/* $Id$ */

#ifndef DIRECTION_H

#define DIRECTION_H

#include "helpers.hpp"

/* Direction as commonly used in v->direction, 8 way. */

typedef enum Direction {

	DIR_BEGIN = 0,

	DIR_N   = 0,

	DIR_E   = 2,

	DIR_SE  = 3,

	DIR_S   = 4,

	DIR_SW  = 5,

	DIR_W   = 6,

	DIR_NW  = 7,

	DIR_END,

	INVALID_DIR = 0xFF,

} Direction;

/** Define basic enum properties */

template <> struct EnumPropsT<Direction> : MakeEnumPropsT<Direction, byte, DIR_BEGIN, DIR_END, INVALID_DIR> {};

}

static inline Direction ChangeDir(Direction d, DirDiff delta)

{

	return (Direction)((d + delta) % 8);

}

/* Direction commonly used as the direction of entering and leaving tiles, 4-way */

typedef enum DiagDirection {

	DIAGDIR_BEGIN = 0,

	DIAGDIR_SE  = 1,

	DIAGDIR_SW  = 2,

	DIAGDIR_NW  = 3,

	DIAGDIR_END,

	INVALID_DIAGDIR = 0xFF,

} DiagDirection;

DECLARE_POSTFIX_INCREMENT(DiagDirection);

/** Define basic enum properties */

template <> struct EnumPropsT<DiagDirection> : MakeEnumPropsT<DiagDirection, byte, DIAGDIR_BEGIN, DIAGDIR_END, INVALID_DIAGDIR> {};

typedef TinyEnumT<DiagDirection> DiagDirectionByte;