits at offset param */
 		case 0x61: {
@@ -263,7 +263,7 @@ static uint32 GetCountAndDistanceOfClosestInstance(byte param_setID, byte layout
 		/* Land info of nearby tiles */
 		case 0x62:
 			if (this->tile == INVALID_TILE) break;
-			return GetNearbyIndustryTileInformation(parameter, this->tile, INVALID_INDUSTRY, false, this->ro->grffile->grf_version >= 8);
+			return GetNearbyIndustryTileInformation(parameter, this->tile, INVALID_INDUSTRY, false, this->ro.grffile->grf_version >= 8);
 
 		/* Animation stage of nearby tiles */
 		case 0x63: {
@@ -429,7 +429,7 @@ static const GRFFile *GetGrffile(IndustryType type)
 IndustriesResolverObject::IndustriesResolverObject(TileIndex tile, Industry *indus, IndustryType type, uint32 random_bits,
 		CallbackID callback, uint32 callback_param1, uint32 callback_param2)
 	: ResolverObject(GetGrffile(type), callback, callback_param1, callback_param2),
-	industries_scope(this, tile, indus, type, random_bits),
+	industries_scope(*this, tile, indus, type, random_bits),
 	town_scope(NULL)
 {
 }
@@ -455,7 +455,7 @@ TownScopeResolver *IndustriesResolverObject::GetTown()
 			t = ClosestTownFromTile(this->industries_scope.tile, UINT_MAX);
 		}
 		if (t == NULL) return NULL;
-		this->town_scope = new TownScopeResolver(this, t, readonly);
+		this->town_scope = new TownScopeResolver(*this, t, readonly);
 	}
 	return this->town_scope;
 }
@@ -468,7 +468,7 @@ TownScopeResolver *IndustriesResolverObject::GetTown()
  * @param type Type of the industry.
  * @param random_bits Random bits of the new industry.
  */
-IndustriesScopeResolver::IndustriesScopeResolver(ResolverObject *ro, TileIndex tile, Industry *industry, IndustryType type, uint32 random_bits)
+IndustriesScopeResolver::IndustriesScopeResolver(ResolverObject &ro, TileIndex tile, Industry *industry, IndustryType type, uint32 random_bits)
 	: ScopeResolver(ro)
 {
 	this->tile = tile;
@@ -490,7 +490,7 @@ IndustriesScopeResolver::IndustriesScopeResolver(ResolverObject *ro, TileIndex t
 uint16 GetIndustryCallback(CallbackID callback, uint32 param1, uint32 param2, Industry *industry, IndustryType type, TileIndex tile)
 {
 	IndustriesResolverObject object(tile, industry, type, 0, callback, param1, param2);
-	const SpriteGroup *group = SpriteGroup::Resolve(GetIndustrySpec(type)->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(GetIndustrySpec(type)->grf_prop.spritegroup[0], object);
 	if (group == NULL) return CALLBACK_FAILED;
 
 	return group->GetCallbackResult();
@@ -523,7 +523,7 @@ CommandCost CheckIfCallBackAllowsCreation(TileIndex tile, IndustryType type, uin
 	ind.psa = NULL;
 
 	IndustriesResolverObject object(tile, &ind, type, seed, CBID_INDUSTRY_LOCATION, 0, creation_type);
-	const SpriteGroup *group = SpriteGroup::Resolve(GetIndustrySpec(type)->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(GetIndustrySpec(type)->grf_prop.spritegroup[0], object);
 
 	/* Unlike the "normal" cases, not having a valid result means we allow
 	 * the building of the industry, as that's how it's done in TTDP. */
@@ -596,7 +596,7 @@ void IndustryProductionCallback(Industry *ind, int reason)
 		}
 
 		SB(object.callback_param2, 8, 16, loop);
-		const SpriteGroup *tgroup = SpriteGroup::Resolve(spec->grf_prop.spritegroup[0], &object);
+		const SpriteGroup *tgroup = SpriteGroup::Resolve(spec->grf_prop.spritegroup[0], object);
 		if (tgroup == NULL || tgroup->type != SGT_INDUSTRY_PRODUCTION) break;
 		const IndustryProductionSpriteGroup *group = (const IndustryProductionSpriteGroup *)tgroup;
 
diff --git a/src/newgrf_industries.h b/src/newgrf_industries.h
index 5c95fcdcb..57e44e8c0 100644
--- a/src/newgrf_industries.h
+++ b/src/newgrf_industries.h
@@ -21,7 +21,7 @@ struct IndustriesScopeResolver : public ScopeResolver {
 	IndustryType type;  ///< Type of the industry.
 	uint32 random_bits; ///< Random bits of the new industry.
 
-	IndustriesScopeResolver(ResolverObject *ro, TileIndex tile, Industry *industry, IndustryType type, uint32 random_bits = 0);
+	IndustriesScopeResolver(ResolverObject &ro, TileIndex tile, Industry *industry, IndustryType type, uint32 random_bits = 0);
 
 	/* virtual */ uint32 GetRandomBits() const;
 	/* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
diff --git a/src/newgrf_industrytiles.cpp b/src/newgrf_industrytiles.cpp
index 65e3c530d..965c55d49 100644
--- a/src/newgrf_industrytiles.cpp
+++ b/src/newgrf_industrytiles.cpp
@@ -78,7 +78,7 @@ uint32 GetRelativePosition(TileIndex tile, TileIndex ind_tile)
 
