From 93bedce286dae2525e8f4a80a8036e67446a7e2e Mon Sep 17 00:00:00 2001 From: rubidium Date: Fri, 3 Aug 2007 12:29:56 +0000 Subject: (svn r10765) -Documentation [FS#1100]: of rail.h. Based on a patch by Progman. --- src/rail.h | 465 +++++++++++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 343 insertions(+), 122 deletions(-) diff --git a/src/rail.h b/src/rail.h index 0ffefdb8e..ab6ea3b9f 100644 --- a/src/rail.h +++ b/src/rail.h @@ -9,14 +9,19 @@ #include "direction.h" #include "tile.h" +/** + * Enumeration for all possible railtypes. + * + * This enumeration defines all 4 possible railtypes. + */ enum RailType { - RAILTYPE_BEGIN = 0, - RAILTYPE_RAIL = 0, - RAILTYPE_ELECTRIC = 1, - RAILTYPE_MONO = 2, - RAILTYPE_MAGLEV = 3, - RAILTYPE_END, - INVALID_RAILTYPE = 0xFF + RAILTYPE_BEGIN = 0, ///< Used for iterations + RAILTYPE_RAIL = 0, ///< Standard non-electric rails + RAILTYPE_ELECTRIC = 1, ///< Electric rails + RAILTYPE_MONO = 2, ///< Monorail + RAILTYPE_MAGLEV = 3, ///< Maglev + RAILTYPE_END, ///< Used for iterations + INVALID_RAILTYPE = 0xFF ///< Flag for invalid railtype }; typedef byte RailTypeMask; @@ -28,18 +33,20 @@ template <> struct EnumPropsT : MakeEnumPropsT 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_X = 0, - TRACK_Y = 1, - TRACK_UPPER = 2, - TRACK_LOWER = 3, - TRACK_LEFT = 4, - TRACK_RIGHT = 5, - TRACK_END, - INVALID_TRACK = 0xFF + TRACK_BEGIN = 0, ///< Used for iterations + TRACK_X = 0, ///< Track along the x-axis (north-east to south-west) + TRACK_Y = 1, ///< Track along the y-axis (north-west to south-east) + TRACK_UPPER = 2, ///< Track in the upper corner of the tile (north) + TRACK_LOWER = 3, ///< Track in the lower corner of the tile (south) + TRACK_LEFT = 4, ///< Track in the left corner of the tile (west) + TRACK_RIGHT = 5, ///< Track in the right corner of the tile (east) + TRACK_END, ///< Used for iterations + INVALID_TRACK = 0xFF ///< Flag for an invalid track }; /** Allow incrementing of Track variables */ @@ -49,10 +56,14 @@ template <> struct EnumPropsT : MakeEnumPropsT 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) { @@ -62,25 +73,25 @@ static inline Track AxisToTrack(Axis a) /** Bitfield corresponding to Track */ enum TrackBits { - TRACK_BIT_NONE = 0U, - TRACK_BIT_X = 1U << TRACK_X, - TRACK_BIT_Y = 1U << TRACK_Y, - TRACK_BIT_UPPER = 1U << TRACK_UPPER, - TRACK_BIT_LOWER = 1U << TRACK_LOWER, - TRACK_BIT_LEFT = 1U << TRACK_LEFT, - TRACK_BIT_RIGHT = 1U << TRACK_RIGHT, - TRACK_BIT_CROSS = TRACK_BIT_X | TRACK_BIT_Y, - TRACK_BIT_HORZ = TRACK_BIT_UPPER | TRACK_BIT_LOWER, - TRACK_BIT_VERT = TRACK_BIT_LEFT | TRACK_BIT_RIGHT, - TRACK_BIT_3WAY_NE = TRACK_BIT_X | TRACK_BIT_UPPER | TRACK_BIT_RIGHT, - TRACK_BIT_3WAY_SE = TRACK_BIT_Y | TRACK_BIT_LOWER | TRACK_BIT_RIGHT, - TRACK_BIT_3WAY_SW = TRACK_BIT_X | TRACK_BIT_LOWER | TRACK_BIT_LEFT, - TRACK_BIT_3WAY_NW = TRACK_BIT_Y | TRACK_BIT_UPPER | TRACK_BIT_LEFT, - TRACK_BIT_ALL = TRACK_BIT_CROSS | TRACK_BIT_HORZ | TRACK_BIT_VERT, - TRACK_BIT_MASK = 0x3FU, - TRACK_BIT_WORMHOLE = 0x40U, - TRACK_BIT_DEPOT = 0x80U, - INVALID_TRACK_BIT = 0xFF + TRACK_BIT_NONE = 0U, ///< No track + TRACK_BIT_X = 1U << TRACK_X, ///< X-axis track + TRACK_BIT_Y = 1U << TRACK_Y, ///< Y-axis track + TRACK_BIT_UPPER = 1U << TRACK_UPPER, ///< Upper track + TRACK_BIT_LOWER = 1U << TRACK_LOWER, ///< Lower track + TRACK_BIT_LEFT = 1U << TRACK_LEFT, ///< Left track + TRACK_BIT_RIGHT = 1U << TRACK_RIGHT, ///< Right