openttd-ottdgrfs: comparison src/rail.h

equal deleted inserted replaced

-:1337d6c9b97b
+:cabfaa4a0295
 #include "gfx.h"
 #include "direction.h"
 #include "tile.h"
+/**
+* Enumeration for all possible railtypes.
+*
+* This enumeration defines all 4 possible railtypes.
+*/
 enum RailType {
-	RAILTYPE_BEGIN    = 0,
+	RAILTYPE_BEGIN    = 0,          ///< Used for iterations
-	RAILTYPE_RAIL     = 0,
+	RAILTYPE_RAIL     = 0,          ///< Standard non-electric rails
-	RAILTYPE_ELECTRIC = 1,
+	RAILTYPE_ELECTRIC = 1,          ///< Electric rails
-	RAILTYPE_MONO     = 2,
+	RAILTYPE_MONO     = 2,          ///< Monorail
-	RAILTYPE_MAGLEV   = 3,
+	RAILTYPE_MAGLEV   = 3,          ///< Maglev
-	RAILTYPE_END,
+	RAILTYPE_END,                   ///< Used for iterations
-	INVALID_RAILTYPE  = 0xFF
+	INVALID_RAILTYPE  = 0xFF        ///< Flag for invalid railtype
 };
 typedef byte RailTypeMask;
 /** Allow incrementing of Track variables */
 /** Define basic enum properties */
 template <> struct EnumPropsT<RailType> : MakeEnumPropsT<RailType, byte, RAILTYPE_BEGIN, RAILTYPE_END, INVALID_RAILTYPE> {};
 typedef TinyEnumT<RailType> RailTypeByte;
-/** These are used to specify a single track.
+/**
-* Can be translated to a trackbit with TrackToTrackbit */
+* These are used to specify a single track.
+* Can be translated to a trackbit with TrackToTrackbit
+*/
 enum Track {
-	TRACK_BEGIN = 0,
+	TRACK_BEGIN = 0,        ///< Used for iterations
-	TRACK_X     = 0,
+	TRACK_X     = 0,        ///< Track along the x-axis (north-east to south-west)
-	TRACK_Y     = 1,
+	TRACK_Y     = 1,        ///< Track along the y-axis (north-west to south-east)
-	TRACK_UPPER = 2,
+	TRACK_UPPER = 2,        ///< Track in the upper corner of the tile (north)
-	TRACK_LOWER = 3,
+	TRACK_LOWER = 3,        ///< Track in the lower corner of the tile (south)
-	TRACK_LEFT  = 4,
+	TRACK_LEFT  = 4,        ///< Track in the left corner of the tile (west)
-	TRACK_RIGHT = 5,
+	TRACK_RIGHT = 5,        ///< Track in the right corner of the tile (east)
-	TRACK_END,
+	TRACK_END,              ///< Used for iterations
-	INVALID_TRACK = 0xFF
+	INVALID_TRACK = 0xFF    ///< Flag for an invalid track
 };
 /** Allow incrementing of Track variables */
 DECLARE_POSTFIX_INCREMENT(Track);
 /** Define basic enum properties */
 template <> struct EnumPropsT<Track> : MakeEnumPropsT<Track, byte, TRACK_BEGIN, TRACK_END, INVALID_TRACK> {};
 typedef TinyEnumT<Track> TrackByte;
-/** Convert an Axis to the corresponding Track
+/**
+* Convert an Axis to the corresponding Track
 * AXIS_X -> TRACK_X
 * AXIS_Y -> TRACK_Y
 * Uses the fact that they share the same internal encoding
+*
+* @param a the axis to convert
+* @return the track corresponding to the axis
 */
 static inline Track AxisToTrack(Axis a)
 {
 	return (Track)a;
 }
 /** Bitfield corresponding to Track */
 enum TrackBits {
-	TRACK_BIT_NONE    = 0U,
+	TRACK_BIT_NONE    = 0U,                                                 ///< No track
-	TRACK_BIT_X       = 1U << TRACK_X,
+	TRACK_BIT_X       = 1U << TRACK_X,                                      ///< X-axis track
-	TRACK_BIT_Y       = 1U << TRACK_Y,
+	TRACK_BIT_Y       = 1U << TRACK_Y,                                      ///< Y-axis track
-	TRACK_BIT_UPPER   = 1U << TRACK_UPPER,
