can do this by parent/child window communication
due to javascript determinism being a pain, aim to run game simulation in one place only, and have simple client renderer.
has commonality with LAN multiplayer, desire to split rendering from mechanics for speed (multithreading) and switching canvas/webgl rendering
possibly run mechanics in a web worker
split rendering, mechanics code such that only one place (in this case parent window) runs the game mechanics
visibility API may be useful for this.
If only one window in focus at a time, possibly should pass control inputs either way.
can do this by parent/child window communication due to javascript determinism being a pain, aim to run game simulation in one place only, and have simple client renderer. has commonality with LAN multiplayer, desire to split rendering from mechanics for speed (multithreading) and switching canvas/webgl rendering possibly run mechanics in a web worker split rendering, mechanics code such that only one place (in this case parent window) runs the game mechanics visibility API may be useful for this. If only one window in focus at a time, possibly should pass control inputs either way.