make this change operation order instead of use snapshots

src/d_netcmd.c

@@ -674,7 +674,7 @@ consvar_t cv_kartairsquish = CVAR_INIT ("kartairsquish", "None", CV_NETVAR, kart
 
 consvar_t cv_kartdebugshrink = CVAR_INIT ("kartdebugshrink", "Off", CV_NETVAR|CV_CHEAT, CV_OnOff, NULL);
 
-consvar_t cv_kartdrift_snapshot = CVAR_INIT ("kartdriftsnapshot", "Off", CV_NETVAR|CV_CHEAT, CV_OnOff, NULL);
+consvar_t cv_kartdrift_operationorder = CVAR_INIT ("kartdriftoperationorder", "Off", CV_NETVAR|CV_CHEAT, CV_OnOff, NULL);
 
 consvar_t cv_kartdebugdistribution = CVAR_INIT ("kartdebugdistribution", "Off", CV_NETVAR|CV_CHEAT, CV_OnOff, NULL);
 consvar_t cv_kartdebughuddrop = CVAR_INIT ("kartdebughuddrop", "Off", CV_NETVAR|CV_CHEAT, CV_OnOff, NULL);

src/d_netcmd.h

@@ -243,7 +243,7 @@ extern consvar_t cv_votetime;
 
 extern consvar_t cv_kartdebugitem, cv_kartdebugamount, cv_kartdebugdistribution, cv_kartdebughuddrop;
 extern consvar_t cv_kartdebugshrink;
-extern consvar_t cv_kartdrift_snapshot;
+extern consvar_t cv_kartdrift_operationorder;
 extern consvar_t cv_kartdebugcheckpoint, cv_kartdebugnodes, cv_kartdebugcolorize, cv_kartdebugdirector;
 extern consvar_t cv_kartdebugwaypoints, cv_kartdebuglap, cv_kartdebugbot, cv_kartdebugcluster, cv_kartdebugrings;
 extern consvar_t cv_gptest;

src/d_player.h

@@ -567,7 +567,6 @@ struct player_t
 	boolean noclip;			// Fix Grow breaking the "noclip" cheat. Also applies noclip as a bonus.
 
 	SINT8 drift;			// (-5 to 5) - Drifting Left or Right, plus a bigger counter = sharper turn
-	INT16 driftturnsnapshot;
 	SINT8 driftlock;		// Prevents you from using drift angle for x tics. Used for zipper fix.
 	fixed_t driftcharge;	// Charge your drift so you can release a burst of speed
 	UINT8 driftboost;		// (0 to 125) - Boost you get from drifting

src/k_kart.c

@@ -453,7 +453,7 @@ void K_RegisterKartStuff(void)
 	CV_RegisterVar(&cv_karteggmine_slotlock);
 	CV_RegisterVar(&cv_karteggmine_slotbrick);
 
-	CV_RegisterVar(&cv_kartdrift_snapshot);
+	CV_RegisterVar(&cv_kartdrift_operationorder);
 }
 
 //}
@@ -7572,17 +7572,16 @@ void K_KartPlayerThink(player_t *player, ticcmd_t *cmd)
 		player->flamecamtime -= 1;
 	}
 
-	if (cmd->buttons & BT_DRIFT)
+	if (!cv_kartdrift_operationorder.value)
 	{
-		player->pflags |= PF_DRIFTINPUT;
+		if (cmd->buttons & BT_DRIFT)
-
+		{
-		player->driftturnsnapshot = player->cmd.turning;
+			player->pflags |= PF_DRIFTINPUT;
-	}
+		}
-	else
+		else
-	{
+		{
-		player->pflags &= ~PF_DRIFTINPUT;
+			player->pflags &= ~PF_DRIFTINPUT;
-
+		}
-		player->driftturnsnapshot = 0;
 	}
 
 	// Respawn Checker
@@ -9369,19 +9368,14 @@ static void K_KartDrift(player_t *player, boolean onground)
 			player->driftcharge = 0;
 	}
 
-	// experiment disabled, drop the snapshot and use the turning value from this tick
-	if (!cv_kartdrift_snapshot.value)
-	{
-		player->driftturnsnapshot = player->cmd.turning;
-	}
 	// Drifting: left or right?
-	if ((player->driftturnsnapshot > 0) && player->speed > minspeed && (player->pflags & PF_DRIFTINPUT) && (player->drift == 0 || (player->pflags & PF_DRIFTEND)))
+	if ((player->cmd.turning > 0) && player->speed > minspeed && (player->pflags & PF_DRIFTINPUT) && (player->drift == 0 || (player->pflags & PF_DRIFTEND)))
 	{
 		// Starting left drift
 		player->drift = 1;
 		player->pflags &= ~PF_DRIFTEND;
 	}
-	else if ((player->driftturnsnapshot < 0) && player->speed > minspeed && (player->pflags & PF_DRIFTINPUT) && (player->drift == 0 || (player->pflags & PF_DRIFTEND)))
+	else if ((player->cmd.turning < 0) && player->speed > minspeed && (player->pflags & PF_DRIFTINPUT) && (player->drift == 0 || (player->pflags & PF_DRIFTEND)))
 	{
 		// Starting right drift
 		player->drift = -1;

src/p_saveg.c

@@ -607,7 +607,6 @@ static void P_NetSyncPlayers(savebuffer_t *save)
 		SYNCBOOLEAN(players[i].noclip);
 
 		SYNC(players[i].drift);
-		SYNC(players[i].driftturnsnapshot);
 		SYNC(players[i].driftlock);
 		SYNC(players[i].driftcharge);
 		SYNC(players[i].driftboost);

src/p_user.c

@@ -4299,6 +4299,19 @@ void P_PlayerThink(player_t *player)
 
 	player->pflags &= ~PF_HITFINISHLINE;
 	
+	// experiment: process the drift input *before* player movement instead of after
+	if (cv_kartdrift_operationorder.value)
+	{
+		if (cmd->buttons & BT_DRIFT)
+		{
+			player->pflags |= PF_DRIFTINPUT;
+		}
+		else
+		{
+			player->pflags &= ~PF_DRIFTINPUT;
+		}
+	}
+
 	// check water content, set stuff in mobj
 	P_MobjCheckWater(player->mo);