code: func (c *Canvas) SetBounds(bounds pixel.Rect) {
  	c.gf.SetBounds(bounds)
  	if c.sprite == nil {
  		c.sprite = pixel.NewSprite(nil, pixel.Rect{})
  	}
  	c.sprite.Set(c, c.Bounds())
  	//c.sprite.SetMatrix(pixel.IM.Moved(c.Bounds().Center()))
  }
docs: // SetBounds resizes the Canvas to the new bounds. Old content will be preserved.