Import town bridges over rails patch

Add setting (default off)

From: https://www.tt-forums.net/viewtopic.php?f=33t=76052

src/lang/english.txt

@@ -1740,6 +1740,8 @@ STR_CONFIG_SETTING_RANDOM_ROAD_RECONSTRUCTION                   :Probability of
 STR_CONFIG_SETTING_RANDOM_ROAD_RECONSTRUCTION_HELPTEXT          :The probability of town roads being randomly re-constructing (0 = off, 1000 = max)
 STR_CONFIG_SETTING_TOWN_MIN_DISTANCE                            :Minimum distance between towns: {STRING2}
 STR_CONFIG_SETTING_TOWN_MIN_DISTANCE_HELPTEXT                   :Set the minimum distance in tiles between towns for map generation and random founding
+STR_CONFIG_SETTING_TOWN_ROAD_OVER_RAIL                          :Towns can build bridges over rails: {STRING2}
+STR_CONFIG_SETTING_TOWN_ROAD_OVER_RAIL_HELPTEXT                 :Allow towns to build road bridges over railway tracks
 
 STR_CONFIG_SETTING_LINKGRAPH_INTERVAL                           :Update distribution graph every {STRING2}{NBSP}day{P 0:2 "" s}
 STR_CONFIG_SETTING_LINKGRAPH_INTERVAL_HELPTEXT                  :Time between subsequent recalculations of the link graph. Each recalculation calculates the plans for one component of the graph. That means that a value X for this setting does not mean the whole graph will be updated every X days. Only some component will. The shorter you set it the more CPU time will be necessary to calculate it. The longer you set it the longer it will take until the cargo distribution starts on new routes.

src/settings_gui.cpp

@@ -1776,6 +1776,7 @@ static SettingsContainer &GetSettingsTree()
 				towns->Add(new SettingEntry("economy.found_town"));
 				towns->Add(new SettingEntry("economy.town_cargo_scale_factor"));
 				towns->Add(new SettingEntry("economy.random_road_reconstruction"));
+				towns->Add(new SettingEntry("economy.town_bridge_over_rail"));
 			}
 
 			SettingsPage *industries = environment->Add(new SettingsPage(STR_CONFIG_SETTING_ENVIRONMENT_INDUSTRIES));

src/settings_type.h

@@ -557,6 +557,7 @@ struct EconomySettings {
 	bool   infrastructure_maintenance;       ///< enable monthly maintenance fee for owner infrastructure
 	uint8  day_length_factor;                ///< factor which the length of day is multiplied
 	uint16 random_road_reconstruction;       ///< chance out of 1000 per tile loop for towns to start random road re-construction
+	bool   town_bridge_over_rail;            ///< enable towns to build bridges over rails
 };
 
 struct LinkGraphSettings {

src/table/settings.ini

@@ -2110,6 +2110,15 @@ strval   = STR_JUST_COMMA
 cat      = SC_BASIC
 patxname = ""economy.random_road_reconstruction""
 
+[SDT_BOOL]
+base     = GameSettings
+var      = economy.town_bridge_over_rail
+def      = false
+str      = STR_CONFIG_SETTING_TOWN_ROAD_OVER_RAIL
+strhelp  = STR_CONFIG_SETTING_TOWN_ROAD_OVER_RAIL_HELPTEXT
+cat      = SC_BASIC
+patxname = ""economy.town_bridge_over_rail""
+
 ##
 [SDT_VAR]
 base     = GameSettings

src/town_cmd.cpp

@@ -1242,14 +1242,14 @@ static bool GrowTownWithBridge(const Town *t, const TileIndex tile, const DiagDi
 	const int delta = TileOffsByDiagDir(bridge_dir);
 
 	if (slope == SLOPE_FLAT) {
-		/* Bridges starting on flat tiles are only allowed when crossing rivers. */
+		/* Bridges starting on flat tiles are only allowed when crossing rivers or rails. */
 		do {
 			if (bridge_length++ >= 4) {
-				/* Allow to cross rivers, not big lakes. */
+				/* Allow to cross rivers, not big lakes, nor large amounts of rails. */
 				return false;
 			}
 			bridge_tile += delta;
-		} while (IsValidTile(bridge_tile) && IsWaterTile(bridge_tile) && !IsSea(bridge_tile));
+		} while (IsValidTile(bridge_tile) && ((IsWaterTile(bridge_tile) && !IsSea(bridge_tile)) || (_settings_game.economy.town_bridge_over_rail && IsPlainRailTile(bridge_tile))));
 	} else {
 		do {
 			if (bridge_length++ >= 11) {
@@ -1257,7 +1257,7 @@ static bool GrowTownWithBridge(const Town *t, const TileIndex tile, const DiagDi
 				return false;
 			}
 			bridge_tile += delta;
-		} while (IsValidTile(bridge_tile) && IsWaterTile(bridge_tile));
+		} while (IsValidTile(bridge_tile) && (IsWaterTile(bridge_tile) || (_settings_game.economy.town_bridge_over_rail && IsPlainRailTile(bridge_tile))));
 	}
 
 	/* no water tiles in between? */