simpler implementation

src/engine/qcommon/common.cpp

@@ -861,16 +861,12 @@ void Com_Frame()
 		minMsec = 1;
 	}
 
-	int beforeProcessing = Sys::Milliseconds();
-
 	Com_EventLoop();
 
 	// It must be called at least once.
 	IN_Frame();
 
-	int afterProcessing = Sys::Milliseconds();
-
-	com_frameTime = afterProcessing;
+	com_frameTime = Sys::Milliseconds();
 
 	// lastTime can be greater than com_frameTime on first frame.
 	lastTime = std::min( lastTime, com_frameTime );
@@ -879,30 +875,21 @@ void Com_Frame()
 
 	while ( msec < minMsec )
 	{
-		int processingTime = afterProcessing - beforeProcessing;
-
-		/* Fill as much as input frames as possible within this timeframe to not
-		let the game process events in a way it would last longer than that. */
-		int jamTime = std::max( afterProcessing, 50 );
+		// Never sleep more than 50ms.
+		// Never sleep when there is 2ms or less remaining.
+		int sleep = std::max( std::min( minMsec - msec, 50 ) - 2, 0 );
 
-		int sleep = minMsec - msec;
-
-		// Let enough time to process events and jam frames after sleeping.
-		if ( sleep > jamTime * 2 )
+		if ( sleep )
 		{
 			// Give cycles back to the OS.
-			Sys::SleepFor( std::chrono::milliseconds( processingTime ) );
+			Sys::SleepFor( std::chrono::milliseconds( sleep ) );
 		}
 
-		beforeProcessing = Sys::Milliseconds();
-
 		Com_EventLoop();
 
 		IN_Frame();
 
-		afterProcessing = Sys::Milliseconds();
-
-		com_frameTime = afterProcessing;
+		com_frameTime = Sys::Milliseconds();
 
 		msec = com_frameTime - lastTime;
 	}