minecraft-src/net/minecraft/world/entity/boss/enderdragon/phases/DragonStrafePlayerPhase.java

package net.minecraft.world.entity.boss.enderdragon.phases;

import com.mojang.logging.LogUtils;
import net.minecraft.core.Vec3i;
import net.minecraft.server.level.ServerLevel;
import net.minecraft.util.Mth;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.entity.boss.enderdragon.EnderDragon;
import net.minecraft.world.entity.projectile.DragonFireball;
import net.minecraft.world.level.pathfinder.Node;
import net.minecraft.world.level.pathfinder.Path;
import net.minecraft.world.phys.Vec3;
import org.jetbrains.annotations.Nullable;
import org.slf4j.Logger;

public class DragonStrafePlayerPhase extends AbstractDragonPhaseInstance {
	private static final Logger LOGGER = LogUtils.getLogger();
	private static final int FIREBALL_CHARGE_AMOUNT = 5;
	private int fireballCharge;
	@Nullable
	private Path currentPath;
	@Nullable
	private Vec3 targetLocation;
	@Nullable
	private LivingEntity attackTarget;
	private boolean holdingPatternClockwise;

	public DragonStrafePlayerPhase(EnderDragon enderDragon) {
		super(enderDragon);
	}

	@Override
	public void doServerTick(ServerLevel level) {
		if (this.attackTarget == null) {
			LOGGER.warn("Skipping player strafe phase because no player was found");
			this.dragon.getPhaseManager().setPhase(EnderDragonPhase.HOLDING_PATTERN);
		} else {
			if (this.currentPath != null && this.currentPath.isDone()) {
				double d = this.attackTarget.getX();
				double e = this.attackTarget.getZ();
				double f = d - this.dragon.getX();
				double g = e - this.dragon.getZ();
				double h = Math.sqrt(f * f + g * g);
				double i = Math.min(0.4F + h / 80.0 - 1.0, 10.0);
				this.targetLocation = new Vec3(d, this.attackTarget.getY() + i, e);
			}

			double d = this.targetLocation == null ? 0.0 : this.targetLocation.distanceToSqr(this.dragon.getX(), this.dragon.getY(), this.dragon.getZ());
			if (d < 100.0 || d > 22500.0) {
				this.findNewTarget();
			}

			double e = 64.0;
			if (this.attackTarget.distanceToSqr(this.dragon) < 4096.0) {
				if (this.dragon.hasLineOfSight(this.attackTarget)) {
					this.fireballCharge++;
					Vec3 vec3 = new Vec3(this.attackTarget.getX() - this.dragon.getX(), 0.0, this.attackTarget.getZ() - this.dragon.getZ()).normalize();
					Vec3 vec32 = new Vec3(Mth.sin(this.dragon.getYRot() * (float) (Math.PI / 180.0)), 0.0, -Mth.cos(this.dragon.getYRot() * (float) (Math.PI / 180.0)))
						.normalize();
					float j = (float)vec32.dot(vec3);
					float k = (float)(Math.acos(j) * 180.0F / (float)Math.PI);
					k += 0.5F;
					if (this.fireballCharge >= 5 && k >= 0.0F && k < 10.0F) {
						double h = 1.0;
						Vec3 vec33 = this.dragon.getViewVector(1.0F);
						double l = this.dragon.head.getX() - vec33.x * 1.0;
						double m = this.dragon.head.getY(0.5) + 0.5;
						double n = this.dragon.head.getZ() - vec33.z * 1.0;
						double o = this.attackTarget.getX() - l;
						double p = this.attackTarget.getY(0.5) - m;
						double q = this.attackTarget.getZ() - n;
						Vec3 vec34 = new Vec3(o, p, q);
						if (!this.dragon.isSilent()) {
							level.levelEvent(null, 1017, this.dragon.blockPosition(), 0);
						}

						DragonFireball dragonFireball = new DragonFireball(level, this.dragon, vec34.normalize());
						dragonFireball.snapTo(l, m, n, 0.0F, 0.0F);
						level.addFreshEntity(dragonFireball);
						this.fireballCharge = 0;
						if (this.currentPath != null) {
							while (!this.currentPath.isDone()) {
								this.currentPath.advance();
							}
						}

						this.dragon.getPhaseManager().setPhase(EnderDragonPhase.HOLDING_PATTERN);
					}
				} else if (this.fireballCharge > 0) {
					this.fireballCharge--;
				}
			} else if (this.fireballCharge > 0) {
				this.fireballCharge--;
			}
		}
	}

	private void findNewTarget() {
		if (this.currentPath == null || this.currentPath.isDone()) {
			int i = this.dragon.findClosestNode();
			int j = i;
			if (this.dragon.getRandom().nextInt(8) == 0) {
				this.holdingPatternClockwise = !this.holdingPatternClockwise;
				j = i + 6;
			}

			if (this.holdingPatternClockwise) {
				j++;
			} else {
				j--;
			}

			if (this.dragon.getDragonFight() != null && this.dragon.getDragonFight().getCrystalsAlive() > 0) {
				j %= 12;
				if (j < 0) {
					j += 12;
				}
			} else {
				j -= 12;
				j &= 7;
				j += 12;
			}

			this.currentPath = this.dragon.findPath(i, j, null);
			if (this.currentPath != null) {
				this.currentPath.advance();
			}
		}

		this.navigateToNextPathNode();
	}

	private void navigateToNextPathNode() {
		if (this.currentPath != null && !this.currentPath.isDone()) {
			Vec3i vec3i = this.currentPath.getNextNodePos();
			this.currentPath.advance();
			double d = vec3i.getX();
			double e = vec3i.getZ();

			double f;
			do {
				f = vec3i.getY() + this.dragon.getRandom().nextFloat() * 20.0F;
			} while (f < vec3i.getY());

			this.targetLocation = new Vec3(d, f, e);
		}
	}

	@Override
	public void begin() {
		this.fireballCharge = 0;
		this.targetLocation = null;
		this.currentPath = null;
		this.attackTarget = null;
	}

	public void setTarget(LivingEntity attackTarget) {
		this.attackTarget = attackTarget;
		int i = this.dragon.findClosestNode();
		int j = this.dragon.findClosestNode(this.attackTarget.getX(), this.attackTarget.getY(), this.attackTarget.getZ());
		int k = this.attackTarget.getBlockX();
		int l = this.attackTarget.getBlockZ();
		double d = k - this.dragon.getX();
		double e = l - this.dragon.getZ();
		double f = Math.sqrt(d * d + e * e);
		double g = Math.min(0.4F + f / 80.0 - 1.0, 10.0);
		int m = Mth.floor(this.attackTarget.getY() + g);
		Node node = new Node(k, m, l);
		this.currentPath = this.dragon.findPath(i, j, node);
		if (this.currentPath != null) {
			this.currentPath.advance();
			this.navigateToNextPathNode();
		}
	}

	@Nullable
	@Override
	public Vec3 getFlyTargetLocation() {
		return this.targetLocation;
	}

	@Override
	public EnderDragonPhase<DragonStrafePlayerPhase> getPhase() {
		return EnderDragonPhase.STRAFE_PLAYER;
	}
}