Entities

Functions

countEntities

▸ countEntities(entityType?, variant?, subType?, ignoreFriendly?): int

Helper function to count the number of entities in room. Use this over the vanilla Isaac.CountEntities method to avoid having to specify a spawner and to handle ignoring charmed enemies.

Parameters

Name	Type	Default value	Description
entityType	-1 | EntityType	-1	Optional. Default is -1, which matches every entity type.
variant	number	-1	Optional. Default is -1, which matches every variant.
subType	number	-1	Optional. Default is -1, which matches every sub-type.
ignoreFriendly	boolean	false	Optional. Default is false. Will throw a runtime error if set to true and the entityType is equal to -1.

Returns

int

Defined in

packages/isaacscript-common/src/functions/entities.ts:47

---

doesAnyEntityExist

▸ doesAnyEntityExist(entityTypes, ignoreFriendly?): boolean

Helper function to check if one or more matching entities exist in the current room. It uses the doesEntityExist helper function to determine this.

Parameters

Name	Type	Default value	Description
entityTypes	ReadonlySet<EntityType> | readonly EntityType[]	undefined	An array or set of the entity types that you want to check for. Will return true if any of the provided entity types exist.
ignoreFriendly	boolean	false	Optional. Default is false.

Returns

boolean

Defined in

packages/isaacscript-common/src/functions/entities.ts:90

---

doesEntityExist

▸ doesEntityExist(entityType?, variant?, subType?, ignoreFriendly?): boolean

Helper function to check if one or more of a specific kind of entity is present in the current room. It uses the countEntities helper function to determine this.

Parameters

Name	Type	Default value	Description
entityType	-1 | EntityType	-1	Optional. Default is -1, which matches every entity type.
variant	number	-1	Optional. Default is -1, which matches every variant.
subType	number	-1	Optional. Default is -1, which matches every sub-type.
ignoreFriendly	boolean	false	Optional. Default is false.

Returns

boolean

Defined in

packages/isaacscript-common/src/functions/entities.ts:114

---

getClosestEntityTo

▸ getClosestEntityTo<T>(referenceEntity, entities, filterFunc?): T | undefined

Given an array of entities, this helper function returns the closest one to a provided reference entity.

For example:

const player = Isaac.GetPlayer();
const gapers = getEntities(EntityType.GAPER);
const closestGaper = getClosestEntityTo(player, gapers);

Type parameters

Name	Type
T	extends AnyEntity

Parameters

Name	Type	Description
referenceEntity	Entity	The entity that is close by.
entities	readonly T[]	The array of entities to look through.
filterFunc?	(entity: T) => boolean	Optional. A function to filter for a specific type of entity, like e.g. an enemy with a certain amount of HP left.

Returns

T | undefined

Defined in

packages/isaacscript-common/src/functions/entities.ts:141

---

getConstituentsFromEntityID

▸ getConstituentsFromEntityID(entityID): [entityType: EntityType, variant: int, subType: int]

Helper function to get the entity type, variant, and sub-type from an EntityID.

Parameters

Name	Type
entityID	EntityID

Returns

[entityType: EntityType, variant: int, subType: int]

Defined in

packages/isaacscript-common/src/functions/entities.ts:164

---

getEntities

▸ getEntities(entityType?, variant?, subType?, ignoreFriendly?): readonly Entity[]

Helper function to get all of the entities in the room or all of the entities that match a specific entity type / variant / sub-type.

Due to bugs with Isaac.FindInRadius, this function uses Isaac.GetRoomEntities, which is more expensive but also more robust. (If a matching entity type is provided, then Isaac.FindByType will be used instead.)

For example:

// Make all of the entities in the room invisible.
for (const entity of getEntities()) {
  entity.Visible = false;
}

Parameters

Name	Type	Default value	Description
entityType	-1 | EntityType	-1	Optional. If specified, will only get the entities that match the type. Default is -1, which matches every type.
variant	number	-1	Optional. If specified, will only get the entities that match the variant. Default is -1, which matches every variant.
subType	number	-1	Optional. If specified, will only get the entities that match the sub-type. Default is -1, which matches every sub-type.
ignoreFriendly	boolean	false	Optional. If set to true, it will exclude friendly NPCs from being returned. Default is false. Will only be taken into account if the entityType is specified.

Returns

readonly Entity[]

Defined in

packages/isaacscript-common/src/functions/entities.ts:237

---

getEntityFields

▸ getEntityFields(entity): LuaMap<string, boolean | number | string>

Helper function to get all the fields on an entity. For example, this is useful for comparing it to another entity later. (One option is to use the logTableDifferences function for this.)

This function will only get fields that are equal to booleans, numbers, or strings, or Vectors, as comparing other types is non-trivial.