+	TRACK_BIT_UPPER   = 1U << TRACK_UPPER,                                  ///< Upper track
-	TRACK_BIT_LOWER   = 1U << TRACK_LOWER,
+	TRACK_BIT_LOWER   = 1U << TRACK_LOWER,                                  ///< Lower track
-	TRACK_BIT_LEFT    = 1U << TRACK_LEFT,
+	TRACK_BIT_LEFT    = 1U << TRACK_LEFT,                                   ///< Left track
-	TRACK_BIT_RIGHT   = 1U << TRACK_RIGHT,
+	TRACK_BIT_RIGHT   = 1U << TRACK_RIGHT,                                  ///< Right track
-	TRACK_BIT_CROSS   = TRACK_BIT_X     | TRACK_BIT_Y,
+	TRACK_BIT_CROSS   = TRACK_BIT_X     | TRACK_BIT_Y,                      ///< X-Y-axis cross
-	TRACK_BIT_HORZ    = TRACK_BIT_UPPER | TRACK_BIT_LOWER,
+	TRACK_BIT_HORZ    = TRACK_BIT_UPPER | TRACK_BIT_LOWER,                  ///< Upper and lower track
-	TRACK_BIT_VERT    = TRACK_BIT_LEFT  | TRACK_BIT_RIGHT,
+	TRACK_BIT_VERT    = TRACK_BIT_LEFT  | TRACK_BIT_RIGHT,                  ///< Left and right track
-	TRACK_BIT_3WAY_NE = TRACK_BIT_X     | TRACK_BIT_UPPER | TRACK_BIT_RIGHT,
+	TRACK_BIT_3WAY_NE = TRACK_BIT_X     | TRACK_BIT_UPPER | TRACK_BIT_RIGHT,///< "Arrow" to the north-east
-	TRACK_BIT_3WAY_SE = TRACK_BIT_Y     | TRACK_BIT_LOWER | TRACK_BIT_RIGHT,
+	TRACK_BIT_3WAY_SE = TRACK_BIT_Y     | TRACK_BIT_LOWER | TRACK_BIT_RIGHT,///< "Arrow" to the south-east
-	TRACK_BIT_3WAY_SW = TRACK_BIT_X     | TRACK_BIT_LOWER | TRACK_BIT_LEFT,
+	TRACK_BIT_3WAY_SW = TRACK_BIT_X     | TRACK_BIT_LOWER | TRACK_BIT_LEFT, ///< "Arrow" to the south-west
-	TRACK_BIT_3WAY_NW = TRACK_BIT_Y     | TRACK_BIT_UPPER | TRACK_BIT_LEFT,
+	TRACK_BIT_3WAY_NW = TRACK_BIT_Y     | TRACK_BIT_UPPER | TRACK_BIT_LEFT, ///< "Arrow" to the north-west
-	TRACK_BIT_ALL     = TRACK_BIT_CROSS | TRACK_BIT_HORZ  | TRACK_BIT_VERT,
+	TRACK_BIT_ALL     = TRACK_BIT_CROSS | TRACK_BIT_HORZ  | TRACK_BIT_VERT, ///< All possible tracks
-	TRACK_BIT_MASK    = 0x3FU,
+	TRACK_BIT_MASK    = 0x3FU,                                              ///< Bitmask for the first 6 bits
-	TRACK_BIT_WORMHOLE = 0x40U,
+	TRACK_BIT_WORMHOLE = 0x40U,                                             ///< Bitflag for a wormhole (used for tunnels)
-	TRACK_BIT_DEPOT   = 0x80U,
+	TRACK_BIT_DEPOT   = 0x80U,                                              ///< Bitflag for a depot
-	INVALID_TRACK_BIT = 0xFF
+	INVALID_TRACK_BIT = 0xFF                                                ///< Flag for an invalid trackbits value
 };
 /** Define basic enum properties */
 template <> struct EnumPropsT<TrackBits> : MakeEnumPropsT<TrackBits, byte, TRACK_BIT_NONE, TRACK_BIT_ALL, INVALID_TRACK_BIT> {};
 typedef TinyEnumT<TrackBits> TrackBitsByte;
 DECLARE_ENUM_AS_BIT_SET(TrackBits);
 /**
 * Maps a Track to the corresponding TrackBits value
+* @param track the track to convert
+* @return the converted TrackBits value of the track
 */
 static inline TrackBits TrackToTrackBits(Track track)
 {
 	return (TrackBits)(1 << track);
 }
+/**
+* Maps an Axis to the corresponding TrackBits value
+* @param a the axis to convert
+* @return the converted TrackBits value of the axis
+*/
 static inline TrackBits AxisToTrackBits(Axis a)
 {
 	return TrackToTrackBits(AxisToTrack(a));
 }
-/** These are a combination of tracks and directions. Values are 0-5 in one
+/**
+* Enumeration for tracks and directions.