 		/* Land info of nearby tiles */
 		case 0x60: return GetNearbyIndustryTileInformation(parameter, this->tile,
-				this->industry == NULL ? (IndustryID)INVALID_INDUSTRY : this->industry->index, true, this->ro->grffile->grf_version >= 8);
+				this->industry == NULL ? (IndustryID)INVALID_INDUSTRY : this->industry->index, true, this->ro.grffile->grf_version >= 8);
 
 		/* Animation stage of nearby tiles */
 		case 0x61: {
@@ -90,7 +90,7 @@ uint32 GetRelativePosition(TileIndex tile, TileIndex ind_tile)
 		}
 
 		/* Get industry tile ID at offset */
-		case 0x62: return GetIndustryIDAtOffset(GetNearbyTile(parameter, this->tile), this->industry, this->ro->grffile->grfid);
+		case 0x62: return GetIndustryIDAtOffset(GetNearbyTile(parameter, this->tile), this->industry, this->ro.grffile->grfid);
 	}
 
 	DEBUG(grf, 1, "Unhandled industry tile variable 0x%X", variable);
@@ -144,8 +144,8 @@ static const GRFFile *GetIndTileGrffile(IndustryGfx gfx)
 IndustryTileResolverObject::IndustryTileResolverObject(IndustryGfx gfx, TileIndex tile, Industry *indus,
 			CallbackID callback, uint32 callback_param1, uint32 callback_param2)
 	: ResolverObject(GetIndTileGrffile(gfx), callback, callback_param1, callback_param2),
-	indtile_scope(this, indus, tile),
-	ind_scope(this, tile, indus, indus->type)
+	indtile_scope(*this, indus, tile),
+	ind_scope(*this, tile, indus, indus->type)
 {
 }
 
@@ -155,7 +155,7 @@ IndustryTileResolverObject::IndustryTileResolverObject(IndustryGfx gfx, TileInde
  * @param industry %Industry owning the tile.
  * @param tile %Tile of the industry.
  */
-IndustryTileScopeResolver::IndustryTileScopeResolver(ResolverObject *ro, Industry *industry, TileIndex tile) : ScopeResolver(ro)
+IndustryTileScopeResolver::IndustryTileScopeResolver(ResolverObject &ro, Industry *industry, TileIndex tile) : ScopeResolver(ro)
 {
 	this->industry = industry;
 	this->tile = tile;
@@ -190,7 +190,7 @@ uint16 GetIndustryTileCallback(CallbackID callback, uint32 param1, uint32 param2
 	assert(industry->index == INVALID_INDUSTRY || IsTileType(tile, MP_INDUSTRY));
 
 	IndustryTileResolverObject object(gfx_id, tile, industry, callback, param1, param2);
-	const SpriteGroup *group = SpriteGroup::Resolve(GetIndustryTileSpec(gfx_id)->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(GetIndustryTileSpec(gfx_id)->grf_prop.spritegroup[0], object);
 	if (group == NULL || group->type != SGT_CALLBACK) return CALLBACK_FAILED;
 
 	return group->GetCallbackResult();
@@ -211,7 +211,7 @@ bool DrawNewIndustryTile(TileInfo *ti, Industry *i, IndustryGfx gfx, const Indus
 
 	IndustryTileResolverObject object(gfx, ti->tile, i);
 
-	const SpriteGroup *group = SpriteGroup::Resolve(inds->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(inds->grf_prop.spritegroup[0], object);
 	if (group == NULL || group->type != SGT_TILELAYOUT) return false;
 
 	/* Limit the building stage to the number of stages supplied. */
@@ -328,7 +328,7 @@ static void DoTriggerIndustryTile(TileIndex tile, IndustryTileTrigger trigger, I
 	IndustryTileResolverObject object(gfx, tile, ind, CBID_RANDOM_TRIGGER);
 	object.trigger = trigger;
 
-	const SpriteGroup *group = SpriteGroup::Resolve(itspec->grf_prop.spritegroup[0], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(itspec->grf_prop.spritegroup[0], object);
 	if (group == NULL) return;
 
 	byte new_random_bits = Random();
diff --git a/src/newgrf_industrytiles.h b/src/newgrf_industrytiles.h
index f5b88db83..394f75e1c 100644
--- a/src/newgrf_industrytiles.h
+++ b/src/newgrf_industrytiles.h
@@ -21,7 +21,7 @@ struct IndustryTileScopeResolver : public ScopeResolver {
 	Industry *industry; ///< Industry owning the tiles.
 	TileIndex tile;     ///< %Tile being resolved.
 
-	IndustryTileScopeResolver(ResolverObject *ro, Industry *industry, TileIndex tile);
+	IndustryTileScopeResolver(ResolverObject &ro, Industry *industry, TileIndex tile);
 
 	/* virtual */ uint32 GetRandomBits() const;
 	/* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
diff --git a/src/newgrf_object.cpp b/src/newgrf_object.cpp
index 57468d7c7..da12a51ee 100644
--- a/src/newgrf_object.cpp
+++ b/src/newgrf_object.cpp
@@ -133,7 +133,7 @@ INSTANTIATE_NEWGRF_CLASS_METHODS(ObjectClass, ObjectSpec, ObjectClassID, OBJECT_
  * @param tile %Tile of the object.
  * @param view View of the object.
  */
-ObjectScopeResolver::ObjectScopeResolver(ResolverObject *ro, Object *obj, TileIndex tile, uint8 view)
+ObjectScopeResolver::ObjectScopeResolver(ResolverObject &ro, Object *obj, TileIndex tile, uint8 view)
 		: ScopeResolver(ro)
 {
 	this->obj = obj;
@@ -326,7 +326,7 @@ static uint32 GetCountAndDistanceOfClosestInstance(byte local_id, uint32 grfid,
 		case 0x48: return this->obj->view;
 
