Pausing renderclock

Pausing RenderClock:

GPauseRenderingRealtimeClock controlled in UGameEngine.Tick.

• Can be paused using SetGamePaused

• Uses fixeddelta time correctly

• But always ticks even when Gworld->IsPaused() == true

• Ticking occurs based on GPauseRenderingRealtimeClock

• Only way it's ever turned off in Engine is through console cmd: PAUSERENDERCLOCK

• HandlePauseRenderClockCommand( Cmd, Ar );

• Sets GPauseRenderingRealtimeClock = !GPauseRenderingRealtimeClock;

Render Thread pausing

• Can be paused with helper class FSuspendRenderingThread (called from Game Thread)

• Flushes Render Commands

• Can call StopRenderingThread()/StartRenderingThread()

  • These functions atomically alter GIsRenderingThreadSuspended

  • Also can alter GRunRenderingThreadHeartbeat which happens on start/stopping the thread. If FSuspendRenderingThread is called to suspend by recreating the render thread, it will destroy the render thread & recreate it so it will set GRunRenderingThreadHeartbeat = false through StopRenderingThread

  • GIsRenderingThreadSuspended is used by FRenderingThreadTickHeartbeat (a separate GameThread to manage heartbeat ticks)

  • Heartbeat tick @ GRenderingThreadMaxIdleTickFrequency from GameThread

  • It ticks FTickableObjectRenderThread objects by enqueing TickingRenderingTickables() on the rendering thread (when GIsRenderingThreadSuspended == false)

  • This thread runs on it's own heartbeat which is disjoint from the GT or the other RT resources

  • It's Tick DeltaSeconds is in system real time, not game time or fixed time