Merge branch 'tracerestrict-sx' into jgrpp

Conflicts:
	src/gfxinit.cpp
	src/rail_cmd.cpp
	src/table/sprites.h

src/gfxinit.cpp

@@ -179,6 +179,9 @@ static void LoadSpriteTables()
 	/* Progsignal sprites. */
 	LoadGrfFile("progsignals.grf", SPR_PROGSIGNAL_BASE, i++);
 
+	/* Tracerestrict sprites. */
+	LoadGrfFile("tracerestrict.grf", SPR_TRACERESTRICT_BASE, i++);
+
 	/*
 	 * The second basic file always starts at the given location and does
 	 * contain a different amount of sprites depending on the "type"; DOS

src/rail_cmd.cpp

@@ -1962,6 +1962,7 @@ static void DrawSingleSignal(TileIndex tile, const RailtypeInfo *rti, Track trac
 	SignalVariant variant = GetSignalVariant(tile, track);
 
 	SpriteID sprite = GetCustomSignalSprite(rti, tile, type, variant, condition);
+	bool is_custom_sprite = (sprite != 0);
 	if (sprite != 0) {
 		sprite += image;
 	} else {
@@ -1972,11 +1973,26 @@ static void DrawSingleSignal(TileIndex tile, const RailtypeInfo *rti, Track trac
 
 	if (type == SIGTYPE_PROG && variant == SIG_SEMAPHORE) {
 		sprite = SPR_PROGSIGNAL_BASE + image * 2 + condition;
+		is_custom_sprite = false;
 	} else if (type == SIGTYPE_PROG && variant == SIG_ELECTRIC) {
 		sprite = SPR_PROGSIGNAL_BASE + 16 + image * 2 + condition;
+		is_custom_sprite = false;
 	}
+
+	if (!is_custom_sprite && variant == SIG_ELECTRIC && IsRestrictedSignal(tile) && GetExistingTraceRestrictProgram(tile, track) != NULL) {
+		if (type == SIGTYPE_PBS || type == SIGTYPE_PBS_ONEWAY) {
+			static const SubSprite lower_part { -50, -10, 50, 50 };
+			static const SubSprite upper_part { -50, -50, 50, -11 };
+
+			AddSortableSpriteToDraw(sprite, SPR_TRACERESTRICT_BASE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track), false, 0, 0, 0, &lower_part);
+			AddSortableSpriteToDraw(sprite,               PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track), false, 0, 0, 0, &upper_part);
+		} else {
+			AddSortableSpriteToDraw(sprite, SPR_TRACERESTRICT_BASE + 1, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track));
+		}
+	} else {
 		AddSortableSpriteToDraw(sprite, PAL_NONE, x, y, 1, 1, BB_HEIGHT_UNDER_BRIDGE, GetSaveSlopeZ(x, y, track));
 	}
+}
 
 static uint32 _drawtile_track_palette;
 

src/table/sprites.h

@@ -318,8 +318,12 @@ static const SpriteID SPR_ZONING_INNER_HIGHLIGHT_LIGHT_BLUE = SPR_ZONING_INNER_H
 static const SpriteID SPR_ZONING_INNER_HIGHLIGHT_ORANGE     = SPR_ZONING_INNER_HIGHLIGHT_BASE + 23;
 static const SpriteID SPR_ZONING_INNER_HIGHLIGHT_WHITE      = SPR_ZONING_INNER_HIGHLIGHT_BASE + 24;
 
+/* Tracerestrict sprites */
+static const SpriteID SPR_TRACERESTRICT_BASE = SPR_ZONING_INNER_HIGHLIGHT_BASE + ZONING_INNER_HIGHLIGHT_SPRITE_COUNT;
+static const uint16 TRACERESTRICT_SPRITE_COUNT = 2;
+
 /* From where can we start putting NewGRFs? */
-static const SpriteID SPR_NEWGRFS_BASE = SPR_ZONING_INNER_HIGHLIGHT_BASE + ZONING_INNER_HIGHLIGHT_SPRITE_COUNT;
+static const SpriteID SPR_NEWGRFS_BASE = SPR_TRACERESTRICT_BASE + TRACERESTRICT_SPRITE_COUNT;
 
 /* Manager face sprites */
 static const SpriteID SPR_GRADIENT = 874; // background gradient behind manager face

src/tracerestrict.cpp

@@ -49,11 +49,10 @@
  * This is not done for shared programs as this would delete the shared aspect whenever
  * the program became empty.
  *
- * Empty programs with a refcount of 1 may still exist due to the edge case where:
- * 1: There is an empty program with refcount 2
- * 2: One of the two mappings is deleted
- * Finding the other mapping would entail a linear search of the mappings, and there is little
- * to be gained by doing so.
+ * Special case: In the case where an empty program with refcount 2 has one of its
+ * mappings removed, the other mapping is left pointing to an empty unshared program.
+ * This other mapping is then removed by performing a linear search of the mappings,
+ * and removing the reference to that program ID.
  */
 
 TraceRestrictProgramPool _tracerestrictprogram_pool("TraceRestrictProgram");
@@ -604,7 +603,13 @@ void TraceRestrictRemoveProgramMapping(TraceRestrictRefId ref)
 	TraceRestrictMapping::iterator iter = _tracerestrictprogram_mapping.find(ref);
 	if (iter != _tracerestrictprogram_mapping.end()) {
 		// Found
-		_tracerestrictprogram_pool.Get(iter->second.program_id)->DecrementRefCount();
+		TraceRestrictProgram *prog = _tracerestrictprogram_pool.Get(iter->second.program_id);
+
+		// check to see if another mapping needs to be removed as well
+		// do this before decrementing the refcount
+		bool remove_other_mapping = prog->refcount == 2 && prog->items.empty();
+
+		prog->DecrementRefCount();
 		_tracerestrictprogram_mapping.erase(iter);
 
 		TileIndex tile = GetTraceRestrictRefIdTileIndex(ref);
@@ -612,6 +617,17 @@ void TraceRestrictRemoveProgramMapping(TraceRestrictRefId ref)
 		SetIsSignalRestrictedBit(tile);
 		MarkTileDirtyByTile(tile);
 		YapfNotifyTrackLayoutChange(tile, track);
+
+		if (remove_other_mapping) {
+			TraceRestrictProgramID id = prog->index;
+			for (TraceRestrictMapping::iterator rm_iter = _tracerestrictprogram_mapping.begin();
+					rm_iter != _tracerestrictprogram_mapping.end(); ++rm_iter) {
+				if (rm_iter->second.program_id == id) {
+					TraceRestrictRemoveProgramMapping(rm_iter->first);
+					break;
+				}
+			}
+		}
 	}
 }