(svn r6800) -Feature change: [train is lost] message is now generated immediately when pathfinder can't find the path. (thanks MeusH, peter1138 and Brianetta for ideas and help).

8 files changed, 53 insertions, 26 deletions

diff --git a/lang/english.txt b/lang/english.txt
index d55e88d91..bf64c92e9 100644
--- a/lang/english.txt
+++ b/lang/english.txt
@@ -1026,8 +1026,7 @@ STR_CONFIG_PATCHES_NEW_PATHFINDING_ALL                          :{LTBLUE}New glo
 
 STR_CONFIG_PATCHES_SMALL_AIRPORTS                               :{LTBLUE}Always allow small airports: {ORANGE}{STRING1}
 
-STR_CONFIG_PATCHES_LOST_TRAIN_DAYS                              :{LTBLUE}A train is lost if no progress is made for: {ORANGE}{STRING1} days
-STR_CONFIG_PATCHES_LOST_TRAIN_DAYS_DISABLED                     :{LTBLUE}A train is lost if no progress is made for: {ORANGE}disabled
+STR_CONFIG_PATCHES_WARN_LOST_TRAIN                              :{LTBLUE}Warn if train is lost: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_ORDER_REVIEW                                 :{LTBLUE}Review vehicles' orders: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_ORDER_REVIEW_OFF                             :no
 STR_CONFIG_PATCHES_ORDER_REVIEW_EXDEPOT                         :yes, but exclude stopped vehicles
diff --git a/settings.c b/settings.c
index 06a4870ba..6ffc63dbf 100644
--- a/settings.c
+++ b/settings.c
@@ -1290,7 +1290,7 @@ const SettingDesc _patch_settings[] = {
 	SDT_BOOL(Patches, train_income_warn,             S, 0,  true,                    STR_CONFIG_PATCHES_WARN_INCOME_LESS,     NULL),
 	 SDT_VAR(Patches, order_review_system,SLE_UINT8, S,MS,     2,     0,       2, 0, STR_CONFIG_PATCHES_ORDER_REVIEW,         NULL),
 	SDT_BOOL(Patches, never_expire_vehicles,         0, 0, false,                    STR_CONFIG_PATCHES_NEVER_EXPIRE_VEHICLES,NULL),
-	 SDT_VAR(Patches, lost_train_days,   SLE_UINT16, S,D0,   180,   180,     720, 0, STR_CONFIG_PATCHES_LOST_TRAIN_DAYS,      NULL),
+	SDT_BOOL(Patches, lost_train_warn,               S, 0,  true,                    STR_CONFIG_PATCHES_WARN_LOST_TRAIN,      NULL),
 	SDT_BOOL(Patches, autorenew,                     S, 0, false,                    STR_CONFIG_PATCHES_AUTORENEW_VEHICLE,    EngineRenewUpdate),
 	 SDT_VAR(Patches, autorenew_months,   SLE_INT16, S, 0,     6,   -12,      12, 0, STR_CONFIG_PATCHES_AUTORENEW_MONTHS,     EngineRenewMonthsUpdate),
 	 SDT_VAR(Patches, autorenew_money,     SLE_UINT, S,CR,100000,     0, 2000000, 0, STR_CONFIG_PATCHES_AUTORENEW_MONEY,      EngineRenewMoneyUpdate),
diff --git a/settings_gui.c b/settings_gui.c
index b93a480c8..95b381f79 100644
--- a/settings_gui.c
+++ b/settings_gui.c
@@ -631,7 +631,7 @@ static const char *_patches_vehicles[] = {
 	"train_income_warn",
 	"order_review_system",
 	"never_expire_vehicles",
-	"lost_train_days",
+	"lost_train_warn",
 	"autorenew",
 	"autorenew_months",
 	"autorenew_money",
diff --git a/train_cmd.c b/train_cmd.c
index 4ae854bba..01849cb7e 100644
--- a/train_cmd.c
+++ b/train_cmd.c
@@ -2278,6 +2278,9 @@ static byte ChooseTrainTrack(Vehicle* v, TileIndex tile, DiagDirection enterdir,
 {
 	TrainTrackFollowerData fd;
 	uint best_track;
+	// pathfinders are able to tell that route was only 'guessed'
+	bool path_not_found = false;
+
 #ifdef PF_BENCHMARK
 	TIC()
 #endif
@@ -2288,7 +2291,7 @@ static byte ChooseTrainTrack(Vehicle* v, TileIndex tile, DiagDirection enterdir,
 	if (KILL_FIRST_BIT(trackdirbits) == 0) return FIND_FIRST_BIT(trackdirbits);
 
