game.js

import * as THREE from 'three';
import { GLTFLoader } from 'three/addons/loaders/GLTFLoader.js';
import { PointerLockControls } from 'three/addons/controls/PointerLockControls.js';

// 게임 상수
const GAME_DURATION = 180;
const MAP_SIZE = 2000;
const TANK_HEIGHT = 0.5;
const ENEMY_GROUND_HEIGHT = 0;
const ENEMY_SCALE = 10;
const MAX_HEALTH = 1000;
const ENEMY_MOVE_SPEED = 0.1;
const ENEMY_COUNT_MAX = 5;
const PARTICLE_COUNT = 15;
const BUILDING_COUNT = 30;  // 건물 수 추가
const ENEMY_CONFIG = {
    ATTACK_RANGE: 100,
    ATTACK_INTERVAL: 2000,
    BULLET_SPEED: 2
};

// TankPlayer 클래스
class TankPlayer {
    constructor() {
        this.body = null;
        this.turret = null;
        this.position = new THREE.Vector3(0, 0, 0);
        this.rotation = new THREE.Euler(0, 0, 0);
        this.turretRotation = 0;
        this.moveSpeed = 0.5;
        this.turnSpeed = 0.03;
        this.turretGroup = new THREE.Group();
        this.health = MAX_HEALTH;
        this.isLoaded = false;
        this.ammo = 10;
        this.lastShootTime = 0;
        this.shootInterval = 1000;
        this.bullets = [];
    }

    async initialize(scene, loader) {
        try {
            const bodyResult = await loader.loadAsync('/models/abramsBody.glb');
            this.body = bodyResult.scene;
            this.body.position.copy(this.position);
            
            const turretResult = await loader.loadAsync('/models/abramsTurret.glb');
            this.turret = turretResult.scene;
            
            this.turretGroup.position.y = 0.2;
            this.turretGroup.add(this.turret);
            this.body.add(this.turretGroup);
            
            this.body.traverse((child) => {
                if (child.isMesh) {
                    child.castShadow = true;
                    child.receiveShadow = true;
                }
            });
            
            this.turret.traverse((child) => {
                if (child.isMesh) {
                    child.castShadow = true;
                    child.receiveShadow = true;
                }
            });

            scene.add(this.body);
            this.isLoaded = true;
            
        } catch (error) {
            console.error('Error loading tank models:', error);
            this.isLoaded = false;
        }
    }

    shoot(scene) {
    const currentTime = Date.now();
    if (currentTime - this.lastShootTime < this.shootInterval || this.ammo <= 0) return null;

    // 총알 생성
    const bulletGeometry = new THREE.SphereGeometry(0.2);
    const bulletMaterial = new THREE.MeshBasicMaterial({ color: 0x00ff00 });
    const bullet = new THREE.Mesh(bulletGeometry, bulletMaterial);

    // 총알 시작 위치 (포탑 끝)
    const bulletOffset = new THREE.Vector3(0, 0.5, 2);
    // 포탑의 회전을 적용
    bulletOffset.applyQuaternion(this.turretGroup.quaternion);
    bulletOffset.applyQuaternion(this.body.quaternion);
    bullet.position.copy(this.body.position).add(bulletOffset);

    // 총알 속도 (포탑 방향)
    const direction = new THREE.Vector3(0, 0, 1);
    direction.applyQuaternion(this.turretGroup.quaternion);
    direction.applyQuaternion(this.body.quaternion);
    bullet.velocity = direction.multiplyScalar(2);

    scene.add(bullet);
    this.bullets.push(bullet);
    this.ammo--;
    this.lastShootTime = currentTime;

    document.getElementById('ammo').textContent = `Ammo: ${this.ammo}/10`;
    
    return bullet;
}

    update(mouseX, mouseY) {
   if (!this.body || !this.turretGroup) return;
   
   // 총알 업데이트만 수행하고 포탑 회전은 Game 클래스의 handleMovement에서 처리
   for (let i = this.bullets.length - 1; i >= 0; i--) {
       const bullet = this.bullets[i];
       bullet.position.add(bullet.velocity);

