TBTR: Refactor train/template match function to return difference flags

src/tbtr_template_vehicle.cpp

@@ -158,8 +158,8 @@ bool ShouldServiceTrainForTemplateReplacement(const Train *t, const TemplateVehi
 	if (tv->IsReplaceOldOnly() && !t->NeedsAutorenewing(c, false)) return false;
 	Money needed_money = c->settings.engine_renew_money;
 	if (needed_money > c->money) return false;
-	bool need_replacement = !TrainMatchesTemplate(t, tv);
+	TBTRDiffFlags diff = TrainTemplateDifference(t, tv);
-	if (need_replacement) {
+	if (diff & TBTRDF_CONSIST) {
 		/* Check money.
 		 * We want 2*(the price of the whole template) without looking at the value of the vehicle(s) we are going to sell, or not need to buy. */
 		for (const TemplateVehicle *tv_unit = tv; tv_unit != nullptr; tv_unit = tv_unit->GetNextUnit()) {
@@ -167,10 +167,8 @@ bool ShouldServiceTrainForTemplateReplacement(const Train *t, const TemplateVehi
 			needed_money += 2 * Engine::Get(tv->engine_type)->GetCost();
 		}
 		return needed_money <= c->money;
-	} else if (!TrainMatchesTemplateRefit(t, tv) && tv->refit_as_template) {
-		return true;
 	} else {
-		return false;
+		return diff != TBTRDF_NONE;
 	}
 }
 

src/tbtr_template_vehicle_func.cpp

@@ -277,35 +277,25 @@ void NeutralizeStatus(Train *t)
 	DoCommand(0, t->index, 0, DC_EXEC, CMD_RENAME_VEHICLE, nullptr);
 }
 
-bool TrainMatchesTemplate(const Train *t, const TemplateVehicle *tv) {
+TBTRDiffFlags TrainTemplateDifference(const Train *t, const TemplateVehicle *tv) {
-	while (t && tv) {
+	TBTRDiffFlags diff = TBTRDF_NONE;
+	while (t != nullptr && tv != nullptr) {
 		if (t->engine_type != tv->engine_type) {
-			return false;
+			return TBTRDF_ALL;
+		}
+		if (tv->refit_as_template && (t->cargo_type != tv->cargo_type || t->cargo_subtype != tv->cargo_subtype)) {
+			diff |= TBTRDF_REFIT;
+		}
+		if (HasBit(t->flags, VRF_REVERSE_DIRECTION) != HasBit(tv->ctrl_flags, TVCF_REVERSED)) {
+			diff |= TBTRDF_DIR;
 		}
 		t = t->GetNextUnit();
 		tv = tv->GetNextUnit();
 	}
-	if ((t && !tv) || (!t && tv)) {
+	if ((t != nullptr) != (tv != nullptr)) {
-		return false;
+		return TBTRDF_ALL;
 	}
-	return true;
+	return diff;
-}
-
-
-bool TrainMatchesTemplateRefit(const Train *t, const TemplateVehicle *tv)
-{
-	if (!tv->refit_as_template) {
-		return true;
-	}
-
-	while (t && tv) {
-		if (t->cargo_type != tv->cargo_type || t->cargo_subtype != tv->cargo_subtype || HasBit(t->flags, VRF_REVERSE_DIRECTION) != HasBit(tv->ctrl_flags, TVCF_REVERSED)) {
-			return false;
-		}
-		t = t->GetNextUnit();
-		tv = tv->GetNextUnit();
-	}
-	return true;
 }
 
 void BreakUpRemainders(Train *t)
@@ -336,7 +326,7 @@ uint CountsTrainsNeedingTemplateReplacement(GroupID g_id, const TemplateVehicle
 	if (!tv) return count;
 
 	for (Train *t : Train::Iterate()) {
-		if (t->IsPrimaryVehicle() && t->group_id == g_id && (!TrainMatchesTemplate(t, tv) || !TrainMatchesTemplateRefit(t, tv))) {
+		if (t->IsPrimaryVehicle() && t->group_id == g_id && TrainTemplateDifference(t, tv) != TBTRDF_NONE) {
 			count++;
 		}
 	}

src/tbtr_template_vehicle_func.h

@@ -55,8 +55,16 @@ void TransferCargoForTrain(Train *old_veh, Train *new_head);
 
 void NeutralizeStatus(Train *t);
 
