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

package net.minecraft.world.entity.vehicle;

import net.minecraft.core.BlockPos;
import net.minecraft.core.particles.ParticleTypes;
import net.minecraft.nbt.CompoundTag;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.sounds.SoundEvents;
import net.minecraft.sounds.SoundSource;
import net.minecraft.tags.BlockTags;
import net.minecraft.tags.DamageTypeTags;
import net.minecraft.util.Mth;
import net.minecraft.world.damagesource.DamageSource;
import net.minecraft.world.entity.EntityType;
import net.minecraft.world.entity.projectile.Projectile;
import net.minecraft.world.item.Item;
import net.minecraft.world.item.ItemStack;
import net.minecraft.world.item.Items;
import net.minecraft.world.level.BlockGetter;
import net.minecraft.world.level.Explosion;
import net.minecraft.world.level.Level;
import net.minecraft.world.level.block.Blocks;
import net.minecraft.world.level.block.state.BlockState;
import net.minecraft.world.level.material.FluidState;
import org.jetbrains.annotations.Nullable;

public class MinecartTNT extends AbstractMinecart {
	private static final byte EVENT_PRIME = 10;
	private static final String TAG_EXPLOSION_POWER = "explosion_power";
	private static final String TAG_EXPLOSION_SPEED_FACTOR = "explosion_speed_factor";
	private static final String TAG_FUSE = "fuse";
	private static final float DEFAULT_EXPLOSION_POWER_BASE = 4.0F;
	private static final float DEFAULT_EXPLOSION_SPEED_FACTOR = 1.0F;
	private int fuse = -1;
	private float explosionPowerBase = 4.0F;
	private float explosionSpeedFactor = 1.0F;

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

	@Override
	public BlockState getDefaultDisplayBlockState() {
		return Blocks.TNT.defaultBlockState();
	}

	@Override
	public void tick() {
		super.tick();
		if (this.fuse > 0) {
			this.fuse--;
			this.level().addParticle(ParticleTypes.SMOKE, this.getX(), this.getY() + 0.5, this.getZ(), 0.0, 0.0, 0.0);
		} else if (this.fuse == 0) {
			this.explode(this.getDeltaMovement().horizontalDistanceSqr());
		}

		if (this.horizontalCollision) {
			double d = this.getDeltaMovement().horizontalDistanceSqr();
			if (d >= 0.01F) {
				this.explode(d);
			}
		}
	}

	@Override
	public boolean hurtServer(ServerLevel level, DamageSource damageSource, float amount) {
		if (damageSource.getDirectEntity() instanceof Projectile projectile && projectile.isOnFire()) {
			DamageSource damageSource2 = this.damageSources().explosion(this, damageSource.getEntity());
			this.explode(damageSource2, projectile.getDeltaMovement().lengthSqr());
		}

		return super.hurtServer(level, damageSource, amount);
	}

	@Override
	public void destroy(ServerLevel level, DamageSource damageSource) {
		double d = this.getDeltaMovement().horizontalDistanceSqr();
		if (!damageSourceIgnitesTnt(damageSource) && !(d >= 0.01F)) {
			this.destroy(level, this.getDropItem());
		} else {
			if (this.fuse < 0) {
				this.primeFuse();
				this.fuse = this.random.nextInt(20) + this.random.nextInt(20);
			}
		}
	}

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

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

	/**
	 * Makes the minecart explode.
	 */
	protected void explode(double radiusModifier) {
		this.explode(null, radiusModifier);
	}

	protected void explode(@Nullable DamageSource damageSource, double radiusModifier) {
		if (this.level() instanceof ServerLevel serverLevel) {
			double d = Math.min(Math.sqrt(radiusModifier), 5.0);
			serverLevel.explode(
				this,
				damageSource,
				null,
				this.getX(),
				this.getY(),
				this.getZ(),
				(float)(this.explosionPowerBase + this.explosionSpeedFactor * this.random.nextDouble() * 1.5 * d),
				false,
				Level.ExplosionInteraction.TNT
			);
			this.discard();
		}
	}

	@Override
	public boolean causeFallDamage(float fallDistance, float multiplier, DamageSource source) {
		if (fallDistance >= 3.0F) {
			float f = fallDistance / 10.0F;
			this.explode(f * f);
		}

		return super.causeFallDamage(fallDistance, multiplier, source);
	}

	@Override
	public void activateMinecart(int x, int y, int z, boolean powered) {
		if (powered && this.fuse < 0) {
			this.primeFuse();
		}
	}

	@Override
	public void handleEntityEvent(byte id) {
		if (id == 10) {
			this.primeFuse();
		} else {
			super.handleEntityEvent(id);
		}
	}

	/**
	 * Ignites this TNT cart.
	 */
	public void primeFuse() {
		this.fuse = 80;
		if (!this.level().isClientSide) {
			this.level().broadcastEntityEvent(this, (byte)10);
			if (!this.isSilent()) {
				this.level().playSound(null, this.getX(), this.getY(), this.getZ(), SoundEvents.TNT_PRIMED, SoundSource.BLOCKS, 1.0F, 1.0F);
			}
		}
	}

	/**
	 * Gets the remaining fuse time in ticks.
	 */
	public int getFuse() {
		return this.fuse;
	}

	/**
	 * Returns {@code true} if the TNT minecart is ignited.
	 */
	public boolean isPrimed() {
		return this.fuse > -1;
	}

	@Override
	public float getBlockExplosionResistance(
		Explosion explosion, BlockGetter level, BlockPos pos, BlockState blockState, FluidState fluidState, float explosionPower
	) {
		return !this.isPrimed() || !blockState.is(BlockTags.RAILS) && !level.getBlockState(pos.above()).is(BlockTags.RAILS)
			? super.getBlockExplosionResistance(explosion, level, pos, blockState, fluidState, explosionPower)
			: 0.0F;
	}

	@Override
	public boolean shouldBlockExplode(Explosion explosion, BlockGetter level, BlockPos pos, BlockState blockState, float explosionPower) {
		return !this.isPrimed() || !blockState.is(BlockTags.RAILS) && !level.getBlockState(pos.above()).is(BlockTags.RAILS)
			? super.shouldBlockExplode(explosion, level, pos, blockState, explosionPower)
			: false;
	}

	@Override
	protected void readAdditionalSaveData(CompoundTag tag) {
		super.readAdditionalSaveData(tag);
		if (tag.contains("fuse", 99)) {
			this.fuse = tag.getInt("fuse");
		}

		if (tag.contains("explosion_power", 99)) {
			this.explosionPowerBase = Mth.clamp(tag.getFloat("explosion_power"), 0.0F, 128.0F);
		}

		if (tag.contains("explosion_speed_factor", 99)) {
			this.explosionSpeedFactor = Mth.clamp(tag.getFloat("explosion_speed_factor"), 0.0F, 128.0F);
		}
	}

	@Override
	protected void addAdditionalSaveData(CompoundTag tag) {
		super.addAdditionalSaveData(tag);
		tag.putInt("fuse", this.fuse);
		if (this.explosionPowerBase != 4.0F) {
			tag.putFloat("explosion_power", this.explosionPowerBase);
		}

		if (this.explosionSpeedFactor != 1.0F) {
			tag.putFloat("explosion_speed_factor", this.explosionSpeedFactor);
		}
	}

	@Override
	boolean shouldSourceDestroy(DamageSource source) {
		return damageSourceIgnitesTnt(source);
	}

	private static boolean damageSourceIgnitesTnt(DamageSource source) {
		return source.is(DamageTypeTags.IS_FIRE) || source.is(DamageTypeTags.IS_EXPLOSION);
	}
}