initial commit

app/Game/Entities/Boss.php

@@ -0,0 +1,84 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Game\Entities;
+
+use App\Game\EntityList;
+use App\Game\Player;
+use App\Game\Room;
+
+final class Boss extends Zombie
+{
+    private float $spawnInterval;
+
+    private int $spawnCount;
+
+    private float $spawnTimer;
+
+    /** @var null|callable(float,float,EntityList,Room,?Player):void */
+    private $spawnZombie;
+
+    public function __construct(
+        float $x,
+        float $y,
+        EntityList $container,
+        Room $room,
+        ?Player $initialTarget,
+        array $config = [],
+        ?callable $onDeath = null,
+    ) {
+        parent::__construct($x, $y, $container, $room, $config, $onDeath);
+        if ($initialTarget !== null) {
+            $this->target = $initialTarget;
+        }
+        $this->spawnInterval = $config['spawnInterval'] ?? 5.0;
+        $this->spawnCount = $config['spawnCount'] ?? 1;
+        $this->spawnTimer = 3.0;
+        $this->spawnZombie = $config['spawnZombie'] ?? null;
+    }
+
+    public function kind(): string
+    {
+        return 'boss';
+    }
+
+    public function update(float $dt): void
+    {
+        parent::update($dt);
+
+        $this->spawnTimer -= $dt;
+        if ($this->spawnTimer > 0.0 || $this->spawnZombie === null) {
+            return;
+        }
+        $this->spawnTimer = $this->spawnInterval;
+
+        $minions = 0;
+        foreach ($this->container as $obj) {
+            if ($obj instanceof Zombie && ! ($obj instanceof self)) {
+                $minions++;
+            }
+        }
+        if ($minions >= 15) {
+            return;
+        }
+        for ($i = 0; $i < $this->spawnCount; $i++) {
+            $angle = ($i / $this->spawnCount) * M_PI * 2.0 + $this->rand01() * 0.6;
+            ($this->spawnZombie)(
+                $this->pos->x + cos($angle) * 70.0,
+                $this->pos->y + sin($angle) * 70.0,
+                $this->container,
+                $this->room,
+                $this->target,
+            );
+        }
+    }
+
+    public function toSnapshot(): array
+    {
+        $data = parent::toSnapshot();
+        $data['type'] = 'boss';
+
+        return $data;
+    }
+}

app/Game/Entities/Bullet.php

@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Game\Entities;
+
+use App\Game\EntityList;
+use App\Game\GameObject;
+use App\Game\Player;
+use App\Game\Room;
+use App\Game\Vector2;
+
+final class Bullet extends GameObject
+{
+    private EntityList $container;
+
+    private Room $room;
+
+    public float $size;
+
+    public int $damage;
+
+    /** @var array<float> */
+    public array $color;
+
+    public Player $owner;
+
+    public function __construct(
+        float $x,
+        float $y,
+        Vector2 $direction,
+        EntityList $container,
+        Room $room,
+        Player $owner,
+        float $speed = 800.0,
+        float $size = 8.0,
+        int $damage = 1,
+    ) {
+        parent::__construct($x, $y);
+        $this->container = $container;
+        $this->room = $room;
+        $this->owner = $owner;
+        $this->velocity = $direction->mulS($speed);
+        $this->size = $size;
+        $this->damage = $damage;
+        $this->color = [1.0, 0.2, 0.2, 1.0];
+        $this->width = $size;
+        $this->height = $size;
+    }
+
+    public function kind(): string
+    {
+        return 'bullet';
+    }
+
+    public function update(float $dt): void
+    {
+        parent::update($dt);
+
+        if (
+            $this->pos->x < -$this->size
+            || $this->pos->x > $this->room->width + $this->size
+            || $this->pos->y < -$this->size
+            || $this->pos->y > $this->room->height + $this->size
+        ) {
+            $this->container->remove($this);
+        }
+    }
+
+    public function toSnapshot(): array
+    {
+        return [
+            'eid' => $this->eid,
+            'd' => $this->kind(),
+            'x' => round($this->pos->x, 1),
+            'y' => round($this->pos->y, 1),
+            'vx' => round($this->velocity->x, 1),
+            'vy' => round($this->velocity->y, 1),
+            's' => $this->size,
+        ];
+    }
+}

