(svn r21932) -Document: some tidbits related to vehicles

1 files changed, 43 insertions, 27 deletions

diff --git a/src/vehicle_base.h b/src/vehicle_base.h
index c5290e770..623f534fb 100644
--- a/src/vehicle_base.h
+++ b/src/vehicle_base.h
@@ -156,27 +156,29 @@ public:
 	int32 lateness_counter;             ///< How many ticks late (or early if negative) this vehicle is.
 	Date timetable_start;               ///< When the vehicle is supposed to start the timetable.
 
-	/* Boundaries for the current position in the world and a next hash link.
-	 * NOSAVE: All of those can be updated with VehiclePositionChanged() */
-	Rect coord;
-	Vehicle *next_hash, **prev_hash;
-	Vehicle *next_new_hash, **prev_new_hash;
-	Vehicle **old_new_hash;
+	Rect coord;                         ///< NOSAVE: Graphical bounding box of the vehicle, i.e. what to redraw on moves.
+
+	Vehicle *next_hash;                 ///< NOSAVE: Next vehicle in the visual location hash.
+	Vehicle **prev_hash;                ///< NOSAVE: Previous vehicle in the visual location hash.
+
+	Vehicle *next_new_hash;             ///< NOSAVE: Next vehicle in the tile location hash.
+	Vehicle **prev_new_hash;            ///< NOSAVE: Previous vehicle in the tile location hash.
+	Vehicle **old_new_hash;             ///< NOSAVE: Cache of the current hash chain.
 
 	SpriteID colourmap;                 ///< NOSAVE: cached colour mapping
 
 	/* Related to age and service time */
-	Year build_year;
+	Year build_year;                    ///< Year the vehicle has been built.
 	Date age;                           ///< Age in days
 	Date max_age;                       ///< Maximum age
-	Date date_of_last_service;
-	Date service_interval;
+	Date date_of_last_service;          ///< Last date the vehicle had a service at a depot.
+	Date service_interval;              ///< The interval for (automatic) servicing; either in days or %.
 	uint16 reliability;                 ///< Reliability.
 	uint16 reliability_spd_dec;         ///< Reliability decrease speed.
 	byte breakdown_ctr;                 ///< Counter for managing breakdown events. @see Vehicle::HandleBreakdown
 	byte breakdown_delay;               ///< Counter for managing breakdown length.
-	byte breakdowns_since_last_service;
-	byte breakdown_chance;
+	byte breakdowns_since_last_service; ///< Counter for the amount of breakdowns.
+	byte breakdown_chance;              ///< Current chance of breakdowns.
 
 	int32 x_pos;                        ///< x coordinate.
 	int32 y_pos;                        ///< y coordinate.
@@ -193,7 +195,7 @@ public:
 	byte z_extent;                      ///< z-extent of vehicle bounding box
 	int8 x_offs;                        ///< x offset for vehicle sprite
 	int8 y_offs;                        ///< y offset for vehicle sprite
-	EngineID engine_type;
+	EngineID engine_type;               ///< The type of engine used for this vehicle.
 
 	TextEffectID fill_percent_te_id;    ///< a text-effect id to a loading indicator object
 	UnitID unitnumber;                  ///< unit number, for display purposes only
@@ -201,16 +203,13 @@ public:
 	uint16 cur_speed;                   ///< current speed
 	byte subspeed;                      ///< fractional speed
 	byte acceleration;                  ///< used by train & aircraft
-	uint32 motion_counter;
-	byte progress;
+	uint32 motion_counter;              ///< counter to occasionally play a vehicle sound.
+	byte progress;                      ///< The percentage (if divided by 256) this vehicle already crossed the tile unit.
 
-	/* for randomized variational spritegroups
-	 * bitmask used to resolve them; parts of it get reseeded when triggers
-	 * of corresponding spritegroups get matched */
-	byte random_bits;
-	byte waiting_triggers;              ///< triggers to be yet matched
+	byte random_bits;                   ///< Bits used for determining which randomized variational spritegroups to use when drawing.
+	byte waiting_triggers;              ///< Triggers to be yet matched before rerandomizing the random bits.
 
