- i_time: Add I_GetBuildTimeFrac().

* Currently not needed, but adding for feature parity.

source/common/utility/i_time.cpp

@@ -79,6 +79,11 @@ static uint64_t TicToNS(int tic)
 	return static_cast<uint64_t>(tic) * 1'000'000'000 / GameTicRate;
 }
 
+static uint64_t BuildTicToNS(int tic)
+{
+	return static_cast<uint64_t>(tic) * 1'000'000'000 / 120;
+}
+
 void I_SetFrameTime()
 {
 	// Must only be called once per frame/swapbuffers.
@@ -184,6 +189,15 @@ double I_GetTimeFrac()
 	return (CurrentFrameStartTime - ticStartTime) / (double)(ticNextTime - ticStartTime);
 }
 
+double I_GetBuildTimeFrac()
+{
+	int currentTic = NSToBuildTic(CurrentFrameStartTime - FirstFrameStartTime);
+	uint64_t ticStartTime = FirstFrameStartTime + BuildTicToNS(currentTic);
+	uint64_t ticNextTime = FirstFrameStartTime + BuildTicToNS(currentTic + 1);
+
+	return (CurrentFrameStartTime - ticStartTime) / (double)(ticNextTime - ticStartTime);
+}
+
 void I_FreezeTime(bool frozen)
 {
 	if (frozen)

source/common/utility/i_time.h

@@ -12,13 +12,14 @@ int I_GetTime();
 // same, but using nanoseconds
 uint64_t I_GetTimeNS();
 
-// Called by Build games in liew of totalclock, returns current time in tics at ticrate of 120.
+// Called by Build games in lieu of totalclock, returns current time in tics at ticrate of 120.
 int I_GetBuildTime();
 
 // Reset timer variables to zero when called.
 void I_ResetTime();
 
 double I_GetTimeFrac();
+double I_GetBuildTimeFrac();
 
 // like I_GetTime, except it waits for a new tic before returning
 int I_WaitForTic(int);