Class PolygonArea

An area with an arbitrary number of sides and corners

Inheritance

object

PolygonArea

Implements

IReadOnlyArea

IMatchable<IReadOnlyArea>

IEnumerable<Point>

IEnumerable

IMatchable<PolygonArea>

Inherited Members

object.GetType()

object.MemberwiseClone()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Namespace: GoRogue.MapGeneration

Assembly: GoRogue.dll

Syntax

public class PolygonArea : IReadOnlyArea, IMatchable<IReadOnlyArea>, IEnumerable<Point>, IEnumerable, IMatchable<PolygonArea>

Constructors

PolygonArea(Algorithm, params Point[])

Returns a new PolygonArea with corners at the provided points.

Declaration

public PolygonArea(Lines.Algorithm algorithm, params Point[] corners)

Parameters

Type	Name	Description
Lines.Algorithm	algorithm	Which Line-drawing algorithm to use
Point[]	corners	The points which are corners for this polygon

Exceptions

Type	Condition
ArgumentException	Must have 3 or more corners; Algorithm must produce ordered lines.

PolygonArea(params Point[])

Returns a new polygon with corners at the provided points, using the algorithm DDA to produce lines

Declaration

public PolygonArea(params Point[] corners)

Parameters

Type	Name	Description
Point[]	corners	The corners of the polygon

Exceptions

Type	Condition
ArgumentException	Must have 3 or more corners; Algorithm must produce ordered lines.

PolygonArea(IEnumerable<Point>, Algorithm)

Creates a new Polygon, with corners at the provided points

Declaration

public PolygonArea(IEnumerable<Point> corners, Lines.Algorithm algorithm = Algorithm.Bresenham)

Parameters

Type	Name	Description
IEnumerable<Point>	corners	Each corner of the polygon, which is copied into a new list
Lines.Algorithm	algorithm	Which Line Algorithm to use

Exceptions

Type	Condition
ArgumentException	Must have 3 or more corners; Algorithm must produce ordered lines.

PolygonArea(ref List<Point>, Algorithm)

Creates a new Polygon, with corners at the provided points

Declaration

public PolygonArea(ref List<Point> corners, Lines.Algorithm algorithm = Algorithm.Bresenham)

Parameters

Type	Name	Description
List<Point>	corners	The corners of this polygon
Lines.Algorithm	algorithm	Which Line Algorithm to use

Exceptions

Type	Condition
ArgumentException	Must have 3 or more corners; Algorithm must produce ordered lines.

Fields

LineAlgorithm

Which Line-Drawing algorithm to use

Declaration

public readonly Lines.Algorithm LineAlgorithm

Field Value

Type	Description
Lines.Algorithm

Properties

Bottom

The bottom-most Y-value of the Polygon

Declaration

public int Bottom { get; }

Property Value

Type	Description
int

Bounds

Smallest possible rectangle that encompasses every position in the area.

Declaration

public Rectangle Bounds { get; }

Property Value

Type	Description
Rectangle

Center

The Center point of this Polygon

Declaration

public Point Center { get; }

Property Value

Type	Description
Point

Remarks

There is no guarantee that the center point lies within the polygon

Corners

The corners of this polygon

Declaration

public IReadOnlyList<Point> Corners { get; }

Property Value

Type	Description
IReadOnlyList<Point>

Count

Number of (unique) positions in the current area.

Declaration

public int Count { get; }

Property Value

Type	Description
int

Height

how tall this Polygon is

Declaration

public int Height { get; }

Property Value

Type	Description
int

InnerPoints

The interior points of the polygon

Declaration

public IReadOnlyArea InnerPoints { get; }

Property Value

Type	Description
IReadOnlyArea

this[int]

Returns positions from the area in the same fashion you would via a list.

Declaration

public Point this[int index] { get; }

Parameters

Type	Name	Description
int	index	Index of list to retrieve.

Property Value

Type	Description
Point

Left

The left-most X-value of the Polygon

Declaration

public int Left { get; }

Property Value

Type	Description
int

OuterPoints

The exterior points of the polygon

Declaration

public IReadOnlyMultiArea OuterPoints { get; }

Property Value

Type	Description
IReadOnlyMultiArea

Right

The right-most X-value of the Polygon

Declaration

public int Right { get; }

Property Value

Type	Description
int

Top

The top-most Y-value of the Polygon

Declaration

public int Top { get; }

Property Value

Type	Description
int

UseIndexEnumeration

Whether or not it is more efficient for this implementation to use enumeration by index, rather than generic IEnumerable, when iterating over positions using ReadOnlyAreaPositionsEnumerator.