       // 총알이 맵 밖으로 나가면 제거
       if (Math.abs(bullet.position.x) > MAP_SIZE/2 || 
           Math.abs(bullet.position.z) > MAP_SIZE/2) {
           scene.remove(bullet);
           this.bullets.splice(i, 1);
       }
   }
}

    move(direction) {
    if (!this.body) return;
    
    const moveVector = new THREE.Vector3();
    moveVector.x = direction.x * this.moveSpeed;
    moveVector.z = direction.z * this.moveSpeed;
    
    this.body.position.add(moveVector);
    }

    rotate(angle) {
        if (!this.body) return;
        this.body.rotation.y += angle * this.turnSpeed;
    }

    getPosition() {
        return this.body ? this.body.position : new THREE.Vector3();
    }

    takeDamage(damage) {
        this.health -= damage;
        return this.health <= 0;
    }
}
// Enemy 클래스 수정
class Enemy {
    constructor(scene, position, type = 'tank') {
        this.scene = scene;
        this.position = position;
        this.mesh = null;
        this.type = type; // 'tank' 또는 'heavy'
        this.health = type === 'tank' ? 100 : 200; // heavy는 체력이 더 높음
        this.lastAttackTime = 0;
        this.bullets = [];
        this.isLoaded = false;
        this.moveSpeed = type === 'tank' ? ENEMY_MOVE_SPEED : ENEMY_MOVE_SPEED * 0.7; // heavy는 더 느림
    }

    async initialize(loader) {
        try {
            // 타입에 따라 다른 모델 로드
            const modelPath = this.type === 'tank' ? '/models/enemy1.glb' : '/models/enemy4.glb';
            const result = await loader.loadAsync(modelPath);
            this.mesh = result.scene;
            this.mesh.position.copy(this.position);
            this.mesh.scale.set(ENEMY_SCALE, ENEMY_SCALE, ENEMY_SCALE);
            
            this.mesh.traverse((child) => {
                if (child.isMesh) {
                    child.castShadow = true;
                    child.receiveShadow = true;
                }
            });
            
            this.scene.add(this.mesh);
            this.isLoaded = true;
        } catch (error) {
            console.error('Error loading enemy model:', error);
            this.isLoaded = false;
        }
    }

    update(playerPosition) {
        if (!this.mesh || !this.isLoaded) return;

        // 플레이어 방향으로 회전
        const direction = new THREE.Vector3()
            .subVectors(playerPosition, this.mesh.position)
            .normalize();
        
        this.mesh.lookAt(playerPosition);

        // 플레이어 방향으로 이동 (타입에 따라 다른 속도)
        this.mesh.position.add(direction.multiplyScalar(this.moveSpeed));

        // 총알 업데이트
        for (let i = this.bullets.length - 1; i >= 0; i--) {
            const bullet = this.bullets[i];
            bullet.position.add(bullet.velocity);

            // 총알이 맵 밖으로 나가면 제거
            if (Math.abs(bullet.position.x) > MAP_SIZE || 
                Math.abs(bullet.position.z) > MAP_SIZE) {
                this.scene.remove(bullet);
                this.bullets.splice(i, 1);
            }
        }
    }

    shoot(playerPosition) {
        const currentTime = Date.now();
        const attackInterval = this.type === 'tank' ? 
            ENEMY_CONFIG.ATTACK_INTERVAL : 
            ENEMY_CONFIG.ATTACK_INTERVAL * 1.5; // heavy는 발사 간격이 더 김

        if (currentTime - this.lastAttackTime < attackInterval) return;

        const bulletGeometry = new THREE.SphereGeometry(this.type === 'tank' ? 0.2 : 0.3);
        const bulletMaterial = new THREE.MeshBasicMaterial({ 
            color: this.type === 'tank' ? 0xff0000 : 0xff6600 
        });
        const bullet = new THREE.Mesh(bulletGeometry, bulletMaterial);

