Game thread:                                 Rendering thread:
  Queue stuff (A)                                                                               |
  Queue rendering (A)                         Do rendering (A) and swap to (B)                 |
  Queue stuff (B)                              Write A to Window FB                            Time
  Queue stuff (B)                                                                               |
  Queue rendering (B)                         Do rendering (B) and swap to (A)                 |
  ...                                                                                          V