Struct Direction

Structure representing the concept of a "direction" on a grid, and "defines" the coordinate plane via the YIncreasesUpward flag. Interacts with Point to allow easy translation of positions in a direction, and contains numerous helper functions for retrieving directions in various orders, getting direction closest to a line, etc.

Implements

IEquatable<Direction>

IMatchable<Direction>

Inherited Members

object.GetType()

object.Equals(object, object)

object.ReferenceEquals(object, object)

Namespace: SadRogue.Primitives

Assembly: TheSadRogue.Primitives.dll

Syntax

[DataContract]
public readonly struct Direction : IEquatable<Direction>, IMatchable<Direction>

Remarks

The static YIncreasesUpward flag defines the way that many algorithms interpret the coordinate plane. By default, this flag is false, meaning that the y-value of positions is assumed to DECREASE as you proceed in the direction defined by Up, and increase as you go downward. If the coordinate plane is displayed on the screen, the origin would be the top left corner. This default setting matches the typical console/computer graphic definition of the coordinate plane. Setting the flag to true inverts this, so that the y-value of positions INCREASES as you proceed in the direction defined by Up. This places the origin in the bottom left corner, and matches a typical mathematical definition of a euclidean coordinate plane, as well as the scene coordinate plane defined by Unity and other game engines.

Fields

Down

Down direction.

Declaration

public static readonly Direction Down

Field Value

Type	Description
Direction

DownLeft

Down-left direction.

Declaration

public static readonly Direction DownLeft

Field Value

Type	Description
Direction

DownRight

Down-right direction.

Declaration

public static readonly Direction DownRight

Field Value

Type	Description
Direction

Left

Left direction.

Declaration

public static readonly Direction Left

Field Value

Type	Description
Direction

None

No direction.

Declaration

public static readonly Direction None

Field Value

Type	Description
Direction

Right

Right direction.

Declaration

public static readonly Direction Right

Field Value

Type	Description
Direction

Type

Enum type corresponding to direction being represented.

Declaration

[DataMember]
public readonly Direction.Types Type

Field Value

Type	Description
Direction.Types

Up

Up direction.

Declaration

public static readonly Direction Up

Field Value

Type	Description
Direction

UpLeft

Up-left direction.

Declaration

public static readonly Direction UpLeft

Field Value

Type	Description
Direction

UpRight

Up-right direction.

Declaration

public static readonly Direction UpRight

Field Value

Type	Description
Direction

Properties

DeltaX

Change in x-value represented by this direction.

Declaration

public int DeltaX { get; }

Property Value

Type	Description
int

DeltaY

Change in y-value represented by this direction.

Declaration

public int DeltaY { get; }

Property Value

Type	Description
int

YIncreasesUpward

Whether or not a positive y-value indicates an upward change. To set this value, use SetYIncreasesUpwardsUnsafe(bool), however note that this is an unsafe operation in a multi-threaded environment where one or more threads may be using Directions. It is intended that this configuration be done as part of an initialization routine.

Declaration

public static bool YIncreasesUpward { get; }

Property Value

Type	Description
bool

Remarks

If true, directions with an upwards component represent a positive change in y-value, and ones with downward components represent a negative change in y-value. Changing this to false (which is the default) inverts this.

Methods

Equals(Direction)

True if the given direction has the same Type the current one.

Declaration

public bool Equals(Direction other)

Parameters

Type	Name	Description
Direction	other	Direction to compare.

Returns

Type	Description
bool	True if the two directions are the same, false if not.

Equals(object?)

Same as operator == in this case; returns false if obj is not a Direction.

Declaration

public override bool Equals(object? obj)

Parameters

Type	Name	Description
object	obj	The object to compare the current Direction to.

Returns

Type	Description
bool	True if obj is a Direction, and the two directions are equal, false otherwise.

Overrides

ValueType.Equals(object)

GetCardinalDirection(Point)

Returns the cardinal direction that most closely matches the degree heading of a line with the given delta-change values. Rounds clockwise if exactly on a diagonal. Similar to GetDirection(Point), except this function returns only cardinal directions.

