diff options
| -rw-r--r-- | src/aircraft_cmd.cpp | 2 | ||||
| -rw-r--r-- | src/direction_func.h | 20 |
2 files changed, 18 insertions, 4 deletions
diff --git a/src/aircraft_cmd.cpp b/src/aircraft_cmd.cpp index 18dcbea27..edb10af32 100644 --- a/src/aircraft_cmd.cpp +++ b/src/aircraft_cmd.cpp @@ -809,7 +809,7 @@ static byte AircraftGetEntryPoint(const Aircraft *v, const AirportFTAClass *apc, /* We are northwest or southeast of the airport */ dir = delta_y < 0 ? DIAGDIR_NW : DIAGDIR_SE; } - dir = ChangeDiagDir(dir, (DiagDirDiff)ReverseDiagDir(DirToDiagDir(rotation))); + dir = ChangeDiagDir(dir, DiagDirDifference(DIAGDIR_NE, DirToDiagDir(rotation))); return apc->entry_points[dir]; } diff --git a/src/direction_func.h b/src/direction_func.h index 888948584..12aee5863 100644 --- a/src/direction_func.h +++ b/src/direction_func.h @@ -61,11 +61,11 @@ static inline Direction ReverseDir(Direction d) /** - * Calculate the difference between to directions + * Calculate the difference between two directions * * @param d0 The first direction as the base * @param d1 The second direction as the offset from the base - * @return The difference how the second directions drifts of the first one. + * @return The difference how the second direction drifts of the first one. */ static inline DirDiff DirDifference(Direction d0, Direction d1) { @@ -79,7 +79,7 @@ static inline DirDiff DirDifference(Direction d0, Direction d1) /** * Applies two differences together * - * This function adds two differences together and return the resulting + * This function adds two differences together and returns the resulting * difference. So adding two DIRDIFF_REVERSE together results in the * DIRDIFF_SAME difference. * @@ -123,6 +123,20 @@ static inline DiagDirection ReverseDiagDir(DiagDirection d) return (DiagDirection)(2 ^ d); } +/** + * Calculate the difference between two DiagDirection values + * + * @param d0 The first direction as the base + * @param d1 The second direction as the offset from the base + * @return The difference how the second direction drifts of the first one. + */ +static inline DiagDirDiff DiagDirDifference(DiagDirection d0, DiagDirection d1) +{ + assert(IsValidDiagDirection(d0)); + assert(IsValidDiagDirection(d1)); + /* Cast to uint so compiler can use bitmask. Result can never be negative. */ + return (DiagDirDiff)((uint)(d0 - d1) % 4); +} /** * Applies a difference on a DiagDirection |