 	if (_patches.yapf.rail_use_yapf) {
-		Trackdir trackdir = YapfChooseRailTrack(v, tile, enterdir, trackdirbits);
+		Trackdir trackdir = YapfChooseRailTrack(v, tile, enterdir, trackdirbits, &path_not_found);
 		if (trackdir != INVALID_TRACKDIR) {
 			best_track = TrackdirToTrack(trackdir);
 		} else {
@@ -2319,6 +2322,7 @@ static byte ChooseTrainTrack(Vehicle* v, TileIndex tile, DiagDirection enterdir,
 			the direction we need to take to get there, if ftd.best_bird_dist is not 0,
 			we did not find our target, but ftd.best_trackdir contains the direction leading
 			to the tile closest to our target. */
+			if (ftd.best_bird_dist != 0) path_not_found = true;
 			/* Discard enterdir information, making it a normal track */
 			best_track = TrackdirToTrack(ftd.best_trackdir);
 		}
@@ -2339,6 +2343,9 @@ static byte ChooseTrainTrack(Vehicle* v, TileIndex tile, DiagDirection enterdir,
 		NewTrainPathfind(tile - TileOffsByDiagDir(enterdir), v->dest_tile,
 			v->u.rail.compatible_railtypes, enterdir, (NTPEnumProc*)NtpCallbFindStation, &fd);
 
+		// check whether the path was found or only 'guessed'
+		if (fd.best_bird_dist != 0) path_not_found = true;
+
 		if (fd.best_track == 0xff) {
 			// blaha
 			best_track = FIND_FIRST_BIT(trackdirbits);
@@ -2349,6 +2356,30 @@ static byte ChooseTrainTrack(Vehicle* v, TileIndex tile, DiagDirection enterdir,
 		time = NpfEndInterval(perf);
 		DEBUG(yapf, 4)("[YAPF][NTPT] %d us - %d rounds - %d open - %d closed -- ", time, 0, 0, 0);
 	}
+	// handle "path not found" state
+	if (path_not_found) {
+		// PF didn't find the route
+		if (!HASBIT(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
+			// it is first time the problem occurred, set the "path not found" flag
+			SETBIT(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
+			// and notify user about the event
+			if (_patches.lost_train_warn) {
+				SetDParam(0, v->unitnumber);
+				AddNewsItem(
+					STR_TRAIN_IS_LOST,
+					NEWS_FLAGS(NM_SMALL, NF_VIEWPORT|NF_VEHICLE, NT_ADVICE, 0),
+					v->index,
+					0);
+			}
+		}
+	} else {
+		// route found, is the train marked with "path not found" flag?
+		if (HASBIT(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION)) {
+			// clear the flag as the PF's problem was solved
+			CLRBIT(v->u.rail.flags, VRF_NO_PATH_TO_DESTINATION);
+			// can we also delete the "News" item somehow?
+		}
+	}
 
 #ifdef PF_BENCHMARK
 	TOC("PF time = ", 1)
@@ -3579,17 +3610,6 @@ void OnNewDay_Train(Vehicle *v)
 
 		CheckIfTrainNeedsService(v);
 
-		// check if train hasn't advanced in its order list for a set number of days
-		if (_patches.lost_train_days && v->num_orders && !(v->vehstatus & (VS_STOPPED | VS_CRASHED) ) && ++v->u.rail.days_since_order_progr >= _patches.lost_train_days && v->owner == _local_player) {
-			v->u.rail.days_since_order_progr = 0;
-			SetDParam(0, v->unitnumber);
-			AddNewsItem(
-				STR_TRAIN_IS_LOST,
-				NEWS_FLAGS(NM_SMALL, NF_VIEWPORT|NF_VEHICLE, NT_ADVICE, 0),
-				v->index,
-				0);
-		}
-
 		CheckOrders(v);
 
 		/* update destination */
diff --git a/variables.h b/variables.h
index ef3d04b42..3c222ad1a 100644
--- a/variables.h
+++ b/variables.h
@@ -97,7 +97,7 @@ typedef struct Patches {
 	bool build_rawmaterial_ind;         // allow building raw material industries
 	bool multiple_industry_per_town;    // allow many industries of the same type per town
 	bool same_industry_close;           // allow same type industries to be built close to each other
-	uint16 lost_train_days;             // if a train doesn't switch order in this amount of days, a train is lost warning is shown
+	bool lost_train_warn;               // if a train can't find its destination, show a warning
 	uint8 order_review_system;
 	bool train_income_warn;             // if train is generating little income, show a warning
 	bool status_long_date;              // always show long date in status bar
diff --git a/vehicle.h b/vehicle.h
index 80b31b30d..fc6645ff1 100644
--- a/vehicle.h
+++ b/vehicle.h
@@ -92,6 +92,9 @@ enum {
 
