tron@3147: /* $Id$ */
tron@3147: 
tron@3147: #ifndef DIRECTION_H
tron@3147: #define DIRECTION_H
tron@3147: 
tron@3147: /* Direction as commonly used in v->direction, 8 way. */
tron@3147: typedef enum Direction {
tron@3147: 	DIR_N   = 0,
tron@3147: 	DIR_NE  = 1,      /* Northeast, upper right on your monitor */
tron@3147: 	DIR_E   = 2,
tron@3147: 	DIR_SE  = 3,
tron@3147: 	DIR_S   = 4,
tron@3147: 	DIR_SW  = 5,
tron@3147: 	DIR_W   = 6,
tron@3147: 	DIR_NW  = 7,
tron@3147: 	DIR_END,
tron@3147: 	INVALID_DIR = 0xFF,
tron@3147: } Direction;
tron@3147: 
tron@3157: static inline Direction ReverseDir(Direction d)
tron@3157: {
tron@3157: 	return (Direction)(4 ^ d);
tron@3157: }
tron@3157: 
tron@3147: 
tron@3158: typedef enum DirDiff {
tron@3158: 	DIRDIFF_SAME    = 0,
tron@3158: 	DIRDIFF_45RIGHT = 1,
tron@3158: 	DIRDIFF_90RIGHT = 2,
tron@3158: 	DIRDIFF_REVERSE = 4,
tron@3158: 	DIRDIFF_90LEFT  = 6,
tron@3158: 	DIRDIFF_45LEFT  = 7
tron@3158: } DirDiff;
tron@3158: 
tron@3158: static inline DirDiff DirDifference(Direction d0, Direction d1)
tron@3158: {
tron@3162: 	return (DirDiff)((d0 + 8 - d1) % 8);
tron@3158: }
tron@3158: 
tron@3158: static inline DirDiff ChangeDirDiff(DirDiff d, DirDiff delta)
tron@3158: {
tron@3158: 	return (DirDiff)((d + delta) % 8);
tron@3158: }
tron@3158: 
tron@3158: 
tron@3158: static inline Direction ChangeDir(Direction d, DirDiff delta)
tron@3158: {
tron@3158: 	return (Direction)((d + delta) % 8);
tron@3158: }
tron@3158: 
tron@3158: 
tron@3147: /* Direction commonly used as the direction of entering and leaving tiles, 4-way */
tron@3147: typedef enum DiagDirection {
tron@3147: 	DIAGDIR_NE  = 0,      /* Northeast, upper right on your monitor */
tron@3147: 	DIAGDIR_SE  = 1,
tron@3147: 	DIAGDIR_SW  = 2,
tron@3147: 	DIAGDIR_NW  = 3,
tron@3147: 	DIAGDIR_END,
tron@3147: 	INVALID_DIAGDIR = 0xFF,
tron@3147: } DiagDirection;
tron@3147: 
tron@3147: static inline DiagDirection ReverseDiagDir(DiagDirection d)
tron@3147: {
tron@3148: 	return (DiagDirection)(2 ^ d);
tron@3147: }
tron@3147: 
tron@3147: 
tron@3163: typedef enum DiagDirDiff {
tron@3163: 	DIAGDIRDIFF_SAME    = 0,
tron@3163: 	DIAGDIRDIFF_90RIGHT = 1,
tron@3163: 	DIAGDIRDIFF_REVERSE = 2,
tron@3163: 	DIAGDIRDIFF_90LEFT  = 3
tron@3163: } DiagDirDiff;
tron@3163: 
tron@3163: static inline DiagDirection ChangeDiagDir(DiagDirection d, DiagDirDiff delta)
tron@3163: {
tron@3163: 	return (DiagDirection)((d + delta) % 4);
tron@3163: }
tron@3163: 
tron@3163: 
tron@3153: static inline DiagDirection DirToDiagDir(Direction dir)
tron@3147: {
tron@3147: 	return (DiagDirection)(dir >> 1);
tron@3147: }
tron@3147: 
tron@3147: 
tron@3153: static inline Direction DiagDirToDir(DiagDirection dir)
tron@3153: {
tron@3153: 	return (Direction)(dir * 2 + 1);
tron@3153: }
tron@3153: 
tron@3153: 
tron@3147: /* the 2 axis */
tron@3147: typedef enum Axis {
tron@3147: 	AXIS_X = 0,
matthijs@3699: 	AXIS_Y = 1,
matthijs@3699: 	AXIS_END
tron@3147: } Axis;
tron@3147: 
tron@3154: 
tron@4158: static inline Axis OtherAxis(Axis a)
tron@4158: {
tron@4158: 	return (Axis)(a ^ 1);
tron@4158: }
tron@4158: 
tron@4158: 
tron@3154: static inline Axis DiagDirToAxis(DiagDirection d)
tron@3154: {
tron@3154: 	return (Axis)(d & 1);
tron@3154: }
tron@3154: 
tron@3209: 
tron@3209: /*
tron@3209:  * Converts an Axis to a DiagDirection
tron@3209:  * Points always in the positive direction, i.e. S[EW]
tron@3209:  */
tron@3209: static inline DiagDirection AxisToDiagDir(Axis a)
tron@3209: {
tron@3209: 	return (DiagDirection)(2 - a);
tron@3209: }
tron@3209: 
tron@3953: /**
tron@3953:  * Convert an axis and a flag for north/south into a DiagDirection
tron@3953:  * @param ns north -> 0, south -> 1
tron@3953:  */
tron@3953: static inline DiagDirection XYNSToDiagDir(Axis xy, uint ns)
tron@3953: {
tron@3953: 	return (DiagDirection)(xy * 3 ^ ns * 2);
tron@3953: }
tron@3953: 
tron@3953: 
matthijs@3699: static inline bool IsValidDiagDirection(DiagDirection d)
matthijs@3699: {
matthijs@3699: 	return d < DIAGDIR_END;
matthijs@3699: }
matthijs@3699: 
glx@3744: static inline bool IsValidDirection(Direction d)
matthijs@3699: {
matthijs@3699: 	return d < DIR_END;
matthijs@3699: }
matthijs@3699: 
glx@3744: static inline bool IsValidAxis(Axis d)
matthijs@3699: {
matthijs@3699: 	return d < AXIS_END;
matthijs@3699: }
matthijs@3699: 
peter1138@4666: #endif /* DIRECTION_H */