Package net.neoforged.neoforge.event.entity.living

Class MobSpawnEvent.SpawnPlacementCheck

java.lang.Object

net.neoforged.bus.api.Event

net.neoforged.neoforge.event.entity.living.MobSpawnEvent.SpawnPlacementCheck

Enclosing class:

MobSpawnEvent

public static class MobSpawnEvent.SpawnPlacementCheck
extends net.neoforged.bus.api.Event

This event is fired when Spawn Placements (aka Spawn Rules) are checked, before a mob attempts to spawn.
Spawn Placement checks include light levels, slime chunks, grass blocks for animals, and others in the same vein.
The purpose of this event is to permit runtime changes to any or all spawn placement logic without having to wrap the placement for each entity.

This event is only fired on the logical server.

This event is not fired for mob spawners which utilize SpawnData.CustomSpawnRules, as they do not check spawn placements.

See Also:

• SpawnPlacementRegisterEvent

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static enum	MobSpawnEvent.SpawnPlacementCheck.Result

Field Summary

Fields

Modifier and Type	Field	Description
private final boolean	defaultResult
private final EntityType<?>	entityType
private final ServerLevelAccessor	level
private final BlockPos	pos
private final RandomSource	random
private MobSpawnEvent.SpawnPlacementCheck.Result	result
private final MobSpawnType	spawnType

Constructor Summary

Constructors

Constructor	Description
SpawnPlacementCheck(EntityType<?> entityType, ServerLevelAccessor level, MobSpawnType spawnType, BlockPos pos, RandomSource random, boolean defaultResult)	Internal.

Method Summary

Modifier and Type	Method	Description
boolean	getDefaultResult()	The default vanilla result is useful if an additional check wants to force invalid reference Result#ALLOW only if the vanilla check would succeed.
EntityType<?>	getEntityType()
ServerLevelAccessor	getLevel()
boolean	getPlacementCheckResult()	Returns If the placement check will succeed or not, based on the current event result.
BlockPos	getPos()
RandomSource	getRandom()	In all vanilla cases, this is equal to LevelAccessor.getRandom().
MobSpawnEvent.SpawnPlacementCheck.Result	getResult()	Returns the result of this event, which controls if the placement check will succeed.
MobSpawnType	getSpawnType()	Retrieves the type of mob spawn that is happening.
void	setResult(MobSpawnEvent.SpawnPlacementCheck.Result result)	Changes the result of this event.

Methods inherited from class java.lang.Object

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

Field Details

entityType

private final EntityType<?> entityType

level

private final ServerLevelAccessor level

spawnType

private final MobSpawnType spawnType

pos

private final BlockPos pos

random

private final RandomSource random

defaultResult

private final boolean defaultResult

result

private MobSpawnEvent.SpawnPlacementCheck.Result result

Constructor Details

SpawnPlacementCheck

@Internal
public SpawnPlacementCheck(EntityType<?> entityType,
 ServerLevelAccessor level,
 MobSpawnType spawnType,
 BlockPos pos,
 RandomSource random,
 boolean defaultResult)

Internal.

Method Details

getEntityType

public EntityType<?> getEntityType()

Returns:

The type of entity that checks are being performed for.

getLevel

public ServerLevelAccessor getLevel()

Returns:

The level relating to the mob spawn action

getSpawnType

public MobSpawnType getSpawnType()

Retrieves the type of mob spawn that is happening.

Returns:

The mob spawn type.

See Also:

• MobSpawnType

getPos

public BlockPos getPos()

Returns:

The position where checks are being evaluated.

getRandom

public RandomSource getRandom()

In all vanilla cases, this is equal to LevelAccessor.getRandom().

Returns:

The random source being used.

getDefaultResult

public boolean getDefaultResult()

The default vanilla result is useful if an additional check wants to force

invalid reference

Result#ALLOW

only if the vanilla check would succeed.

Returns:

The result of the vanilla spawn placement check.

setResult

public void setResult(MobSpawnEvent.SpawnPlacementCheck.Result result)

Changes the result of this event.

getResult

public MobSpawnEvent.SpawnPlacementCheck.Result getResult()

Returns the result of this event, which controls if the placement check will succeed.

Returns:

the result of this event, which controls if the placement check will succeed

getPlacementCheckResult

public boolean getPlacementCheckResult()

Returns If the placement check will succeed or not, based on the current event result.

Returns:

If the placement check will succeed or not, based on the current event result