minecraft-src/net/minecraft/world/waypoints/WaypointTransmitter.java

package net.minecraft.world.waypoints;

import java.util.Optional;
import net.minecraft.core.BlockPos;
import net.minecraft.network.protocol.game.ClientboundTrackedWaypointPacket;
import net.minecraft.server.level.ServerPlayer;
import net.minecraft.util.Mth;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.ai.attributes.Attributes;
import net.minecraft.world.level.ChunkPos;
import net.minecraft.world.phys.Vec3;

public interface WaypointTransmitter extends Waypoint {
	int REALLY_FAR_DISTANCE = 332;

	boolean isTransmittingWaypoint();

	Optional<WaypointTransmitter.Connection> makeWaypointConnectionWith(ServerPlayer player);

	Waypoint.Icon waypointIcon();

	static boolean doesSourceIgnoreReceiver(LivingEntity entity, ServerPlayer player) {
		if (player.isSpectator()) {
			return false;
		} else if (!entity.isSpectator() && !entity.hasIndirectPassenger(player)) {
			double d = Math.min(entity.getAttributeValue(Attributes.WAYPOINT_TRANSMIT_RANGE), player.getAttributeValue(Attributes.WAYPOINT_RECEIVE_RANGE));
			return entity.distanceTo(player) >= d;
		} else {
			return true;
		}
	}

	static boolean isChunkVisible(ChunkPos pos, ServerPlayer player) {
		return player.getChunkTrackingView().isInViewDistance(pos.x, pos.z);
	}

	static boolean isReallyFar(LivingEntity entity, ServerPlayer player) {
		return entity.distanceTo(player) > 332.0F;
	}

	public interface BlockConnection extends WaypointTransmitter.Connection {
		int distanceManhattan();

		@Override
		default boolean isBroken() {
			return this.distanceManhattan() > 1;
		}
	}

	public interface ChunkConnection extends WaypointTransmitter.Connection {
		int distanceChessboard();

		@Override
		default boolean isBroken() {
			return this.distanceChessboard() > 1;
		}
	}

	public interface Connection {
		void connect();

		void disconnect();

		void update();

		boolean isBroken();
	}

	public static class EntityAzimuthConnection implements WaypointTransmitter.Connection {
		private final LivingEntity source;
		private final Waypoint.Icon icon;
		private final ServerPlayer receiver;
		private float lastAngle;

		public EntityAzimuthConnection(LivingEntity source, Waypoint.Icon icon, ServerPlayer reciever) {
			this.source = source;
			this.icon = icon;
			this.receiver = reciever;
			Vec3 vec3 = reciever.position().subtract(source.position()).rotateClockwise90();
			this.lastAngle = (float)Mth.atan2(vec3.z(), vec3.x());
		}

		@Override
		public boolean isBroken() {
			return WaypointTransmitter.doesSourceIgnoreReceiver(this.source, this.receiver)
				|| WaypointTransmitter.isChunkVisible(this.source.chunkPosition(), this.receiver)
				|| !WaypointTransmitter.isReallyFar(this.source, this.receiver);
		}

		@Override
		public void connect() {
			this.receiver.connection.send(ClientboundTrackedWaypointPacket.addWaypointAzimuth(this.source.getUUID(), this.icon, this.lastAngle));
		}

		@Override
		public void disconnect() {
			this.receiver.connection.send(ClientboundTrackedWaypointPacket.removeWaypoint(this.source.getUUID()));
		}

		@Override
		public void update() {
			Vec3 vec3 = this.receiver.position().subtract(this.source.position()).rotateClockwise90();
			float f = (float)Mth.atan2(vec3.z(), vec3.x());
			if (Mth.abs(f - this.lastAngle) > 0.008726646F) {
				this.receiver.connection.send(ClientboundTrackedWaypointPacket.updateWaypointAzimuth(this.source.getUUID(), this.icon, f));
				this.lastAngle = f;
			}
		}
	}

	public static class EntityBlockConnection implements WaypointTransmitter.BlockConnection {
		private final LivingEntity source;
		private final Waypoint.Icon icon;
		private final ServerPlayer receiver;
		private BlockPos lastPosition;

		public EntityBlockConnection(LivingEntity source, Waypoint.Icon icon, ServerPlayer reciever) {
			this.source = source;
			this.receiver = reciever;
			this.icon = icon;
			this.lastPosition = source.blockPosition();
		}

		@Override
		public void connect() {
			this.receiver.connection.send(ClientboundTrackedWaypointPacket.addWaypointPosition(this.source.getUUID(), this.icon, this.lastPosition));
		}

		@Override
		public void disconnect() {
			this.receiver.connection.send(ClientboundTrackedWaypointPacket.removeWaypoint(this.source.getUUID()));
		}

		@Override
		public void update() {
			BlockPos blockPos = this.source.blockPosition();
			if (blockPos.distManhattan(this.lastPosition) > 0) {
				this.receiver.connection.send(ClientboundTrackedWaypointPacket.updateWaypointPosition(this.source.getUUID(), this.icon, blockPos));
				this.lastPosition = blockPos;
			}
		}

		@Override
		public int distanceManhattan() {
			return this.lastPosition.distManhattan(this.source.blockPosition());
		}

		@Override
		public boolean isBroken() {
			return WaypointTransmitter.BlockConnection.super.isBroken() || WaypointTransmitter.doesSourceIgnoreReceiver(this.source, this.receiver);
		}
	}

	public static class EntityChunkConnection implements WaypointTransmitter.ChunkConnection {
		private final LivingEntity source;
		private final Waypoint.Icon icon;
		private final ServerPlayer receiver;
		private ChunkPos lastPosition;

		public EntityChunkConnection(LivingEntity source, Waypoint.Icon icon, ServerPlayer receiver) {
			this.source = source;
			this.icon = icon;
			this.receiver = receiver;
			this.lastPosition = source.chunkPosition();
		}

		@Override
		public int distanceChessboard() {
			return this.lastPosition.getChessboardDistance(this.source.chunkPosition());
		}

		@Override
		public void connect() {
			this.receiver.connection.send(ClientboundTrackedWaypointPacket.addWaypointChunk(this.source.getUUID(), this.icon, this.lastPosition));
		}

		@Override
		public void disconnect() {
			this.receiver.connection.send(ClientboundTrackedWaypointPacket.removeWaypoint(this.source.getUUID()));
		}

		@Override
		public void update() {
			ChunkPos chunkPos = this.source.chunkPosition();
			if (chunkPos.getChessboardDistance(this.lastPosition) > 0) {
				this.receiver.connection.send(ClientboundTrackedWaypointPacket.updateWaypointChunk(this.source.getUUID(), this.icon, chunkPos));
				this.lastPosition = chunkPos;
			}
		}

		@Override
		public boolean isBroken() {
			return !WaypointTransmitter.ChunkConnection.super.isBroken() && !WaypointTransmitter.doesSourceIgnoreReceiver(this.source, this.receiver)
				? WaypointTransmitter.isChunkVisible(this.lastPosition, this.receiver)
				: true;
		}
	}
}