+*
+* These are a combination of tracks and directions. Values are 0-5 in one
 * direction (corresponding to the Track enum) and 8-13 in the other direction.
 * 6, 7, 14 and 15 are used to encode the reversing of road vehicles. Those
 * reversing track dirs are not considered to be 'valid' except in a small
 * corner in the road vehicle controller.
 */
 enum Trackdir {
-	TRACKDIR_BEGIN    =  0,
+	TRACKDIR_BEGIN    =  0,         ///< Used for iterations
-	TRACKDIR_X_NE     =  0,
+	TRACKDIR_X_NE     =  0,         ///< X-axis and direction to north-east
-	TRACKDIR_Y_SE     =  1,
+	TRACKDIR_Y_SE     =  1,         ///< Y-axis and direction to south-east
-	TRACKDIR_UPPER_E  =  2,
+	TRACKDIR_UPPER_E  =  2,         ///< Upper track and direction to east
-	TRACKDIR_LOWER_E  =  3,
+	TRACKDIR_LOWER_E  =  3,         ///< Lower track and direction to east
-	TRACKDIR_LEFT_S   =  4,
+	TRACKDIR_LEFT_S   =  4,         ///< Left track and direction to south
-	TRACKDIR_RIGHT_S  =  5,
+	TRACKDIR_RIGHT_S  =  5,         ///< Right track and direction to south
-	TRACKDIR_RVREV_NE =  6,
+	TRACKDIR_RVREV_NE =  6,         ///< (Road vehicle) reverse direction north-east
-	TRACKDIR_RVREV_SE =  7,
+	TRACKDIR_RVREV_SE =  7,         ///< (Road vehicle) reverse direction south-east
-	TRACKDIR_X_SW     =  8,
+	TRACKDIR_X_SW     =  8,         ///< X-axis and direction to south-west
-	TRACKDIR_Y_NW     =  9,
+	TRACKDIR_Y_NW     =  9,         ///< Y-axis and direction to north-west
-	TRACKDIR_UPPER_W  = 10,
+	TRACKDIR_UPPER_W  = 10,         ///< Upper track and direction to west
-	TRACKDIR_LOWER_W  = 11,
+	TRACKDIR_LOWER_W  = 11,         ///< Lower track and direction to west
-	TRACKDIR_LEFT_N   = 12,
+	TRACKDIR_LEFT_N   = 12,         ///< Left track and direction to north
-	TRACKDIR_RIGHT_N  = 13,
+	TRACKDIR_RIGHT_N  = 13,         ///< Right track and direction to north
-	TRACKDIR_RVREV_SW = 14,
+	TRACKDIR_RVREV_SW = 14,         ///< (Road vehicle) reverse direction south-west
-	TRACKDIR_RVREV_NW = 15,
+	TRACKDIR_RVREV_NW = 15,         ///< (Road vehicle) reverse direction north-west
-	TRACKDIR_END,
+	TRACKDIR_END,                   ///< Used for iterations
-	INVALID_TRACKDIR  = 0xFF,
+	INVALID_TRACKDIR  = 0xFF,       ///< Flag for an invalid trackdir
 };
 /** Define basic enum properties */
 template <> struct EnumPropsT<Trackdir> : MakeEnumPropsT<Trackdir, byte, TRACKDIR_BEGIN, TRACKDIR_END, INVALID_TRACKDIR> {};
 typedef TinyEnumT<Trackdir> TrackdirByte;
-/** These are a combination of tracks and directions. Values are 0-5 in one
+/**
-* direction (corresponding to the Track enum) and 8-13 in the other direction. */
+* Enumeration of bitmasks for the TrackDirs
+*
+* These are a combination of tracks and directions. Values are 0-5 in one
+* direction (corresponding to the Track enum) and 8-13 in the other direction.