Parameters

Name	Type
entity	Entity

Returns

LuaMap<string, boolean | number | string>

Defined in

packages/isaacscript-common/src/functions/entities.ts:257

---

getEntityFromPtrHash

▸ getEntityFromPtrHash(ptrHash): Entity | undefined

Helper function to get an entity from a PtrHash. Note that doing this is very expensive, so you should only use this function when debugging. (Normally, if you need to work backwards from a reference, you would use an EntityPtr instead of a PtrHash.

Parameters

Name	Type
ptrHash	PtrHash

Returns

Entity | undefined

Defined in

packages/isaacscript-common/src/functions/entities.ts:320

---

getEntityID

▸ getEntityID(entity): EntityID

Helper function to get a string containing the entity's type, variant, and sub-type.

Parameters

Name	Type
entity	Entity

Returns

EntityID

Defined in

packages/isaacscript-common/src/functions/entities.ts:326

---

getEntityIDFromConstituents

▸ getEntityIDFromConstituents(entityType, variant, subType): EntityID

Helper function to get a formatted string in the format returned by the getEntityID function.

Parameters

Name	Type
entityType	EntityType
variant	int
subType	int

Returns

EntityID

Defined in

packages/isaacscript-common/src/functions/entities.ts:333

---

getFilteredNewEntities

▸ getFilteredNewEntities<T>(oldEntities, newEntities): readonly T[]

Helper function to compare two different arrays of entities. Returns the entities that are in the second array but not in the first array.

Type parameters

Name	Type
T	extends AnyEntity

Parameters

Name	Type
oldEntities	readonly T[]
newEntities	readonly T[]

Returns

readonly T[]

Defined in

packages/isaacscript-common/src/functions/entities.ts:345

---

hasArmor

▸ hasArmor(entity): boolean

Helper function to see if a particular entity has armor. In this context, armor refers to the damage scaling mechanic. For example, Ultra Greed has armor, but a Gaper does not.

For more on armor, see the wiki: https://bindingofisaacrebirth.fandom.com/wiki/Damage_Scaling

Parameters

Name	Type
entity	Entity

Returns

boolean

Defined in

packages/isaacscript-common/src/functions/entities.ts:367

---

isActiveEnemy

▸ isActiveEnemy(entity): boolean

Helper function to detect if a particular entity is an active enemy. Use this over the Entity.IsActiveEnemy method since it is bugged with friendly enemies, Grimaces, Ultra Greed, and Mother.

Parameters

Name	Type
entity	Entity

Returns

boolean

Defined in

packages/isaacscript-common/src/functions/entities.ts:377

---

isEntityMoving

▸ isEntityMoving(entity, threshold?): boolean

Helper function to measure an entity's velocity to see if it is moving.

Use this helper function over checking if the velocity length is equal to 0 because entities can look like they are completely immobile but yet still have a non zero velocity. Thus, using a threshold is needed.

Parameters

Name	Type	Default value	Description
entity	Entity	undefined	The entity whose velocity to measure.
threshold	number	0.01	Optional. The threshold from 0 to consider to be moving. Default is 0.01.

Returns

boolean

Defined in

packages/isaacscript-common/src/functions/entities.ts:458

---

parseEntityID

▸ parseEntityID(entityID): [entityType: EntityType, variant: int, subType: int] | undefined

Helper function to parse a string that contains an entity type, a variant, and a sub-type, separated by periods.

For example, passing "45.0.1" would return an array of [45, 0, 1].

Returns undefined if the string cannot be parsed.

Parameters

Name	Type
entityID	string

Returns

[entityType: EntityType, variant: int, subType: int] | undefined

Defined in

packages/isaacscript-common/src/functions/entities.ts:470

---

parseEntityTypeVariantString

▸ parseEntityTypeVariantString(entityTypeVariantString): [entityType: EntityType, variant: int] | undefined

Helper function to parse a string that contains an entity type and a variant separated by a period.

For example, passing "45.0" would return an array of [45, 0].

Returns undefined if the string cannot be parsed.

Parameters

Name	Type
entityTypeVariantString	string

Returns

[entityType: EntityType, variant: int] | undefined

Defined in

packages/isaacscript-common/src/functions/entities.ts:511

---

removeAllMatchingEntities

▸ removeAllMatchingEntities(entityType, entityVariant?, entitySubType?, cap?): readonly Entity[]

Helper function to remove all of the matching entities in the room.

Parameters

Name	Type	Default value	Description
entityType	EntityType	undefined	The entity type to match.
entityVariant	number	-1	Optional. The variant to match. Default is -1, which matches every variant.
entitySubType	number	-1	Optional. The sub-type to match. Default is -1, which matches every sub-type.
cap	undefined | int	undefined	Optional. If specified, will only remove the given amount of collectibles.

