minecraft-src/net/minecraft/world/entity/ai/goal/TemptGoal.java

package net.minecraft.world.entity.ai.goal;

import java.util.EnumSet;
import java.util.function.Predicate;
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.targeting.TargetingConditions;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.phys.Vec3;
import org.jetbrains.annotations.Nullable;

public class TemptGoal extends Goal {
	private static final TargetingConditions TEMPT_TARGETING = TargetingConditions.forNonCombat().ignoreLineOfSight();
	private static final double DEFAULT_STOP_DISTANCE = 2.5;
	private final TargetingConditions targetingConditions;
	protected final Mob mob;
	protected final double speedModifier;
	private double px;
	private double py;
	private double pz;
	private double pRotX;
	private double pRotY;
	@Nullable
	protected Player player;
	private int calmDown;
	private boolean isRunning;
	private final Predicate<ItemStack> items;
	private final boolean canScare;
	private final double stopDistance;

	public TemptGoal(PathfinderMob mob, double speedModifier, Predicate<ItemStack> items, boolean canScare) {
		this((Mob)mob, speedModifier, items, canScare, 2.5);
	}

	public TemptGoal(PathfinderMob mob, double speedModifier, Predicate<ItemStack> items, boolean canScare, double stopDistance) {
		this((Mob)mob, speedModifier, items, canScare, stopDistance);
	}

	TemptGoal(Mob mob, double speedModifier, Predicate<ItemStack> items, boolean canScare, double stopDistance) {
		this.mob = mob;
		this.speedModifier = speedModifier;
		this.items = items;
		this.canScare = canScare;
		this.stopDistance = stopDistance;
		this.setFlags(EnumSet.of(Goal.Flag.MOVE, Goal.Flag.LOOK));
		this.targetingConditions = TEMPT_TARGETING.copy().selector((livingEntity, serverLevel) -> this.shouldFollow(livingEntity));
	}

	@Override
	public boolean canUse() {
		if (this.calmDown > 0) {
			this.calmDown--;
			return false;
		} else {
			this.player = getServerLevel(this.mob).getNearestPlayer(this.targetingConditions.range(this.mob.getAttributeValue(Attributes.TEMPT_RANGE)), this.mob);
			return this.player != null;
		}
	}

	private boolean shouldFollow(LivingEntity entity) {
		return this.items.test(entity.getMainHandItem()) || this.items.test(entity.getOffhandItem());
	}

	@Override
	public boolean canContinueToUse() {
		if (this.canScare()) {
			if (this.mob.distanceToSqr(this.player) < 36.0) {
				if (this.player.distanceToSqr(this.px, this.py, this.pz) > 0.010000000000000002) {
					return false;
				}

				if (Math.abs(this.player.getXRot() - this.pRotX) > 5.0 || Math.abs(this.player.getYRot() - this.pRotY) > 5.0) {
					return false;
				}
			} else {
				this.px = this.player.getX();
				this.py = this.player.getY();
				this.pz = this.player.getZ();
			}

			this.pRotX = this.player.getXRot();
			this.pRotY = this.player.getYRot();
		}

		return this.canUse();
	}

	protected boolean canScare() {
		return this.canScare;
	}

	@Override
	public void start() {
		this.px = this.player.getX();
		this.py = this.player.getY();
		this.pz = this.player.getZ();
		this.isRunning = true;
	}

	@Override
	public void stop() {
		this.player = null;
		this.stopNavigation();
		this.calmDown = reducedTickDelay(100);
		this.isRunning = false;
	}

	@Override
	public void tick() {
		this.mob.getLookControl().setLookAt(this.player, this.mob.getMaxHeadYRot() + 20, this.mob.getMaxHeadXRot());
		if (this.mob.distanceToSqr(this.player) < this.stopDistance * this.stopDistance) {
			this.stopNavigation();
		} else {
			this.navigateTowards(this.player);
		}
	}

	protected void stopNavigation() {
		this.mob.getNavigation().stop();
	}

	protected void navigateTowards(Player player) {
		this.mob.getNavigation().moveTo(player, this.speedModifier);
	}

	/**
	 * @see #isRunning
	 */
	public boolean isRunning() {
		return this.isRunning;
	}

	public static class ForNonPathfinders extends TemptGoal {
		public ForNonPathfinders(Mob mob, double d, Predicate<ItemStack> predicate, boolean bl, double e) {
			super(mob, d, predicate, bl, e);
		}

		@Override
		protected void stopNavigation() {
			this.mob.getMoveControl().setWait();
		}

		@Override
		protected void navigateTowards(Player player) {
			Vec3 vec3 = player.getEyePosition().subtract(this.mob.position()).scale(this.mob.getRandom().nextDouble()).add(this.mob.position());
			this.mob.getMoveControl().setWantedPosition(vec3.x, vec3.y, vec3.z, this.speedModifier);
		}
	}
}