+*/
 enum TrackdirBits {
-	TRACKDIR_BIT_NONE     = 0x0000,
+	TRACKDIR_BIT_NONE     = 0x0000, ///< No track build
-	TRACKDIR_BIT_X_NE     = 0x0001,
+	TRACKDIR_BIT_X_NE     = 0x0001, ///< Track x-axis, direction north-east
-	TRACKDIR_BIT_Y_SE     = 0x0002,
+	TRACKDIR_BIT_Y_SE     = 0x0002, ///< Track y-axis, direction south-east
-	TRACKDIR_BIT_UPPER_E  = 0x0004,
+	TRACKDIR_BIT_UPPER_E  = 0x0004, ///< Track upper, direction east
-	TRACKDIR_BIT_LOWER_E  = 0x0008,
+	TRACKDIR_BIT_LOWER_E  = 0x0008, ///< Track lower, direction east
-	TRACKDIR_BIT_LEFT_S   = 0x0010,
+	TRACKDIR_BIT_LEFT_S   = 0x0010, ///< Track left, direction south
-	TRACKDIR_BIT_RIGHT_S  = 0x0020,
+	TRACKDIR_BIT_RIGHT_S  = 0x0020, ///< Track right, direction south
 	/* Again, note the two missing values here. This enables trackdir -> track conversion by doing (trackdir & 0xFF) */
-	TRACKDIR_BIT_X_SW     = 0x0100,
+	TRACKDIR_BIT_X_SW     = 0x0100, ///< Track x-axis, direction south-west
-	TRACKDIR_BIT_Y_NW     = 0x0200,
+	TRACKDIR_BIT_Y_NW     = 0x0200, ///< Track y-axis, direction north-west
-	TRACKDIR_BIT_UPPER_W  = 0x0400,
+	TRACKDIR_BIT_UPPER_W  = 0x0400, ///< Track upper, direction west
-	TRACKDIR_BIT_LOWER_W  = 0x0800,
+	TRACKDIR_BIT_LOWER_W  = 0x0800, ///< Track lower, direction west
-	TRACKDIR_BIT_LEFT_N   = 0x1000,
+	TRACKDIR_BIT_LEFT_N   = 0x1000, ///< Track left, direction north
-	TRACKDIR_BIT_RIGHT_N  = 0x2000,
+	TRACKDIR_BIT_RIGHT_N  = 0x2000, ///< Track right, direction north
-	TRACKDIR_BIT_MASK     = 0x3F3F,
+	TRACKDIR_BIT_MASK     = 0x3F3F, ///< Bitmask for bit-operations
-	INVALID_TRACKDIR_BIT  = 0xFFFF,
+	INVALID_TRACKDIR_BIT  = 0xFFFF, ///< Flag for an invalid trackdirbit value
 };
 /** Define basic enum properties */
 template <> struct EnumPropsT<TrackdirBits> : MakeEnumPropsT<TrackdirBits, uint16, TRACKDIR_BIT_NONE, TRACKDIR_BIT_MASK, INVALID_TRACKDIR_BIT> {};
 typedef TinyEnumT<TrackdirBits> TrackdirBitsShort;
 		SpriteID build_tunnel;       ///< button for building a tunnel
 		SpriteID convert_rail;       ///< button for converting rail
 	} gui_sprites;
 	struct {
-		CursorID rail_ns;
+		CursorID rail_ns;    ///< Cursor for building rail in N-S direction
-		CursorID rail_swne;
+		CursorID rail_swne;  ///< Cursor for building rail in X direction
-		CursorID rail_ew;
+		CursorID rail_ew;    ///< Cursor for building rail in E-W direction
-		CursorID rail_nwse;
+		CursorID rail_nwse;  ///< Cursor for building rail in Y direction
-		CursorID autorail;
+		CursorID autorail;   ///< Cursor for autorail tool
-		CursorID depot;
+		CursorID depot;      ///< Cursor for building a depot
-		CursorID tunnel;
+		CursorID tunnel;     ///< Cursor for building a tunnel
-		CursorID convert;
+		CursorID convert;    ///< Cursor for converting track
 	} cursor;
 	struct {
 		StringID toolbar_caption;
 	} strings;
 	NUM_SSD_STACK =  32, ///< max amount of blocks to check recursively
 };
 /**
 * Maps a Trackdir to the corresponding TrackdirBits value
-*/
+* @param trackdir the track direction to convert
-static inline TrackdirBits TrackdirToTrackdirBits(Trackdir trackdir) { return (TrackdirBits)(1 << trackdir); }
+* @return the converted TrackdirBits value
+*/
-/**
+static inline TrackdirBits TrackdirToTrackdirBits(Trackdir trackdir)
-* Removes first Track from TrackBits and returns it
+{
-*/
+	return (TrackdirBits)(1 << trackdir);
+}
+/**
+* Removes first Track from TrackBits and returns it
+*
+* This function searchs for the first bit in the TrackBits,
+* remove this bit from the parameter and returns the found
+* bit as Track value. It returns INVALID_TRACK if the
+* parameter was TRACK_BIT_NONE or INVALID_TRACK_BIT. This
+* is basically used in while-loops to get up to 6 possible
+* tracks on a tile until the parameter becomes TRACK_BIT_NONE.
