(svn r2147) - Add: [NPF] Give red presignal exit signals a different (higher) penalty, to discourage trains from waiting at presignal exits.

npf.c

@@ -373,6 +373,12 @@ int32 NPFRailPathCost(AyStar* as, AyStarNode* current, OpenListNode* parent) {
 			if (!NPFGetFlag(current, NPF_FLAG_SEEN_SIGNAL)) {
 				/* Penalize the first signal we
 				 * encounter, if it is red */
+
+				/* Is this a presignal exit or combo? */
+				if ((_map3_hi[tile] & 0x3) == 0x2 || (_map3_hi[tile] & 0x3) == 0x3)
+					/* Penalise exit and combo signals differently (heavier) */
+					cost += _patches.npf_rail_firstred_exit_penalty;
+				else
 					cost += _patches.npf_rail_firstred_penalty;
 			}
 			/* Record the state of this signal */

settings.c

@@ -937,8 +937,11 @@ const SettingDesc patch_settings[] = {
 	* again, just because the sign at the right side was red. If we take
 	* a typical 5 length station, this detour is 10 or 11 tiles (not
 	* sure), so we set the default penalty at 10 (the station tile
-	* penalty will further prevent this */
+	* penalty will further prevent this.
+	* We give presignal exits (and combo's) a different (larger) penalty, because we really
+	* don't want trains waiting in front of a presignal exit. */
 	{"npf_rail_firstred_penalty",   SDT_UINT32, (void*)(10 * NPF_TILE_LENGTH),  &_patches.npf_rail_firstred_penalty,		NULL},
+	{"npf_rail_firstred_exit_penalty", SDT_UINT32, (void*)(100 * NPF_TILE_LENGTH),	&_patches.npf_rail_firstred_exit_penalty,		NULL},
 	/* This penalty is for when the last signal before the target is red.
 	 * This is useful for train stations, where there are multiple
 	 * platforms to choose from, which lie in different signal blocks.

variables.h

@@ -195,7 +195,8 @@ typedef struct Patches {
 	/* New Path Finding */
 	bool new_pathfinding_all; /* Use the newest pathfinding algorithm for all */
 
-	uint32 npf_rail_firstred_penalty; /* The penalty for when the first signal is red */
+	uint32 npf_rail_firstred_penalty; /* The penalty for when the first signal is red (and it is not an exit or combo signal) */
+	uint32 npf_rail_firstred_exit_penalty; /* The penalty for when the first signal is red (and it is an exit or combo signal) */
 	uint32 npf_rail_lastred_penalty; /* The penalty for when the last signal is red */
 	uint32 npf_rail_station_penalty; /* The penalty for station tiles */
 	uint32 npf_rail_slope_penalty; /* The penalty for sloping upwards */