 		/* Get object ID at offset param */
-		case 0x60: return GetObjectIDAtOffset(GetNearbyTile(parameter, this->tile), this->ro->grffile->grfid);
+		case 0x60: return GetObjectIDAtOffset(GetNearbyTile(parameter, this->tile), this->ro.grffile->grfid);
 
 		/* Get random tile bits at offset param */
 		case 0x61: {
@@ -335,7 +335,7 @@ static uint32 GetCountAndDistanceOfClosestInstance(byte local_id, uint32 grfid,
 		}
 
 		/* Land info of nearby tiles */
-		case 0x62: return GetNearbyObjectTileInformation(parameter, this->tile, this->obj == NULL ? INVALID_OBJECT : this->obj->index, this->ro->grffile->grf_version >= 8);
+		case 0x62: return GetNearbyObjectTileInformation(parameter, this->tile, this->obj == NULL ? INVALID_OBJECT : this->obj->index, this->ro.grffile->grf_version >= 8);
 
 		/* Animation counter of nearby tile */
 		case 0x63: {
@@ -344,7 +344,7 @@ static uint32 GetCountAndDistanceOfClosestInstance(byte local_id, uint32 grfid,
 		}
 
 		/* Count of object, distance of closest instance */
-		case 0x64: return GetCountAndDistanceOfClosestInstance(parameter, this->ro->grffile->grfid, this->tile, this->obj);
+		case 0x64: return GetCountAndDistanceOfClosestInstance(parameter, this->ro.grffile->grfid, this->tile, this->obj);
 	}
 
 unhandled:
@@ -383,7 +383,7 @@ static const SpriteGroup *GetObjectSpriteGroup(const ObjectSpec *spec, const Obj
  */
 ObjectResolverObject::ObjectResolverObject(const ObjectSpec *spec, Object *obj, TileIndex tile, uint8 view,
 		CallbackID callback, uint32 param1, uint32 param2)
-	: ResolverObject(spec->grf_prop.grffile, callback, param1, param2), object_scope(this, obj, tile, view)
+	: ResolverObject(spec->grf_prop.grffile, callback, param1, param2), object_scope(*this, obj, tile, view)
 {
 	this->town_scope = NULL;
 }
@@ -408,7 +408,7 @@ TownScopeResolver *ObjectResolverObject::GetTown()
 			t = ClosestTownFromTile(this->object_scope.tile, UINT_MAX);
 		}
 		if (t == NULL) return NULL;
-		this->town_scope = new TownScopeResolver(this, t, this->object_scope.obj == NULL);
+		this->town_scope = new TownScopeResolver(*this, t, this->object_scope.obj == NULL);
 	}
 	return this->town_scope;
 }
@@ -427,7 +427,7 @@ TownScopeResolver *ObjectResolverObject::GetTown()
 uint16 GetObjectCallback(CallbackID callback, uint32 param1, uint32 param2, const ObjectSpec *spec, Object *o, TileIndex tile, uint8 view)
 {
 	ObjectResolverObject object(spec, o, tile, view, callback, param1, param2);
-	const SpriteGroup *group = SpriteGroup::Resolve(GetObjectSpriteGroup(spec, o), &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(GetObjectSpriteGroup(spec, o), object);
 	if (group == NULL) return CALLBACK_FAILED;
 
 	return group->GetCallbackResult();
@@ -470,7 +470,7 @@ void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec)
 	Object *o = Object::GetByTile(ti->tile);
 	ObjectResolverObject object(spec, o, ti->tile);
 
-	const SpriteGroup *group = SpriteGroup::Resolve(GetObjectSpriteGroup(spec, o), &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(GetObjectSpriteGroup(spec, o), object);
 	if (group == NULL || group->type != SGT_TILELAYOUT) return;
 
 	DrawTileLayout(ti, (const TileLayoutSpriteGroup *)group, spec);
@@ -486,7 +486,7 @@ void DrawNewObjectTile(TileInfo *ti, const ObjectSpec *spec)
 void DrawNewObjectTileInGUI(int x, int y, const ObjectSpec *spec, uint8 view)
 {
 	ObjectResolverObject object(spec, NULL, INVALID_TILE, view);
-	const SpriteGroup *group = SpriteGroup::Resolve(GetObjectSpriteGroup(spec, NULL), &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(GetObjectSpriteGroup(spec, NULL), object);
 	if (group == NULL || group->type != SGT_TILELAYOUT) return;
 
 	const DrawTileSprites *dts = ((const TileLayoutSpriteGroup *)group)->ProcessRegisters(NULL);
diff --git a/src/newgrf_object.h b/src/newgrf_object.h
index 55b34e466..4a3b770d2 100644
--- a/src/newgrf_object.h
+++ b/src/newgrf_object.h
@@ -104,7 +104,7 @@ struct ObjectScopeResolver : public ScopeResolver {
 	TileIndex tile;     ///< The tile related to the object.
 	uint8 view;         ///< The view of the object.
 