Declaration

public static Direction GetCardinalDirection(Point deltaChange)

Parameters

Type	Name	Description
Point	deltaChange	Vector representing the change in x and change in y across the line (deltaChange.X is the change in x, deltaChange.Y is the change in y).

Returns

Type	Description
Direction	The cardinal direction that most closely matches the degree heading of the given line.

GetCardinalDirection(Point, Point)

Returns the cardinal direction that most closely matches the degree heading of the given line. Rounds clockwise if the heading is exactly on a diagonal direction. Similar to GetDirection(Point, Point), except this function returns only cardinal directions.

Declaration

public static Direction GetCardinalDirection(Point start, Point end)

Parameters

Type	Name	Description
Point	start	Starting coordinate of the line.
Point	end	Ending coordinate of the line.

Returns

Type	Description
Direction	The cardinal direction that most closely matches the heading indicated by the given line.

GetCardinalDirection(int, int)

Returns the cardinal direction that most closely matches the degree heading of a line with the given delta-change values. Rounds clockwise if exactly on a diagonal. Similar to GetDirection(Point), except this function returns only cardinal directions.

Declaration

public static Direction GetCardinalDirection(int dx, int dy)

Parameters

Type	Name	Description
int	dx	Change in x along the line.
int	dy	Change in y along the line.

Returns

Type	Description
Direction	The cardinal direction that most closely matches the degree heading of the given line.

GetCardinalDirection(int, int, int, int)

Returns the cardinal direction that most closely matches the degree heading of the given line. Rounds clockwise if the heading is exactly on a diagonal direction. Similar to GetDirection(Point, Point), except this function returns only cardinal directions.

Declaration

public static Direction GetCardinalDirection(int startX, int startY, int endX, int endY)

Parameters

Type	Name	Description
int	startX	X-value of the starting coordinate of the line.
int	startY	Y-value of the starting coordinate of the line.
int	endX	X-value of the ending coordinate of the line.
int	endY	Y-value of the ending coordinate of the line.

Returns

Type	Description
Direction	The cardinal direction that most closely matches the heading indicated by the given line.

GetDirection(Point)

Returns the direction that most closely matches the degree heading of a line with the given delta-change values. Rounds clockwise if the heading is exactly between two directions.

Declaration

public static Direction GetDirection(Point deltaChange)

Parameters

Type	Name	Description
Point	deltaChange	Vector representing the change in x and change in y across the line (deltaChange.X is the change in x, deltaChange.Y is the change in y).

Returns

Type	Description
Direction	The direction that most closely matches the heading indicated by the given input.

GetDirection(Point, Point)

Returns the direction that most closely matches the degree heading of the given line. Rounds clockwise if the heading is exactly between two directions.

Declaration

public static Direction GetDirection(Point start, Point end)

Parameters

Type	Name	Description
Point	start	Starting coordinate of the line.
Point	end	Ending coordinate of the line.

Returns

Type	Description
Direction	The direction that most closely matches the heading indicated by the given line.

GetDirection(int, int)

Returns the direction that most closely matches the degree heading of a line with the given delta-change values. Rounds clockwise if the heading is exactly between two directions.

Declaration

public static Direction GetDirection(int dx, int dy)

Parameters

Type	Name	Description
int	dx	Change in x-value across the line.
int	dy	Change in y-value across the line.

Returns

Type	Description
Direction	The direction that most closely matches the heading indicated by the given input.

GetDirection(int, int, int, int)

Returns the direction that most closely matches the degree heading of the given line. Rounds clockwise if the heading is exactly between two directions.

Declaration

public static Direction GetDirection(int startX, int startY, int endX, int endY)

Parameters

Type	Name	Description
int	startX	X-value of the starting coordinate of the line.
int	startY	Y-value of the starting coordinate of the line.
int	endX	X-value of the ending coordinate of the line.
int	endY	Y-value of the ending coordinate of the line.

Returns

Type	Description
Direction	The direction that most closely matches the heading indicated by the given line.

GetHashCode()

Returns a hash-map value for the current object.