        bullet.position.copy(this.mesh.position);
        
        const direction = new THREE.Vector3()
            .subVectors(playerPosition, this.mesh.position)
            .normalize();
        
        const bulletSpeed = this.type === 'tank' ? 
            ENEMY_CONFIG.BULLET_SPEED : 
            ENEMY_CONFIG.BULLET_SPEED * 0.8;
        
        bullet.velocity = direction.multiplyScalar(bulletSpeed);
        
        this.scene.add(bullet);
        this.bullets.push(bullet);
        this.lastAttackTime = currentTime;
    }

    takeDamage(damage) {
        this.health -= damage;
        return this.health <= 0;
    }

    destroy() {
        if (this.mesh) {
            this.scene.remove(this.mesh);
            this.bullets.forEach(bullet => this.scene.remove(bullet));
            this.bullets = [];
            this.isLoaded = false;
        }
    }
}

// Particle 클래스는 그대로 유지
class Particle {
    constructor(scene, position) {
        const geometry = new THREE.SphereGeometry(0.1);
        const material = new THREE.MeshBasicMaterial({ color: 0xff0000 });
        this.mesh = new THREE.Mesh(geometry, material);
        this.mesh.position.copy(position);
        
        this.velocity = new THREE.Vector3(
            (Math.random() - 0.5) * 0.3,
            Math.random() * 0.2,
            (Math.random() - 0.5) * 0.3
        );
        
        this.gravity = -0.01;
        this.lifetime = 60;
        this.age = 0;
        
        scene.add(this.mesh);
    }

    update() {
        this.velocity.y += this.gravity;
        this.mesh.position.add(this.velocity);
        this.age++;
        return this.age < this.lifetime;
    }

    destroy(scene) {
        scene.remove(this.mesh);
    }
}
// Game 클래스
class Game {
    constructor() {
        // 기본 Three.js 설정
        this.scene = new THREE.Scene();
        this.camera = new THREE.PerspectiveCamera(75, window.innerWidth / window.innerHeight, 0.1, 1000);
        this.renderer = new THREE.WebGLRenderer({ antialias: true });
        this.renderer.setSize(window.innerWidth, window.innerHeight);
        this.renderer.shadowMap.enabled = true;
        document.getElementById('gameContainer').appendChild(this.renderer.domElement);

        // 게임 요소 초기화
        this.tank = new TankPlayer();
        this.enemies = [];
        this.particles = [];
        this.buildings = [];
        this.loader = new GLTFLoader();
        this.controls = null;
        this.gameTime = GAME_DURATION;
        this.score = 0;
        this.isGameOver = false;
        this.isLoading = true;
        this.previousTankPosition = new THREE.Vector3();
        this.lastTime = performance.now();

        // 마우스/키보드 상태
        this.mouse = { x: 0, y: 0 };
        this.keys = {
            forward: false,
            backward: false,
            left: false,
            right: false
        };

        // 이벤트 리스너 설정
        this.setupEventListeners();
        this.initialize();
        this.disposedObjects = new Set(); // 제거된 객체 추적
    }

        // 리소스 정리를 위한 메서드 추가
    dispose(object) {
        if (this.disposedObjects.has(object)) return;
        
        if (object.geometry) object.geometry.dispose();
        if (object.material) {
            if (Array.isArray(object.material)) {
                object.material.forEach(material => material.dispose());
            } else {
                object.material.dispose();
            }
        }
        if (object.parent) object.parent.remove(object);
        this.disposedObjects.add(object);
    }
    // 총알 제거 시 리소스 정리
    cleanupBullets() {
        // 플레이어 총알 정리
        for (let i = this.tank.bullets.length - 1; i >= 0; i--) {
            const bullet = this.tank.bullets[i];
            if (Math.abs(bullet.position.x) > MAP_SIZE/2 || 
                Math.abs(bullet.position.z) > MAP_SIZE/2) {
                this.dispose(bullet);
                this.tank.bullets.splice(i, 1);
            }
        }
      // 적 총알 정리
        this.enemies.forEach(enemy => {
            for (let i = enemy.bullets.length - 1; i >= 0; i--) {
                const bullet = enemy.bullets[i];
                if (Math.abs(bullet.position.x) > MAP_SIZE/2 || 
                    Math.abs(bullet.position.z) > MAP_SIZE/2) {
                    this.dispose(bullet);
                    enemy.bullets.splice(i, 1);
                }
            }
        });
    }
}
      

