tanqiu/assets/scripts/LaunchScreen.ts

import { _decorator, Component, Node, director, assetManager, ProgressBar, Label, Sprite, SpriteFrame, resources } from 'cc';
const { ccclass, property } = _decorator;

@ccclass('LaunchScreen')
export class LaunchScreen extends Component {
    @property(ProgressBar)
    progressBar: ProgressBar = null;

    @property(Label)
    progressLabel: Label = null;

    @property(Sprite)
    backgroundSprite: Sprite = null;

    @property(SpriteFrame)
    launchBackground: SpriteFrame = null;

    private totalAssets = 0;
    private loadedAssets = 0;

    start() {
        console.log('[LaunchScreen] 启动页开始初始化');
        
        // 设置启动页背景
        this.setupBackground();
        
        // 开始预加载游戏资源
        this.preloadGameAssets();
    }

    /**
     * 设置启动页背景
     */
    private setupBackground() {
        if (this.backgroundSprite && this.launchBackground) {
            this.backgroundSprite.spriteFrame = this.launchBackground;
            console.log('[LaunchScreen] 启动页背景设置完成');
        }
    }

    /**
     * 预加载游戏资源
     */
    private async preloadGameAssets() {
        try {
            console.log('[LaunchScreen] 开始预加载游戏资源');
            
            // 更新进度显示
            this.updateProgress(0, '正在加载游戏资源...');

            // 预加载game-level分包
            await this.loadSubpackage('game-level');
            
            // 预加载完成，跳转到游戏场景
            this.loadGameScene();
            
        } catch (error) {
            console.error('[LaunchScreen] 资源预加载失败:', error);
            this.updateProgress(0, '资源加载失败，请重试');
        }
    }

    /**
     * 加载分包
     */
    private loadSubpackage(bundleName: string): Promise<void> {
        return new Promise((resolve, reject) => {
            console.log(`[LaunchScreen] 开始加载分包: ${bundleName}`);
            
            // 检查是否在微信小游戏环境
            if (typeof wx !== 'undefined' && wx && wx.loadSubpackage) {
                // 微信小游戏分包加载
                const loadTask = wx.loadSubpackage({
                    name: bundleName,
                    success: () => {
                        console.log(`[LaunchScreen] 微信分包 ${bundleName} 加载成功`);
                        // 分包加载成功后，再加载bundle
                        this.loadBundleAfterSubpackage(bundleName, resolve, reject);
                    },
                    fail: (err) => {
                        console.error(`[LaunchScreen] 微信分包 ${bundleName} 加载失败:`, err);
                        // 微信分包加载失败时，尝试直接加载bundle作为降级方案
                        console.log(`[LaunchScreen] 尝试直接加载bundle作为降级方案`);
                        this.loadBundleAfterSubpackage(bundleName, resolve, reject);
                    }
                });
                
                // 监听分包加载进度
                if (loadTask && loadTask.onProgressUpdate) {
                    loadTask.onProgressUpdate((res) => {
                        const progress = res.progress || 0;
                        this.updateProgress(progress, `正在下载分包... ${progress}%`);
                    });
                }
            } else {
                // 非微信环境，直接加载bundle
                console.log(`[LaunchScreen] 非微信环境，直接加载bundle`);
                this.loadBundleAfterSubpackage(bundleName, resolve, reject);
            }
        });
    }
    
    /**
     * 分包下载完成后加载bundle
     */
    private loadBundleAfterSubpackage(bundleName: string, resolve: Function, reject: Function) {
        assetManager.loadBundle(bundleName, (err, bundle) => {
            if (err) {
                console.error(`[LaunchScreen] Bundle ${bundleName} 加载失败:`, err);
                // 如果bundle加载失败，尝试跳过分包直接进入主场景
                console.log(`[LaunchScreen] Bundle加载失败，尝试跳过分包加载`);
                this.skipSubpackageAndLoadMainScene(resolve, reject);
                return;
            }
            
            console.log(`[LaunchScreen] Bundle ${bundleName} 加载成功`);
            
            // 预加载分包中的场景
            bundle.preloadScene('GameLevel', (finished: number, total: number) => {
                const progress = finished / total;
                this.updateProgress(progress * 100, `正在加载游戏场景... ${Math.floor(progress * 100)}%`);
            }, (err) => {
                if (err) {
                    console.error('[LaunchScreen] GameLevel场景预加载失败:', err);
                    // 场景预加载失败时，也尝试跳过分包
                    this.skipSubpackageAndLoadMainScene(resolve, reject);
                    return;
                }
                
                console.log('[LaunchScreen] GameLevel场景预加载完成');
                this.updateProgress(100, '加载完成！');
                resolve();
            });
        });
    }
    
    /**
     * 更新加载进度
     */
    private updateProgress(progress: number, message: string) {
        if (this.progressBar) {
            this.progressBar.progress = progress / 100;
        }
        
        if (this.progressLabel) {
            this.progressLabel.string = message;
        }
        
        console.log(`[LaunchScreen] ${message} (${progress.toFixed(1)}%)`);
    }

    /**
     * 跳过分包加载，直接进入主场景的降级方案
     */
    private skipSubpackageAndLoadMainScene(resolve: Function, reject: Function) {
        console.log('[LaunchScreen] 执行降级方案：跳过分包，尝试加载主场景');
        
        // 尝试加载主场景（如果存在的话）
        director.loadScene('First', (err) => {
            if (err) {
                console.error('[LaunchScreen] 主场景加载也失败:', err);
                this.updateProgress(0, '游戏加载失败，请刷新重试');
                reject(err);
            } else {
                console.log('[LaunchScreen] 成功加载主场景作为降级方案');
                this.updateProgress(100, '加载完成（降级模式）');
                resolve();
            }
        });
    }

    /**
     * 跳转到游戏场景
     */
    private loadGameScene() {
        console.log('[LaunchScreen] 准备跳转到GameLevel场景');
        
        // 延迟一秒后跳转，让用户看到加载完成的提示
        this.scheduleOnce(() => {
            // 使用分包中的场景
            const bundle = assetManager.getBundle('game-level');
            if (bundle) {
                bundle.loadScene('GameLevel', (err, scene) => {
                    if (err) {
                        console.error('[LaunchScreen] GameLevel场景加载失败:', err);
                        // 如果分包场景加载失败，尝试加载主场景
                        this.loadFallbackScene();
                        return;
                    }
                    
                    console.log('[LaunchScreen] 正在切换到GameLevel场景');
                    director.runScene(scene);
                });
            } else {
                console.error('[LaunchScreen] game-level分包未找到，尝试加载主场景');
                this.loadFallbackScene();
            }
        }, 1.0);
    }

    /**
     * 加载降级场景
     */
    private loadFallbackScene() {
        console.log('[LaunchScreen] 尝试加载降级场景');
        director.loadScene('First', (err) => {
            if (err) {
                console.error('[LaunchScreen] 降级场景加载失败:', err);
                this.updateProgress(0, '游戏启动失败，请刷新页面重试');
            } else {
                console.log('[LaunchScreen] 成功加载降级场景');
            }
        });
    }
}