app/Game/Entities/Leaper.php

@@ -0,0 +1,103 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Game\Entities;
+
+use App\Game\EntityList;
+use App\Game\Player;
+use App\Game\Room;
+use App\Game\Vector2;
+
+final class Leaper extends Zombie
+{
+    private float $dashRange;
+
+    private float $windupTime;
+
+    private float $dashTime;
+
+    private float $dashSpeed;
+
+    private float $dashCooldown;
+
+    private float $dashTimer = 0.0;
+
+    private float $windupTimer = 0.0;
+
+    private float $dashCooldownTimer = 0.0;
+
+    private Vector2 $dashDirection;
+
+    public function __construct(
+        float $x,
+        float $y,
+        EntityList $container,
+        Room $room,
+        ?Player $initialTarget,
+        array $config = [],
+        ?callable $onDeath = null,
+    ) {
+        parent::__construct($x, $y, $container, $room, $config, $onDeath);
+        if ($initialTarget !== null) {
+            $this->target = $initialTarget;
+        }
+        $this->dashRange = $config['dashRange'] ?? 300.0;
+        $this->windupTime = $config['windupTime'] ?? 0.35;
+        $this->dashTime = $config['dashTime'] ?? 0.28;
+        $this->dashSpeed = $config['dashSpeed'] ?? 680.0;
+        $this->dashCooldown = $config['dashCooldown'] ?? 1.8;
+        $this->dashDirection = new Vector2(1.0, 0.0);
+    }
+
+    public function kind(): string
+    {
+        return 'leaper';
+    }
+
+    public function update(float $dt): void
+    {
+        $this->time += $dt;
+        if ($this->updateEmerge($dt)) {
+            return;
+        }
+        $this->dashCooldownTimer = max(0.0, $this->dashCooldownTimer - $dt);
+
+        $target = $this->target;
+        $delta = $target !== null ? $target->pos->subV($this->pos) : Vector2::zero();
+        $distance = $delta->length();
+
+        $move = Vector2::zero();
+        if ($this->windupTimer > 0.0) {
+            $this->windupTimer -= $dt;
+            if ($this->windupTimer <= 0.0) {
+                $this->dashTimer = $this->dashTime;
+                $this->dashDirection = $distance > 1.0 ? $delta->divS($distance) : new Vector2(1.0, 0.0);
+            }
+        } elseif ($this->dashTimer > 0.0) {
+            $this->dashTimer -= $dt;
+            $move = $this->dashDirection->mulS($this->dashSpeed);
+        } elseif ($distance > 1.0) {
+            if ($distance < $this->dashRange && $this->dashCooldownTimer <= 0.0) {
+                $this->windupTimer = $this->windupTime;
+            } else {
+                $move = $delta->divS($distance)->mulS($this->speed);
+            }
+        }
+
+        $this->velocity = $move->addV($this->hitKnockback);
+        $this->move($dt);
+
+        $this->hitKnockback = $this->hitKnockback->mulS(max(0.0, 1 - $dt * $this->knockbackDamping));
+        $this->flash = max(0.0, $this->flash - $dt);
+    }
+
+    public function toSnapshot(): array
+    {
+        $data = parent::toSnapshot();
+        $data['dash'] = $this->dashTimer > 0.0;
+        $data['wind'] = $this->windupTimer > 0.0;
+
+        return $data;
+    }
+}