    async initialize() {
   try {
       // 조명 설정
       const ambientLight = new THREE.AmbientLight(0xffffff, 0.5);
       this.scene.add(ambientLight);

       const directionalLight = new THREE.DirectionalLight(0xffffff, 0.8);
       directionalLight.position.set(50, 50, 50);
       directionalLight.castShadow = true;
       directionalLight.shadow.mapSize.width = 2048;
       directionalLight.shadow.mapSize.height = 2048;
       this.scene.add(directionalLight);

       // 지형 생성
       const ground = new THREE.Mesh(
           new THREE.PlaneGeometry(MAP_SIZE, MAP_SIZE),
           new THREE.MeshStandardMaterial({ 
               color: 0x333333,
               roughness: 0.9,
               metalness: 0.1
           })
       );
       ground.rotation.x = -Math.PI / 2;
       ground.receiveShadow = true;
       this.scene.add(ground);

       // 건물 생성
       await this.createBuildings();

       // 탱크 초기화
       await this.tank.initialize(this.scene, this.loader);
       if (!this.tank.isLoaded) {
           throw new Error('Tank loading failed');
       }

       // 카메라 설정 수정
             // 탱크의 현재 위치 가져오기
      const tankPosition = this.tank.getPosition();
      // 카메라를 탱크 위치 기준으로 설정
      this.camera.position.set(
          tankPosition.x,
          tankPosition.y + 15,  // 탱크보다 15 유닛 위에
          tankPosition.z - 30   // 탱크보다 30 유닛 뒤에
      );
      // 카메라가 탱크를 바라보도록 설정
      this.camera.lookAt(new THREE.Vector3(
          tankPosition.x,
          tankPosition.y + 2,  // 탱크의 상단 부분을 바라보도록
          tankPosition.z
      ));

       // 로딩 완료
       this.isLoading = false;
       document.getElementById('loading').style.display = 'none';

       // 게임 시작
       this.animate();
       this.spawnEnemies();
       this.startGameTimer();

   } catch (error) {
       console.error('Game initialization error:', error);
       this.handleLoadingError();
   }
}

    setupEventListeners() {
    // 키보드 이벤트는 그대로 유지
    document.addEventListener('keydown', (event) => {
        if (this.isLoading) return;
        switch(event.code) {
            case 'KeyW': this.keys.forward = true; break;
            case 'KeyS': this.keys.backward = true; break;
            case 'KeyA': this.keys.left = true; break;
            case 'KeyD': this.keys.right = true; break;
        }
    });

    document.addEventListener('keyup', (event) => {
        if (this.isLoading) return;
        switch(event.code) {
            case 'KeyW': this.keys.forward = false; break;
            case 'KeyS': this.keys.backward = false; break;
            case 'KeyA': this.keys.left = false; break;
            case 'KeyD': this.keys.right = false; break;
        }
    });

    // 마우스 움직임 이벤트를 수정
    document.addEventListener('mousemove', (event) => {
        if (this.isLoading || !document.pointerLockElement) return;
        
        // movementX/Y를 사용하여 마우스 회전 계산
        this.mouse.x += event.movementX * 0.002;
        this.mouse.y += event.movementY * 0.002;
    });

    // 클릭 이벤트 수정 - 포인터 락과 발사를 함께 처리
    document.addEventListener('click', () => {
        if (!document.pointerLockElement) {
            document.body.requestPointerLock();
        } else {
            const bullet = this.tank.shoot(this.scene);
            if (bullet) {
                // 총알 발사 효과음이나 시각효과 추가 가능
            }
        }
    });