+*
+* @param tracks The value with the TrackBits
+* @return The first Track from the TrackBits value
+* @see FindFirstTrack
+*/
 static inline Track RemoveFirstTrack(TrackBits *tracks)
 {
 	if (*tracks != TRACK_BIT_NONE && *tracks != INVALID_TRACK_BIT) {
 		Track first = (Track)FIND_FIRST_BIT(*tracks);
 		ClrBitT(*tracks, first);
 	}
 	return INVALID_TRACK;
 }
 /**
 * Removes first Trackdir from TrackdirBits and returns it
-*/
+*
+* This function searchs for the first bit in the TrackdirBits parameter,
+* remove this bit from the parameter and returns the fnound bit as
+* Trackdir value. It returns INVALID_TRACKDIR if the trackdirs is
+* TRACKDIR_BIT_NONE or INVALID_TRACKDIR_BIT. This is basically used in a
+* while-loop to get all track-directions step by step until the value
+* reaches TRACKDIR_BIT_NONE.
+*
+* @param trackdirs The value with the TrackdirBits
+* @return The first Trackdir from the TrackdirBits value
+* @see FindFirstTrackdir
+*/
 static inline Trackdir RemoveFirstTrackdir(TrackdirBits *trackdirs)
 {
 	if (*trackdirs != TRACKDIR_BIT_NONE && *trackdirs != INVALID_TRACKDIR_BIT) {
 		Trackdir first = (Trackdir)FindFirstBit2x64(*trackdirs);
 		ClrBitT(*trackdirs, first);
 	}
 	return INVALID_TRACKDIR;
 }
 /**
 * Returns first Track from TrackBits or INVALID_TRACK
-*/
+*
+* This function returns the first Track found in the TrackBits value as Track-value.
+* It returns INVALID_TRACK if the parameter is TRACK_BIT_NONE or INVALID_TRACK_BIT.
+*
+* @param tracks The TrackBits value
+* @return The first Track found or INVALID_TRACK
+* @see RemoveFirstTrack
+*/
 static inline Track FindFirstTrack(TrackBits tracks)
 {
 	return (tracks != TRACK_BIT_NONE && tracks != INVALID_TRACK_BIT) ? (Track)FIND_FIRST_BIT(tracks) : INVALID_TRACK;
 }
 /**
-* Converts TrackBits to Track. TrackBits must contain just one Track or INVALID_TRACK_BIT!
+* Converts TrackBits to Track.
-*/
+*
+* This function converts a TrackBits value to a Track value. As it
+* is not possible to convert two or more tracks to one track the
+* parameter must contain only one track or be the INVALID_TRACK_BIT value.
+*
+* @param tracks The TrackBits value to convert
+* @return The Track from the value or INVALID_TRACK
+* @pre tracks must contains only one Track or be INVALID_TRACK_BIT
+*/
 static inline Track TrackBitsToTrack(TrackBits tracks)
 {
 	assert(tracks == INVALID_TRACK_BIT || (tracks != TRACK_BIT_NONE && KILL_FIRST_BIT(tracks & TRACK_BIT_MASK) == 0));
 	return tracks != INVALID_TRACK_BIT ? (Track)FIND_FIRST_BIT(tracks & TRACK_BIT_MASK) : INVALID_TRACK;
 }
 /**
 * Returns first Trackdir from TrackdirBits or INVALID_TRACKDIR
-*/
+*
+* This function returns the first Trackdir in the given TrackdirBits value or
+* INVALID_TRACKDIR if the value is TRACKDIR_BIT_NONE. The TrackdirBits must
+* not be INVALID_TRACKDIR_BIT.
+*
+* @param trackdirs The TrackdirBits value
+* @return The first Trackdir from the TrackdirBits or INVALID_TRACKDIR on TRACKDIR_BIT_NONE.
+* @pre trackdirs must not be INVALID_TRACKDIR_BIT
+* @see RemoveFirstTrackdir
+*/
 static inline Trackdir FindFirstTrackdir(TrackdirBits trackdirs)
 {
 	assert((trackdirs & ~TRACKDIR_BIT_MASK) == TRACKDIR_BIT_NONE);
 	return (trackdirs != TRACKDIR_BIT_NONE) ? (Trackdir)FindFirstBit2x64(trackdirs) : INVALID_TRACKDIR;
 }
 /**
-* These functions check the validity of Tracks and Trackdirs. assert against
+* Checks if a Track is valid.
-* them when convenient.
