[nercury]

I would not sing praises for Microsoft Flight Simulator 2020. First, the cockpit displays are rendered at lower framerate, because they take considerable chunk of frame time. Second... It may be fine to render display and UI using js, but if you dig in, you will also find the autopilot there on top of inheritance hell.

[Stevvo]

In the recent versions of the simulator, most cockpit displays render in less than 1ms per aircraft. Early versions were a mess; the cockpit displays were not only slow, but also entirety fictional. At some point Microsoft hired WorkingTitle, a studio of web developers with no C++ experience, to optimize and improve the cockpit displays. They also wrote that autopilot code you mention. It's not "the autopilot" however; the PID controllers that fly the plane are on C++ side, in JS are huge amounts of input related code to make it behave like a Garmin or Airbus system.