(svn r13948) -Add [YAPP]: Extend NPF with a function to find a safe tile and reserve a path. (michi_cc)

2 files changed, 54 insertions, 0 deletions

diff --git a/src/npf.cpp b/src/npf.cpp
index 4aa817b70..d5f431b43 100644
--- a/src/npf.cpp
+++ b/src/npf.cpp
@@ -456,6 +456,17 @@ static int32 NPFFindDepot(AyStar* as, OpenListNode *current)
 		AYSTAR_FOUND_END_NODE : AYSTAR_DONE;
 }
 
+/** Find any safe and free tile. */
+static int32 NPFFindSafeTile(AyStar *as, OpenListNode *current)
+{
+	const Vehicle *v = ((NPFFindStationOrTileData*)as->user_target)->v;
+
+	return
+		IsSafeWaitingPosition(v, current->path.node.tile, (Trackdir)current->path.node.direction, true, _settings_game.pf.forbid_90_deg) &&
+		IsWaitingPositionFree(v, current->path.node.tile, (Trackdir)current->path.node.direction, _settings_game.pf.forbid_90_deg) ?
+			AYSTAR_FOUND_END_NODE : AYSTAR_DONE;
+}
+
 /* Will find a station identified using the NPFFindStationOrTileData */
 static int32 NPFFindStationOrTile(AyStar* as, OpenListNode *current)
 {
@@ -820,6 +831,18 @@ static void NPFFollowTrack(AyStar* aystar, OpenListNode* current)
 		}
 	}
 
+	if (NPFGetFlag(&current->path.node, NPF_FLAG_IGNORE_RESERVED)) {
+		/* Mask out any reserved tracks. */
+		TrackBits reserved = GetReservedTrackbits(dst_tile);
+		trackdirbits &= ~TrackBitsToTrackdirBits(reserved);
+
+		uint bits = TrackdirBitsToTrackBits(trackdirbits);
+		int i;
+		FOR_EACH_SET_BIT(i, bits) {
+			if (TracksOverlap(reserved | TrackToTrackBits((Track)i))) trackdirbits &= ~TrackToTrackdirBits((Track)i);
+		}
+	}
+
 	/* Enumerate possible track */
 	uint i = 0;
 	while (trackdirbits != 0) {
@@ -1065,6 +1088,30 @@ NPFFoundTargetData NPFRouteToDepotTrialError(TileIndex tile, Trackdir trackdir,
 	return best_result;
 }
 
+NPFFoundTargetData NPFRouteToSafeTile(const Vehicle *v, TileIndex tile, Trackdir trackdir, bool override_railtype)
+{
+	assert(v->type == VEH_TRAIN);
+
+	NPFFindStationOrTileData fstd;
+	fstd.v = v;
+	fstd.reserve_path = true;
+
+	AyStarNode start1;
+	start1.tile = tile;
+	/* We set this in case the target is also the start tile, we will just
+	 * return a not found then */
+	start1.user_data[NPF_TRACKDIR_CHOICE] = INVALID_TRACKDIR;
+	start1.direction = trackdir;
+	NPFSetFlag(&start1, NPF_FLAG_IGNORE_RESERVED, true);
+
+	RailTypes railtypes = v->u.rail.compatible_railtypes;
+	if (override_railtype) railtypes |= GetRailTypeInfo(v->u.rail.railtype)->compatible_railtypes;
+
+	/* perform a breadth first search. Target is NULL,
+	 * since we are just looking for any safe tile...*/
+	return NPFRouteInternal(&start1, true, NULL, false, &fstd, NPFFindSafeTile, NPFCalcZero, TRANSPORT_RAIL, 0, v->owner, railtypes, 0);
+}
+
 void InitializeNPF()
 {
 	static bool first_init = true;
diff --git a/src/npf.h b/src/npf.h
index 9ab9a456b..bf19b62d5 100644
--- a/src/npf.h
+++ b/src/npf.h
@@ -72,6 +72,7 @@ enum NPFNodeFlag {
 	NPF_FLAG_LAST_SIGNAL_RED,   ///< Used to mark that the last signal on this path was red
 	NPF_FLAG_IGNORE_START_TILE, ///< Used to mark that the start tile is invalid, and searching should start from the second tile on
 	NPF_FLAG_TARGET_RESERVED,   ///< Used to mark that the possible reservation target is already reserved
+	NPF_FLAG_IGNORE_RESERVED,   ///< Used to mark that reserved tiles should be considered impassable
 };
 
 /* Meant to be stored in AyStar.userpath */
@@ -111,6 +112,12 @@ NPFFoundTargetData NPFRouteToDepotBreadthFirstTwoWay(TileIndex tile1, Trackdir t
  * of choices and accurate heuristics, such as water. */
 NPFFoundTargetData NPFRouteToDepotTrialError(TileIndex tile, Trackdir trackdir, bool ignore_start_tile, TransportType type, uint sub_type, Owner owner, RailTypes railtypes);
 
+/**
+ * Search for any safe tile using a breadth first search and try to reserve a path.
+ */
+NPFFoundTargetData NPFRouteToSafeTile(const Vehicle *v, TileIndex tile, Trackdir trackdir,bool override_railtype);
+
+
 void NPFFillWithOrderData(NPFFindStationOrTileData *fstd, Vehicle *v, bool reserve_path = false);