minecraft-src/net/minecraft/world/level/portal/TeleportTransition.java

package net.minecraft.world.level.portal;

import java.util.Set;
import net.minecraft.core.BlockPos;
import net.minecraft.network.protocol.game.ClientboundLevelEventPacket;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.server.level.ServerPlayer;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.Relative;
import net.minecraft.world.phys.Vec3;

public record TeleportTransition(
	ServerLevel newLevel,
	Vec3 position,
	Vec3 deltaMovement,
	float yRot,
	float xRot,
	boolean missingRespawnBlock,
	boolean asPassenger,
	Set<Relative> relatives,
	TeleportTransition.PostTeleportTransition postTeleportTransition
) {
	public static final TeleportTransition.PostTeleportTransition DO_NOTHING = entity -> {};
	public static final TeleportTransition.PostTeleportTransition PLAY_PORTAL_SOUND = TeleportTransition::playPortalSound;
	public static final TeleportTransition.PostTeleportTransition PLACE_PORTAL_TICKET = TeleportTransition::placePortalTicket;

	public TeleportTransition(
		ServerLevel newLevel, Vec3 position, Vec3 deltaMovement, float yRot, float xRot, TeleportTransition.PostTeleportTransition postTeleportTransition
	) {
		this(newLevel, position, deltaMovement, yRot, xRot, Set.of(), postTeleportTransition);
	}

	public TeleportTransition(
		ServerLevel newLevel,
		Vec3 position,
		Vec3 deltaMovement,
		float yRot,
		float xRot,
		Set<Relative> relatives,
		TeleportTransition.PostTeleportTransition postTeleportTransition
	) {
		this(newLevel, position, deltaMovement, yRot, xRot, false, false, relatives, postTeleportTransition);
	}

	public TeleportTransition(ServerLevel level, Entity entity, TeleportTransition.PostTeleportTransition postTeleportTransition) {
		this(level, findAdjustedSharedSpawnPos(level, entity), Vec3.ZERO, 0.0F, 0.0F, false, false, Set.of(), postTeleportTransition);
	}

	private static void playPortalSound(Entity entity) {
		if (entity instanceof ServerPlayer serverPlayer) {
			serverPlayer.connection.send(new ClientboundLevelEventPacket(1032, BlockPos.ZERO, 0, false));
		}
	}

	private static void placePortalTicket(Entity entity) {
		entity.placePortalTicket(BlockPos.containing(entity.position()));
	}

	public static TeleportTransition missingRespawnBlock(ServerLevel level, Entity entity, TeleportTransition.PostTeleportTransition postTeleportTransition) {
		return new TeleportTransition(level, findAdjustedSharedSpawnPos(level, entity), Vec3.ZERO, 0.0F, 0.0F, true, false, Set.of(), postTeleportTransition);
	}

	private static Vec3 findAdjustedSharedSpawnPos(ServerLevel level, Entity entity) {
		return entity.adjustSpawnLocation(level, level.getSharedSpawnPos()).getBottomCenter();
	}

	public TeleportTransition withRotation(float yRot, float xRot) {
		return new TeleportTransition(
			this.newLevel(),
			this.position(),
			this.deltaMovement(),
			yRot,
			xRot,
			this.missingRespawnBlock(),
			this.asPassenger(),
			this.relatives(),
			this.postTeleportTransition()
		);
	}

	public TeleportTransition withPosition(Vec3 position) {
		return new TeleportTransition(
			this.newLevel(),
			position,
			this.deltaMovement(),
			this.yRot(),
			this.xRot(),
			this.missingRespawnBlock(),
			this.asPassenger(),
			this.relatives(),
			this.postTeleportTransition()
		);
	}

	public TeleportTransition transitionAsPassenger() {
		return new TeleportTransition(
			this.newLevel(),
			this.position(),
			this.deltaMovement(),
			this.yRot(),
			this.xRot(),
			this.missingRespawnBlock(),
			true,
			this.relatives(),
			this.postTeleportTransition()
		);
	}

	@FunctionalInterface
	public interface PostTeleportTransition {
		void onTransition(Entity entity);

		default TeleportTransition.PostTeleportTransition then(TeleportTransition.PostTeleportTransition postTeleportTransition) {
			return entity -> {
				this.onTransition(entity);
				postTeleportTransition.onTransition(entity);
			};
		}
	}
}