-bool TrainMatchesTemplate(const Train *t, const TemplateVehicle *tv);
+enum TBTRDiffFlags {
-bool TrainMatchesTemplateRefit(const Train *t, const TemplateVehicle *tv);
+	TBTRDF_NONE    = 0,      ///< no difference between train and template
+	TBTRDF_CONSIST = 1 << 0, ///< consist (vehicle units) differs between train and template
+	TBTRDF_REFIT   = 1 << 1, ///< refit differs between train and template
+	TBTRDF_DIR     = 1 << 2, ///< unit direction differs between train and template
+	TBTRDF_ALL     = TBTRDF_CONSIST | TBTRDF_REFIT | TBTRDF_DIR,
+};
+DECLARE_ENUM_AS_BIT_SET(TBTRDiffFlags)
+
+TBTRDiffFlags TrainTemplateDifference(const Train *t, const TemplateVehicle *tv);
 
 void UpdateAllTemplateVehicleImages();
 

src/train_cmd.cpp

@@ -7185,13 +7185,17 @@ CommandCost CmdTemplateReplaceVehicle(TileIndex tile, DoCommandFlag flags, uint3
 	if (tv->IsReplaceOldOnly() && !incoming->NeedsAutorenewing(Company::Get(incoming->owner), false)) {
 		return CommandCost();
 	}
-	bool need_replacement = !TrainMatchesTemplate(incoming, tv);
+	const TBTRDiffFlags diff = TrainTemplateDifference(incoming, tv);
-	bool need_refit = !TrainMatchesTemplateRefit(incoming, tv);
+	if (diff == TBTRDF_NONE) return CommandCost();
-	bool use_refit = tv->refit_as_template;
+
+	const bool need_replacement = (diff & TBTRDF_CONSIST);
+	const bool need_refit = (diff & TBTRDF_REFIT);
+	const bool refit_to_template = tv->refit_as_template;
+
 	CargoID store_refit_ct = CT_INVALID;
 	uint16 store_refit_csubt = 0;
 	// if a train shall keep its old refit, store the refit setting of its first vehicle
-	if (!use_refit) {
+	if (!refit_to_template) {
 		for (Train *getc = incoming; getc != nullptr; getc = getc->GetNextUnit()) {
 			if (getc->cargo_type != CT_INVALID && getc->cargo_cap > 0) {
 				store_refit_ct = getc->cargo_type;
@@ -7200,11 +7204,7 @@ CommandCost CmdTemplateReplaceVehicle(TileIndex tile, DoCommandFlag flags, uint3
 		}
 	}
 
-	if (!need_replacement) {
+	if (need_replacement) {
-		if (!need_refit || !use_refit) {
-			return CommandCost();
-		}
-	} else {
 		CommandCost buy_cost = TestBuyAllTemplateVehiclesInChain(tv, tile);
 		if (buy_cost.Failed()) {
 			if (buy_cost.GetErrorMessage() == INVALID_STRING_ID) return CommandCost(STR_ERROR_CAN_T_BUY_TRAIN);
@@ -7214,7 +7214,7 @@ CommandCost CmdTemplateReplaceVehicle(TileIndex tile, DoCommandFlag flags, uint3
 		}
 	}
 
-	if (need_replacement || (need_refit && use_refit)) RegisterGameEvents(GEF_TBTR_REPLACEMENT);
+	RegisterGameEvents(GEF_TBTR_REPLACEMENT);
 
 	TemplateDepotVehicles depot_vehicles;
 	if (tv->IsSetReuseDepotVehicles()) depot_vehicles.Init(tile);
@@ -7291,7 +7291,7 @@ CommandCost CmdTemplateReplaceVehicle(TileIndex tile, DoCommandFlag flags, uint3
 
 			// additionally, if we don't want to use the template refit, refit as incoming
 			// the template refit will be set further down, if we use it at all
-			if (!use_refit) {
+			if (!refit_to_template) {
 				buy.AddCost(DoCommand(new_chain->tile, new_chain->index, store_refit_ct | store_refit_csubt << 8 | (1 << 16) | (1 << 31), flags, GetCmdRefitVeh(new_chain)));
 			}
 		}
@@ -7352,7 +7352,7 @@ CommandCost CmdTemplateReplaceVehicle(TileIndex tile, DoCommandFlag flags, uint3
 			}
 			// TODO: is this enough ? might it be that we bought a new wagon here and it now has std refit ?
 			if (need_refit && new_part != nullptr) {
-				if (use_refit) {
+				if (refit_to_template) {
 					DoCommand(tile, new_part->index, cur_tmpl->cargo_type | (cur_tmpl->cargo_subtype << 8) | (1 << 16) | (1 << 31), flags, GetCmdRefitVeh(new_part));
 				} else {
 					DoCommand(tile, new_part->index, store_refit_ct | (store_refit_csubt << 8) | (1 << 16) | (1 << 31), flags, GetCmdRefitVeh(new_part));
@@ -7374,7 +7374,7 @@ CommandCost CmdTemplateReplaceVehicle(TileIndex tile, DoCommandFlag flags, uint3
 	// neutralize each remaining engine's status
 
 	// refit, only if the template option is set so
-	if (use_refit && (need_refit || need_replacement)) {
+	if (refit_to_template && (need_refit || need_replacement)) {
 		buy.AddCost(CmdRefitTrainFromTemplate(new_chain, tv, flags));
 	}