app/Game/Entities/MegaTank.php

@@ -0,0 +1,49 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Game\Entities;
+
+use App\Game\EntityList;
+use App\Game\Player;
+use App\Game\Room;
+
+final class MegaTank extends Zombie
+{
+    public function __construct(
+        float $x,
+        float $y,
+        EntityList $container,
+        Room $room,
+        ?Player $initialTarget,
+        array $config = [],
+        ?callable $onDeath = null,
+    ) {
+        $spawnCount = $config['spawnCount'] ?? 3;
+        $spawnOnDeath = $config['spawnOnDeath'] ?? null;
+        parent::__construct($x, $y, $container, $room, $config, $onDeath ?? function (Zombie $mega) use ($spawnCount, $spawnOnDeath): void {
+            if ($spawnOnDeath === null) {
+                return;
+            }
+            for ($i = 0; $i < $spawnCount; $i++) {
+                $angle = ($i / $spawnCount) * M_PI * 2.0;
+                $offset = $mega->size + 28.0;
+                $spawnOnDeath(
+                    $mega->pos->x + cos($angle) * $offset,
+                    $mega->pos->y + sin($angle) * $offset,
+                    $mega->container,
+                    $mega->room,
+                    $mega->target,
+                );
+            }
+        });
+        if ($initialTarget !== null) {
+            $this->target = $initialTarget;
+        }
+    }
+
+    public function kind(): string
+    {
+        return 'megatank';
+    }
+}

app/Game/Entities/MegaWitch.php

@@ -0,0 +1,142 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Game\Entities;
+
+use App\Game\EntityList;
+use App\Game\Player;
+use App\Game\Room;
+use App\Game\Vector2;
+
+final class MegaWitch extends Witch
+{
+    private float $novaInterval;
+
+    private int $novaCount;
+
+    private float $novaProjectileSpeed;
+
+    private float $novaTimer;
+
+    private float $novaRotation;
+
+    /** @var array<int, array{0:float, 1:\Closure}> */
+    private array $pendingNova = [];
+
+    public function __construct(
+        float $x,
+        float $y,
+        EntityList $container,
+        Room $room,
+        ?Player $initialTarget,
+        array $config = [],
+        ?callable $onDeath = null,
+    ) {
+        $spawnCount = $config['spawnCount'] ?? 3;
+        $spawnOnDeath = $config['spawnOnDeath'] ?? null;
+        parent::__construct($x, $y, $container, $room, $initialTarget, $config, $onDeath ?? function (Zombie $mega) use ($spawnCount, $spawnOnDeath): void {
+            if ($spawnOnDeath === null) {
+                return;
+            }
+            for ($i = 0; $i < $spawnCount; $i++) {
+                $angle = ($i / $spawnCount) * M_PI * 2.0;
+                $offset = $mega->size + 30.0;
+                $spawnOnDeath(
+                    $mega->pos->x + cos($angle) * $offset,
+                    $mega->pos->y + sin($angle) * $offset,
+                    $mega->container,
+                    $mega->room,
+                    $mega->target,
+                );
+            }
+        });
+        if ($initialTarget !== null) {
+            $this->target = $initialTarget;
+        }
+        $this->novaInterval = $config['novaInterval'] ?? 5.0;
+        $this->novaCount = $config['novaCount'] ?? 16;
+        $this->novaProjectileSpeed = $config['novaProjectileSpeed'] ?? 250.0;
+        $this->novaTimer = $this->novaInterval * 0.5;
+        $this->novaRotation = $config['novaRotation'] ?? $this->rand01() * M_PI * 2.0;
+    }
+
+    public function kind(): string
+    {
+        return 'megawitch';
+    }
+
+    public function update(float $dt): void
+    {
+        parent::update($dt);
+
+        $target = $this->target;
+        if ($target !== null && $target->dead) {
+            return;
+        }
+
+        foreach (array_keys($this->pendingNova) as $i) {
+            $this->pendingNova[$i][0] -= $dt;
+            if ($this->pendingNova[$i][0] <= 0.0) {
+                $closure = $this->pendingNova[$i][1];
+                unset($this->pendingNova[$i]);
+                $closure();
+            }
+        }
+
+        $this->novaTimer -= $dt;
+        if ($this->novaTimer <= 0.0) {
+            $this->novaTimer = $this->novaInterval * (0.85 + $this->rand01() * 0.3);
+            $this->nova();
+        }
+    }
+
+    private function nova(): void
+    {
+        $lost = 1.0 - max(0.0, $this->health / max(1, $this->maxHealth));
+        $count = max(6, (int) round($this->novaCount * (0.75 + 0.25 * $lost)));
+        $speed = $this->novaProjectileSpeed * (1.0 + $lost * 0.45);
+        $size = max(8.0, $this->size * 0.3);
+        $color = [1.0, 0.5, 0.3, 1.0];
+        $this->novaRotation += 0.36;
+
+        $fireRing = function (float $offset) use ($count, $speed, $size, $color): void {
+            for ($i = 0; $i < $count; $i++) {
+                $angle = ($i / $count) * M_PI * 2.0 + $this->novaRotation + $offset;
+                $direction = new Vector2(cos($angle), sin($angle));
+                $this->container->append(new WitchProjectile(
+                    $this->pos->x,
+                    $this->pos->y,
+                    $direction,
+                    $this->container,
+                    $this->room,
+                    $speed,
+                    $size,
+                    $color,
+                ));
+            }
+        };
+
+        $fireRing(0.0);
+        $this->pendingNova[] = [0.22, function () use ($fireRing, $count): void {
+            $fireRing(M_PI / $count);
+        }];
+        if ($lost > 0.34) {
+            $this->pendingNova[] = [0.44, function () use ($fireRing): void {
+                $fireRing(0.0);
+            }];
+        }
+    }
+
+    public function toSnapshot(): array
+    {
+        $data = parent::toSnapshot();
+        $data['charge'] = 1.0 - max(0.0, $this->novaTimer) / $this->novaInterval;
+
+        if ($data['hp'] < $data['mhp'] && $data['charge'] > 0.72) {
+            $data['nova'] = true;
+        }
+
+        return $data;
+    }
+}

