(svn r11219) [NewGRF_ports] -Sync: with trunk r11035:11218.
/* $Id$ */
/** @file direction.h */
#ifndef DIRECTION_H
#define DIRECTION_H
#include "helpers.hpp"
/**
* Defines the 8 directions on the map.
*
* This enum defines 8 possible directions which are used for
* the vehicles in the game. The directions are aligned straight
* to the viewport, not to the map. So north points to the top of
* your viewport and not rotated by 45 degrees left or right to get
* a "north" used in you games.
*/
enum Direction {
DIR_BEGIN = 0, ///< Used to iterate
DIR_N = 0, ///< North
DIR_NE = 1, ///< Northeast
DIR_E = 2, ///< East
DIR_SE = 3, ///< Southeast
DIR_S = 4, ///< South
DIR_SW = 5, ///< Southwest
DIR_W = 6, ///< West
DIR_NW = 7, ///< Northwest
DIR_END, ///< Used to iterate
INVALID_DIR = 0xFF, ///< Flag for an invalid direction
};
/** Define basic enum properties */
template <> struct EnumPropsT<Direction> : MakeEnumPropsT<Direction, byte, DIR_BEGIN, DIR_END, INVALID_DIR> {};
typedef TinyEnumT<Direction> DirectionByte; //typedefing-enumification of Direction
/**
* Return the reverse of a direction
*
* @param d The direction to get the reverse from
* @return The reverse Direction
*/
static inline Direction ReverseDir(Direction d)
{
return (Direction)(4 ^ d);
}
/**
* Enumeration for the difference between two directions.
*
* This enumeration is used to mark differences between
* two directions. If you get one direction you can align
* a second direction in 8 different ways. This enumeration
* only contains 6 of these 8 differences, but the remaining
* two can be calculated by adding to differences together.
* This also means you can add two differences together and
* get the difference you really want to get. The difference
* of 45 degrees left + the difference of 45 degrees right results in the
* difference of 0 degrees.
*
* @note To get this mentioned addition of direction you must use
* modulo DIR_END or use the #ChangeDirDiff(DirDiff, DirDiff) function.
* @see ChangeDirDiff(DirDiff, DirDiff)
*/
enum DirDiff {
DIRDIFF_SAME = 0, ///< Both directions faces to the same direction
DIRDIFF_45RIGHT = 1, ///< Angle of 45 degrees right
DIRDIFF_90RIGHT = 2, ///< Angle of 90 degrees right
DIRDIFF_REVERSE = 4, ///< One direction is the opposit of the other one
DIRDIFF_90LEFT = 6, ///< Angle of 90 degrees left
DIRDIFF_45LEFT = 7 ///< Angle of 45 degrees left
};
/**
* Calculate the difference between to 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.
*/
static inline DirDiff DirDifference(Direction d0, Direction d1)
{
return (DirDiff)((d0 + 8 - d1) % 8);
}
/**
* Applies two differences together
*
* This function adds two differences together and return the resulting
* difference. So adding two DIRDIFF_REVERSE together results in the
* DIRDIFF_SAME difference.
*
* @param d The first difference
* @param delta The second difference to add on
* @return The resulting difference
*/
static inline DirDiff ChangeDirDiff(DirDiff d, DirDiff delta)
{
return (DirDiff)((d + delta) % 8);
}
/**
* Change a direction by a given difference
*
* This functions returns a new direction of the given direction
* which is rotated by the given difference.
*
* @param d The direction to get a new direction from
* @param delta The offset/drift applied to the direction
* @return The new direction
*/
static inline Direction ChangeDir(Direction d, DirDiff delta)
{
return (Direction)((d + delta) % 8);
}
/**
* Enumeration for diagonal directions.
*
* This enumeration is used for the 4 direction of the tile-edges.
*/
enum DiagDirection {
DIAGDIR_BEGIN = 0, ///< Used for iterations
DIAGDIR_NE = 0, ///< Northeast, upper right on your monitor
DIAGDIR_SE = 1, ///< Southeast
DIAGDIR_SW = 2, ///< Southwest
DIAGDIR_NW = 3, ///< Northwest
DIAGDIR_END, ///< Used for iterations
INVALID_DIAGDIR = 0xFF, ///< Flag for an invalid 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; //typedefing-enumification of DiagDirection
/**
* Returns the reverse direction of the given DiagDirection
*
* @param d The DiagDirection to get the reverse from
* @return The reverse direction
*/
static inline DiagDirection ReverseDiagDir(DiagDirection d)
{
return (DiagDirection)(2 ^ d);
}
/**
* Enumeration for the difference between to DiagDirection.
