From b01e0fa06e265bc6d321d422d0fd62fccd91f1d7 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <c.oelckers@zdoom.fake>
Date: Wed, 24 Feb 2016 10:08:23 +0100
Subject: [PATCH] - removed debug output from portal transition code. - handle
 the case where a portal transition crosses more than a single boundary in one
 move.

---
 src/actor.h       |  2 +-
 src/p_mobj.cpp    | 45 +++++++++++++++++++++++++--------------------
 src/r_utility.cpp | 22 +++++++++++++++-------
 3 files changed, 41 insertions(+), 28 deletions(-)

diff --git a/src/actor.h b/src/actor.h
index 47f6ef44b0..15c2ea2abd 100644
--- a/src/actor.h
+++ b/src/actor.h
@@ -742,7 +742,7 @@ public:
 	bool IsHostile (AActor *other);
 
 	inline bool IsNoClip2() const;
-	void CheckPortalTransition();
+	void CheckPortalTransition(bool islinked);
 
 	// What species am I?
 	virtual FName GetSpecies();
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 73683824b9..dafbaffbaa 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -3289,40 +3289,45 @@ void AActor::SetRoll(angle_t r, bool interpolate)
 }
 
 
-void AActor::CheckPortalTransition()
+void AActor::CheckPortalTransition(bool islinked)
 {
-	if (!Sector->PortalBlocksMovement(sector_t::ceiling))
+	bool moved = false;
+	while (!Sector->PortalBlocksMovement(sector_t::ceiling))
 	{
 		AActor *port = Sector->SkyBoxes[sector_t::ceiling];
 		if (Z() > port->threshold)
 		{
 			fixedvec3 oldpos = Pos();
-			UnlinkFromWorld();
+			if (islinked && !moved) UnlinkFromWorld();
 			SetXYZ(PosRelative(port->Sector));
 			PrevX += X() - oldpos.x;
 			PrevY += Y() - oldpos.y;
 			PrevZ += Z() - oldpos.z;
-			LinkToWorld();
-			if (player) Printf("Transitioned upwards to sector %d\n", Sector->sectornum);
-			return;
+			Sector = P_PointInSector(X(), Y());
+			moved = true;
 		}
+		else break;
 	}
-	if (!Sector->PortalBlocksMovement(sector_t::floor))
+	if (!moved)
 	{
-		AActor *port = Sector->SkyBoxes[sector_t::floor];
-		if (Z() < port->threshold && floorz < port->threshold)
+		while (!Sector->PortalBlocksMovement(sector_t::floor))
 		{
-			fixedvec3 oldpos = Pos();
-			UnlinkFromWorld();
-			SetXYZ(PosRelative(port->Sector));
-			PrevX += X() - oldpos.x;
-			PrevY += Y() - oldpos.y;
-			PrevZ += Z() - oldpos.z;
-			LinkToWorld();
-			if (player) Printf("Transitioned downwards to sector %d\n", Sector->sectornum);
-			return;
+			AActor *port = Sector->SkyBoxes[sector_t::floor];
+			if (Z() < port->threshold && floorz < port->threshold)
+			{
+				fixedvec3 oldpos = Pos();
+				if (islinked && !moved) UnlinkFromWorld();
+				SetXYZ(PosRelative(port->Sector));
+				PrevX += X() - oldpos.x;
+				PrevY += Y() - oldpos.y;
+				PrevZ += Z() - oldpos.z;
+				Sector = P_PointInSector(X(), Y());
+				moved = true;
+			}
+			else break;
 		}
 	}
+	if (islinked && moved) LinkToWorld();
 }
 
 //
@@ -3392,7 +3397,7 @@ void AActor::Tick ()
 		UnlinkFromWorld ();
 		flags |= MF_NOBLOCKMAP;
 		SetXYZ(Vec3Offset(velx, vely, velz));
-		CheckPortalTransition();
+		CheckPortalTransition(false);
 		SetMovement(velx, vely, velz);
 		LinkToWorld ();
 	}
@@ -3860,7 +3865,7 @@ void AActor::Tick ()
 			Crash();
 		}
 
-		CheckPortalTransition();
+		CheckPortalTransition(true);
 
 		UpdateWaterLevel (oldz);
 
diff --git a/src/r_utility.cpp b/src/r_utility.cpp
index 60a415d807..a97ebc65ec 100644
--- a/src/r_utility.cpp
+++ b/src/r_utility.cpp
@@ -640,7 +640,8 @@ void R_InterpolateView (player_t *player, fixed_t frac, InterpolationViewer *ivi
 	
 	// Due to interpolation this is not necessarily the same as the sector the camera is in.
 	viewsector = R_PointInSubsector(viewx, viewy)->sector;
-	if (!viewsector->PortalBlocksMovement(sector_t::ceiling))
+	bool moved = false;
+	while (!viewsector->PortalBlocksMovement(sector_t::ceiling))
 	{
 		AActor *point = viewsector->SkyBoxes[sector_t::ceiling];
 		if (viewz > point->threshold)
@@ -648,16 +649,23 @@ void R_InterpolateView (player_t *player, fixed_t frac, InterpolationViewer *ivi
 			viewx += point->scaleX;
 			viewy += point->scaleY;
 			viewsector = R_PointInSubsector(viewx, viewy)->sector;
+			moved = true;
 		}
+		else break;
 	}
-	if (!viewsector->PortalBlocksMovement(sector_t::floor))
+	if (!moved)
 	{
-		AActor *point = viewsector->SkyBoxes[sector_t::floor];
-		if (viewz < point->threshold)
+		while (!viewsector->PortalBlocksMovement(sector_t::floor))
 		{
-			viewx += point->scaleX;
-			viewy += point->scaleY;
-			viewsector = R_PointInSubsector(viewx, viewy)->sector;
+			AActor *point = viewsector->SkyBoxes[sector_t::floor];
+			if (viewz < point->threshold)
+			{
+				viewx += point->scaleX;
+				viewy += point->scaleY;
+				viewsector = R_PointInSubsector(viewx, viewy)->sector;
+				moved = true;
+			}
+			else break;
 		}
 	}
 }