-	ObjectScopeResolver(ResolverObject *ro, Object *obj, TileIndex tile, uint8 view = 0);
+	ObjectScopeResolver(ResolverObject &ro, Object *obj, TileIndex tile, uint8 view = 0);
 
 	/* virtual */ uint32 GetRandomBits() const;
 	/* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
diff --git a/src/newgrf_railtype.cpp b/src/newgrf_railtype.cpp
index 36ac7260a..de735193f 100644
--- a/src/newgrf_railtype.cpp
+++ b/src/newgrf_railtype.cpp
@@ -71,7 +71,7 @@
  * @param tile %Tile containing the track. For track on a bridge this is the southern bridgehead.
  * @param context Are we resolving sprites for the upper halftile, or on a bridge?
  */
-RailTypeScopeResolver::RailTypeScopeResolver(ResolverObject *ro, TileIndex tile, TileContext context) : ScopeResolver(ro)
+RailTypeScopeResolver::RailTypeScopeResolver(ResolverObject &ro, TileIndex tile, TileContext context) : ScopeResolver(ro)
 {
 	this->tile = tile;
 	this->context = context;
@@ -86,7 +86,7 @@ RailTypeScopeResolver::RailTypeScopeResolver(ResolverObject *ro, TileIndex tile,
  * @param param2 Extra parameter (second parameter of the callback, except railtypes do not have callbacks).
  */
 RailTypeResolverObject::RailTypeResolverObject(TileIndex tile, TileContext context, const GRFFile *grffile, uint32 param1, uint32 param2)
-	: ResolverObject(grffile, CBID_NO_CALLBACK, param1, param2), railtype_scope(this, tile, context)
+	: ResolverObject(grffile, CBID_NO_CALLBACK, param1, param2), railtype_scope(*this, tile, context)
 {
 }
 
@@ -105,7 +105,7 @@ SpriteID GetCustomRailSprite(const RailtypeInfo *rti, TileIndex tile, RailTypeSp
 	if (rti->group[rtsg] == NULL) return 0;
 
 	RailTypeResolverObject object(tile, context, rti->grffile[rtsg]);
-	const SpriteGroup *group = SpriteGroup::Resolve(rti->group[rtsg], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(rti->group[rtsg], object);
 	if (group == NULL || group->GetNumResults() == 0) return 0;
 
 	return group->GetResult();
@@ -129,7 +129,7 @@ SpriteID GetCustomSignalSprite(const RailtypeInfo *rti, TileIndex tile, SignalTy
 	uint32 param2 = (type << 16) | (var << 8) | state;
 	RailTypeResolverObject object(tile, TCX_NORMAL, rti->grffile[RTSG_SIGNALS], param1, param2);
 
-	const SpriteGroup *group = SpriteGroup::Resolve(rti->group[RTSG_SIGNALS], &object);
+	const SpriteGroup *group = SpriteGroup::Resolve(rti->group[RTSG_SIGNALS], object);
 	if (group == NULL || group->GetNumResults() == 0) return 0;
 
 	return group->GetResult();
diff --git a/src/newgrf_railtype.h b/src/newgrf_railtype.h
index c1977eaf8..8c5bce843 100644
--- a/src/newgrf_railtype.h
+++ b/src/newgrf_railtype.h
@@ -21,7 +21,7 @@ struct RailTypeScopeResolver : public ScopeResolver {
 	TileIndex tile;      ///< Tracktile. For track on a bridge this is the southern bridgehead.
 	TileContext context; ///< Are we resolving sprites for the upper halftile, or on a bridge?
 
-	RailTypeScopeResolver(ResolverObject *ro, TileIndex tile, TileContext context);
+	RailTypeScopeResolver(ResolverObject &ro, TileIndex tile, TileContext context);
 
 	/* virtual */ uint32 GetRandomBits() const;
 	/* virtual */ uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
diff --git a/src/newgrf_spritegroup.cpp b/src/newgrf_spritegroup.cpp
index 7e60e82b1..2c3d19ff1 100644
--- a/src/newgrf_spritegroup.cpp
+++ b/src/newgrf_spritegroup.cpp
@@ -37,35 +37,35 @@ RandomizedSpriteGroup::~RandomizedSpriteGroup()
 TemporaryStorageArray<int32, 0x110> _temp_store;
 
 
-static inline uint32 GetVariable(const ResolverObject *object, ScopeResolver *scope, byte variable, uint32 parameter, bool *available)
+static inline uint32 GetVariable(const ResolverObject &object, ScopeResolver *scope, byte variable, uint32 parameter, bool *available)
 {
 	/* First handle variables common with Action7/9/D */
 	uint32 value;
-	if (GetGlobalVariable(variable, &value, object->grffile)) return value;
+	if (GetGlobalVariable(variable, &value, object.grffile)) return value;
 
 	/* Non-common variable */
 	switch (variable) {
-		case 0x0C: return object->callback;
-		case 0x10: return object->callback_param1;
-		case 0x18: return object->callback_param2;
-		case 0x1C: return object->last_value;
+		case 0x0C: return object.callback;
+		case 0x10: return object.callback_param1;
+		case 0x18: return object.callback_param2;
+		case 0x1C: return object.last_value;
 
 		case 0x5F: return (scope->GetRandomBits() << 8) | scope->GetTriggers();
 
 		case 0x7D: return _temp_store.GetValue(parameter);
 
 		case 0x7F:
-			if (object == NULL || object->grffile == NULL) return 0;
-			return object->grffile->GetParam(parameter);
+			if (object.grffile == NULL) return 0;
+			return object.grffile->GetParam(parameter);
 
 		/* Not a common variable, so evaluate the feature specific variables */
 		default: return scope->GetVariable(variable, parameter, available);
 	}
 }
 
-ScopeResolver::ScopeResolver(ResolverObject *ro)
+ScopeResolver::ScopeResolver(ResolverObject &ro)
+		: ro(ro)
 {
-	this->ro = ro;
 }
 
