(svn r8455) -Codechange: Give a more meaningful name (railveh_type)to member flags of RailVehInfo, as well as changing the code to reflect the fact that it was not a flag but rather a one value only variable. Doing so, some evaluations have been simplified.

-Codechange: Add and use RAILVEH_SINGLEHEAD when railveh_type is set to 0, which was implicit before.
-Cleanup: Remove some extraneous parenthesis.

src/engine.h

@@ -9,9 +9,15 @@
 #include "rail.h"
 #include "sound.h"
 
+enum RailVehicleTypes {
+	RAILVEH_SINGLEHEAD,
+	RAILVEH_MULTIHEAD,
+	RAILVEH_WAGON,
+};
+
 typedef struct RailVehicleInfo {
 	byte image_index;
-	byte flags; /* 1=multihead engine, 2=wagon */
+	RailVehicleTypes railveh_type;
 	byte base_cost;
 	RailTypeByte railtype;
 	uint16 max_speed;
@@ -117,11 +123,6 @@ enum {
 	EF_RAIL_IS_MU = 2, ///< Rail vehicle is a multiple-unit (DMU/EMU)
 };
 
-enum {
-	RVI_MULTIHEAD = 1,
-	RVI_WAGON = 2,
-};
-
 enum {
 	NUM_VEHICLE_TYPES = 6
 };