+*
-*/
+* @param track The value to check
-static inline bool IsValidTrack(Track track) { return track < TRACK_END; }
+* @return true if the given value is a valid track.
-static inline bool IsValidTrackdir(Trackdir trackdir) { return (TrackdirToTrackdirBits(trackdir) & TRACKDIR_BIT_MASK) != 0; }
+* @note Use this in an assert()
+*/
-/**
+static inline bool IsValidTrack(Track track)
+{
+	return track < TRACK_END;
+}
+/**
+* Checks if a Trackdir is valid.
+*
+* @param trackdir The value to check
+* @return true if the given valie is a valid Trackdir
+* @note Use this in an assert()
+*/
+static inline bool IsValidTrackdir(Trackdir trackdir)
+{
+	return (TrackdirToTrackdirBits(trackdir) & TRACKDIR_BIT_MASK) != 0;
+}
+/*
 * Functions to map tracks to the corresponding bits in the signal
 * presence/status bytes in the map. You should not use these directly, but
 * wrapper functions below instead. XXX: Which are these?
 */
 * TrackdirBits, Direction and DiagDirections.
 */
 /**
 * Maps a trackdir to the reverse trackdir.
+*
+* Returns the reverse trackdir of a Trackdir value. The reverse trackdir
+* is the same track with the other direction on it.
+*
+* @param trackdir The Trackdir value
+* @return The reverse trackdir
+* @pre trackdir must not be INVALID_TRACKDIR
 */
 static inline Trackdir ReverseTrackdir(Trackdir trackdir)
 {
 	assert(trackdir != INVALID_TRACKDIR);
 	return (Trackdir)(trackdir ^ 8);
 }
 /**
 * Returns the Track that a given Trackdir represents
-*/
+*
-static inline Track TrackdirToTrack(Trackdir trackdir) { return (Track)(trackdir & 0x7); }
+* This function filters the Track which is used in the Trackdir value and
+* returns it as a Track value.
-/**
+*
-* Returns a Trackdir for the given Track. Since every Track corresponds to
+* @param trackdir The trackdir value
-* two Trackdirs, we choose the one which points between NE and S.
+* @return The Track which is used in the value
-* Note that the actual implementation is quite futile, but this might change
+*/
+static inline Track TrackdirToTrack(Trackdir trackdir)
+{
+	return (Track)(trackdir & 0x7);
+}
+/**
+* Returns a Trackdir for the given Track
+*
+* Since every Track corresponds to two Trackdirs, we choose the
+* one which points between NE and S. Note that the actual
+* implementation is quite futile, but this might change
 * in the future.
-*/
+*
-static inline Trackdir TrackToTrackdir(Track track) { return (Trackdir)track; }
+* @param track The given Track
+* @return The Trackdir from the given Track
-/**
+*/
-* Returns a TrackdirBit mask that contains the two TrackdirBits that
+static inline Trackdir TrackToTrackdir(Track track)
+{
+	return (Trackdir)track;
+}
+/**
+* Returns a TrackdirBit mask from a given Track
+*
+* The TrackdirBit mask contains the two TrackdirBits that
 * correspond with the given Track (one for each direction).
+*
+* @param track The track to get the TrackdirBits from
+* @return The TrackdirBits which the selected tracks
 */
 static inline TrackdirBits TrackToTrackdirBits(Track track)
 {
 	Trackdir td = TrackToTrackdir(track);
 	return (TrackdirBits)(TrackdirToTrackdirBits(td) | TrackdirToTrackdirBits(ReverseTrackdir(td)));
 }
 /**
-* Discards all directional information from the given TrackdirBits. Any
+* Discards all directional information from a TrackdirBits value
-* Track which is present in either direction will be present in the result.
+*
+* Any Track which is present in either direction will be present in the result.
+*
+* @param bits The TrackdirBits to get the TrackBits from
+* @return The TrackBits
 */
 static inline TrackBits TrackdirBitsToTrackBits(TrackdirBits bits)
 {
 	return (TrackBits)((bits | (bits >> 8)) & TRACK_BIT_MASK);
 }
 /**
 * Maps a trackdir to the trackdir that you will end up on if you go straight
-* ahead. This will be the same trackdir for diagonal trackdirs, but a
+* ahead.
+*
+* This will be the same trackdir for diagonal trackdirs, but a
 * different (alternating) one for straight trackdirs
+*
+* @param trackdir The given trackdir
+* @return The next Trackdir value of the next tile.