 ScopeResolver::~ScopeResolver() {}
@@ -123,7 +123,7 @@ ScopeResolver::~ScopeResolver() {}
  * @param callback_param2 Second parameter (var 18) of the callback (only used when \a callback is also set).
  */
 ResolverObject::ResolverObject(const GRFFile *grffile, CallbackID callback, uint32 callback_param1, uint32 callback_param2)
-		: default_scope(this)
+		: default_scope(*this)
 {
 	this->callback = callback;
 	this->callback_param1 = callback_param1;
@@ -216,13 +216,13 @@ static U EvalAdjustT(const DeterministicSpriteGroupAdjust *adjust, ScopeResolver
 }
 
 
-const SpriteGroup *DeterministicSpriteGroup::Resolve(ResolverObject *object) const
+const SpriteGroup *DeterministicSpriteGroup::Resolve(ResolverObject &object) const
 {
 	uint32 last_value = 0;
 	uint32 value = 0;
 	uint i;
 
-	ScopeResolver *scope = object->GetScope(this->var_scope);
+	ScopeResolver *scope = object.GetScope(this->var_scope);
 
 	for (i = 0; i < this->num_adjusts; i++) {
 		DeterministicSpriteGroupAdjust *adjust = &this->adjusts[i];
@@ -259,7 +259,7 @@ const SpriteGroup *DeterministicSpriteGroup::Resolve(ResolverObject *object) con
 		last_value = value;
 	}
 
-	object->last_value = last_value;
+	object.last_value = last_value;
 
 	if (this->num_ranges == 0) {
 		/* nvar == 0 is a special case -- we turn our value into a callback result */
@@ -279,21 +279,21 @@ const SpriteGroup *DeterministicSpriteGroup::Resolve(ResolverObject *object) con
 }
 
 
-const SpriteGroup *RandomizedSpriteGroup::Resolve(ResolverObject *object) const
+const SpriteGroup *RandomizedSpriteGroup::Resolve(ResolverObject &object) const
 {
-	ScopeResolver *scope = object->GetScope(this->var_scope, this->count);
-	if (object->trigger != 0) {
+	ScopeResolver *scope = object.GetScope(this->var_scope, this->count);
+	if (object.trigger != 0) {
 		/* Handle triggers */
 		/* Magic code that may or may not do the right things... */
 		byte waiting_triggers = scope->GetTriggers();
-		byte match = this->triggers & (waiting_triggers | object->trigger);
+		byte match = this->triggers & (waiting_triggers | object.trigger);
 		bool res = (this->cmp_mode == RSG_CMP_ANY) ? (match != 0) : (match == this->triggers);
 
 		if (res) {
 			waiting_triggers &= ~match;
-			object->reseed[this->var_scope] |= (this->num_groups - 1) << this->lowest_randbit;
+			object.reseed[this->var_scope] |= (this->num_groups - 1) << this->lowest_randbit;
 		} else {
-			waiting_triggers |= object->trigger;
+			waiting_triggers |= object.trigger;
 		}
 
 		scope->SetTriggers(waiting_triggers);
@@ -306,9 +306,9 @@ const SpriteGroup *RandomizedSpriteGroup::Resolve(ResolverObject *object) const
 }
 
 
-const SpriteGroup *RealSpriteGroup::Resolve(ResolverObject *object) const
+const SpriteGroup *RealSpriteGroup::Resolve(ResolverObject &object) const
 {
-	return object->ResolveReal(this);
+	return object.ResolveReal(this);
 }
 
 /**
diff --git a/src/newgrf_spritegroup.h b/src/newgrf_spritegroup.h
index dc05fe4f1..da26c1a0e 100644
--- a/src/newgrf_spritegroup.h
+++ b/src/newgrf_spritegroup.h
@@ -57,6 +57,7 @@ enum SpriteGroupType {
 
 struct SpriteGroup;
 typedef uint32 SpriteGroupID;
+struct ResolverObject;
 
 /* SPRITE_WIDTH is 24. ECS has roughly 30 sprite groups per real sprite.
  * Adding an 'extra' margin would be assuming 64 sprite groups per real
@@ -69,7 +70,7 @@ struct SpriteGroup : SpriteGroupPool::PoolItem<&_spritegroup_pool> {
 protected:
 	SpriteGroup(SpriteGroupType type) : type(type) {}
 	/** Base sprite group resolver */
-	virtual const SpriteGroup *Resolve(struct ResolverObject *object) const { return this; };
+	virtual const SpriteGroup *Resolve(ResolverObject &object) const { return this; };
 
 public:
 	virtual ~SpriteGroup() {}
@@ -89,7 +90,7 @@ public:
 	 * @param object information needed to resolve the group
 	 * @return the resolved group
 	 */
-	static const SpriteGroup *Resolve(const SpriteGroup *group, ResolverObject *object)
+	static const SpriteGroup *Resolve(const SpriteGroup *group, ResolverObject &object)
 	{
 		return group == NULL ? NULL : group->Resolve(object);
 	}
@@ -115,7 +116,7 @@ struct RealSpriteGroup : SpriteGroup {
 	const SpriteGroup **loading; ///< List of loading groups (can be SpriteIDs or Callback results)
 
 protected:
-	const SpriteGroup *Resolve(ResolverObject *object) const;
+	const SpriteGroup *Resolve(ResolverObject &object) const;
 };
 
