minecraft-src/net/minecraft/world/entity/vehicle/MinecartFurnace.java

package net.minecraft.world.entity.vehicle;

import net.minecraft.core.Direction;
import net.minecraft.core.particles.ParticleTypes;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.network.syncher.EntityDataAccessor;
import net.minecraft.network.syncher.EntityDataSerializers;
import net.minecraft.network.syncher.SynchedEntityData;
import net.minecraft.network.syncher.SynchedEntityData.Builder;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.tags.ItemTags;
import net.minecraft.world.InteractionHand;
import net.minecraft.world.InteractionResult;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.player.Player;
import net.minecraft.world.item.Item;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.Items;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.block.FurnaceBlock;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.phys.Vec3;

public class MinecartFurnace extends AbstractMinecart {
	private static final EntityDataAccessor<Boolean> DATA_ID_FUEL = SynchedEntityData.defineId(MinecartFurnace.class, EntityDataSerializers.BOOLEAN);
	private static final int FUEL_TICKS_PER_ITEM = 3600;
	private static final int MAX_FUEL_TICKS = 32000;
	private static final short DEFAULT_FUEL = 0;
	private static final Vec3 DEFAULT_PUSH = Vec3.ZERO;
	private int fuel = 0;
	public Vec3 push = DEFAULT_PUSH;

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

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

	@Override
	protected void defineSynchedData(Builder builder) {
		super.defineSynchedData(builder);
		builder.define(DATA_ID_FUEL, false);
	}

	@Override
	public void tick() {
		super.tick();
		if (!this.level().isClientSide()) {
			if (this.fuel > 0) {
				this.fuel--;
			}

			if (this.fuel <= 0) {
				this.push = Vec3.ZERO;
			}

			this.setHasFuel(this.fuel > 0);
		}

		if (this.hasFuel() && this.random.nextInt(4) == 0) {
			this.level().addParticle(ParticleTypes.LARGE_SMOKE, this.getX(), this.getY() + 0.8, this.getZ(), 0.0, 0.0, 0.0);
		}
	}

	@Override
	protected double getMaxSpeed(ServerLevel level) {
		return this.isInWater() ? super.getMaxSpeed(level) * 0.75 : super.getMaxSpeed(level) * 0.5;
	}

	@Override
	protected Item getDropItem() {
		return Items.FURNACE_MINECART;
	}

	@Override
	public ItemStack getPickResult() {
		return new ItemStack(Items.FURNACE_MINECART);
	}

	@Override
	protected Vec3 applyNaturalSlowdown(Vec3 speed) {
		Vec3 vec3;
		if (this.push.lengthSqr() > 1.0E-7) {
			this.push = this.calculateNewPushAlong(speed);
			vec3 = speed.multiply(0.8, 0.0, 0.8).add(this.push);
			if (this.isInWater()) {
				vec3 = vec3.scale(0.1);
			}
		} else {
			vec3 = speed.multiply(0.98, 0.0, 0.98);
		}

		return super.applyNaturalSlowdown(vec3);
	}

	private Vec3 calculateNewPushAlong(Vec3 speed) {
		double d = 1.0E-4;
		double e = 0.001;
		return this.push.horizontalDistanceSqr() > 1.0E-4 && speed.horizontalDistanceSqr() > 0.001
			? this.push.projectedOn(speed).normalize().scale(this.push.length())
			: this.push;
	}

	@Override
	public InteractionResult interact(Player player, InteractionHand hand) {
		ItemStack itemStack = player.getItemInHand(hand);
		if (itemStack.is(ItemTags.FURNACE_MINECART_FUEL) && this.fuel + 3600 <= 32000) {
			itemStack.consume(1, player);
			this.fuel += 3600;
		}

		if (this.fuel > 0) {
			this.push = this.position().subtract(player.position()).horizontal();
		}

		return InteractionResult.SUCCESS;
	}

	@Override
	protected void addAdditionalSaveData(CompoundTag tag) {
		super.addAdditionalSaveData(tag);
		tag.putDouble("PushX", this.push.x);
		tag.putDouble("PushZ", this.push.z);
		tag.putShort("Fuel", (short)this.fuel);
	}

	@Override
	protected void readAdditionalSaveData(CompoundTag tag) {
		super.readAdditionalSaveData(tag);
		double d = tag.getDoubleOr("PushX", DEFAULT_PUSH.x);
		double e = tag.getDoubleOr("PushZ", DEFAULT_PUSH.z);
		this.push = new Vec3(d, 0.0, e);
		this.fuel = tag.getShortOr("Fuel", (short)0);
	}

	protected boolean hasFuel() {
		return this.entityData.get(DATA_ID_FUEL);
	}

	protected void setHasFuel(boolean hasFuel) {
		this.entityData.set(DATA_ID_FUEL, hasFuel);
	}

	@Override
	public BlockState getDefaultDisplayBlockState() {
		return Blocks.FURNACE.defaultBlockState().setValue(FurnaceBlock.FACING, Direction.NORTH).setValue(FurnaceBlock.LIT, this.hasFuel());
	}
}