Add Pre/PostTeleport virtuals, for special handling of actor teleportation.

src/playsim/p_teleport.cpp

@@ -148,6 +148,19 @@ bool P_Teleport (AActor *thing, DVector3 pos, DAngle angle, int flags)
 			pos.Z = floorheight;
 		}
 	}
+	// [MK] notify thing of incoming teleport, check for an early cancel
+	// if it returns false
+	{
+		int nocancel = 1;
+		IFVIRTUALPTR(thing, AActor, PreTeleport)
+		{
+			VMValue params[] = { thing, pos.X, pos.Y, pos.Z, angle.Degrees, flags };
+			VMReturn ret;
+			ret.IntAt(&nocancel);
+			VMCall(func, params, countof(params), &ret, 1);
+		}
+		if ( !nocancel ) return false;
+	}
 	if (!P_TeleportMove (thing, pos, false))
 	{
 		return false;
@@ -213,6 +226,14 @@ bool P_Teleport (AActor *thing, DVector3 pos, DAngle angle, int flags)
 		// killough 10/98: kill all bobbing velocity too
 		if (player)	player->Vel.Zero();
 	}
+	// [MK] notify thing of successful teleport
+	{
+		IFVIRTUALPTR(thing, AActor, PostTeleport)
+		{
+			VMValue params[] = { thing, pos.X, pos.Y, pos.Z, angle.Degrees, flags };
+			VMCall(func, params, countof(params), nullptr, 1);
+		}
+	}
 	return true;
 }
 

wadsrc/static/zscript/actors/actor.zs

@@ -589,6 +589,11 @@ class Actor : Thinker native
 	// called on getting a secret, return false to disable default "secret found" message/sound
 	virtual bool OnGiveSecret(bool printmsg, bool playsound) { return true; }
 
+	// called before and after triggering a teleporter
+	// return false in PreTeleport() to cancel the action early
+	virtual bool PreTeleport( Vector3 destpos, double destangle, int flags ) { return true; }
+	virtual void PostTeleport( Vector3 destpos, double destangle, int flags ) {}
+	
 	native virtual bool OkayToSwitchTarget(Actor other);
 	native static class<Actor> GetReplacement(class<Actor> cls);
 	native static class<Actor> GetReplacee(class<Actor> cls);