 /* Shared by deterministic and random groups. */
@@ -204,7 +205,7 @@ struct DeterministicSpriteGroup : SpriteGroup {
 	const SpriteGroup *default_group;
 
 protected:
-	const SpriteGroup *Resolve(ResolverObject *object) const;
+	const SpriteGroup *Resolve(ResolverObject &object) const;
 };
 
 enum RandomizedSpriteGroupCompareMode {
@@ -228,7 +229,7 @@ struct RandomizedSpriteGroup : SpriteGroup {
 	const SpriteGroup **groups; ///< Take the group with appropriate index:
 
 protected:
-	const SpriteGroup *Resolve(ResolverObject *object) const;
+	const SpriteGroup *Resolve(ResolverObject &object) const;
 };
 
 
@@ -301,8 +302,6 @@ struct IndustryProductionSpriteGroup : SpriteGroup {
 	uint8 again;
 };
 
-struct ResolverObject;
-
 /**
  * Interface to query and set values specific to a single #VarSpriteGroupScope (action 2 scope).
  *
@@ -310,9 +309,9 @@ struct ResolverObject;
  * to different game entities from a #SpriteGroup-chain (action 1-2-3 chain).
  */
 struct ScopeResolver {
-	ResolverObject *ro; ///< Surrounding resolver object.
+	ResolverObject &ro; ///< Surrounding resolver object.
 
-	ScopeResolver(ResolverObject *ro);
+	ScopeResolver(ResolverObject &ro);
 	virtual ~ScopeResolver();
 
 	virtual uint32 GetRandomBits() const;
diff --git a/src/newgrf_station.cpp b/src/newgrf_station.cpp
index a993acdfe..4bfb125d6 100644
--- a/src/newgrf_station.cpp
+++ b/src/newgrf_station.cpp
@@ -270,7 +270,7 @@ TownScopeResolver *StationResolverObject::GetTown()
 			t = ClosestTownFromTile(this->station_scope.tile, UINT_MAX);
 		}
 		if (t == NULL) return NULL;
-		this->town_scope = new TownScopeResolver(this, t, this->station_scope.st == NULL);
+		this->town_scope = new TownScopeResolver(*this, t, this->station_scope.st == NULL);
 	}
 	return this->town_scope;
 }
@@ -296,7 +296,7 @@ TownScopeResolver *StationResolverObject::GetTown()
 					Slope tileh = GetTileSlope(tile);
 					bool swap = (this->axis == AXIS_Y && HasBit(tileh, CORNER_W) != HasBit(tileh, CORNER_E));
 
-					return GetNearbyTileInformation(tile, this->ro->grffile->grf_version >= 8) ^ (swap ? SLOPE_EW : 0);
+					return GetNearbyTileInformation(tile, this->ro.grffile->grf_version >= 8) ^ (swap ? SLOPE_EW : 0);
 				}
 				break;
 
@@ -355,7 +355,7 @@ TownScopeResolver *StationResolverObject::GetTown()
 			Slope tileh = GetTileSlope(tile);
 			bool swap = (axis == AXIS_Y && HasBit(tileh, CORNER_W) != HasBit(tileh, CORNER_E));
 
-			return GetNearbyTileInformation(tile, this->ro->grffile->grf_version >= 8) ^ (swap ? SLOPE_EW : 0);
+			return GetNearbyTileInformation(tile, this->ro.grffile->grf_version >= 8) ^ (swap ? SLOPE_EW : 0);
 		}
 
 		case 0x68: { // Station info of nearby tiles
@@ -386,7 +386,7 @@ TownScopeResolver *StationResolverObject::GetTown()
 	return this->st->GetNewGRFVariable(this->ro, variable, parameter, available);
 }
 
-uint32 Station::GetNewGRFVariable(const ResolverObject *object, byte variable, byte parameter, bool *available) const
+uint32 Station::GetNewGRFVariable(const ResolverObject &object, byte variable, byte parameter, bool *available) const
 {
 	switch (variable) {
 		case 0x48: { // Accepted cargo types
@@ -409,7 +409,7 @@ uint32 Station::GetNewGRFVariable(const ResolverObject *object, byte variable, b
 
 	/* Handle cargo variables with parameter, 0x60 to 0x65 and 0x69 */
 	if ((variable >= 0x60 && variable <= 0x65) || variable == 0x69) {
-		CargoID c = GetCargoTranslation(parameter, object->grffile);
+		CargoID c = GetCargoTranslation(parameter, object.grffile);
 
 		if (c == CT_INVALID) {
 			switch (variable) {
@@ -457,7 +457,7 @@ uint32 Station::GetNewGRFVariable(const ResolverObject *object, byte variable, b
 	return UINT_MAX;
 }
 
-uint32 Waypoint::GetNewGRFVariable(const ResolverObject *object, byte variable, byte parameter, bool *available) const
+uint32 Waypoint::GetNewGRFVariable(const ResolverObject &object, byte variable, byte parameter, bool *available) const
 {
 	switch (variable) {
 		case 0x48: return 0; // Accepted cargo types
@@ -546,7 +546,7 @@ uint32 Waypoint::GetNewGRFVariable(const ResolverObject *object, byte variable,
 StationResolverObject::StationResolverObject(const StationSpec *statspec, BaseStation *st, TileIndex tile,
 		CallbackID callback, uint32 callback_param1, uint32 callback_param2)
 	: ResolverObject((statspec != NULL ? statspec->grf_prop.grffile : NULL), callback, callback_param1, callback_param2),
-	station_scope(this, statspec, st, tile), town_scope(NULL)
+	station_scope(*this, statspec, st, tile), town_scope(NULL)
 {
 	/* Invalidate all cached vars */
 	_svc.valid = 0;
@@ -564,7 +564,7 @@ StationResolverObject::~StationResolverObject()
  * @param st Instance of the station.
  * @param tile %Tile of the station.
  */
-StationScopeResolver::StationScopeResolver(ResolverObject *ro, const StationSpec *statspec, BaseStation *st, TileIndex tile)
+StationScopeResolver::StationScopeResolver(ResolverObject &ro, const StationSpec *statspec, BaseStation *st, TileIndex tile)
 	: ScopeResolver(ro)
 {
 	this->tile = tile;
@@ -574,19 +574,19 @@ StationScopeResolver::StationScopeResolver(ResolverObject *ro, const StationSpec
 	this->axis = INVALID_AXIS;
 }
 