Declaration

public bool UseIndexEnumeration { get; }

Property Value

Type	Description
bool

Remarks

Set this to true if your indexer implementation scales well (constant time), and is relatively fast. Implementations with more complex indexers should set this to false.

The default interface implementation returns false, in order to preserve backwards compatibility with previous versions.

If you set this to false, your IEnumerable.GetEnumerator() implementations must NOT call return a ReadOnlyAreaPositionsEnumerator, as this will create an infinite loop.

Width

How Wide this Polygon is

Declaration

public int Width { get; }

Property Value

Type	Description
int

Methods

Contains(IReadOnlyArea)

Returns whether or not the given area is completely contained within the current one.

Declaration

public bool Contains(IReadOnlyArea area)

Parameters

Type	Name	Description
IReadOnlyArea	area	Area to check.

Returns

Type	Description
bool	True if the given area is completely contained within the current one, false otherwise.

Contains(Point)

Determines whether or not the given position is considered within the area or not.

Declaration

public bool Contains(Point position)

Parameters

Type	Name	Description
Point	position	The position to check.

Returns

Type	Description
bool	True if the specified position is within the area, false otherwise.

Contains(int, int)

Determines whether or not the given position is considered within the area or not.

Declaration

public bool Contains(int positionX, int positionY)

Parameters

Type	Name	Description
int	positionX	X-value of the position to check.
int	positionY	X-value of the position to check.

Returns

Type	Description
bool	True if the specified position is within the area, false otherwise.

FlipHorizontal(int)

Flip horizontally around an X-axis

Declaration

public PolygonArea FlipHorizontal(int x)

Parameters

Type	Name	Description
int	x	The value around which to flip.

Returns

Type	Description
PolygonArea	A new, flipped PolygonArea

FlipVertical(int)

Flip vertically around a Y-axis

Declaration

public PolygonArea FlipVertical(int y)

Parameters

Type	Name	Description
int	y	The value around which to flip.

Returns

Type	Description
PolygonArea

GetEnumerator()

Declaration

public IEnumerator<Point> GetEnumerator()

Returns

Type	Description
IEnumerator<Point>

Intersects(IReadOnlyArea)

Returns whether or not the given map area intersects the current one. If you intend to determine/use the exact intersection based on this return value, it is best to instead call GetIntersection(IReadOnlyArea, IReadOnlyArea, IEqualityComparer<Point>), and check the number of positions in the result (0 if no intersection).

Declaration

public bool Intersects(IReadOnlyArea area)

Parameters

Type	Name	Description
IReadOnlyArea	area	The area to check.

Returns

Type	Description
bool	True if the given area intersects the current one, false otherwise.

IsCorner(Point)

Returns true if the position provided is a corner of this polygon

Declaration

public bool IsCorner(Point position)

Parameters

Type	Name	Description
Point	position

Returns

Type	Description
bool

Matches(PolygonArea?)

Compares the polygons to ensure that they are defined by the same corners, and thus represent the same area.

Declaration

public bool Matches(PolygonArea? other)

Parameters

Type	Name	Description
PolygonArea	other

Returns

Type	Description
bool	True if the polygons represent the same area; false otherwise.

Matches(IReadOnlyArea?)

Returns true if the given object is considered "equal" to the current one, based on the definition of equality for the object.

Declaration

public bool Matches(IReadOnlyArea? other)

Parameters

Type	Name	Description
IReadOnlyArea	other	Object to compare to.

Returns

Type	Description
bool	True if the objects are considered equal, false, otherwise.

Parallelogram(Point, int, int, bool, Algorithm)

Creates a new Polygon in the shape of a parallelogram.

Declaration

public static PolygonArea Parallelogram(Point origin, int width, int height, bool fromTop = false, Lines.Algorithm algorithm = Algorithm.Bresenham)

Parameters

Type	Name	Description
Point	origin	Origin of the parallelogram.
int	width	Width of the parallelogram.
int	height	Height of the parallelogram.
bool	fromTop	Whether the parallelogram extends downward-right or upwards-right from the start
Lines.Algorithm	algorithm	Line-drawing algorithm to use for finding boundaries.

Returns

Type	Description
PolygonArea	A new Polygon in the shape of a parallelogram

Exceptions

Type	Condition
ArgumentException	Must have 3 or more corners; Algorithm must produce ordered lines.

