Change: add an on/off parameter for 'Build some vehicles reversed'

src/lang/english.toml

@@ -72,6 +72,12 @@ base = "Wagon colour fading"
 [STR_PARAM_WAGON_COLOUR_RANDOMISATION_STRATEGY_DESC]
 base = "Faded freight wagon colours add variety to trains (random chance each wagon is faded)."
 
+[STR_PARAM_VEHICLE_RANDOM_REVERSE_ON_BUILD]
+base = "Build some vehicles reversed"
+
+[STR_PARAM_VEHICLE_RANDOM_REVERSE_ON_BUILD_DESC]
+base = "Iron Horse will randomly build some vehicles as reversed, for example steam tank engines or diesel engines that have cabs at both ends.  This feature can be turned off with this parameter setting."
+
 [STR_ERROR_INFLATION_INCOMPATIBLE]
 base = "Iron Horse is not compatible with OpenTTD Inflation. Please turn Inflation off in OpenTTD settings."
 # substrings of the grf name _could_ be used here

src/templates/header.pynml

@@ -63,8 +63,15 @@ grf {
             };
         }
     }
-    <!--! param 3 deleted -->
-    <!--! param 4 deleted -->
+	param 1 {
+        param_vehicle_random_reverse_on_build {
+            name: string(STR_PARAM_VEHICLE_RANDOM_REVERSE_ON_BUILD);
+            desc: string(STR_PARAM_VEHICLE_RANDOM_REVERSE_ON_BUILD_DESC);
+			type: bool;
+			def_value: 1;
+			bit: 1;
+        }
+	}
 	param 5 {
         param_wagon_colour_randomisation {
             name: string(STR_PARAM_WAGON_COLOUR_RANDOMISATION);

src/templates/properties.pynml

@@ -155,8 +155,8 @@
                 create_effect:      ${vehicle.id}_switch_create_effect_check_railtype;
             </tal:create_effect>
             <tal:random_reverse_on_build condition="consist.random_reverse">
-                <!--! 50% chance of being reversed when built, if this property is set -->
-                reverse_build_probability:  return 50;
+                <!--! 50% chance of being reversed when built, if this property is set (player bool parameter can turn this off) -->
+                reverse_build_probability: return 50 * param_vehicle_random_reverse_on_build;
             </tal:random_reverse_on_build>
         }
     }