Returns

readonly Entity[]

An array of the entities that were removed.

Defined in

packages/isaacscript-common/src/functions/entities.ts:545

---

removeEntities

▸ removeEntities<T>(entities, cap?): readonly T[]

Helper function to remove all of the entities in the supplied array.

Type parameters

Name	Type
T	extends AnyEntity

Parameters

Name	Type	Description
entities	readonly T[]	The array of entities to remove.
cap?	int	Optional. If specified, will only remove the given amount of entities.

Returns

readonly T[]

An array of the entities that were removed.

Defined in

packages/isaacscript-common/src/functions/entities.ts:562

---

rerollEnemy

▸ rerollEnemy(entity): Entity | undefined

Helper function to reroll an enemy. Use this instead of the vanilla "Game.RerollEnemy" function if you want the rerolled enemy to be returned.

Parameters

Name	Type	Description
entity	Entity	The entity to reroll.

Returns

Entity | undefined

If the game failed to reroll the enemy, returns undefined. Otherwise, returns the rerolled entity.

Defined in

packages/isaacscript-common/src/functions/entities.ts:591

---

setEntityDamageFlash

▸ setEntityDamageFlash(entity): void

Helper function to make an entity flash red like it is taking damage. This is useful when you want to make it appear as if an entity is taking damage without actually dealing any damage to it.

Parameters

Name	Type
entity	Entity

Returns

void

Defined in

packages/isaacscript-common/src/functions/entities.ts:614

---

setEntityOpacity

▸ setEntityOpacity(entity, alpha): void

Helper function to keep an entity's color the same values as it already is but set the opacity to a specific value.

Parameters

Name	Type	Description
entity	Entity	The entity to set.
alpha	float	A value between 0 and 1 that represents the fade amount.

Returns

void

Defined in

packages/isaacscript-common/src/functions/entities.ts:625

---

setEntityRandomColor

▸ setEntityRandomColor(entity): void

Parameters

Name	Type
entity	Entity

Returns

void

Defined in

packages/isaacscript-common/src/functions/entities.ts:630

---

spawn

▸ spawn(entityType, variant, subType, positionOrGridIndex, velocity?, spawner?, seedOrRNG?): Entity

Helper function to spawn an entity. Use this instead of the Isaac.Spawn method if you do not need to specify the velocity or spawner.

Also see the spawnWithSeed helper function.

Parameters

Name	Type	Default value	Description
entityType	EntityType	undefined	The EntityType of the entity to spawn.
variant	int	undefined	The variant of the entity to spawn.
subType	int	undefined	The sub-type of the entity to spawn.
positionOrGridIndex	int | Vector	undefined	The position or grid index of the entity to spawn.
velocity	Vector	VectorZero	Optional. The velocity of the entity to spawn. Default is VectorZero.
spawner	undefined | Entity	undefined	Optional. The entity that will be the SpawnerEntity. Default is undefined.
seedOrRNG	undefined | RNG | Seed	undefined	Optional. The seed or RNG object to use to generate the InitSeed of the entity. Default is undefined, which will make the entity spawn with a random seed using the Isaac.Spawn method.

Returns

Entity

Defined in

packages/isaacscript-common/src/functions/entities.ts:658

---

spawnEntityID

▸ spawnEntityID(entityID, positionOrGridIndex, velocity?, spawner?, seedOrRNG?): Entity

Helper function to spawn the entity corresponding to an EntityID.

Parameters

Name	Type	Default value	Description
entityID	EntityID	undefined	The EntityID of the entity to spawn.
positionOrGridIndex	int | Vector	undefined	The position or grid index of the entity to spawn.
velocity	Vector	VectorZero	Optional. The velocity of the entity to spawn. Default is VectorZero.
spawner	undefined | Entity	undefined	Optional. The entity that will be the SpawnerEntity. Default is undefined.
seedOrRNG	undefined | RNG | Seed	undefined	Optional. The seed or RNG object to use to generate the InitSeed of the entity. Default is undefined, which will make the entity spawn with a random seed using the Isaac.Spawn method.

Returns

Entity

Defined in

packages/isaacscript-common/src/functions/entities.ts:715

---

spawnWithSeed

▸ spawnWithSeed(entityType, variant, subType, positionOrGridIndex, seedOrRNG, velocity?, spawner?): Entity

Helper function to spawn an entity. Use this instead of the Game.Spawn method if you do not need to specify the velocity or spawner.

Parameters

Name	Type	Default value
entityType	EntityType	undefined
variant	int	undefined
subType	int	undefined
positionOrGridIndex	int | Vector	undefined
seedOrRNG	RNG | Seed	undefined
velocity	Vector	VectorZero
spawner	undefined | Entity	undefined

Returns

Entity

Defined in

packages/isaacscript-common/src/functions/entities.ts:738