track + TRACK_BIT_CROSS = TRACK_BIT_X | TRACK_BIT_Y, ///< X-Y-axis cross + TRACK_BIT_HORZ = TRACK_BIT_UPPER | TRACK_BIT_LOWER, ///< Upper and lower track + 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,///< "Arrow" to the north-east + 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, ///< "Arrow" to the south-west + 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, ///< All possible tracks + TRACK_BIT_MASK = 0x3FU, ///< Bitmask for the first 6 bits + TRACK_BIT_WORMHOLE = 0x40U, ///< Bitflag for a wormhole (used for tunnels) + TRACK_BIT_DEPOT = 0x80U, ///< Bitflag for a depot + INVALID_TRACK_BIT = 0xFF ///< Flag for an invalid trackbits value }; /** Define basic enum properties */ @@ -91,70 +102,83 @@ 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_X_NE = 0, - TRACKDIR_Y_SE = 1, - TRACKDIR_UPPER_E = 2, - TRACKDIR_LOWER_E = 3, - TRACKDIR_LEFT_S = 4, - TRACKDIR_RIGHT_S = 5, - TRACKDIR_RVREV_NE = 6, - TRACKDIR_RVREV_SE = 7, - TRACKDIR_X_SW = 8, - TRACKDIR_Y_NW = 9, - TRACKDIR_UPPER_W = 10, - TRACKDIR_LOWER_W = 11, - TRACKDIR_LEFT_N = 12, - TRACKDIR_RIGHT_N = 13, - TRACKDIR_RVREV_SW = 14, - TRACKDIR_RVREV_NW = 15, - TRACKDIR_END, - INVALID_TRACKDIR = 0xFF, + TRACKDIR_BEGIN = 0, ///< Used for iterations + TRACKDIR_X_NE = 0, ///< X-axis and direction to north-east + TRACKDIR_Y_SE = 1, ///< Y-axis and direction to south-east + TRACKDIR_UPPER_E = 2, ///< Upper track and direction to east + TRACKDIR_LOWER_E = 3, ///< Lower track and direction to east + TRACKDIR_LEFT_S = 4, ///< Left track and direction to south + TRACKDIR_RIGHT_S = 5, ///< Right track and direction to south + TRACKDIR_RVREV_NE = 6, ///< (Road vehicle) reverse direction north-east + TRACKDIR_RVREV_SE = 7, ///< (Road vehicle) reverse direction south-east + TRACKDIR_X_SW = 8, ///< X-axis and direction to south-west + TRACKDIR_Y_NW = 9, ///< Y-axis and direction to north-west + TRACKDIR_UPPER_W = 10, ///< Upper track and direction to west + TRACKDIR_LOWER_W = 11, ///< Lower track and direction to west + TRACKDIR_LEFT_N = 12, ///< Left track and direction to north + TRACKDIR_RIGHT_N = 13, ///< Right track and direction to north + TRACKDIR_RVREV_SW = 14, ///< (Road vehicle) reverse direction south-west + TRACKDIR_RVREV_NW = 15, ///< (Road vehicle) reverse direction north-west + TRACKDIR_END, ///< Used for iterations + INVALID_TRACKDIR = 0xFF, ///< Flag for an invalid trackdir }; /** Define basic enum properties */ template <> struct EnumPropsT : MakeEnumPropsT {}; typedef TinyEnumT 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_X_NE = 0x0001, - TRACKDIR_BIT_Y_SE = 0x0002, - TRACKDIR_BIT_UPPER_E = 0x0004, - TRACKDIR_BIT_LOWER_E = 0x0008, - TRACKDIR_BIT_LEFT_S = 0x0010, - TRACKDIR_BIT_RIGHT_S = 0x0020, + TRACKDIR_BIT_NONE = 0x0000, ///< No track build + TRACKDIR_BIT_X_NE = 0x0001, ///< Track x-axis, direction north-east + TRACKDIR_BIT_Y_SE = 0x0002, ///< Track y-axis, direction south-east + TRACKDIR_BIT_UPPER_E = 0x0004, ///< Track upper, direction east + TRACKDIR_BIT_LOWER_E = 0x0008, ///< Track lower, direction east + TRACKDIR_BIT_LEFT_S = 0x0010, ///< Track left, direction south + 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_Y_NW = 0x0200, - TRACKDIR_BIT_UPPER_W = 0x0400, - TRACKDIR_BIT_LOWER_W = 0x0800, - TRACKDIR_BIT_LEFT_N = 0x1000, - TRACKDIR_BIT_RIGHT_N = 0x2000, - TRACKDIR_BIT_MASK = 0x3F3F, - INVALID_TRACKDIR_BIT = 0xFFFF, + TRACKDIR_BIT_X_SW = 0x0100, ///< Track x-axis, direction south-west + TRACKDIR_BIT_Y_NW = 0x0200, ///< Track y-axis, direction north-west + TRACKDIR_BIT_UPPER_W = 0x0400, ///< Track upper, direction west + TRACKDIR_BIT_LOWER_W = 0x0800, ///< Track lower, direction west + TRACKDIR_BIT_LEFT_N = 0x1000, ///< Track left, direction north + TRACKDIR_BIT_RIGHT_N = 0x2000, ///< Track right, direction north + TRACKDIR_BIT_MASK = 0x3F3F, ///< Bitmask for bit-operations + INVALID_TRACKDIR_BIT = 0xFFFF, ///< Flag for an invalid trackdirbit value }; /** Define basic enum properties */ @@ -195,14 +219,14 @@ struct RailtypeInfo { } gui_sprites; struct { - CursorID rail_ns; - CursorID rail_swne; - CursorID rail_ew; - CursorID rail_nwse; - CursorID autorail; - CursorID depot; - CursorID tunnel; - CursorID convert; + CursorID rail_ns; ///< Cursor for building rail in N-S direction + CursorID rail_swne; ///< Cursor for building rail in X direction + CursorID rail_ew; ///< Cursor for building rail in E-W direction + CursorID rail_nwse; ///< Cursor for building rail in Y direction + CursorID autorail; ///< Cursor for autorail tool + CursorID depot; ///< Cursor for building a depot + CursorID tunnel; ///< Cursor for building a tunnel + CursorID convert; ///< Cursor for converting track } cursor; struct { @@ -248,12 +272,28 @@ enum { /** * Maps a Trackdir to the corresponding TrackdirBits value + * @param trackdir the track direction to convert + * @return the converted TrackdirBits value */ -static inline TrackdirBits TrackdirToTrackdirBits(Trackdir trackdir) { return (TrackdirBits)(1 << trackdir); } +static inline TrackdirBits TrackdirToTrackdirBits(Trackdir trackdir) +{ + return (TrackdirBits)(1 << trackdir); +} /** -* Removes first Track from TrackBits and returns it -*/ + * 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) { @@ -265,8 +305,19 @@ static inline Track RemoveFirstTrack(TrackBits *tracks) } /** -* Removes first Trackdir from TrackdirBits and returns it -*/ + * 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) { @@ -278,16 +329,31 @@ static inline Trackdir RemoveFirstTrackdir(TrackdirBits *trackdirs) } /** -* Returns first Track from TrackBits or INVALID_TRACK -*/ + * 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)); @@ -295,8 +361,17 @@ static inline Track TrackBitsToTrack(TrackBits tracks) } /** -* Returns first Trackdir from TrackdirBits or INVALID_TRACKDIR -*/ + * 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); @@ -304,13 +379,30 @@ static inline Trackdir FindFirstTrackdir(TrackdirBits trackdirs) } /** - * These functions check the validity of Tracks and Trackdirs. assert against - * them when convenient. + * Checks if a Track is valid. + * + * @param track The value to check + * @return true if the given value is a valid track. + * @note Use this in an assert() */ -static inline bool IsValidTrack(Track track) { return track < TRACK_END; } -static inline bool IsValidTrackdir(Trackdir trackdir) { return (TrackdirToTrackdirBits(trackdir) & TRACKDIR_BIT_MASK) != 0; } +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? @@ -354,6 +446,13 @@ static inline byte SignalOnTrack(Track track) /** * 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) { @@ -363,20 +462,42 @@ static inline Trackdir ReverseTrackdir(Trackdir trackdir) /** * Returns the Track that a given Trackdir represents + * + * This function filters the Track which is used in