 	// used to reverse the visible direction of the vehicle
 	VRF_REVERSE_DIRECTION = 4,
+
+	// used to mark train as lost because PF can't find the route
+	VRF_NO_PATH_TO_DESTINATION = 5,
 };
 
 typedef struct VehicleAir {
diff --git a/yapf/yapf.h b/yapf/yapf.h
index 55b9f73ca..3bf8468e9 100644
--- a/yapf/yapf.h
+++ b/yapf/yapf.h
@@ -27,10 +27,11 @@ Trackdir YapfChooseRoadTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir)
  * @param v        the train that needs to find a path
  * @param tile     the tile to find the path from (should be next tile the train is about to enter)
  * @param enterdir diagonal direction which the RV will enter this new tile from
- * @param tracks   available tracks on the new tile (to choose from)
+ * @param trackdirs available trackdirs on the new tile (to choose from)
+ * @param no_path_found [out] true is returned if no path can be found (returned Trackdir is only a 'guess')
  * @return         the best trackdir for next turn or INVALID_TRACKDIR if the path could not be found
  */
-Trackdir YapfChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs);
+Trackdir YapfChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs, bool *path_not_found);
 
 /** Used by RV multistop feature to find the nearest road stop that has a free slot.
  * @param v      RV (its current tile will be the origin)
diff --git a/yapf/yapf_rail.cpp b/yapf/yapf_rail.cpp
index e80614662..0dc596927 100644
--- a/yapf/yapf_rail.cpp
+++ b/yapf/yapf_rail.cpp
@@ -103,21 +103,25 @@ public:
 	/// return debug report character to identify the transportation type
 	FORCEINLINE char TransportTypeChar() const {return 't';}
 
-	static Trackdir stChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs)
+	static Trackdir stChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs, bool *path_not_found)
 	{
 		// create pathfinder instance
 		Tpf pf;
-		return pf.ChooseRailTrack(v, tile, enterdir, trackdirs);
+		return pf.ChooseRailTrack(v, tile, enterdir, trackdirs, path_not_found);
 	}
 
-	FORCEINLINE Trackdir ChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs)
+	FORCEINLINE Trackdir ChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs, bool *path_not_found)
 	{
 		// set origin and destination nodes
 		Yapf().SetOrigin(v->tile, GetVehicleTrackdir(v), INVALID_TILE, INVALID_TRACKDIR, 1, true);
 		Yapf().SetDestination(v);
 
 		// find the best path
-		Yapf().FindPath(v);
+		bool path_found = Yapf().FindPath(v);
+		if (!path_found && path_not_found != NULL) {
+			// tell controller that the path was only 'guessed'
+			*path_not_found = !path_found;
+		}
 
 		// if path not found - return INVALID_TRACKDIR
 		Trackdir next_trackdir = INVALID_TRACKDIR;
@@ -195,10 +199,10 @@ struct CYapfAnyDepotRail2 : CYapfT<CYapfRail_TypesT<CYapfAnyDepotRail2, CFollowT
 struct CYapfAnyDepotRail3 : CYapfT<CYapfRail_TypesT<CYapfAnyDepotRail3, CFollowTrackRailNo90, CRailNodeListTrackDir, CYapfDestinationAnyDepotRailT     , CYapfFollowAnyDepotRailT> > {};
 
 
-Trackdir YapfChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs)
+Trackdir YapfChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackdirBits trackdirs, bool *path_not_found)
 {
 	// default is YAPF type 2
-	typedef Trackdir (*PfnChooseRailTrack)(Vehicle*, TileIndex, DiagDirection, TrackdirBits);
+	typedef Trackdir (*PfnChooseRailTrack)(Vehicle*, TileIndex, DiagDirection, TrackdirBits, bool*);
 	PfnChooseRailTrack pfnChooseRailTrack = &CYapfRail2::stChooseRailTrack;
 
 	// check if non-default YAPF type needed
@@ -207,7 +211,7 @@ Trackdir YapfChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir,
 	else if (_patches.yapf.disable_node_optimization)
 		pfnChooseRailTrack = &CYapfRail1::stChooseRailTrack; // Trackdir, allow 90-deg
 
-	Trackdir td_ret = pfnChooseRailTrack(v, tile, enterdir, trackdirs);
+	Trackdir td_ret = pfnChooseRailTrack(v, tile, enterdir, trackdirs, path_not_found);
 
 	return td_ret;
 }