minecraft-src/net/minecraft/world/entity/projectile/Projectile.java

package net.minecraft.world.entity.projectile;

import com.google.common.base.MoreObjects;
import it.unimi.dsi.fastutil.doubles.DoubleDoubleImmutablePair;
import java.util.function.Consumer;
import net.minecraft.core.BlockPos;
import net.minecraft.network.protocol.Packet;
import net.minecraft.network.protocol.game.ClientGamePacketListener;
import net.minecraft.network.protocol.game.ClientboundAddEntityPacket;
import net.minecraft.server.level.ServerEntity;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.tags.EntityTypeTags;
import net.minecraft.util.Mth;
import net.minecraft.world.damagesource.DamageSource;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.EntityReference;
import net.minecraft.world.entity.EntitySelector;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.TraceableEntity;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.item.Item;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.enchantment.EnchantmentHelper;
import net.minecraft.world.level.GameRules;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.gameevent.GameEvent;
import net.minecraft.world.level.storage.ValueInput;
import net.minecraft.world.level.storage.ValueOutput;
import net.minecraft.world.phys.AABB;
import net.minecraft.world.phys.BlockHitResult;
import net.minecraft.world.phys.EntityHitResult;
import net.minecraft.world.phys.HitResult;
import net.minecraft.world.phys.Vec3;
import org.jetbrains.annotations.Nullable;

public abstract class Projectile extends Entity implements TraceableEntity {
	private static final boolean DEFAULT_LEFT_OWNER = false;
	private static final boolean DEFAULT_HAS_BEEN_SHOT = false;
	@Nullable
	protected EntityReference<Entity> owner;
	private boolean leftOwner = false;
	private boolean hasBeenShot = false;
	@Nullable
	private Entity lastDeflectedBy;

	Projectile(EntityType<? extends Projectile> entityType, Level level) {
		super(entityType, level);
	}

	protected void setOwner(@Nullable EntityReference<Entity> owner) {
		this.owner = owner;
	}

	public void setOwner(@Nullable Entity owner) {
		this.setOwner(owner != null ? new EntityReference<>(owner) : null);
	}

	@Nullable
	@Override
	public Entity getOwner() {
		return EntityReference.get(this.owner, this.level(), Entity.class);
	}

	public Entity getEffectSource() {
		return MoreObjects.firstNonNull(this.getOwner(), this);
	}

	@Override
	protected void addAdditionalSaveData(ValueOutput output) {
		EntityReference.store(this.owner, output, "Owner");
		if (this.leftOwner) {
			output.putBoolean("LeftOwner", true);
		}

		output.putBoolean("HasBeenShot", this.hasBeenShot);
	}

	protected boolean ownedBy(Entity entity) {
		return this.owner != null && this.owner.matches(entity);
	}

	@Override
	protected void readAdditionalSaveData(ValueInput input) {
		this.setOwner(EntityReference.read(input, "Owner"));
		this.leftOwner = input.getBooleanOr("LeftOwner", false);
		this.hasBeenShot = input.getBooleanOr("HasBeenShot", false);
	}

	@Override
	public void restoreFrom(Entity entity) {
		super.restoreFrom(entity);
		if (entity instanceof Projectile projectile) {
			this.owner = projectile.owner;
		}
	}

	@Override
	public void tick() {
		if (!this.hasBeenShot) {
			this.gameEvent(GameEvent.PROJECTILE_SHOOT, this.getOwner());
			this.hasBeenShot = true;
		}

		if (!this.leftOwner) {
			this.leftOwner = this.checkLeftOwner();
		}

		super.tick();
	}

	private boolean checkLeftOwner() {
		Entity entity = this.getOwner();
		if (entity != null) {
			AABB aABB = this.getBoundingBox().expandTowards(this.getDeltaMovement()).inflate(1.0);
			return entity.getRootVehicle().getSelfAndPassengers().filter(EntitySelector.CAN_BE_PICKED).noneMatch(entityx -> aABB.intersects(entityx.getBoundingBox()));
		} else {
			return true;
		}
	}

	public Vec3 getMovementToShoot(double x, double y, double z, float velocity, float inaccuracy) {
		return new Vec3(x, y, z)
			.normalize()
			.add(this.random.triangle(0.0, 0.0172275 * inaccuracy), this.random.triangle(0.0, 0.0172275 * inaccuracy), this.random.triangle(0.0, 0.0172275 * inaccuracy))
			.scale(velocity);
	}