    // 포인터 락 상태 변경 이벤트 추가
    document.addEventListener('pointerlockchange', () => {
        if (!document.pointerLockElement) {
            // 포인터 락이 해제되었을 때의 처리
            this.mouse.x = 0;
            this.mouse.y = 0;
        }
    });

    // 창 크기 변경 이벤트는 그대로 유지
    window.addEventListener('resize', () => {
        this.camera.aspect = window.innerWidth / window.innerHeight;
        this.camera.updateProjectionMatrix();
        this.renderer.setSize(window.innerWidth, window.innerHeight);
    });
}
   handleMovement() {
    if (!this.tank.isLoaded) return;
    
    const direction = new THREE.Vector3();
    
    if (this.keys.forward) direction.z += 1;
    if (this.keys.backward) direction.z -= 1;
    if (this.keys.left) direction.x -= 1;
    if (this.keys.right) direction.x += 1;
    
    if (direction.length() > 0) {
        direction.normalize();
        
        // A,D 키로 탱크 회전
        if (this.keys.left) this.tank.rotate(-1);
        if (this.keys.right) this.tank.rotate(1);
        
        // 현재 탱크의 방향으로 이동
        direction.applyEuler(this.tank.body.rotation);
        this.tank.move(direction);
    }

    // 마우스 위치를 탱크 기준으로 변환
    const mouseVector = new THREE.Vector2(this.mouse.x, -this.mouse.y);
    const rotationAngle = Math.atan2(mouseVector.x, mouseVector.y);
    
    // 포탑 회전
    if (this.tank.turretGroup) {
        this.tank.turretGroup.rotation.y = rotationAngle;
    }

    // 여기부터 카메라 로직을 수정합니다
    const tankPos = this.tank.getPosition();
    const cameraDistance = 30; // 카메라와 탱크 사이의 거리
    const cameraHeight = 15;   // 카메라의 높이
    const lookAtHeight = 5;    // 카메라가 바라보는 높이
    
    // 탱크의 회전에 따라 카메라 위치 계산
    const tankRotation = this.tank.body.rotation.y;
    
    // 카메라 위치 계산 수정
    this.camera.position.set(
        tankPos.x - Math.sin(tankRotation) * cameraDistance,
        tankPos.y + cameraHeight,
        tankPos.z - Math.cos(tankRotation) * cameraDistance
    );

    // 카메라가 바라보는 지점을 탱크 위치보다 약간 앞쪽으로 설정
    const lookAtPoint = new THREE.Vector3(
        tankPos.x + Math.sin(tankRotation) * 10, // 탱크 앞쪽 10 유닛
        tankPos.y + lookAtHeight,                 // 탱크보다 약간 위
        tankPos.z + Math.cos(tankRotation) * 10   // 탱크 앞쪽 10 유닛
    );
    
    this.camera.lookAt(lookAtPoint);
}
createBuildings() {
        const buildingTypes = [
            { width: 10, height: 30, depth: 10, color: 0x808080 },
            { width: 15, height: 40, depth: 15, color: 0x606060 },
            { width: 20, height: 50, depth: 20, color: 0x404040 }
        ];

        for (let i = 0; i < BUILDING_COUNT; i++) {
            const type = buildingTypes[Math.floor(Math.random() * buildingTypes.length)];
            const building = this.createBuilding(type);
            
            let position;
            let attempts = 0;
            do {
                position = new THREE.Vector3(
                    (Math.random() - 0.5) * (MAP_SIZE - type.width),
                    type.height / 2,
                    (Math.random() - 0.5) * (MAP_SIZE - type.depth)
                );
                attempts++;
            } while (this.checkBuildingCollision(position, type) && attempts < 50);

            if (attempts < 50) {
                building.position.copy(position);
                this.buildings.push(building);
                this.scene.add(building);
            }
        }
    }

