Road stops: Add inferred one way road state to var 50/roadstop_misc_info

docs/newgrf-roadstops-nml.html

@@ -142,6 +142,7 @@
 		<tr><td>random_bits</td><td>0..16777215</td><td>All random bits</td></tr>
 		<tr><td>random_bits_tile</td><td>0..255</td><td>Random bits (per tile), see also <a href="https://newgrf-specs.tt-wiki.net/wiki/NML:Stations#Base_station_variables">random_bits_station</a></td></tr>
 		<tr><td>one_way_info</td><td>RST_OWI_XXX</td><td>One-way road information of drive-through stop tile<br />XXX = TWO_WAY | WEST_BOUND | EAST_BOUND | NO_ENTRY</td></tr>
+		<tr><td>one_way_info_inferred</td><td>RST_OWI_XXX</td><td>Inferred one-way road information of drive-through stop tile<br />XXX = TWO_WAY | WEST_BOUND | EAST_BOUND | NO_ENTRY</td></tr>
 	</table>
 	<br />
 	Variables that require one or more parameters:

docs/newgrf-roadstops.html

@@ -309,6 +309,14 @@
 		2 - East-bound only<br />
 		3 - No entry
 	</td></tr>
+	<tr><td>2 - 3</td><td>
+		Inferred one-way road information, from examining the road layout:<br />
+		0 - Two-way traffic<br />
+		1 - West-bound only<br />
+		2 - East-bound only<br />
+		3 - No entry<br />
+		This requires <font face="monospace">road_stops</font>, version 8.
+	</td></tr>
 	</table>
 	<br />
 	The remaining bits are reserved for future use and should be masked.

src/newgrf_extension.cpp

@@ -58,7 +58,7 @@ extern const GRFFeatureInfo _grf_feature_list[] = {
 	GRFFeatureInfo("action0_object_edge_foundation_mode", 2),
 	GRFFeatureInfo("action0_object_flood_resistant", 1),
 	GRFFeatureInfo("action0_object_viewport_map_tile_type", 1),
-	GRFFeatureInfo("road_stops", 7),
+	GRFFeatureInfo("road_stops", 8),
 	GRFFeatureInfo("new_landscape", 2),
 	GRFFeatureInfo("more_objects_per_grf", 1, GFTOF_MORE_OBJECTS_PER_GRF),
 	GRFFeatureInfo("more_action2_ids", 1, GFTOF_MORE_ACTION2_IDS),

src/newgrf_roadstop.cpp

@@ -159,7 +159,11 @@ uint32 RoadStopScopeResolver::GetVariable(uint16 variable, uint32 parameter, Get
 		case 0x50: {
 			uint32 result = 0;
 			if (this->tile != INVALID_TILE) {
-				if (IsDriveThroughStopTile(this->tile)) result |= GetDriveThroughStopDisallowedRoadDirections(this->tile);
+				if (IsDriveThroughStopTile(this->tile)) {
+					result |= GetDriveThroughStopDisallowedRoadDirections(this->tile);
+					RoadCachedOneWayState rcows = GetRoadCachedOneWayState(this->tile);
+					if (rcows <= RCOWS_NO_ACCESS) result |= (rcows << 2);
+				}
 			}
 			return result;
 		}

src/road_cmd.cpp

@@ -259,9 +259,21 @@ static btree::btree_set<TileIndex> _road_cache_one_way_state_pending_interpolate
 static bool _defer_update_road_cache_one_way_state = false;
 bool _mark_tile_dirty_on_road_cache_one_way_state_update = false;
 
+static void RefreshTileOnCachedOneWayStateChange(TileIndex tile)
+{
+	if (IsAnyRoadStopTile(tile) && IsCustomRoadStopSpecIndex(tile)) {
+		MarkTileGroundDirtyByTile(tile, VMDF_NOT_MAP_MODE);
+		return;
+	}
+	if (unlikely(_mark_tile_dirty_on_road_cache_one_way_state_update)) {
+		MarkTileGroundDirtyByTile(tile, VMDF_NOT_MAP_MODE);
+		return;
+	}
+}
+
 static void UpdateTileRoadCachedOneWayState(TileIndex tile)
 {
-	if (unlikely(_mark_tile_dirty_on_road_cache_one_way_state_update)) MarkTileGroundDirtyByTile(tile, VMDF_NOT_MAP_MODE);
+	RefreshTileOnCachedOneWayStateChange(tile);
 
 	DisallowedRoadDirections drd = GetOneWayRoadTileDisallowedRoadDirections(tile);
 	if (drd != DRD_NONE) {
@@ -364,7 +376,7 @@ static void InterpolateRoadFollowRoadBitSetState(TileIndex tile, uint8 bit, Inte
 			SetRoadCachedOneWayState(tile, (RoadCachedOneWayState)(irr ^ (HasBit(bits_to_rcows, (inbit << 2) | bit) ? 0 : 3)));
 		}
 		_road_cache_one_way_state_pending_interpolate_tiles.erase(tile);
-		if (unlikely(_mark_tile_dirty_on_road_cache_one_way_state_update)) MarkTileGroundDirtyByTile(tile, VMDF_NOT_MAP_MODE);
+		RefreshTileOnCachedOneWayStateChange(tile);
 		TileIndex next = InterpolateRoadFollowTileStep(tile, bit);
 		if (next == INVALID_TILE) return;
 		DisallowedRoadDirections drd = GetOneWayRoadTileDisallowedRoadDirections(next);