Window.prototype._createBackSprite = function () {
  this._backSprite = new Sprite();
  this._backSprite.addChild(new TilingSprite());
  this._backSprite.addChild(new Sprite());
  this._backSprite.addChild(new Sprite());
  this._container.addChild(this._backSprite);
};
Window.prototype._refreshBack = function () {
  var m = this._margin;
  var w = Math.max(0, this._width - m * 2);
  var h = Math.max(0, this._height - m * 2);
  var sprite = this._backSprite;
  var tilingSprite = sprite.children[0];
  // [Note] We use 95 instead of 96 here to avoid blurring edges.
  var sprite2 = sprite.children[1];
  sprite2.bitmap = this._windowskin;
  sprite2.setFrame(0, 0, 95, 95);
  sprite2.move(m, m);
  sprite2.scale.x = w / 95;
  sprite2.scale.y = h / 95;
  tilingSprite.bitmap = this._windowskin;
  tilingSprite.setFrame(0, 96, 96, 96);
  tilingSprite.move(0, 0, w, h);
  tilingSprite.scale.x = 1 / sprite.scale.x;
  tilingSprite.scale.y = 1 / sprite.scale.y;
  //tilingSprite.alpha = 0.8
  //sprite2.alpha = 0.2
  sprite.setColorTone(this._colorTone);
  var mm = 10;
  var sumiSprite = sprite.children[2];
  sumiSprite.removeChildren();
  if (this._isNoSumi) {
    return;
  }
  var baseTexture = Nore.getSystemBaseTexture("Window_sumi");
  var ww = baseTexture.width / 2;
  var hh = baseTexture.height / 2;
  {
    var texture = new PIXI.Texture(baseTexture, new Rectangle(0, 0, ww, hh));
    var spriteOption1 = new PIXI.Sprite(texture);
    spriteOption1.x = mm;
    spriteOption1.y = mm;
    sumiSprite.addChild(spriteOption1);
  }
  {
    var texture = new PIXI.Texture(baseTexture, new Rectangle(ww, 0, ww, hh));
    var spriteOption2 = new PIXI.Sprite(texture);
    spriteOption2.x = this._width - mm - ww;
    spriteOption2.y = mm;
    sumiSprite.addChild(spriteOption2);
  }
  {
    var texture = new PIXI.Texture(baseTexture, new Rectangle(0, hh, ww, hh));
    var spriteOption2 = new PIXI.Sprite(texture);
    spriteOption2.x = mm;
    spriteOption2.y = this._height - mm - hh;
    sumiSprite.addChild(spriteOption2);
  }
  {
    var texture = new PIXI.Texture(baseTexture, new Rectangle(ww, hh, ww, hh));
    var spriteOption2 = new PIXI.Sprite(texture);
    spriteOption2.x = this._width - mm - ww;
    spriteOption2.y = this._height - mm - hh;
    sumiSprite.addChild(spriteOption2);
  }
};