(svn r11961) -Feature[newGRF]: Add support for Action 0D, var 13: informations about current map size.

src/map_func.h

@@ -56,6 +56,17 @@ static inline uint MapLogX()
 	return _map_log_x;
 }
 
+/**
+ * Logarithm of the map size along the y side.
+ * @note try to avoid using this one
+ * @return 2^"return value" == MapSizeY()
+ */
+static inline uint MapLogY()
+{
+	extern uint _map_log_y;
+	return _map_log_y;
+}
+
 /**
  * Get the size of the map along the X
  * @return the number of tiles along the X of the map