Declaration

public override int GetHashCode()

Returns

Type	Description
int

Overrides

ValueType.GetHashCode()

IsCardinal()

Returns true if the current direction is a cardinal direction.

Declaration

public bool IsCardinal()

Returns

Type	Description
bool	True if the current direction is a cardinal direction, false otherwise.

Matches(Direction)

True if the given direction has the same Type the current one.

Declaration

public bool Matches(Direction other)

Parameters

Type	Name	Description
Direction	other	Direction to compare.

Returns

Type	Description
bool	True if the two directions are the same, false if not.

SetYIncreasesUpwardsUnsafe(bool)

Changes the value of YIncreasesUpward. This operation is not safe to perform if another thread may be directly or indirectly using Directions. It is intended that this value be set once to match your environment as part of an initialization routine.

Declaration

public static void SetYIncreasesUpwardsUnsafe(bool newValue)

Parameters

Type	Name	Description
bool	newValue	New value to assign to YIncreasesUpward.

ToString()

Writes the string (eg. "UP", "UP_RIGHT", etc.) for the direction.

Declaration

public override string ToString()

Returns

Type	Description
string	String representation of the direction.

Overrides

ValueType.ToString()

Operators

operator +(Direction, int)

Moves the direction clockwise i times.

Declaration

public static Direction operator +(Direction d, int i)

Parameters

Type	Name	Description
Direction	d
int	i

Returns

Type	Description
Direction	The given direction moved clockwise i times.

operator +((int x, int y), Direction)

Translates the given position by one unit in the given direction.

Declaration

public static (int x, int y) operator +((int x, int y) tuple, Direction d)

Parameters

Type	Name	Description
(int x, int y)	tuple
Direction	d

Returns

Type	Description
(int x, int y)	Tuple (tuple.y + d.DeltaX, tuple.y + d.DeltaY).

operator --(Direction)

Moves the direction counter-clockwise by one.

Declaration

public static Direction operator --(Direction d)

Parameters

Type	Name	Description
Direction	d

Returns

Type	Description
Direction	The direction one unit counterclockwise of d.

operator ==(Direction, Direction)

True if the two directions have the same Type.

Declaration

public static bool operator ==(Direction lhs, Direction rhs)

Parameters

Type	Name	Description
Direction	lhs
Direction	rhs

Returns

Type	Description
bool	True if the two directions are equal, false if not.

implicit operator Types(Direction)

Implicitly converts a Direction to its corresponding Type.

Declaration

public static implicit operator Direction.Types(Direction direction)

Parameters

Type	Name	Description
Direction	direction

Returns

Type	Description
Direction.Types

implicit operator Direction(Types)

Implicitly converts an Direction.Types enum value to its corresponding Direction.

Declaration

public static implicit operator Direction(Direction.Types type)

Parameters

Type	Name	Description
Direction.Types	type

Returns

Type	Description
Direction

operator ++(Direction)

Moves the direction clockwise by one.

Declaration

public static Direction operator ++(Direction d)

Parameters

Type	Name	Description
Direction	d

Returns

Type	Description
Direction	The direction one unit clockwise of d.

operator !=(Direction, Direction)

True if the types are not equal.

Declaration

public static bool operator !=(Direction lhs, Direction rhs)

Parameters

Type	Name	Description
Direction	lhs
Direction	rhs

Returns

Type	Description
bool	True if the types are not equal, false if they are both equal.

operator -(Direction, int)

Moves the direction counter-clockwise i times.

Declaration

public static Direction operator -(Direction d, int i)

Parameters

Type	Name	Description
Direction	d
int	i

Returns

Type	Description
Direction	The given direction moved counter-clockwise i times.

Implements

IEquatable<T>

IMatchable<T>

Extension Methods

PropertyChangedEventHelpers.SafelySetProperty<TObject, TProperty>(TObject, ref TProperty, TProperty, EventHandler<ValueChangedEventArgs<TProperty>>?)

PropertyChangedEventHelpers.SafelySetProperty<TObject, TProperty>(TObject, ref TProperty, TProperty, EventHandler<ValueChangedEventArgs<TProperty>>?, EventHandler<ValueChangedEventArgs<TProperty>>?)