-static const SpriteGroup *ResolveStation(StationResolverObject *object)
+static const SpriteGroup *ResolveStation(StationResolverObject &object)
 {
 	CargoID ctype = CT_DEFAULT_NA;
 
-	if (object->station_scope.st == NULL) {
+	if (object.station_scope.st == NULL) {
 		/* No station, so we are in a purchase list */
 		ctype = CT_PURCHASE;
-	} else if (Station::IsExpected(object->station_scope.st)) {
-		const Station *st = Station::From(object->station_scope.st);
+	} else if (Station::IsExpected(object.station_scope.st)) {
+		const Station *st = Station::From(object.station_scope.st);
 		/* Pick the first cargo that we have waiting */
 		const CargoSpec *cs;
 		FOR_ALL_CARGOSPECS(cs) {
-			if (object->station_scope.statspec->grf_prop.spritegroup[cs->Index()] != NULL &&
+			if (object.station_scope.statspec->grf_prop.spritegroup[cs->Index()] != NULL &&
 					st->goods[cs->Index()].cargo.TotalCount() > 0) {
 				ctype = cs->Index();
 				break;
@@ -594,15 +594,15 @@ static const SpriteGroup *ResolveStation(StationResolverObject *object)
 		}
 	}
 
-	const SpriteGroup *group = object->station_scope.statspec->grf_prop.spritegroup[ctype];
+	const SpriteGroup *group = object.station_scope.statspec->grf_prop.spritegroup[ctype];
 	if (group == NULL) {
 		ctype = CT_DEFAULT;
-		group = object->station_scope.statspec->grf_prop.spritegroup[ctype];
+		group = object.station_scope.statspec->grf_prop.spritegroup[ctype];
 		if (group == NULL) return NULL;
 	}
 
 	/* Remember the cargo type we've picked */
-	object->station_scope.cargo_type = ctype;
+	object.station_scope.cargo_type = ctype;
 
 	return SpriteGroup::Resolve(group, object);
 }
@@ -618,7 +618,7 @@ static const SpriteGroup *ResolveStation(StationResolverObject *object)
 SpriteID GetCustomStationRelocation(const StationSpec *statspec, BaseStation *st, TileIndex tile, uint32 var10)
 {
 	StationResolverObject object(statspec, st, tile, CBID_NO_CALLBACK, var10);
-	const SpriteGroup *group = ResolveStation(&object);
+	const SpriteGroup *group = ResolveStation(object);
 	if (group == NULL || group->type != SGT_RESULT) return 0;
 	return group->GetResult() - 0x42D;
 }
@@ -638,7 +638,7 @@ SpriteID GetCustomStationFoundationRelocation(const StationSpec *statspec, BaseS
 	StationResolverObject object(statspec, st, tile, CBID_NO_CALLBACK, 2, layout | (edge_info << 16));
 
 	ClearRegister(0x100);
-	const SpriteGroup *group = ResolveStation(&object);
+	const SpriteGroup *group = ResolveStation(object);
 	if (group == NULL || group->type != SGT_RESULT) return 0;
 	return group->GetResult() + GetRegister(0x100);
 }
@@ -647,7 +647,7 @@ SpriteID GetCustomStationFoundationRelocation(const StationSpec *statspec, BaseS
 uint16 GetStationCallback(CallbackID callback, uint32 param1, uint32 param2, const StationSpec *statspec, BaseStation *st, TileIndex tile)
 {
 	StationResolverObject object(statspec, st, tile, callback, param1, param2);
-	const SpriteGroup *group = ResolveStation(&object);
+	const SpriteGroup *group = ResolveStation(object);
 	if (group == NULL) return CALLBACK_FAILED;
 	return group->GetCallbackResult();
 }
@@ -672,7 +672,7 @@ CommandCost PerformStationTileSlopeCheck(TileIndex north_tile, TileIndex cur_til
 			(numtracks << 24) | (plat_len << 16) | (axis == AXIS_Y ? TileX(diff) << 8 | TileY(diff) : TileY(diff) << 8 | TileX(diff)));
 	object.station_scope.axis = axis;
 
-	const SpriteGroup *group = ResolveStation(&object);
+	const SpriteGroup *group = ResolveStation(object);
 	uint16 cb_res = group != NULL ? group->GetCallbackResult() : CALLBACK_FAILED;
 
 	/* Failed callback means success. */
@@ -1023,7 +1023,7 @@ void TriggerStationRandomisation(Station *st, TileIndex tile, StationRandomTrigg
 				StationResolverObject object(ss, st, tile, CBID_RANDOM_TRIGGER, 0);
 				object.trigger = trigger_bit;
 
-				const SpriteGroup *group = ResolveStation(&object);
+				const SpriteGroup *group = ResolveStation(object);
 				if (group == NULL) continue;
 
 				uint32 reseed = object.GetReseedSum();
diff --git a/src/newgrf_station.h b/src/newgrf_station.h
index 62bb940a4..ffb827cb3 100644
--- a/src/newgrf_station.h
+++ b/src/newgrf_station.h
@@ -30,7 +30,7 @@ struct StationScopeResolver : public ScopeResolver {
 	CargoID cargo_type;                 ///< Type of cargo of the station.
 	Axis axis;                          ///< Station axis, used only for the slope check callback.
 