-	StationID last_station_visited;
+	StationID last_station_visited;     ///< The last station we stopped at.
 
 	CargoID cargo_type;                 ///< type of cargo this vehicle is carrying
 	byte cargo_subtype;                 ///< Used for livery refits (NewGRF variations)
@@ -228,15 +227,12 @@ public:
 	union {
 		OrderList *list;            ///< Pointer to the order list for this vehicle
 		Order     *old;             ///< Only used during conversion of old save games
-	} orders;
+	} orders;                           ///< The orders currently assigned to the vehicle.
 
 	byte vehicle_flags;                 ///< Used for gradual loading and other miscellaneous things (@see VehicleFlags enum)
 
-	/** Ticks to wait before starting next cycle. */
-	uint16 load_unload_ticks;
-
+	uint16 load_unload_ticks;	          ///< Ticks to wait before starting next cycle.
 	GroupID group_id;                   ///< Index of group Pool array
-
 	byte subtype;                       ///< subtype (Filled with values from #EffectVehicles/#TrainSubTypes/#AircraftSubTypes)
 
 	NewGRFCache grf_cache;              ///< Cache of often used calculated NewGRF values
@@ -736,7 +732,17 @@ public:
 	}
 };
 
+/**
+ * Iterate over all vehicles from a given point.
+ * @param var   The variable used to iterate over.
+ * @param start The vehicle to start the iteration at.
+ */
 #define FOR_ALL_VEHICLES_FROM(var, start) FOR_ALL_ITEMS_FROM(Vehicle, vehicle_index, var, start)
+
+/**
+ * Iterate over all vehicles.
+ * @param var The variable used to iterate over.
+ */
 #define FOR_ALL_VEHICLES(var) FOR_ALL_VEHICLES_FROM(var, 0)
 
 /**
@@ -896,14 +902,19 @@ struct SpecializedVehicle : public Vehicle {
 	}
 };
 
+/**
+ * Iterate over all vehicles of a particular type.
+ * @param name The type of vehicle to iterate over.
+ * @param var  The variable used to iterate over.
+ */
 #define FOR_ALL_VEHICLES_OF_TYPE(name, var) FOR_ALL_ITEMS_FROM(name, vehicle_index, var, 0) if (var->type == name::EXPECTED_TYPE)
 
 /**
  * Disasters, like submarines, skyrangers and their shadows, belong to this class.
  */
 struct DisasterVehicle : public SpecializedVehicle<DisasterVehicle, VEH_DISASTER> {
-	uint16 image_override;
-	VehicleID big_ufo_destroyer_target;
+	SpriteID image_override;            ///< Override for the default disaster vehicle sprite.
+	VehicleID big_ufo_destroyer_target; ///< The big UFO that this destroyer is supposed to bomb.
 
 	/** We don't want GCC to zero our struct! It already is zeroed and has an index! */
 	DisasterVehicle() : SpecializedVehicleBase() {}
@@ -914,6 +925,10 @@ struct DisasterVehicle : public SpecializedVehicle<DisasterVehicle, VEH_DISASTER
 	bool Tick();
 };
 
+/**
+ * Iterate over disaster vehicles.
+ * @param var The variable used to iterate over.
+ */
 #define FOR_ALL_DISASTERVEHICLES(var) FOR_ALL_VEHICLES_OF_TYPE(DisasterVehicle, var)
 
 /** Generates sequence of free UnitID numbers */
@@ -929,6 +944,7 @@ struct FreeUnitIDGenerator {
 	~FreeUnitIDGenerator() { free(this->cache); }
 };
 
+/** Sentinel for an invalid coordinate. */
 static const int32 INVALID_COORD = 0x7fffffff;
 
 #endif /* VEHICLE_BASE_H */