Module technology.sola.engine

Package technology.sola.engine.physics.utils

Class SpatialHashMap

java.lang.Object

technology.sola.engine.physics.utils.SpatialHashMap

@NullMarked
public class SpatialHashMap
extends Object

The SpatialHashMap class is a spatial hashmap implementation that maps Entity into a bucket with other entities based on its 2D coordinate. This helps reduce the number of collision checks that are needed during broad phase collision detection.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final record	SpatialHashMap.BucketId	BucketId holds the top, left coordinate that identifies a bucket.

Constructor Summary

Constructors

Constructor	Description
SpatialHashMap(Collection<technology.sola.ecs.view.View2Entry<ColliderComponent,TransformComponent>> viewEntries)	Creates a SpatialHashMap with cellSize set to twice the max width/height of the largest Entity.
SpatialHashMap(Collection<technology.sola.ecs.view.View2Entry<ColliderComponent,TransformComponent>> viewEntries, int cellSize)	Creates a SpatialHashMap with desired cell size.

Method Summary

Modifier and Type	Method	Description
Set<SpatialHashMap.BucketId>	getBucketIds()
int	getCellSize()
List<technology.sola.ecs.view.View2Entry<ColliderComponent,TransformComponent>>	getNearbyViewEntries(technology.sola.ecs.view.View2Entry<ColliderComponent,TransformComponent> viewEntry)	Returns a list of ViewEntry containing an Entity that is in the same bucket as the entity to check.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

SpatialHashMap

public SpatialHashMap(Collection<technology.sola.ecs.view.View2Entry<ColliderComponent,TransformComponent>> viewEntries)

Creates a SpatialHashMap with cellSize set to twice the max width/height of the largest Entity.

Parameters:

viewEntries - the list of View2Entry of ColliderComponent and TransformComponent

SpatialHashMap

public SpatialHashMap(Collection<technology.sola.ecs.view.View2Entry<ColliderComponent,TransformComponent>> viewEntries,
 int cellSize)

Creates a SpatialHashMap with desired cell size. Ensure that the cellSize is greater than the max width or height of the largest Entity.

Parameters:

viewEntries - the list of View2Entry of ColliderComponent and TransformComponent

cellSize - the cell size of the SpatialHashMap

Method Details

getCellSize

public int getCellSize()

Returns:

the current cell size of this spatial hashmap

getNearbyViewEntries

public List<technology.sola.ecs.view.View2Entry<ColliderComponent,TransformComponent>> getNearbyViewEntries(technology.sola.ecs.view.View2Entry<ColliderComponent,TransformComponent> viewEntry)

Returns a list of ViewEntry containing an Entity that is in the same bucket as the entity to check.

Parameters:

viewEntry - the view entry containing the entity to check

Returns:

list of nearby entities

getBucketIds

public Set<SpatialHashMap.BucketId> getBucketIds()

Returns:

the set of current SpatialHashMap.BucketIds