app/Game/Entities/Pickup.php

@@ -0,0 +1,109 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Game\Entities;
+
+use App\Game\EntityList;
+use App\Game\GameObject;
+use App\Game\Player;
+use App\Game\Room;
+
+final class Pickup extends GameObject
+{
+    public const TYPES = [
+        'rapid' => 'Rapid Fire',
+        'damage' => 'Damage +1',
+        'multishot' => 'Multishot',
+        'speed' => 'Bullet Speed',
+    ];
+
+    private EntityList $container;
+
+    private Room $room;
+
+    public string $type;
+
+    public float $life;
+
+    private float $time = 0.0;
+
+    public float $collectRadius;
+
+    public float $size;
+
+    /** @var array<float> */
+    public array $color;
+
+    public function __construct(
+        float $x,
+        float $y,
+        string $type,
+        EntityList $container,
+        Room $room,
+        float $life = 10.0,
+        float $collectRadius = 46.0,
+    ) {
+        parent::__construct($x, $y);
+        $this->container = $container;
+        $this->room = $room;
+        $this->type = $type;
+        $this->life = $life;
+        $this->collectRadius = $collectRadius;
+        $this->time = 0.0;
+        $this->size = 16.0;
+        $this->width = $this->size;
+        $this->height = $this->size;
+        $this->color = self::colorFor($type);
+    }
+
+    public function kind(): string
+    {
+        return 'pickup';
+    }
+
+    public static function colorFor(string $type): array
+    {
+        return match ($type) {
+            'rapid' => [1.0, 0.8, 0.2, 1.0],
+            'damage' => [1.0, 0.3, 0.3, 1.0],
+            'multishot' => [0.2, 0.8, 1.0, 1.0],
+            'speed' => [0.6, 0.9, 1.0, 1.0],
+            default => [1.0, 1.0, 1.0, 1.0],
+        };
+    }
+
+    public function collectableBy(Player $player): bool
+    {
+        if ($player instanceof Player && ! $player->dead) {
+            return $player->maxUpgradeLevel > ($player->upgrades[$this->type] ?? 0);
+        }
+
+        return false;
+    }
+
+    public function update(float $dt): void
+    {
+        $this->time += $dt;
+        if ($this->time >= $this->life) {
+            $this->container->remove($this);
+        }
+    }
+
+    public function remaining(): float
+    {
+        return max(0.0, $this->life - $this->time);
+    }
+
+    public function toSnapshot(): array
+    {
+        return [
+            'eid' => $this->eid,
+            'd' => $this->kind(),
+            'x' => round($this->pos->x, 1),
+            'y' => round($this->pos->y, 1),
+            't' => $this->type,
+            'life' => round($this->remaining(), 2),
+        ];
+    }
+}