    createBuilding(type) {
        const geometry = new THREE.BoxGeometry(type.width, type.height, type.depth);
        const material = new THREE.MeshPhongMaterial({ 
            color: type.color,
            emissive: 0x222222,
            specular: 0x111111,
            shininess: 30
        });
        const building = new THREE.Mesh(geometry, material);
        building.castShadow = true;
        building.receiveShadow = true;
        return building;
    }

    checkBuildingCollision(position, type) {
        const margin = 5;
        const bbox = new THREE.Box3(
            new THREE.Vector3(
                position.x - (type.width / 2 + margin),
                0,
                position.z - (type.depth / 2 + margin)
            ),
            new THREE.Vector3(
                position.x + (type.width / 2 + margin),
                type.height,
                position.z + (type.depth / 2 + margin)
            )
        );

        return this.buildings.some(building => {
            const buildingBox = new THREE.Box3().setFromObject(building);
            return bbox.intersectsBox(buildingBox);
        });
    }

    handleLoadingError() {
        this.isLoading = false;
        const loadingElement = document.getElementById('loading');
        if (loadingElement) {
            loadingElement.innerHTML = `
                <div class="loading-text" style="color: red;">
                    Loading failed. Please refresh the page.
                </div>
            `;
        }
    }

   spawnEnemies() {
    let spawnTimeout;
    
    const spawnEnemy = () => {
        if (this.isGameOver) {
            clearTimeout(spawnTimeout);
            return;
        }

        if (this.enemies.length < ENEMY_COUNT_MAX) {
            const position = this.getValidEnemySpawnPosition();
            if (position) {
                const type = Math.random() < 0.7 ? 'tank' : 'heavy';
                const enemy = new Enemy(this.scene, position, type);
                enemy.initialize(this.loader).catch(console.error);
                this.enemies.push(enemy);
            }
        }
        
        spawnTimeout = setTimeout(spawnEnemy, 3000);
    };
    
    spawnEnemy();
}

    getValidEnemySpawnPosition() {
        const margin = 20;
        let position;
        let attempts = 0;
        const maxAttempts = 50;

        do {
            position = new THREE.Vector3(
                (Math.random() - 0.5) * (MAP_SIZE - margin * 2),
                ENEMY_GROUND_HEIGHT,
                (Math.random() - 0.5) * (MAP_SIZE - margin * 2)
            );

            const distanceToPlayer = position.distanceTo(this.tank.getPosition());
            if (distanceToPlayer < 100) continue;

            let collisionFound = false;
            for (const building of this.buildings) {
                const buildingBox = new THREE.Box3().setFromObject(building);
                if (buildingBox.containsPoint(position)) {
                    collisionFound = true;
                    break;
                }
            }

            if (!collisionFound) return position;

            attempts++;
        } while (attempts < maxAttempts);

        return null;
    }

    startGameTimer() {
        const timer = setInterval(() => {
            if (this.isLoading) return;
            
            this.gameTime--;
            if (this.gameTime <= 0 || this.isGameOver) {
                clearInterval(timer);
                this.endGame();
            }
        }, 1000);
    }

    updateParticles() {
        for (let i = this.particles.length - 1; i >= 0; i--) {
            const particle = this.particles[i];
            if (!particle.update()) {
                particle.destroy(this.scene);
                this.particles.splice(i, 1);
            }
        }
    }

    createExplosion(position) {
        for (let i = 0; i < PARTICLE_COUNT; i++) {
            this.particles.push(new Particle(this.scene, position));
        }
    }

    checkCollisions() {
    if (this.isLoading || !this.tank.isLoaded) return;

    const tankPosition = this.tank.getPosition();
    const tankBoundingBox = new THREE.Box3().setFromObject(this.tank.body);

