- avoid killing timer precision when there's no time scale active.

# Conflicts:
#	src/i_time.cpp

src/i_time.cpp

@@ -75,7 +75,8 @@ CUSTOM_CVAR(Float, i_timescale, 1.0f, CVAR_NOINITCALL)
 static uint64_t GetClockTimeNS()
 {
 	using namespace std::chrono;
-	return (uint64_t)((duration_cast<microseconds>(steady_clock::now().time_since_epoch()).count()) * (uint64_t)(TimeScale * 1000));
+	if (TimeScale == 1.0) return (uint64_t)(duration_cast<nanoseconds>(steady_clock::now().time_since_epoch()).count());
+	else return (uint64_t)((duration_cast<microseconds>(steady_clock::now().time_since_epoch()).count()) * (uint64_t)(TimeScale * 1000));
 }
 
 static uint64_t MSToNS(unsigned int ms)
@@ -164,11 +165,21 @@ uint64_t I_msTime()
 	return NSToMS(I_nsTime());
 }
 
+double I_msTimeF(void)
+{
+	return I_nsTime() / 1'000'000.;
+}
+
 uint64_t I_msTimeFS() // from "start"
 {
 	return (FirstFrameStartTime == 0) ? 0 : NSToMS(I_nsTime() - FirstFrameStartTime);
 }
 
+uint64_t I_GetTimeNS()
+{
+	return CurrentFrameStartTime - FirstFrameStartTime;
+}
+
 int I_GetTime()
 {
 	return NSToTic(CurrentFrameStartTime - FirstFrameStartTime);

src/i_time.h

@@ -7,6 +7,8 @@ void I_SetFrameTime();
 
 // Called by D_DoomLoop, returns current time in tics.
 int I_GetTime();
+// same, but using nanoseconds
+uint64_t I_GetTimeNS();
 
 double I_GetTimeFrac();
 
@@ -22,6 +24,9 @@ void I_FreezeTime(bool frozen);
 // [RH] Returns millisecond-accurate time
 uint64_t I_msTime();
 
+// [RH] Returns nanosecond-accurate time in milliseconds
+double I_msTimeF(void);
+
 // [SP] Returns millisecond-accurate time from start
 uint64_t I_msTimeFS();