Rectangle(Rectangle, Algorithm)

Creates a new Polygon from a GoRogue.Rectangle.

Declaration

public static PolygonArea Rectangle(Rectangle rectangle, Lines.Algorithm algorithm = Algorithm.Bresenham)

Parameters

Type	Name	Description
Rectangle	rectangle	The rectangle
Lines.Algorithm	algorithm	Line-drawing algorithm to use for finding boundaries.

Returns

Type	Description
PolygonArea	A new Polygon in the shape of a rectangle

Exceptions

Type	Condition
ArgumentException	Must have 3 or more corners; Algorithm must produce ordered lines.

RegularPolygon(Point, int, double, Algorithm)

Creates a polygon whose sides are even-length

Declaration

public static PolygonArea RegularPolygon(Point center, int numberOfSides, double radius, Lines.Algorithm algorithm = Algorithm.Bresenham)

Parameters

Type	Name	Description
Point	center	The center point of this polygon
int	numberOfSides	Number of sides and corners on this polygon
double	radius	The desired distance between the center and each corner
Lines.Algorithm	algorithm	Which line-drawing algorithm to use

Returns

Type	Description
PolygonArea

Exceptions

Type	Condition
ArgumentException	Must have 3 or more corners; Algorithm must produce ordered lines.

RegularStar(Point, int, double, double, Algorithm)

Creates a new star-shaped polygon

Declaration

public static PolygonArea RegularStar(Point center, int points, double outerRadius, double innerRadius, Lines.Algorithm algorithm = Algorithm.Bresenham)

Parameters

Type	Name	Description
Point	center	The center point of the star
int	points	How many points this star has
double	outerRadius	The distance between the center and a tip of the star
double	innerRadius	The distance between the center and an armpit of the star
Lines.Algorithm	algorithm	Which line-drawing algorithm to use

Returns

Type	Description
PolygonArea

Exceptions

Type	Condition
ArgumentException	Stars must have 3 or more points; algorithm must be ordered; inner and outer radius must be positive

Rotate(double)

Rotates the Polygon around it's center.

Declaration

public PolygonArea Rotate(double degrees)

Parameters

Type	Name	Description
double	degrees	The amount of degrees to rotate

Returns

Type	Description
PolygonArea	A new, rotated PolygonArea

Rotate(double, Point)

Rotates the Polygon around a point of origin

Declaration

public PolygonArea Rotate(double degrees, Point origin)

Parameters

Type	Name	Description
double	degrees	The amount of degrees to rotate
Point	origin	The Point around which to rotate

Returns

Type	Description
PolygonArea	A new, rotated PolygonArea

ToString()

Returns a string detailing the region's corner locations.

Declaration

public override string ToString()

Returns

Type	Description
string

Overrides

object.ToString()

Translate(Point)

Moves the Polygon in the indicated direction.

Declaration

public PolygonArea Translate(Point delta)

Parameters

Type	Name	Description
Point	delta	The amount (X and Y) to translate by.

Returns

Type	Description
PolygonArea	A new, translated PolygonArea

Translate(int, int)

Moves the Polygon in the indicated direction.

Declaration

public PolygonArea Translate(int dx, int dy)

Parameters

Type	Name	Description
int	dx	The X-value by which to shift
int	dy	The Y-value by which to shift

Returns

Type	Description
PolygonArea

Transpose(Point)

Invert the X and Y values of a Polygon, respective to a diagonal line

Declaration

public PolygonArea Transpose(Point xy)

Parameters

Type	Name	Description
Point	xy	Any point which intersects the line around which to transpose

Returns

Type	Description
PolygonArea	A new PolygonArea

Transpose(int, int)

Invert the X and Y values of a Polygon, respective to a diagonal line

Declaration

public PolygonArea Transpose(int x, int y)

Parameters

Type	Name	Description
int	x	Any X-value of a point which intersects the line around which to transpose
int	y	Any Y-value of a Point which intersects the line around which to transpose

Returns

Type	Description
PolygonArea	A new PolygonArea

Implements

IReadOnlyArea

IMatchable<T>

IEnumerable<T>

IEnumerable

IMatchable<T>

Extension Methods

Utility.Yield<T>(T)

LineHelpers.BottomAt(IEnumerable<Point>, int)

LineHelpers.LeftAt(IEnumerable<Point>, int)

LineHelpers.RightAt(IEnumerable<Point>, int)

LineHelpers.TopAt(IEnumerable<Point>, int)