title: A-Buffer method with metal and memory economy
body: <p>I have an idea to extend linked list by reducing rendering area, i.e by using a small render target that then blitted into main render target, tile by tile.
  The main problem is how to render into a small render target as it would be just a scissor rect of main render target?
  The main idea of using small render target is taken there - <a href="https://stackoverflow.com/questions/59111013/metal-limit-mtlrendercommandencoder-texture-loading-to-only-part-of-texture">Metal: limit MTLRenderCommandEncoder texture loading to only part of texture</a></p>
  <p><strong>UPD</strong>
  This is not for realtime rendering</p>