app/Game/Entities/Witch.php

@@ -0,0 +1,125 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Game\Entities;
+
+use App\Game\EntityList;
+use App\Game\Player;
+use App\Game\Room;
+use App\Game\Vector2;
+
+class Witch extends Zombie
+{
+    public float $preferredDistance;
+
+    public float $fireInterval;
+
+    public float $projectileSpeed;
+
+    public int $projectileCount;
+
+    public float $projectileSpread;
+
+    /** @var array<float> */
+    public array $projectileColor;
+
+    protected float $fireTimer = 0.0;
+
+    public function __construct(
+        float $x,
+        float $y,
+        EntityList $container,
+        Room $room,
+        ?Player $initialTarget,
+        array $config = [],
+        ?callable $onDeath = null,
+    ) {
+        parent::__construct($x, $y, $container, $room, $config, $onDeath);
+        if ($initialTarget !== null) {
+            $this->target = $initialTarget;
+        }
+        $this->preferredDistance = $config['preferredDistance'] ?? 220.0;
+        $this->fireInterval = $config['fireInterval'] ?? 2.2;
+        $this->projectileSpeed = $config['projectileSpeed'] ?? 220.0;
+        $this->projectileCount = $config['projectileCount'] ?? 1;
+        $this->projectileSpread = $config['projectileSpread'] ?? 0.08;
+        $this->projectileColor = $config['projectileColor'] ?? [0.7, 0.2, 1.0, 1.0];
+    }
+
+    public function kind(): string
+    {
+        return 'witch';
+    }
+
+    public function update(float $dt): void
+    {
+        $this->time += $dt;
+
+        if ($this->updateEmerge($dt)) {
+            return;
+        }
+
+        $this->fireTimer -= $dt;
+
+        $target = $this->target;
+        if ($target === null) {
+            return;
+        }
+
+        $delta = $target->pos->subV($this->pos);
+        $distance = $delta->length();
+
+        $move = Vector2::zero();
+        if ($distance > 1.0) {
+            $dir = $delta->divS($distance);
+            if ($distance < $this->preferredDistance) {
+                $move = $dir->mulS(-$this->speed);
+            } elseif ($distance > $this->preferredDistance + 40.0) {
+                $move = $dir->mulS($this->speed);
+            }
+        }
+
+        $this->velocity = $move->addV($this->hitKnockback);
+        $this->move($dt);
+
+        $this->hitKnockback = $this->hitKnockback->mulS(max(0.0, 1 - $dt * $this->knockbackDamping));
+        $this->flash = max(0.0, $this->flash - $dt);
+
+        if ($this->fireTimer <= 0.0 && ! $target->dead && $distance < 480.0) {
+            $this->fireTimer = $this->fireInterval * (0.8 + $this->rand01() * 0.4);
+            $this->fire();
+        }
+    }
+
+    protected function onEmergeComplete(): void
+    {
+        $this->fireTimer = $this->fireInterval * (0.4 + $this->rand01() * 0.4);
+    }
+
+    public function fire(): void
+    {
+        $target = $this->target;
+        if ($target === null) {
+            return;
+        }
+        $aim = $target->pos->subV($this->pos);
+        $aimAngle = $aim->lengthSquared() > 1.0 ? atan2($aim->y, $aim->x) : $this->time;
+
+        $offset = (($this->projectileCount - 1) / 2.0) * $this->projectileSpread;
+        for ($i = 0; $i < $this->projectileCount; $i++) {
+            $angle = $aimAngle - $offset + $i * $this->projectileSpread;
+            $direction = new Vector2(cos($angle), sin($angle));
+            $this->container->append(new WitchProjectile(
+                $this->pos->x,
+                $this->pos->y,
+                $direction,
+                $this->container,
+                $this->room,
+                $this->projectileSpeed,
+                $this->size * 0.4,
+                $this->projectileColor,
+            ));
+        }
+    }
+}

