engine: client: implement HL25's cl_fixmodelinterpolationartifacts cvar

engine/client/cl_frame.c

@@ -1228,7 +1228,13 @@ void CL_LinkPacketEntities( frame_t *frame )
 #else
 					if( ent->lastmove >= cl.time )
 					{
+						float at = ent->curstate.animtime;
+
 						CL_ResetLatchedVars( ent, true );
+
+						if( cl_fixmodelinterpolationartifacts.value )
+							ent->latched.prevanimtime = ent->curstate.animtime = at;
+
 						VectorCopy( ent->curstate.origin, ent->latched.prevorigin );
 						VectorCopy( ent->curstate.angles, ent->latched.prevangles );
 

engine/client/cl_main.c

@@ -78,6 +78,8 @@ CVAR_DEFINE_AUTO( cl_trace_events, "0", FCVAR_ARCHIVE|FCVAR_CHEAT, "enable event
 static CVAR_DEFINE_AUTO( cl_nat, "0", 0, "show servers running under NAT" );
 CVAR_DEFINE_AUTO( hud_utf8, "0", FCVAR_ARCHIVE, "Use utf-8 encoding for hud text" );
 CVAR_DEFINE_AUTO( ui_renderworld, "0", FCVAR_ARCHIVE, "render world when UI is visible" );
+static CVAR_DEFINE_AUTO( cl_maxframetime, "0", 0, "set deadline timer for client rendering to catch freezes" );
+CVAR_DEFINE_AUTO( cl_fixmodelinterpolationartifacts, "1", 0, "try to fix up models interpolation on a moving platforms (monsters on trains for example)" );
 
 //
 // userinfo
@@ -87,7 +89,6 @@ static CVAR_DEFINE_AUTO( model, "", FCVAR_USERINFO|FCVAR_ARCHIVE|FCVAR_FILTERABL
 static CVAR_DEFINE_AUTO( topcolor, "0", FCVAR_USERINFO|FCVAR_ARCHIVE|FCVAR_FILTERABLE, "player top color" );
 static CVAR_DEFINE_AUTO( bottomcolor, "0", FCVAR_USERINFO|FCVAR_ARCHIVE|FCVAR_FILTERABLE, "player bottom color" );
 CVAR_DEFINE_AUTO( rate, "3500", FCVAR_USERINFO|FCVAR_ARCHIVE|FCVAR_FILTERABLE, "player network rate" );
-static CVAR_DEFINE_AUTO( cl_maxframetime, "0", 0, "set deadline timer for client rendering to catch freezes" );
 
 client_t		cl;
 client_static_t	cls;
@@ -2919,6 +2920,7 @@ void CL_InitLocal( void )
 	Cvar_Get( "lastdemo", "", FCVAR_ARCHIVE, "last played demo" );
 	Cvar_RegisterVariable( &ui_renderworld );
 	Cvar_RegisterVariable( &cl_maxframetime );
+	Cvar_RegisterVariable( &cl_fixmodelinterpolationartifacts );
 
 	// these two added to shut up CS 1.5 about 'unknown' commands
 	Cvar_Get( "lightgamma", "1", FCVAR_ARCHIVE, "ambient lighting level (legacy, unused)" );

engine/client/client.h

@@ -700,6 +700,7 @@ extern convar_t	rate;
 extern convar_t	m_ignore;
 extern convar_t	r_showtree;
 extern convar_t	ui_renderworld;
+extern convar_t cl_fixmodelinterpolationartifacts;
 
 //=============================================================================