*
* As the DiagDirection only contains 4 possible directions the
* difference between two of these directions can only be in 4 ways.
* As the DirDiff enumeration the values can be added together and
* you will get the resulting difference (use modulo DIAGDIR_END).
*
* @see DirDiff
*/
enum DiagDirDiff {
DIAGDIRDIFF_SAME = 0, ///< Same directions
DIAGDIRDIFF_90RIGHT = 1, ///< 90 degrees right
DIAGDIRDIFF_REVERSE = 2, ///< Reverse directions
DIAGDIRDIFF_90LEFT = 3 ///< 90 degrees left
};
/** Allow incrementing of DiagDirDiff variables */
DECLARE_POSTFIX_INCREMENT(DiagDirDiff);
/**
* Applies a difference on a DiagDirection
*
* This function applies a difference on a DiagDirection and returns
* the new DiagDirection.
*
* @param d The DiagDirection
* @param delta The difference to applie on
* @return The new direction which was calculated
*/
static inline DiagDirection ChangeDiagDir(DiagDirection d, DiagDirDiff delta)
{
return (DiagDirection)((d + delta) % 4);
}
/**
* Convert a Direction to a DiagDirection.
*
* This function can be used to convert the 8-way Direction to
* the 4-way DiagDirection. If the direction cannot be mapped its
* "rounded clockwise". So DIR_N becomes DIAGDIR_NE.
*
* @param dir The direction to convert
* @return The resulting DiagDirection, maybe "rounded clockwise".
*/
static inline DiagDirection DirToDiagDir(Direction dir)
{
return (DiagDirection)(dir >> 1);
}
/**
* Convert a DiagDirection to a Direction.
*
* This function can be used to convert the 4-way DiagDirection
* to the 8-way Direction. As 4-way are less than 8-way not all
* possible directions can be calculated.
*
* @param dir The direction to convert
* @return The resulting Direction
*/
static inline Direction DiagDirToDir(DiagDirection dir)
{
return (Direction)(dir * 2 + 1);
}
/**
* Enumeration for the two axis X and Y
*
* This enumeration represente the two axis X and Y in the game.
* The X axis is the one which goes align the north-west edge
* (and south-east edge). The Y axis must be so the one which goes
* align the north-east edge (and south-west) edge.
*/
enum Axis {
AXIS_X = 0, ///< The X axis
AXIS_Y = 1, ///< The y axis
AXIS_END ///< Used for iterations
};
/**
* Select the other axis as provided.
*
* This is basically the not-operator for the axis.
*
* @param a The given axis
* @return The other axis
*/
static inline Axis OtherAxis(Axis a)
{
return (Axis)(a ^ 1);
}
/**
* Convert a DiagDirection to the axis.
*
* This function returns the axis which belongs to the given
* DiagDirection. The axis X belongs to the DiagDirection
* north-east and south-west.
*
* @param d The DiagDirection
* @return The axis which belongs to the direction
*/
static inline Axis DiagDirToAxis(DiagDirection d)
{
return (Axis)(d & 1);
}
/**
* Converts an Axis to a DiagDirection
*
* This function returns the DiagDirection which
* belongs to the axis. As 2 directions are mapped to an axis
* this function returns the one which points to south,
* either south-west (on X axis) or south-east (on Y axis)
*
* @param a The axis
* @return The direction pointed to south
*/
static inline DiagDirection AxisToDiagDir(Axis a)
{
return (DiagDirection)(2 - a);
}
/**
* Convert an axis and a flag for north/south into a DiagDirection
* @param xy axis to convert
* @param ns north -> 0, south -> 1
* @return the desired DiagDirection
*/
static inline DiagDirection XYNSToDiagDir(Axis xy, uint ns)
{
return (DiagDirection)(xy * 3 ^ ns * 2);
}
/**
* Checks if an interger value is a valid DiagDirection
*
* @param d The value to check
* @return True if the value belongs to a DiagDirection, else false
*/
static inline bool IsValidDiagDirection(DiagDirection d)
{
return d < DIAGDIR_END;
}
/**
* Checks if an integer value is a valid Direction
*
* @param d The value to check
* @return True if the value belongs to a Direction, else false
*/
static inline bool IsValidDirection(Direction d)
{
return d < DIR_END;
}
/**
* Checks if an integer value is a valid Axis
*
* @param d The value to check
* @return True if the value belongs to an Axis, else false
*/
static inline bool IsValidAxis(Axis d)
{
return d < AXIS_END;
}
#endif /* DIRECTION_H */