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Add cl_localTime: PLL-based local rendering clock for smooth gameplay #65

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Merged
neyoneit merged 1 commit into from
Apr 3, 2026
Merged

Add cl_localTime: PLL-based local rendering clock for smooth gameplay #65

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32 changes: 31 additions & 1 deletion code/client/cl_cgame.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1162,7 +1162,37 @@ void CL_SetCGameTime( void ) {
// cl_timeNudge is a user adjustable cvar that allows more
// or less latency to be added in the interest of better
// smoothness or better responsiveness.
cl.serverTime = cls.realtime + cl.serverTimeDelta - CL_TimeNudge();

if ( cl_localTime->integer && !clc.demoplaying ) {
// PLL: advance serverTime at constant local rate instead of
// jumping to network-derived value each frame. Eliminates
// rendering jitter from snapshot arrival variance.
static int lastRealtime = 0;
int frameDelta, targetTime, error;

if ( lastRealtime == 0 || lastRealtime > cls.realtime )
lastRealtime = cls.realtime;

frameDelta = cls.realtime - lastRealtime;
lastRealtime = cls.realtime;

targetTime = cls.realtime + cl.serverTimeDelta - CL_TimeNudge();
error = targetTime - cl.serverTime;
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@Garux Garux Apr 24, 2026

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variable name is error, while value is time difference with previous frame


// soft rate adjustment: speed up/slow down max 2% to track server
if ( error > 2 )
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@Garux Garux Apr 24, 2026

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this is always true pratically

cl.serverTime += (int)( frameDelta * 1.02f );
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@Garux Garux Apr 24, 2026

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frameDelta is typically 8, (int)( 8 * 1.02f ) = 8
'soft rate adjustment' is missing
practically, if time drifts away, additional weapon knockback lag is experienced, and this is visible on lagometer, until time resets by >100ms lag

else if ( error < -2 )
cl.serverTime += (int)( frameDelta * 0.98f );
else
cl.serverTime += frameDelta;

// hard clamp: never diverge more than 100ms from server
if ( error > 100 || error < -100 )
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@Garux Garux Apr 24, 2026

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in case if ping spike this will add two lags by forth and back adjustments

cl.serverTime = targetTime;
} else {
cl.serverTime = cls.realtime + cl.serverTimeDelta - CL_TimeNudge();
}

// guarantee that time will never flow backwards, even if
// serverTimeDelta made an adjustment or cl_timeNudge was changed
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5 changes: 5 additions & 0 deletions code/client/cl_main.c
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Expand Up @@ -39,6 +39,7 @@ cvar_t *cl_timeout;
cvar_t *cl_autoNudge;
cvar_t *cl_timeNudge;
cvar_t *cl_showTimeDelta;
cvar_t *cl_localTime;

cvar_t *cl_shownet;
cvar_t *cl_autoRecordDemo;
Expand Down Expand Up @@ -3908,6 +3909,10 @@ void CL_Init( void ) {
Cvar_CheckRange( cl_timeNudge, "-250", "250", CV_INTEGER );
Cvar_SetDescription( cl_timeNudge, "Allows more or less latency to be added in the interest of better smoothness or better responsiveness." );

cl_localTime = Cvar_Get( "cl_localTime", "0", CVAR_ARCHIVE_ND );
Cvar_CheckRange( cl_localTime, "0", "1", CV_INTEGER );
Cvar_SetDescription( cl_localTime, "Local time mode: cl.serverTime advances at constant local rate instead of jumping to network-derived values.\n 0 - standard network-synced time (default)\n 1 - smooth local clock, eliminates rendering jitter from network\n" );

cl_shownet = Cvar_Get ("cl_shownet", "0", CVAR_TEMP );
Cvar_SetDescription( cl_shownet, "Toggle the display of current network status." );
cl_showTimeDelta = Cvar_Get ("cl_showTimeDelta", "0", CVAR_TEMP );
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1 change: 1 addition & 0 deletions code/client/client.h
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Expand Up @@ -392,6 +392,7 @@ extern cvar_t *cl_shownet;
extern cvar_t *cl_autoNudge;
extern cvar_t *cl_timeNudge;
extern cvar_t *cl_showTimeDelta;
extern cvar_t *cl_localTime;

extern cvar_t *com_timedemo;
extern cvar_t *cl_aviFrameRate;
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