    // 적 총알과의 충돌 검사를 최적화
    for (const enemy of this.enemies) {
        if (!enemy.mesh || !enemy.isLoaded) continue;

        for (let i = enemy.bullets.length - 1; i >= 0; i--) {
            const bullet = enemy.bullets[i];
            const distance = bullet.position.distanceTo(tankPosition);
            
            if (distance > 50) continue; // 먼 총알은 검사 스킵
            
            if (distance < 1) {
                if (this.tank.takeDamage(10)) {
                    this.endGame();
                    return;
                }
                this.dispose(bullet);
                enemy.bullets.splice(i, 1);
                this.createExplosion(bullet.position);
                document.getElementById('health').style.width = 
                    `${(this.tank.health / MAX_HEALTH) * 100}%`;
            }
        }
    }

    // 건물과의 충돌 검사 최적화
    for (const building of this.buildings) {
        const buildingBox = new THREE.Box3().setFromObject(building);
        if (tankBoundingBox.intersectsBox(buildingBox)) {
            this.tank.body.position.copy(this.previousTankPosition);
            break;
        }
    }
    
    this.previousTankPosition = this.tank.body.position.clone();
}

    endGame() {
        this.isGameOver = true;
        const gameOverDiv = document.createElement('div');
        gameOverDiv.style.position = 'absolute';
        gameOverDiv.style.top = '50%';
        gameOverDiv.style.left = '50%';
        gameOverDiv.style.transform = 'translate(-50%, -50%)';
        gameOverDiv.style.color = 'white';
        gameOverDiv.style.fontSize = '48px';
        gameOverDiv.style.backgroundColor = 'rgba(0, 0, 0, 0.7)';
        gameOverDiv.style.padding = '20px';
        gameOverDiv.style.borderRadius = '10px';
        gameOverDiv.innerHTML = `
            Game Over<br>
            Score: ${this.score}<br>
            Time Survived: ${GAME_DURATION - this.gameTime}s<br>
            <button onclick="location.reload()" 
                    style="font-size: 24px; padding: 10px; margin-top: 20px; 
                           cursor: pointer; background: #4CAF50; border: none; 
                           color: white; border-radius: 5px;">
                Play Again
            </button>
        `;
        document.body.appendChild(gameOverDiv);
    }

    animate() {
    if (this.isGameOver) return;

    requestAnimationFrame(() => this.animate());

    const currentTime = performance.now();
    const deltaTime = (currentTime - this.lastTime) / 1000;
    this.lastTime = currentTime;

    if (this.isLoading) {
        this.renderer.render(this.scene, this.camera);
        return;
    }

    // 프레임 제한 (60fps)
    if (deltaTime < 1/60) return;

    this.handleMovement();
    this.tank.update(this.mouse.x, this.mouse.y);
    
    const tankPosition = this.tank.getPosition();
    
    // 화면에 보이는 적만 업데이트
    this.enemies.forEach(enemy => {
        if (!enemy.mesh || !enemy.isLoaded) return;
        
        const distance = enemy.mesh.position.distanceTo(tankPosition);
        if (distance > 200) return; // 먼 적은 업데이트 스킵
        
        enemy.update(tankPosition);
        if (distance < ENEMY_CONFIG.ATTACK_RANGE) {
            enemy.shoot(tankPosition);
        }
    });

    this.updateParticles();
    this.checkCollisions();
    this.cleanupBullets();
    this.updateUI();
    this.renderer.render(this.scene, this.camera);
}

    updateUI() {
        const healthBar = document.getElementById('health');
        if (healthBar) {
            healthBar.style.width = `${(this.tank.health / MAX_HEALTH) * 100}%`;
        }

        const timeElement = document.getElementById('time');
        if (timeElement) {
            timeElement.textContent = `Time: ${this.gameTime}s`;
        }

        const scoreElement = document.getElementById('score');
        if (scoreElement) {
            scoreElement.textContent = `Score: ${this.score}`;
        }
    }
}

// HTML의 startGame 함수와 연결
window.startGame = function() {
    document.getElementById('startScreen').style.display = 'none';
    document.body.requestPointerLock();
};

// 게임 인스턴스 생성
const game = new Game();