	/**
	 * Similar to setArrowHeading, it's point the throwable entity to a x, y, z direction.
	 */
	public void shoot(double x, double y, double z, float velocity, float inaccuracy) {
		Vec3 vec3 = this.getMovementToShoot(x, y, z, velocity, inaccuracy);
		this.setDeltaMovement(vec3);
		this.hasImpulse = true;
		double d = vec3.horizontalDistance();
		this.setYRot((float)(Mth.atan2(vec3.x, vec3.z) * 180.0F / (float)Math.PI));
		this.setXRot((float)(Mth.atan2(vec3.y, d) * 180.0F / (float)Math.PI));
		this.yRotO = this.getYRot();
		this.xRotO = this.getXRot();
	}

	public void shootFromRotation(Entity shooter, float x, float y, float z, float velocity, float inaccuracy) {
		float f = -Mth.sin(y * (float) (Math.PI / 180.0)) * Mth.cos(x * (float) (Math.PI / 180.0));
		float g = -Mth.sin((x + z) * (float) (Math.PI / 180.0));
		float h = Mth.cos(y * (float) (Math.PI / 180.0)) * Mth.cos(x * (float) (Math.PI / 180.0));
		this.shoot(f, g, h, velocity, inaccuracy);
		Vec3 vec3 = shooter.getKnownMovement();
		this.setDeltaMovement(this.getDeltaMovement().add(vec3.x, shooter.onGround() ? 0.0 : vec3.y, vec3.z));
	}

	@Override
	public void onAboveBubbleColumn(boolean downwards, BlockPos pos) {
		double d = downwards ? -0.03 : 0.1;
		this.setDeltaMovement(this.getDeltaMovement().add(0.0, d, 0.0));
		sendBubbleColumnParticles(this.level(), pos);
	}

	@Override
	public void onInsideBubbleColumn(boolean downwards) {
		double d = downwards ? -0.03 : 0.06;
		this.setDeltaMovement(this.getDeltaMovement().add(0.0, d, 0.0));
		this.resetFallDistance();
	}

	public static <T extends Projectile> T spawnProjectileFromRotation(
		Projectile.ProjectileFactory<T> factory, ServerLevel level, ItemStack spawnedFrom, LivingEntity owner, float z, float velocity, float inaccuracy
	) {
		return spawnProjectile(
			factory.create(level, owner, spawnedFrom),
			level,
			spawnedFrom,
			projectile -> projectile.shootFromRotation(owner, owner.getXRot(), owner.getYRot(), z, velocity, inaccuracy)
		);
	}

	public static <T extends Projectile> T spawnProjectileUsingShoot(
		Projectile.ProjectileFactory<T> factory,
		ServerLevel level,
		ItemStack spawnedFrom,
		LivingEntity owner,
		double x,
		double y,
		double z,
		float velocity,
		float inaccuracy
	) {
		return spawnProjectile(factory.create(level, owner, spawnedFrom), level, spawnedFrom, projectile -> projectile.shoot(x, y, z, velocity, inaccuracy));
	}

	public static <T extends Projectile> T spawnProjectileUsingShoot(
		T projectile, ServerLevel level, ItemStack spawnedFrom, double x, double y, double z, float velocity, float inaccuracy
	) {
		return spawnProjectile(projectile, level, spawnedFrom, projectile2 -> projectile.shoot(x, y, z, velocity, inaccuracy));
	}

	public static <T extends Projectile> T spawnProjectile(T projectile, ServerLevel level, ItemStack spawnedFrom) {
		return spawnProjectile(projectile, level, spawnedFrom, projectilex -> {});
	}

	public static <T extends Projectile> T spawnProjectile(T projectile, ServerLevel level, ItemStack stack, Consumer<T> adapter) {
		adapter.accept(projectile);
		level.addFreshEntity(projectile);
		projectile.applyOnProjectileSpawned(level, stack);
		return projectile;
	}

	public void applyOnProjectileSpawned(ServerLevel level, ItemStack spawnedFrom) {
		EnchantmentHelper.onProjectileSpawned(level, spawnedFrom, this, item -> {});
		if (this instanceof AbstractArrow abstractArrow) {
			ItemStack itemStack = abstractArrow.getWeaponItem();
			if (itemStack != null && !itemStack.isEmpty() && !spawnedFrom.getItem().equals(itemStack.getItem())) {
				EnchantmentHelper.onProjectileSpawned(level, itemStack, this, abstractArrow::onItemBreak);
			}
		}
	}

	protected ProjectileDeflection hitTargetOrDeflectSelf(HitResult hitResult) {
		if (hitResult.getType() == HitResult.Type.ENTITY) {
			EntityHitResult entityHitResult = (EntityHitResult)hitResult;
			Entity entity = entityHitResult.getEntity();
			ProjectileDeflection projectileDeflection = entity.deflection(this);
			if (projectileDeflection != ProjectileDeflection.NONE) {
				if (entity != this.lastDeflectedBy && this.deflect(projectileDeflection, entity, this.getOwner(), false)) {
					this.lastDeflectedBy = entity;
				}

				return projectileDeflection;
			}
		} else if (this.shouldBounceOnWorldBorder() && hitResult instanceof BlockHitResult blockHitResult && blockHitResult.isWorldBorderHit()) {
			ProjectileDeflection projectileDeflection2 = ProjectileDeflection.REVERSE;
			if (this.deflect(projectileDeflection2, null, this.getOwner(), false)) {
				this.setDeltaMovement(this.getDeltaMovement().scale(0.2));
				return projectileDeflection2;
			}
		}

