minecraft-src/net/minecraft/world/entity/monster/Monster.java

package net.minecraft.world.entity.monster;

import java.util.function.Predicate;
import net.minecraft.core.BlockPos;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.sounds.SoundEvent;
import net.minecraft.sounds.SoundEvents;
import net.minecraft.sounds.SoundSource;
import net.minecraft.util.RandomSource;
import net.minecraft.world.Difficulty;
import net.minecraft.world.damagesource.DamageSource;
import net.minecraft.world.entity.EntitySpawnReason;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.Mob;
import net.minecraft.world.entity.PathfinderMob;
import net.minecraft.world.entity.ai.attributes.Attributes;
import net.minecraft.world.entity.ai.attributes.AttributeSupplier.Builder;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.Items;
import net.minecraft.world.item.ProjectileWeaponItem;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.LevelAccessor;
import net.minecraft.world.level.LevelReader;
import net.minecraft.world.level.LightLayer;
import net.minecraft.world.level.ServerLevelAccessor;
import net.minecraft.world.level.dimension.DimensionType;

public abstract class Monster extends PathfinderMob implements Enemy {
	protected Monster(EntityType<? extends Monster> entityType, Level level) {
		super(entityType, level);
		this.xpReward = 5;
	}

	@Override
	public SoundSource getSoundSource() {
		return SoundSource.HOSTILE;
	}

	@Override
	public void aiStep() {
		this.updateSwingTime();
		this.updateNoActionTime();
		super.aiStep();
	}

	protected void updateNoActionTime() {
		float f = this.getLightLevelDependentMagicValue();
		if (f > 0.5F) {
			this.noActionTime += 2;
		}
	}

	@Override
	protected boolean shouldDespawnInPeaceful() {
		return true;
	}

	@Override
	protected SoundEvent getSwimSound() {
		return SoundEvents.HOSTILE_SWIM;
	}

	@Override
	protected SoundEvent getSwimSplashSound() {
		return SoundEvents.HOSTILE_SPLASH;
	}

	@Override
	protected SoundEvent getHurtSound(DamageSource damageSource) {
		return SoundEvents.HOSTILE_HURT;
	}

	@Override
	protected SoundEvent getDeathSound() {
		return SoundEvents.HOSTILE_DEATH;
	}

	@Override
	public LivingEntity.Fallsounds getFallSounds() {
		return new LivingEntity.Fallsounds(SoundEvents.HOSTILE_SMALL_FALL, SoundEvents.HOSTILE_BIG_FALL);
	}

	@Override
	public float getWalkTargetValue(BlockPos pos, LevelReader level) {
		return -level.getPathfindingCostFromLightLevels(pos);
	}

	/**
	 * Static predicate for determining if the current light level and environmental conditions allow for a monster to spawn.
	 */
	public static boolean isDarkEnoughToSpawn(ServerLevelAccessor level, BlockPos pos, RandomSource random) {
		if (level.getBrightness(LightLayer.SKY, pos) > random.nextInt(32)) {
			return false;
		} else {
			DimensionType dimensionType = level.dimensionType();
			int i = dimensionType.monsterSpawnBlockLightLimit();
			if (i < 15 && level.getBrightness(LightLayer.BLOCK, pos) > i) {
				return false;
			} else {
				int j = level.getLevel().isThundering() ? level.getMaxLocalRawBrightness(pos, 10) : level.getMaxLocalRawBrightness(pos);
				return j <= dimensionType.monsterSpawnLightTest().sample(random);
			}
		}
	}

	public static boolean checkMonsterSpawnRules(
		EntityType<? extends Monster> entityType, ServerLevelAccessor level, EntitySpawnReason spawnReason, BlockPos pos, RandomSource random
	) {
		return level.getDifficulty() != Difficulty.PEACEFUL
			&& (EntitySpawnReason.ignoresLightRequirements(spawnReason) || isDarkEnoughToSpawn(level, pos, random))
			&& checkMobSpawnRules(entityType, level, spawnReason, pos, random);
	}

	public static boolean checkAnyLightMonsterSpawnRules(
		EntityType<? extends Monster> entityType, LevelAccessor level, EntitySpawnReason spawnReason, BlockPos pos, RandomSource random
	) {
		return level.getDifficulty() != Difficulty.PEACEFUL && checkMobSpawnRules(entityType, level, spawnReason, pos, random);
	}

	public static Builder createMonsterAttributes() {
		return Mob.createMobAttributes().add(Attributes.ATTACK_DAMAGE);
	}

	@Override
	public boolean shouldDropExperience() {
		return true;
	}

	@Override
	protected boolean shouldDropLoot() {
		return true;
	}

	public boolean isPreventingPlayerRest(ServerLevel level, Player player) {
		return true;
	}

	@Override
	public ItemStack getProjectile(ItemStack weaponStack) {
		if (weaponStack.getItem() instanceof ProjectileWeaponItem) {
			Predicate<ItemStack> predicate = ((ProjectileWeaponItem)weaponStack.getItem()).getSupportedHeldProjectiles();
			ItemStack itemStack = ProjectileWeaponItem.getHeldProjectile(this, predicate);
			return itemStack.isEmpty() ? new ItemStack(Items.ARROW) : itemStack;
		} else {
			return ItemStack.EMPTY;
		}
	}
}