Add some effects for null-drifting

src/d_player.h

@@ -596,6 +596,10 @@ struct player_t
 
 	INT32 drift_wannaturn;  // Turn values the game uses to determine the direction you want to drift.
 
+	INT32 nulldrift;        // When you drift without accelerating, this value ticks up/down depending on your drift's angle.
+	INT32 nulldrifttilt;    // Sliptide-like kart tilting! (Can be toggled off)
+	tic_t nulldrifttime;
+
 	// (Delay-drift) - Delay in tics before the final drift angle is determined.
 	// Potentially influenced by player lag.
 	tic_t driftdelay;

src/k_kart.c

@@ -9605,6 +9605,30 @@ static void K_KartDrift(player_t *player, boolean onground)
 		}
 	}
 
+	if (player->nulldrift)
+	{
+		if (abs(player->nulldrifttilt) < ANGLE_11hh)
+		{
+			player->nulldrifttilt = (abs(player->nulldrifttilt) + (ANGLE_11hh / 8)) * player->nulldrift;
+		}
+
+		// Increment nulldrift timer.
+		player->nulldrifttime++;
+
+		// Let's have some faith that the driftspark thinker will set this value again
+		player->nulldrift = 0;
+	}
+	else
+	{
+		player->nulldrifttime = 0;
+		player->nulldrifttilt -= player->nulldrifttilt / 4;
+
+		if (abs(player->nulldrifttilt) < (ANGLE_11hh / 4))
+		{
+			player->nulldrifttilt = 0;
+		}
+	}
+
 	if (!K_Sliptiding(player))
 	{
 		player->aizdrifttilt -= player->aizdrifttilt / 4;
@@ -11894,4 +11918,10 @@ boolean K_CheckWaterskipLockout(player_t *player)
 	}
 }
 
+// Check to render the tilt VFX for null-drifts.
+boolean K_NullDriftTiltEnalbed()
+{
+	return ((cv_nulldriftefx.value) && (cv_nulldrifttilt.value));
+}
+
 //}

src/k_kart.h

@@ -419,6 +419,8 @@ typedef enum
 	BUMPSPARK_ALL
 } bumpsparktype_t;
 
+boolean K_NullDriftTiltEnalbed();
+
 #ifdef __cplusplus
 } // extern "C"
 #endif

src/p_mobj.c

@@ -9052,10 +9052,14 @@ static boolean P_MobjRegularThink(mobj_t *mobj)
 		P_MoveOrigin(mobj, mobj->target->x, mobj->target->y, mobj->target->z);
 		break;
 	case MT_BRAKEDRIFT:
+
+		// Letting go of accel functions about the same as brake-drifting
+		boolean nullDrift = (!(K_GetKartButtons(mobj->target->player) & BT_ACCELERATE));
+
 		if ((!mobj->target || !mobj->target->health || !mobj->target->player || !P_IsObjectOnGround(mobj->target))
 			|| !mobj->target->player->drift || !(mobj->target->player->pflags & PF_BRAKEDRIFT)
 			|| !((mobj->target->player->cmd.buttons & BT_BRAKE)
-			|| !(K_GetKartButtons(mobj->target->player) & BT_ACCELERATE))) // Letting go of accel functions about the same as brake-drifting
+			|| nullDrift))
 		{
 			P_RemoveMobj(mobj);
 			return false;
@@ -9080,8 +9084,27 @@ static boolean P_MobjRegularThink(mobj_t *mobj)
 			else
 				mobj->color = SKINCOLOR_SILVER;
 
-			if (!S_SoundPlaying(mobj, sfx_cdfm17))
-				S_StartSound(mobj, sfx_cdfm17);
+			if (nullDrift)
+			{
+				if (cv_nulldriftefx.value)
+				{
+					// Play a harsher sound when you null-drift.
+					if (mobj->target->player->nulldrifttime % 4 == 0)
+						S_StartSound(mobj, sfx_s3k67);
+				}
+				else if (!S_SoundPlaying(mobj, sfx_cdfm17))
+				{
+					S_StartSound(mobj, sfx_cdfm17);
+				}
+
+				// Set the player's nulldrift variables for any relevant VFX.
+				mobj->target->player->nulldrift = intsign(mobj->target->player->drift);
+			}
+			else
+			{
+				if (!S_SoundPlaying(mobj, sfx_cdfm17))
+					S_StartSound(mobj, sfx_cdfm17);
+			}
 