the Trackdir value and + * returns it as a Track value. + * + * @param trackdir The trackdir value + * @return The Track which is used in the value */ -static inline Track TrackdirToTrack(Trackdir trackdir) { return (Track)(trackdir & 0x7); } +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 + * 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. + * + * @param track The given Track + * @return The Trackdir from the given Track */ -static inline Trackdir TrackToTrackdir(Track track) { return (Trackdir)track; } +static inline Trackdir TrackToTrackdir(Track track) +{ + return (Trackdir)track; +} /** - * Returns a TrackdirBit mask that contains the two TrackdirBits that + * 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) { @@ -385,8 +506,12 @@ static inline TrackdirBits TrackToTrackdirBits(Track track) } /** - * Discards all directional information from the given TrackdirBits. Any - * Track which is present in either direction will be present in the result. + * Discards all directional information from a TrackdirBits value + * + * 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) { @@ -395,8 +520,13 @@ static inline TrackBits TrackdirBitsToTrackBits(TrackdirBits bits) /** * 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) { @@ -406,6 +536,13 @@ static inline Trackdir NextTrackdir(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) { @@ -416,6 +553,14 @@ static inline TrackBits TrackCrossesTracks(Track 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) { @@ -426,6 +571,17 @@ static inline DiagDirection TrackdirToExitdir(Trackdir 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) { @@ -435,7 +591,20 @@ static inline Trackdir TrackExitdirToTrackdir(Track track, DiagDirection 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) { @@ -456,6 +625,9 @@ static inline Trackdir TrackDirectionToTrackdir(Track track, Direction dir) /** * 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) { @@ -465,8 +637,15 @@ static inline Trackdir DiagdirToDiagTrackdir(DiagDirection 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 - * information is available about the exact angle of entering */ + * (diagonal) direction. + * + * 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]; @@ -475,26 +654,46 @@ static inline TrackdirBits DiagdirReachesTrackdirs(DiagDirection 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 - * information is available about the exact angle of entering */ + * (diagonal) direction. + * + * 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) { @@ -502,13 +701,27 @@ static inline TrackdirBits TrackdirCrossesTrackdirs(Trackdir trackdir) return _track_crosses_trackdirs[TrackdirToTrack(trackdir)]; } +/** + * Checks if a given Track is diagonal + * + * @param track The given track to check + * @return true if diagonal, else false + */ +static inline bool IsDiagonalTrack(Track track) +{ + return (track == TRACK_X) || (track == TRACK_Y); +} -/* Checks if a given Track is diagonal */ -static inline bool IsDiagonalTrack(Track track) { return (track == TRACK_X) || (track == TRACK_Y); } - -/* Checks if a given Trackdir is diagonal. */ -static inline bool IsDiagonalTrackdir(Trackdir trackdir) { return IsDiagonalTrack(TrackdirToTrack(trackdir)); } - +/** + * 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 @@ -535,6 +748,14 @@ 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); -- cgit v1.2.3-70-g09d2