 */
 static inline Trackdir NextTrackdir(Trackdir trackdir)
 {
 	extern const Trackdir _next_trackdir[TRACKDIR_END];
 	return _next_trackdir[trackdir];
 }
 /**
 * Maps a track to all tracks that make 90 deg turns with it.
+*
+* For the diagonal directions these are the complement of the
+* direction, for the straight directions these are the
+* two vertical or horizontal tracks, depend on the given direction
+*
+* @param track The given track
+* @return The TrackBits with the tracks marked which cross the given track by 90 deg.
 */
 static inline TrackBits TrackCrossesTracks(Track track)
 {
 	extern const TrackBits _track_crosses_tracks[TRACK_END];
 	return _track_crosses_tracks[track];
 }
 /**
 * Maps a trackdir to the (4-way) direction the tile is exited when following
 * that trackdir.
+*
+* For the diagonal directions these are the same directions. For
+* the straight directions these are the directions from the imagined
+* base-tile to the bordering tile which will be joined if the given
+* straight direction is leaved from the base-tile.
+*
+* @param trackdir The given track direction
+* @return The direction which points to the resulting tile if following the Trackdir
 */
 static inline DiagDirection TrackdirToExitdir(Trackdir trackdir)
 {
 	extern const DiagDirection _trackdir_to_exitdir[TRACKDIR_END];
 	return _trackdir_to_exitdir[trackdir];
 }
 /**
 * Maps a track and an (4-way) dir to the trackdir that represents the track
 * with the exit in the given direction.
+*
+* For the diagonal tracks the resulting track direction are clear for a given
+* DiagDirection. It either matches the direction or it returns INVALID_TRACKDIR,
+* as a TRACK_X cannot be applied with DIAG_SE.
+* For the straight tracks the resulting track direction will be the
+* direction which the DiagDirection is pointing. But this will be INVALID_TRACKDIR
+* if the DiagDirection is pointing 'away' the track.
+*
+* @param track The track to applie an direction on
+* @param diagdir The DiagDirection to applie on
+* @return The resulting track direction or INVALID_TRACKDIR if not possible.
 */
 static inline Trackdir TrackExitdirToTrackdir(Track track, DiagDirection diagdir)
 {
 	extern const Trackdir _track_exitdir_to_trackdir[TRACK_END][DIAGDIR_END];
 	return _track_exitdir_to_trackdir[track][diagdir];
 }
 /**
 * Maps a track and an (4-way) dir to the trackdir that represents the track
-* with the exit in the given direction.
+* with the entry in the given direction.
+*
+* For the diagonal tracks the return value is clear, its either the matching
+* track direction or INVALID_TRACKDIR.
+* For the straight tracks this returns the track direction which results if
+* you follow the DiagDirection and then turn by 45 deg left or right on the
+* next tile. The new direction on the new track will be the returning Trackdir
+* value. If the parameters makes no sense like the track TRACK_UPPER and the
+* diraction DIAGDIR_NE (target track cannot be reached) this function returns
+* INVALID_TRACKDIR.
+*
+* @param track The target track
+* @param diagdir The direction to "come from"
+* @return the resulting Trackdir or INVALID_TRACKDIR if not possible.
 */
 static inline Trackdir TrackEnterdirToTrackdir(Track track, DiagDirection diagdir)
 {
 	extern const Trackdir _track_enterdir_to_trackdir[TRACK_END][DIAGDIR_END];
 	return _track_enterdir_to_trackdir[track][diagdir];
 }
 /**
 * Maps a (4-way) direction to the diagonal trackdir that runs in that
 * direction.
+*
+* @param diagdir The direction
+* @return The resulting Trackdir direction
 */
 static inline Trackdir DiagdirToDiagTrackdir(DiagDirection diagdir)
 {
 	extern const Trackdir _dir_to_diag_trackdir[DIAGDIR_END];
 	return _dir_to_diag_trackdir[diagdir];
 }
 /**
 * Returns all trackdirs that can be reached when entering a tile from a given
-* (diagonal) direction. This will obviously include 90 degree turns, since no
+* (diagonal) direction.
-* information is available about the exact angle of entering */
+*
+* This will obviously include 90 degree turns, since no information is available
+* about the exact angle of entering
+*
+* @param diagdir The joining direction
+* @return The TrackdirBits which can be used from the given direction
+* @see DiagdirReachesTracks
+*/
 static inline TrackdirBits DiagdirReachesTrackdirs(DiagDirection diagdir)
 {
 	extern const TrackdirBits _exitdir_reaches_trackdirs[DIAGDIR_END];
 	return _exitdir_reaches_trackdirs[diagdir];
 }
 /**
 * Returns all tracks that can be reached when entering a tile from a given
-* (diagonal) direction. This will obviously include 90 degree turns, since no
+* (diagonal) direction.