		this.onHit(hitResult);
		return ProjectileDeflection.NONE;
	}

	protected boolean shouldBounceOnWorldBorder() {
		return false;
	}

	public boolean deflect(ProjectileDeflection deflection, @Nullable Entity entity, @Nullable Entity owner, boolean deflectedByPlayer) {
		deflection.deflect(this, entity, this.random);
		if (!this.level().isClientSide) {
			this.setOwner(owner);
			this.onDeflection(entity, deflectedByPlayer);
		}

		return true;
	}

	protected void onDeflection(@Nullable Entity entity, boolean deflectedByPlayer) {
	}

	protected void onItemBreak(Item item) {
	}

	/**
	 * Called when this EntityFireball hits a block or entity.
	 */
	protected void onHit(HitResult result) {
		HitResult.Type type = result.getType();
		if (type == HitResult.Type.ENTITY) {
			EntityHitResult entityHitResult = (EntityHitResult)result;
			Entity entity = entityHitResult.getEntity();
			if (entity.getType().is(EntityTypeTags.REDIRECTABLE_PROJECTILE) && entity instanceof Projectile projectile) {
				projectile.deflect(ProjectileDeflection.AIM_DEFLECT, this.getOwner(), this.getOwner(), true);
			}

			this.onHitEntity(entityHitResult);
			this.level().gameEvent(GameEvent.PROJECTILE_LAND, result.getLocation(), GameEvent.Context.of(this, null));
		} else if (type == HitResult.Type.BLOCK) {
			BlockHitResult blockHitResult = (BlockHitResult)result;
			this.onHitBlock(blockHitResult);
			BlockPos blockPos = blockHitResult.getBlockPos();
			this.level().gameEvent(GameEvent.PROJECTILE_LAND, blockPos, GameEvent.Context.of(this, this.level().getBlockState(blockPos)));
		}
	}

	/**
	 * Called when the arrow hits an entity
	 */
	protected void onHitEntity(EntityHitResult result) {
	}

	protected void onHitBlock(BlockHitResult result) {
		BlockState blockState = this.level().getBlockState(result.getBlockPos());
		blockState.onProjectileHit(this.level(), blockState, result, this);
	}

	protected boolean canHitEntity(Entity target) {
		if (!target.canBeHitByProjectile()) {
			return false;
		} else {
			Entity entity = this.getOwner();
			return entity == null || this.leftOwner || !entity.isPassengerOfSameVehicle(target);
		}
	}

	protected void updateRotation() {
		Vec3 vec3 = this.getDeltaMovement();
		double d = vec3.horizontalDistance();
		this.setXRot(lerpRotation(this.xRotO, (float)(Mth.atan2(vec3.y, d) * 180.0F / (float)Math.PI)));
		this.setYRot(lerpRotation(this.yRotO, (float)(Mth.atan2(vec3.x, vec3.z) * 180.0F / (float)Math.PI)));
	}

	protected static float lerpRotation(float currentRotation, float targetRotation) {
		while (targetRotation - currentRotation < -180.0F) {
			currentRotation -= 360.0F;
		}

		while (targetRotation - currentRotation >= 180.0F) {
			currentRotation += 360.0F;
		}

		return Mth.lerp(0.2F, currentRotation, targetRotation);
	}

	@Override
	public Packet<ClientGamePacketListener> getAddEntityPacket(ServerEntity entity) {
		Entity entity2 = this.getOwner();
		return new ClientboundAddEntityPacket(this, entity, entity2 == null ? 0 : entity2.getId());
	}

	@Override
	public void recreateFromPacket(ClientboundAddEntityPacket packet) {
		super.recreateFromPacket(packet);
		Entity entity = this.level().getEntity(packet.getData());
		if (entity != null) {
			this.setOwner(entity);
		}
	}

	@Override
	public boolean mayInteract(ServerLevel level, BlockPos pos) {
		Entity entity = this.getOwner();
		return entity instanceof Player ? entity.mayInteract(level, pos) : entity == null || level.getGameRules().getBoolean(GameRules.RULE_MOBGRIEFING);
	}

	public boolean mayBreak(ServerLevel level) {
		return this.getType().is(EntityTypeTags.IMPACT_PROJECTILES) && level.getGameRules().getBoolean(GameRules.RULE_PROJECTILESCANBREAKBLOCKS);
	}

	@Override
	public boolean isPickable() {
		return this.getType().is(EntityTypeTags.REDIRECTABLE_PROJECTILE);
	}

	@Override
	public float getPickRadius() {
		return this.isPickable() ? 1.0F : 0.0F;
	}

	public DoubleDoubleImmutablePair calculateHorizontalHurtKnockbackDirection(LivingEntity entity, DamageSource damageSource) {
		double d = this.getDeltaMovement().x;
		double e = this.getDeltaMovement().z;
		return DoubleDoubleImmutablePair.of(d, e);
	}

	@Override
	public int getDimensionChangingDelay() {
		return 2;
	}

	@Override
	public boolean hurtServer(ServerLevel level, DamageSource damageSource, float amount) {
		if (!this.isInvulnerableToBase(damageSource)) {
			this.markHurt();
		}

		return false;
	}

	@FunctionalInterface
	public interface ProjectileFactory<T extends Projectile> {
		T create(ServerLevel serverLevel, LivingEntity livingEntity, ItemStack itemStack);
	}
}