cocosjs 截屏功能，输出截屏的base64data

// var texture = new cc.Texture2D();

    // texture.initWithElement(img);

    // texture.handleLoadedTexture();

    // var newframe = new cc.SpriteFrame(texture);

var renderText = new cc.RenderTexture(size.width,size.height);

    renderText.begin();

    cc.director.getRunningScene().visit();

    renderText.end();

    var test = cc.Sprite.create(renderText.getSprite().getTexture(), cc.rect(size.width / 3,size.height / 3 * 2,size.width/3*2,size.height/3*2))//cc.rect的坐标0点是左上角，游戏的坐标0点是左下角

    test.setPosition(0, 0)

    test.setAnchorPoint(0, 0)

    test.setScale(1/2)

    this.addChild(test, 10)

    var canvas = cc.newElement('canvas') // 创建一个新的元素节点

      canvas.width = size.width

      canvas.height = size.height

      var ctx = canvas.getContext('2d') // 获得一个2d的画布(通过它就可以这个画布上的像素信息,我们只在上面绘制一张图片)

      ctx.drawImage(renderText.getSprite().getTexture().getHtmlElementObj(), 0, 0)

    var href = canvas.toDataURL("image/png")

   // var img = new Image();

    //img.src = href;

    cc.log(href)