-* information is available about the exact angle of entering */
+*
+* This will obviously include 90 degree turns, since no
+* information is available about the exact angle of entering
+*
+* @param diagdir The joining irection
+* @return The tracks which can be used
+* @see DiagdirReachesTrackdirs
+*/
 static inline TrackBits DiagdirReachesTracks(DiagDirection diagdir) { return TrackdirBitsToTrackBits(DiagdirReachesTrackdirs(diagdir)); }
 /**
 * Maps a trackdir to the trackdirs that can be reached from it (ie, when
-* entering the next tile. This will include 90 degree turns!
+* entering the next tile.
+*
+* This will include 90 degree turns!
+*
+* @param trackdir The track direction which will be leaved
+* @return The track directions which can be used from this direction (in the next tile)
 */
 static inline TrackdirBits TrackdirReachesTrackdirs(Trackdir trackdir)
 {
 	extern const TrackdirBits _exitdir_reaches_trackdirs[DIAGDIR_END];
 	return _exitdir_reaches_trackdirs[TrackdirToExitdir(trackdir)];
 }
 /* Note that there is no direct table for this function (there used to be),
 * but it uses two simpeler tables to achieve the result */
 /**
 * Maps a trackdir to all trackdirs that make 90 deg turns with it.
+*
+* For the diagonal tracks this returns the track direction bits
+* of the other axis in both directions, which cannot be joined by
+* the given track direction.
+* For the straight tracks this returns all possible 90 deg turns
+* either on the current tile (which no train can joined) or on the
+* bordering tiles.
+*
+* @param trackdir The track direction
+* @return The TrackdirBits which are (more or less) 90 deg turns.
 */
 static inline TrackdirBits TrackdirCrossesTrackdirs(Trackdir trackdir)
 {
 	extern const TrackdirBits _track_crosses_trackdirs[TRACKDIR_END];
 	return _track_crosses_trackdirs[TrackdirToTrack(trackdir)];
 }
+/**
-/* Checks if a given Track is diagonal */
+* Checks if a given Track is diagonal
-static inline bool IsDiagonalTrack(Track track) { return (track == TRACK_X) || (track == TRACK_Y); }
+*
+* @param track The given track to check
-/* Checks if a given Trackdir is diagonal. */
+* @return true if diagonal, else false
-static inline bool IsDiagonalTrackdir(Trackdir trackdir) { return IsDiagonalTrack(TrackdirToTrack(trackdir)); }
+*/
+static inline bool IsDiagonalTrack(Track track)
+{
+	return (track == TRACK_X) || (track == TRACK_Y);
+}
+/**
+* Checks if a given Trackdir is diagonal.
+*
+* @param trackdir The given trackdir
+* @return true if the trackdir use a diagonal track
+*/
+static inline bool IsDiagonalTrackdir(Trackdir trackdir)
+{
+	return IsDiagonalTrack(TrackdirToTrack(trackdir));
+}
 /**
 * Returns a pointer to the Railtype information for a given railtype
 * @param railtype the rail type which the information is requested for
 * @return The pointer to the RailtypeInfo
 static inline bool IsCompatibleRail(RailType enginetype, RailType tiletype)
 {
 	return HASBIT(GetRailTypeInfo(enginetype)->compatible_railtypes, tiletype);
 }
+/**
+* Checks if an engine of the given RailType got power on a tile with a given
+* RailType. This would normally just be an equality check, but for electric
+* rails (which also support non-electric engines).
+* @return Whether the engine got power on this tile.
+* @param  enginetype The RailType of the engine we are considering.
+* @param  tiletype   The RailType of the tile we are considering.
+*/
 static inline bool HasPowerOnRail(RailType enginetype, RailType tiletype)
 {
 	return HASBIT(GetRailTypeInfo(enginetype)->powered_railtypes, tiletype);
 }
 * @param ti The TileInfo struct of the tile being drawn
 * @see DrawCatenaryRailway
 */
 void DrawCatenary(const TileInfo *ti);
-uint GetRailFoundation(Slope tileh, TrackBits bits);
+Foundation GetRailFoundation(Slope tileh, TrackBits bits);
 int32 SettingsDisableElrail(int32 p1); ///< _patches.disable_elrail callback
 #endif /* RAIL_H */

branch	NewGRF_ports
changeset 6743	cabfaa4a0295
parent 6720	35756db7e577
child 6870	ca3fd1fbe311