Class GoalMap

Implementation of a goal map system, also known as Dijkstra maps, based on this article

Inheritance

object

GridViewBase<double?>

GoalMap

Implements

IGridView<double?>

Inherited Members

GridViewBase<double?>.Count

GridViewBase<double?>.this[int, int]

GridViewBase<double?>.this[int]

object.GetType()

object.MemberwiseClone()

object.Equals(object)

object.Equals(object, object)

object.ReferenceEquals(object, object)

object.GetHashCode()

Namespace: GoRogue.Pathing

Assembly: GoRogue.dll

Syntax

public class GoalMap : GridViewBase<double?>, IGridView<double?>

Remarks

This class encapsulates the work of building a goal map from your map level. You provide the constructor with a map view representing the map as GoalState values, and GoalMap will compute the goal map for the level. When the underlying circumstances of the level change, the GoalMap instance will need to be updated. Call Update() if obstacles have changed, or UpdatePathsOnly() if the goals have changed but not the obstacles. This class exposes the resulting goal map to you via indexers -- GoalMap implements IGridView<T>, where null indicates a square is an obstacle, and any other value indicates distance from the nearest goal. Thus, a value of 0 indicates a tile contains a goal. For items following the GoalMap, they can simply call GetDirectionOfMinValue(Point)

Constructors

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GoalMap(IGridView<GoalState>, Distance)

Constructor. Takes a base map and a distance measurement to use for calculation.

Declaration

public GoalMap(IGridView<GoalState> baseMap, Distance distanceMeasurement)

Parameters

Type	Name	Description
IGridView<GoalState>	baseMap	A map view that represents the map as an IGridView<T> of GoalState. Must not change width/height after the goal map has been constructed.
Distance	distanceMeasurement	The distance measurement (and implicitly the AdjacencyRule) to use for calculation.

Fields

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DistanceMeasurement

The distance measurement the GoalMap is using to calculate distance.

Declaration

public readonly Distance DistanceMeasurement

Field Value

Type	Description
Distance

Properties

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BaseMap

The map view of the underlying map used to determine where obstacles/goals are. Must not change width or height after the GoalMap has been constructed.

Declaration

public IGridView<GoalState> BaseMap { get; }

Property Value

Type	Description
IGridView<GoalState>

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Height

Height of the goal map.

Declaration

public override int Height { get; }

Property Value

Type	Description
int

Overrides

SadRogue.Primitives.GridViews.GridViewBase<double?>.Height

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this[Point]

Returns the goal-map value for the given position.

Declaration

public override double? this[Point pos] { get; }

Parameters

Type	Name	Description
Point	pos	The position to return the goal-map value for.

Property Value

Type	Description
double?	The goal-map value for the given position.

Overrides

SadRogue.Primitives.GridViews.GridViewBase<double?>.this[SadRogue.Primitives.Point]

View Source

Width

Width of the goal map.

Declaration

public override int Width { get; }

Property Value

Type	Description
int

Overrides

SadRogue.Primitives.GridViews.GridViewBase<double?>.Width

Methods

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GetDirectionOfMinValue(Point)

Gets the direction of the neighbor with the minimum goal-map value from the given position.

Declaration

public Direction GetDirectionOfMinValue(Point position)

Parameters

Type	Name	Description
Point	position	The position to get the minimum value for.

Returns

Type	Description
Direction	The direction that has the minimum value in the goal-map, or None if the neighbors are all obstacles.

View Source

GetDirectionOfMinValue(int, int)

Gets the direction of the neighbor with the minimum goal-map value from the given position.

Declaration

public Direction GetDirectionOfMinValue(int positionX, int positionY)

Parameters

Type	Name	Description
int	positionX	The x-value of the position to get the minimum value for.
int	positionY	The y-value of the position to get the minimum value for.

Returns

Type	Description
Direction	The direction that has the minimum value in the goal-map, or None if the neighbors are all obstacles.

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ToString()

Returns the goal-map values represented as a 2D grid-style string.

Declaration

public override string ToString()

Returns

Type	Description
string	A string representing the goal map values.

Overrides

object.ToString()

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ToString(int)

Returns the goal-map values represented as a 2D-grid-style string, with the given field size.

Declaration

public string ToString(int fieldSize)

Parameters

Type	Name	Description
int	fieldSize	Number of characters allocated to each value in the string.

Returns

Type	Description
string	A string representing the goal-map values.

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ToString(int, string)

Returns the goal-map values represented as a 2D-grid-style string, with the given field size, and any non-null values formatted using the given format string.

Declaration

public string ToString(int fieldSize, string formatString)

Parameters

Type	Name	Description
int	fieldSize	Number of characters allocated to each value in the string.
string	formatString	Format string to use for non-null values.

Returns

Type	Description
string	A string representing the goal-map values.

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ToString(string)

Returns the goal-map values represented as a 2D-grid-style string, where any value that isn't null is formatted as per the specified format string.

Declaration

public string ToString(string formatString)

Parameters

Type	Name	Description
string	formatString	Format string to use for non-null values.

Returns

Type	Description
string	A string representing the goal-map values.

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Update()

Re-evaluates the entire goal map. Should be called when obstacles change. If the obstacles have not changed but the goals have, call UpdatePathsOnly() for better efficiency.

Declaration

public bool Update()

Returns

Type	Description
bool	False if no goals were produced by the evaluator, true otherwise

View Source

UpdatePathsOnly()

Re-evaluates the walkable portion of the goal map. Should be called anytime the goals change but the obstacles haven't. If the obstacles have also changed, call Update() instead.

Declaration

public bool UpdatePathsOnly()

Returns

Type	Description
bool	False if no goals were produced by the evaluator, true otherwise

Events

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Updated

Triggers when the GoalMap is updated.

Declaration

public event Action Updated

Event Type

Type	Description
Action

Implements

IGridView<T>

Extension Methods

Utility.Yield<T>(T)

GoalMapExtensions.GetDirectionOfMinValue(IGridView<double?>, Point, AdjacencyRule)

GoalMapExtensions.GetDirectionOfMinValue(IGridView<double?>, int, int, AdjacencyRule)