direction_func.h

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00001 /* $Id: direction_func.h 17248 2009-08-21 20:21:05Z rubidium $ */
00002 
00003 /*
00004  * This file is part of OpenTTD.
00005  * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
00006  * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00007  * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
00008  */
00009 
00012 #ifndef DIRECTION_FUNC_H
00013 #define DIRECTION_FUNC_H
00014 
00015 #include "direction_type.h"
00016 
00023 static inline Direction ReverseDir(Direction d)
00024 {
00025   return (Direction)(4 ^ d);
00026 }
00027 
00028 
00036 static inline DirDiff DirDifference(Direction d0, Direction d1)
00037 {
00038   return (DirDiff)((d0 + 8 - d1) % 8);
00039 }
00040 
00052 static inline DirDiff ChangeDirDiff(DirDiff d, DirDiff delta)
00053 {
00054   return (DirDiff)((d + delta) % 8);
00055 }
00056 
00067 static inline Direction ChangeDir(Direction d, DirDiff delta)
00068 {
00069   return (Direction)((d + delta) % 8);
00070 }
00071 
00072 
00079 static inline DiagDirection ReverseDiagDir(DiagDirection d)
00080 {
00081   return (DiagDirection)(2 ^ d);
00082 }
00083 
00084 
00095 static inline DiagDirection ChangeDiagDir(DiagDirection d, DiagDirDiff delta)
00096 {
00097   return (DiagDirection)((d + delta) % 4);
00098 }
00099 
00110 static inline DiagDirection DirToDiagDir(Direction dir)
00111 {
00112   return (DiagDirection)(dir >> 1);
00113 }
00114 
00125 static inline Direction DiagDirToDir(DiagDirection dir)
00126 {
00127   return (Direction)(dir * 2 + 1);
00128 }
00129 
00130 
00139 static inline Axis OtherAxis(Axis a)
00140 {
00141   return (Axis)(a ^ 1);
00142 }
00143 
00144 
00155 static inline Axis DiagDirToAxis(DiagDirection d)
00156 {
00157   return (Axis)(d & 1);
00158 }
00159 
00160 
00172 static inline DiagDirection AxisToDiagDir(Axis a)
00173 {
00174   return (DiagDirection)(2 - a);
00175 }
00176 
00188 static inline Direction AxisToDirection(Axis a)
00189 {
00190   return (Direction)(5 - 2 * a);
00191 }
00192 
00199 static inline DiagDirection XYNSToDiagDir(Axis xy, uint ns)
00200 {
00201   return (DiagDirection)(xy * 3 ^ ns * 2);
00202 }
00203 
00210 static inline bool IsValidDiagDirection(DiagDirection d)
00211 {
00212   return d < DIAGDIR_END;
00213 }
00214 
00221 static inline bool IsValidDirection(Direction d)
00222 {
00223   return d < DIR_END;
00224 }
00225 
00232 static inline bool IsValidAxis(Axis d)
00233 {
00234   return d < AXIS_END;
00235 }
00236 
00237 #endif /* DIRECTION_H */

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