-	StationScopeResolver(ResolverObject *ro, const StationSpec *statspec, BaseStation *st, TileIndex tile);
+	StationScopeResolver(ResolverObject &ro, const StationSpec *statspec, BaseStation *st, TileIndex tile);
 
 	/* virtual */ uint32 GetRandomBits() const;
 	/* virtual */ uint32 GetTriggers() const;
diff --git a/src/newgrf_town.cpp b/src/newgrf_town.cpp
index 95cab9643..b6693d9ae 100644
--- a/src/newgrf_town.cpp
+++ b/src/newgrf_town.cpp
@@ -20,7 +20,7 @@
  * @param t %Town of the scope.
  * @param readonly Scope may change persistent storage of the town.
  */
-TownScopeResolver::TownScopeResolver(ResolverObject *ro, Town *t, bool readonly) : ScopeResolver(ro)
+TownScopeResolver::TownScopeResolver(ResolverObject &ro, Town *t, bool readonly) : ScopeResolver(ro)
 {
 	this->t = t;
 	this->readonly = readonly;
@@ -43,8 +43,8 @@ TownScopeResolver::TownScopeResolver(ResolverObject *ro, Town *t, bool readonly)
 			/* Check the persistent storage for the GrfID stored in register 100h. */
 			uint32 grfid = GetRegister(0x100);
 			if (grfid == 0xFFFFFFFF) {
-				if (this->ro->grffile == NULL) return 0;
-				grfid = this->ro->grffile->grfid;
+				if (this->ro.grffile == NULL) return 0;
+				grfid = this->ro.grffile->grfid;
 			}
 
 			std::list<PersistentStorage *>::iterator iter;
@@ -135,14 +135,14 @@ TownScopeResolver::TownScopeResolver(ResolverObject *ro, Town *t, bool readonly)
 
 	assert(this->t != NULL);
 	/* We can't store anything if the caller has no #GRFFile. */
-	if (this->ro->grffile == NULL) return;
+	if (this->ro.grffile == NULL) return;
 
 	/* Check the persistent storage for the GrfID stored in register 100h. */
 	uint32 grfid = GetRegister(0x100);
 
 	/* A NewGRF can only write in the persistent storage associated to its own GRFID. */
-	if (grfid == 0xFFFFFFFF) grfid = this->ro->grffile->grfid;
-	if (grfid != this->ro->grffile->grfid) return;
+	if (grfid == 0xFFFFFFFF) grfid = this->ro.grffile->grfid;
+	if (grfid != this->ro.grffile->grfid) return;
 
 	/* Check if the storage exists. */
 	std::list<PersistentStorage *>::iterator iter;
@@ -167,7 +167,7 @@ TownScopeResolver::TownScopeResolver(ResolverObject *ro, Town *t, bool readonly)
  * @param readonly Scope may change persistent storage of the town.
  */
 TownResolverObject::TownResolverObject(const struct GRFFile *grffile, Town *t, bool readonly)
-		: ResolverObject(grffile), town_scope(this, t, readonly)
+		: ResolverObject(grffile), town_scope(*this, t, readonly)
 {
 }
 
diff --git a/src/newgrf_town.h b/src/newgrf_town.h
index 3f6094cdb..145571e8a 100644
--- a/src/newgrf_town.h
+++ b/src/newgrf_town.h
@@ -25,7 +25,7 @@ struct TownScopeResolver : public ScopeResolver {
 	Town *t;       ///< %Town of the scope.
 	bool readonly; ///< When set, persistent storage of the town is read-only,
 
-	TownScopeResolver(ResolverObject *ro, Town *t, bool readonly);
+	TownScopeResolver(ResolverObject &ro, Town *t, bool readonly);
 
 	virtual uint32 GetVariable(byte variable, uint32 parameter, bool *available) const;
 	virtual void StorePSA(uint reg, int32 value);
diff --git a/src/station_base.h b/src/station_base.h
index 63a2ca5e5..c0bb96cd9 100644
--- a/src/station_base.h
+++ b/src/station_base.h
@@ -492,7 +492,7 @@ public:
 		return IsAirportTile(tile) && GetStationIndex(tile) == this->index;
 	}
 
-	/* virtual */ uint32 GetNewGRFVariable(const ResolverObject *object, byte variable, byte parameter, bool *available) const;
+	/* virtual */ uint32 GetNewGRFVariable(const ResolverObject &object, byte variable, byte parameter, bool *available) const;
 
 	/* virtual */ void GetTileArea(TileArea *ta, StationType type) const;
 };
diff --git a/src/waypoint_base.h b/src/waypoint_base.h
index c97c6089c..8d544a3b9 100644
--- a/src/waypoint_base.h
+++ b/src/waypoint_base.h
@@ -32,7 +32,7 @@ struct Waypoint FINAL : SpecializedStation<Waypoint, true> {
 		return IsRailWaypointTile(tile) && GetStationIndex(tile) == this->index;
 	}
 
-	/* virtual */ uint32 GetNewGRFVariable(const struct ResolverObject *object, byte variable, byte parameter, bool *available) const;
+	/* virtual */ uint32 GetNewGRFVariable(const struct ResolverObject &object, byte variable, byte parameter, bool *available) const;
 
 	/* virtual */ void GetTileArea(TileArea *ta, StationType type) const;