 			K_MatchGenericExtraFlags(mobj, mobj->target);
 			if (leveltime & 1)

src/p_saveg.c

@@ -637,6 +637,9 @@ static void P_NetSyncPlayers(savebuffer_t *save)
 		SYNC(players[i].driftcharge);
 		SYNC(players[i].driftboost);
 		SYNC(players[i].airdriftspeed);
+		SYNC(players[i].nulldrift);
+		SYNC(players[i].nulldrifttilt);
+		SYNC(players[i].nulldrifttime);
 
 		SYNC(players[i].recoverydashcharge);
 		SYNC(players[i].recoverydash);

src/r_main.cpp

@@ -194,6 +194,8 @@ consvar_t cv_renderstats = CVAR_INIT ("renderstats", "Off", 0, CV_OnOff, NULL);
 consvar_t cv_sloperoll = CVAR_INIT ("spritesloperoll", "On", CV_SAVE, CV_OnOff, NULL);
 
 consvar_t cv_sliptidetilt = CVAR_INIT ("sliptidetilt", "On", CV_SAVE, CV_OnOff, NULL);
+consvar_t cv_nulldriftefx = CVAR_INIT ("nulldriftefx", "On", CV_SAVE, CV_OnOff, NULL);
+consvar_t cv_nulldrifttilt = CVAR_INIT ("nulldrifttilt", "On", CV_SAVE, CV_OnOff, NULL);
 
 void SplitScreen_OnChange(void)
 {
@@ -1804,6 +1806,8 @@ void R_RegisterEngineStuff(void)
 	CV_RegisterVar(&cv_actionmovie);
 	CV_RegisterVar(&cv_sloperoll);
 	CV_RegisterVar(&cv_sliptidetilt);
+	CV_RegisterVar(&cv_nulldriftefx);
+	CV_RegisterVar(&cv_nulldrifttilt);
 
 	CV_RegisterVar(&cv_showhud);
 	CV_RegisterVar(&cv_translucenthud);

src/r_main.h

@@ -159,6 +159,7 @@ extern consvar_t cv_secbright;
 
 extern consvar_t cv_sloperoll;
 extern consvar_t cv_sliptidetilt;
+extern consvar_t cv_nulldriftefx, cv_nulldrifttilt;
 
 // debugging
 

src/r_patchrotation.c

@@ -61,11 +61,18 @@ static angle_t R_PlayerSpriteRotation(player_t *player, player_t *viewPlayer)
 	angle_t viewingAngle = R_PointToAnglePlayer(viewPlayer, player->mo->x, player->mo->y);
 	angle_t angleDelta = (viewingAngle - player->mo->angle);
 
-	angle_t sliptideLift = player->aizdrifttilt;
+	INT32 nulltilt = (K_NullDriftTiltEnalbed()) ? player->nulldrifttilt : 0;
+	INT32 aiztilt = (cv_sliptidetilt.value) ? player->aizdrifttilt : 0;
+
+	boolean nullBeforeSlip = (abs(aiztilt) < abs(nulltilt));
+	INT32 liftsign = ((nullBeforeSlip) ? intsign(nulltilt) : intsign(aiztilt));
+
+	// Sliptide tilt: Nulldrifts take priority if and ONLY if they're the larger value compared to sliptides.
+	angle_t sliptideLift = max(abs(aiztilt), abs(nulltilt)) * liftsign;
 
 	angle_t rollAngle = 0;
 
-	if (sliptideLift && cv_sliptidetilt.value)
+	if (sliptideLift)
 	{
 		/* (from side) tilt downward if turning
 		   toward camera, upward if away. */