app/Game/Entities/WitchProjectile.php

@@ -0,0 +1,77 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Game\Entities;
+
+use App\Game\EntityList;
+use App\Game\GameObject;
+use App\Game\Room;
+use App\Game\Vector2;
+
+final class WitchProjectile extends GameObject
+{
+    private EntityList $container;
+
+    private Room $room;
+
+    public float $size;
+
+    /** @var array<float> */
+    public array $color;
+
+    private float $time = 0.0;
+
+    public function __construct(
+        float $x,
+        float $y,
+        Vector2 $direction,
+        EntityList $container,
+        Room $room,
+        float $speed = 220.0,
+        float $size = 12.0,
+        array $color = [0.7, 0.2, 1.0, 1.0],
+    ) {
+        parent::__construct($x, $y);
+        $this->container = $container;
+        $this->room = $room;
+        $this->velocity = $direction->mulS($speed);
+        $this->size = $size;
+        $this->color = $color;
+        $this->width = $size;
+        $this->height = $size;
+    }
+
+    public function kind(): string
+    {
+        return 'projectile';
+    }
+
+    public function update(float $dt): void
+    {
+        parent::update($dt);
+        $this->time += $dt;
+
+        if (
+            $this->pos->x < -$this->size
+            || $this->pos->x > $this->room->width + $this->size
+            || $this->pos->y < -$this->size
+            || $this->pos->y > $this->room->height + $this->size
+        ) {
+            $this->container->remove($this);
+        }
+    }
+
+    public function toSnapshot(): array
+    {
+        return [
+            'eid' => $this->eid,
+            'd' => $this->kind(),
+            'x' => round($this->pos->x, 1),
+            'y' => round($this->pos->y, 1),
+            'vx' => round($this->velocity->x, 1),
+            'vy' => round($this->velocity->y, 1),
+            's' => $this->size,
+        ];
+    }
+}

