想做更深入的加载优化？剖析Cocos引擎底层架构后，乐府大佬交出「90分答案」

[
  1,
  [
    "e8Ueib+qJEhL6mXAHdnwbi"
  ],
  [
    "_textureSetter"
  ],
  [
    "cc.SpriteFrame"
  ],
  0,
  [
    {
      "name": "default_btn_normal",
      "rect": [
        0,
        0,
        40,
        40
      ],
      "offset": [
        0,
        0
      ],
      "originalSize": [
        40,
        40
      ],
      "capInsets": [
        12,
        12,
        12,
        12
      ]
    }
  ],
  [
    0
  ],
  0,
  [
    0
  ],
  [
    0
  ],
  [
    0
  ]
]

{[
{
      "name": "default_btn_normal",
      "rect": [
        0,
        0,
        40,
        40
      ],
      "offset": [
        0,
        0
      ],
      "originalSize": [
        40,
        40
      ],
      "capInsets": [
        12,
        12,
        12,
        12
      ],
      "depend": "e8Ueib+qJEhL6mXAHdnwbi" // 额外加入字段
 },
 ...
 ],
 [uuid1,uuid2,...] // 额外加入字段为文件的uuid，与上面的顺序保持一致
}

setJsonReadHandler(handler) {
        fsUtils._customJsonLoadHandler = handler
    },

    readJson (filePath, onComplete) {
        let jsonLoadhandler = fsUtils._customJsonLoadHandler
        if (jsonLoadhandler && jsonLoadhandler(filePath, onComplete)) {
            return
        }
        fsUtils.readFile(filePath, 'utf8', function (err, text) {
            var out = null;
            if (!err) {
                try {
                    out = JSON.parse(text);
                }
                catch (e) {
                    cc.warn(`Read json failed: path: ${filePath} message: ${e.message}`);
                    err = new Error(e.message);
                }
            }
            onComplete && onComplete(err, out);
        });
    },

[
  1,
  [
    "e8Ueib+qJEhL6mXAHdnwbi"
  ],
  [
    "_textureSetter"
  ],
  [
    "cc.SpriteFrame"
  ],
  0,
  [
    // flatbuffer对象
  ],
  [
    0
  ],
  0,
  [
    0
  ],
  [
    0
  ],
  [
    0
  ]
]

_deserialize: function (data, handle) {
        if (!CC_EDITOR && data.bb) {
            this._deserializeWithFlatbuffers(data);
            return;
        }
        ...
}

[
  1,
  0,
  0,
  [
    "cc.Texture2D"
  ],
  0,
  [
    "0,9729,9729,33071,33071,0,0,1",
    -1
  ],
  [
    0
  ],
  0,
  [],
  [],
  []
]

...
if (loadSucceed)
{
  se::Object* retObj = se::Object::createPlainObject();
  retObj->root();
  refs.push_back(retObj);
  cocos2d::renderer::Texture2D* cobj = new (std::nothrow) cocos2d::renderer::Texture2D();
  auto obj = se::Object::createObjectWithClass(__jsb_cocos2d_renderer_Texture2D_class);
  obj->setPrivateData(cobj);

  cocos2d::renderer::Texture::Options options;
  options.bpp = imgInfo->bpp;
  options.width = imgInfo->width;
  options.height = imgInfo->height;

  options.glType = imgInfo->type;
  options.glFormat = imgInfo->glFormat;
  options.glInternalFormat = imgInfo->glInternalFormat;

  options.compressed = imgInfo->compressed;
  options.hasMipmap = false;
  options.premultiplyAlpha = imgInfo->hasPremultipliedAlpha;

  std::vector<cocos2d::renderer::Texture::Image> images;
  cocos2d::renderer::Texture::Image image;
  image.data = imgInfo->data;
  image.length = imgInfo->length;
  images.push_back(image);
  options.images = images;

  cobj->initWithOptions(options);

  retObj->setProperty("texture", se::Value(obj));
  retObj->setProperty("width", se::Value(imgInfo->width));
  retObj->setProperty("height", se::Value(imgInfo->height));
  seArgs.push_back(se::Value(retObj));

  imgInfo = nullptr;
}
...

set src(src) {
 this._src = src;
 jsb.loadImage(src, (info) => {

    if (!info) {

        this._data = null;

        return;

    } else if (info && info.errorMsg) {

        this._data = null;

        var event = new Event('error');

        this.dispatchEvent(event);

        return;

    }

    this.width = this.naturalWidth = info.width;

    this.height = this.naturalHeight = info.height;

   if (info.texture) {

        info.texture._ctor()

        this.texture = info.texture

    }

    else {

         ...

    }

    this.complete = true;

    var event = new Event('load');

    this.dispatchEvent(event);

});

}

_nativeAsset: {
    get () {
        // maybe returned to pool in webgl
        return this._image;
    },
    set (data) {
        if (data.texture) {
            this.initWithTexture(data.texture, data.width, data.height)
            return
        }
        ...
    }
}，
// 添加如下函数
initWithTexture (texture, pixelsWidth, pixelsHeight) {
    this._texture = texture
    this.width = pixelsWidth;
    this.height = pixelsHeight;

    // 通知原生端更新配置，如果没有修改texture属性的，代码基本跑不到。
    // _updateNative标志在当前对象序列化的时候记录如果配置中的信息和默认值不一致时为true
    if (this._updateNative) {
        var opts = _getSharedOptions();
        opts.minFilter = FilterIndex[this._minFilter];
        opts.magFilter = FilterIndex[this._magFilter];
        opts.wrapS = this._wrapS;
        opts.wrapT = this._wrapT;
        texture.update(opts, true) // 这里需要在原生端添加一个简易的更新函数。就拿原来的更新函数提出纹理数据就好了，这里就不贴了。
    }
    this.loaded = true;
    this.emit("load");
    return true;
},

function deserialize (json, options) {
    ...    
    // 不是原生端或者不是骨骼文件，spine原生端不加载骨骼文件
    asset._native && (asset.__nativeDepend__ = !CC_JSB || !(asset instanceof sp.SkeletonData));

    pool.put(tdInfo);
    return asset;
}