app/Game/Entities/Zombie.php

@@ -0,0 +1,173 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Game\Entities;
+
+use App\Game\EntityList;
+use App\Game\GameObject;
+use App\Game\Player;
+use App\Game\Room;
+use App\Game\Vector2;
+
+class Zombie extends GameObject
+{
+    public ?Player $target = null;
+
+    protected EntityList $container;
+
+    protected Room $room;
+
+    public float $speed;
+
+    public float $size;
+
+    /** @var array<float> */
+    public array $baseColor;
+
+    public int $health;
+
+    public int $maxHealth;
+
+    public float $knockback;
+
+    public float $knockbackDamping;
+
+    public int $scoreValue;
+
+    /** @var null|callable(Zombie):void */
+    public $onDeath;
+
+    protected Vector2 $hitKnockback;
+
+    protected float $flash = 0.0;
+
+    protected float $time = 0.0;
+
+    public float $broken;
+
+    protected float $emergeTotal;
+
+    protected float $emerge;
+
+    public function __construct(
+        float $x,
+        float $y,
+        EntityList $container,
+        Room $room,
+        array $config = [],
+        ?callable $onDeath = null,
+    ) {
+        parent::__construct($x, $y);
+        $this->container = $container;
+        $this->room = $room;
+        $this->speed = $config['speed'] ?? 110.0;
+        $this->size = $config['size'] ?? 24.0;
+        $this->baseColor = $config['color'] ?? [0.15, 0.65, 0.2, 1.0];
+        $this->health = $config['health'] ?? 1;
+        $this->maxHealth = $this->health;
+        $this->knockback = $config['knockback'] ?? 260.0;
+        $this->knockbackDamping = $config['knockbackDamping'] ?? 10.0;
+        $this->scoreValue = $config['scoreValue'] ?? 1;
+        $emergeTime = $config['emergeTime'] ?? 0.0;
+        $this->emergeTotal = $emergeTime;
+        $this->emerge = $emergeTime;
+        $this->onDeath = $onDeath;
+        $this->broken = rand(0, 100000) / 100000.0 * M_PI * 2.0;
+        $this->hitKnockback = Vector2::zero();
+        $this->width = $this->size;
+        $this->height = $this->size;
+    }
+
+    public function kind(): string
+    {
+        return 'zombie';
+    }
+
+    public function die(): void
+    {
+        if ($this->onDeath !== null) {
+            ($this->onDeath)($this);
+        }
+        $this->removeAllReferences();
+        $this->container->remove($this);
+    }
+
+    protected function removeAllReferences(): void {}
+
+    public function hit(Vector2 $impulse, int $damage = 1): bool
+    {
+        $this->health -= $damage;
+        if ($this->health < 0) {
+            $this->health = 0;
+        }
+        $this->hitKnockback = $impulse->mulS($this->knockback);
+        $this->flash = 0.08;
+
+        return $this->health <= 0;
+    }
+
+    public function update(float $dt): void
+    {
+        $this->time += $dt;
+        if ($this->updateEmerge($dt)) {
+            return;
+        }
+        if ($this->target === null) {
+            return;
+        }
+        $delta = $this->target->pos->subV($this->pos);
+        $distance = $delta->length();
+        $chaseVelocity = Vector2::zero();
+        if ($distance > 1.0) {
+            $chaseVelocity = $delta->divS($distance)->mulS($this->speed);
+        }
+
+        $this->velocity = $chaseVelocity->addV($this->hitKnockback);
+        parent::update($dt);
+
+        $this->hitKnockback = $this->hitKnockback->mulS(max(0.0, 1 - $dt * $this->knockbackDamping));
+        $this->flash = max(0.0, $this->flash - $dt);
+    }
+
+    public function updateEmerge(float $dt): bool
+    {
+        if ($this->emerge <= 0.0) {
+            return false;
+        }
+        $this->emerge -= $dt;
+        if ($this->emerge <= 0.0) {
+            $this->emerge = 0.0;
+            $this->onEmergeComplete();
+        }
+
+        return true;
+    }
+
+    protected function onEmergeComplete(): void {}
+
+    protected function rand01(): float
+    {
+        return random_int(0, 1000000) / 1000000.0;
+    }
+
+    public function toSnapshot(): array
+    {
+        $snapshot = [
+            'eid' => $this->eid,
+            'd' => $this->kind(),
+            'x' => round($this->pos->x, 1),
+            'y' => round($this->pos->y, 1),
+            's' => $this->size,
+            'hp' => $this->health,
+            'mhp' => $this->maxHealth,
+            'c' => array_slice($this->baseColor, 0, 3),
+        ];
+        if ($this->emergeTotal > 0.0) {
+            $snapshot['et'] = round($this->emergeTotal, 2);
+            $snapshot['er'] = round($this->emerge, 2);
+        }
+
+        return $snapshot;
+    }
+}