- made arbitrary portals passable.

This includes:

* allow one sided portal linedefs to be crossable when part of a polyobject. Due to the limitations, two-sided linedefs won't work here. For general use this is still not allowed because making them passable would require some crippling fudging.
* delay portal finalization until after polyobjects have been spawned.
* the camera interpolation also needs to handle angle differences.

The code is still not 100% complete - the most important thing that is still missing is proper handling of P_CheckPosition through arbitrary portals.

src/p_map.cpp

@@ -808,6 +808,18 @@ bool PIT_CheckLine(FMultiBlockLinesIterator &mit, FMultiBlockLinesIterator::Chec
 
 	if (!ld->backsector)
 	{ // One sided line
+
+		// Needed for polyobject portals. Having two-sided lines just for portals on otherwise solid polyobjects is a messy subject.
+		if ((cres.line->sidedef[0]->Flags & WALLF_POLYOBJ) && cres.line->isLinePortal())
+		{
+			spechit_t spec;
+			spec.line = ld;
+			spec.refpos = cres.position;
+			spec.oldrefpos = tm.thing->PosRelative(ld);
+			portalhit.Push(spec);
+			return true;
+		}
+
 		if (((cres.portalflags & FFCF_NOFLOOR) && LineIsAbove(cres.line, tm.thing) != 0) ||
 			((cres.portalflags & FFCF_NOCEILING) && LineIsBelow(cres.line, tm.thing) != 0))
 		{
@@ -2143,7 +2155,7 @@ bool P_TryMove(AActor *thing, fixed_t x, fixed_t y,
 	while (true)
 	{
 		fixed_t bestfrac = FIXED_MAX;
-		spechit_t *besthit = NULL;
+		spechit_t besthit;
 		// find the portal nearest to the crossing actor
 		for (auto &spec : portalhit)
 		{
@@ -2160,7 +2172,7 @@ bool P_TryMove(AActor *thing, fixed_t x, fixed_t y,
 				fixed_t frac = P_InterceptVector(&dl1, &dl2);
 				if (frac < bestfrac)
 				{
-					besthit = &spec;
+					besthit = spec;
 					bestfrac = frac;
 				}
 			}
@@ -2168,7 +2180,7 @@ bool P_TryMove(AActor *thing, fixed_t x, fixed_t y,
 
 		if (bestfrac < FIXED_MAX)
 		{
-			line_t *ld = besthit->line;
+			line_t *ld = besthit.line;
 			FLinePortal *port = ld->getPortal();
 			if (port->mType == PORTT_LINKED)
 			{
@@ -2192,8 +2204,6 @@ bool P_TryMove(AActor *thing, fixed_t x, fixed_t y,
 				// so that the spechit array gets proper positions assigned that can be evaluated later.
 				P_TranslatePortalXY(ld, out, pos.x, pos.y);
 				P_TranslatePortalXY(ld, out, thingpos.x, thingpos.y);
-				P_TranslatePortalVXVY(ld, out, thing->velx, thing->vely);
-				P_TranslatePortalAngle(ld, out, thing->angle);
 				P_TranslatePortalZ(ld, out, pos.z);
 				thing->SetXYZ(thingpos.x, thingpos.y, pos.z);
 				if (!P_CheckPosition(thing, pos.x, pos.y))
@@ -2204,16 +2214,19 @@ bool P_TryMove(AActor *thing, fixed_t x, fixed_t y,
 				}
 				thing->UnlinkFromWorld();
 				thing->SetXYZ(pos);
+				P_TranslatePortalVXVY(ld, out, thing->velx, thing->vely);
+				P_TranslatePortalAngle(ld, out, thing->angle);
 				thing->LinkToWorld();
 				P_FindFloorCeiling(thing);
 				thing->ClearInterpolation();
+				portalcrossed = true;
 			}
 			// if this is the current camera we need to store the point where the portal was crossed and the exit
 			// so that the renderer can properly calculate an interpolated position along the movement path.
 			if (thing == players[consoleplayer].camera)
 			{
-				divline_t dl1 = { besthit->oldrefpos.x,besthit-> oldrefpos.y, besthit->refpos.x - besthit->oldrefpos.x, besthit->refpos.y - besthit->oldrefpos.y };
-				fixedvec3 hit = { dl1.x + FixedMul(dl1.dx, bestfrac), dl1.y + FixedMul(dl1.dy, bestfrac), 0 };
+				divline_t dl1 = { besthit.oldrefpos.x,besthit. oldrefpos.y, besthit.refpos.x - besthit.oldrefpos.x, besthit.refpos.y - besthit.oldrefpos.y };
+				fixedvec3a hit = { dl1.x + FixedMul(dl1.dx, bestfrac), dl1.y + FixedMul(dl1.dy, bestfrac), 0, 0 };
 				line_t *out = port->mDestination;
 
 				R_AddInterpolationPoint(hit);
@@ -2226,6 +2239,8 @@ bool P_TryMove(AActor *thing, fixed_t x, fixed_t y,
 				{
 					P_TranslatePortalXY(ld, out, hit.x, hit.y);
 					P_TranslatePortalZ(ld, out, hit.z);
+					players[consoleplayer].viewz += hit.z;	// needs to be done here because otherwise the renderer will not catch the change.
+					P_TranslatePortalAngle(ld, out, hit.angle);
 				}
 				R_AddInterpolationPoint(hit);
 			}
@@ -5450,7 +5465,7 @@ void PIT_FloorDrop(AActor *thing, FChangePosition *cpos)
 	}
 	if (thing->player && thing->player->mo == thing)
 	{
-		thing->player->viewz += thing->Z() - oldz;
+		//thing->player->viewz += thing->Z() - oldz;
 	}
 }
 

src/p_setup.cpp

@@ -4046,6 +4046,7 @@ void P_SetupLevel (const char *lumpname, int position)
 	times[16].Clock();
 	if (reloop) P_LoopSidedefs (false);
 	PO_Init ();				// Initialize the polyobjs
+	P_FinalizePortals();	// finalize line portals after polyobjects have been initialized. This info is needed for properly flagging them.
 	times[16].Unclock();
 
 	assert(sidetemp != NULL);

src/p_spec.cpp

@@ -1531,8 +1531,6 @@ void P_SpawnSpecials (void)
 	}
 	// [RH] Start running any open scripts on this map
 	FBehavior::StaticStartTypedScripts (SCRIPT_Open, NULL, false);
-	P_FinalizePortals();
-	P_CreateLinkedPortals();
 }
 
 // killough 2/28/98:

src/portal.cpp

@@ -323,6 +323,12 @@ void P_UpdatePortal(FLinePortal *port)
 		// Portal has no destination: switch it off
 		port->mFlags = 0;
 	}
+	else if ((port->mOrigin->backsector == NULL && !(port->mOrigin->sidedef[0]->Flags & WALLF_POLYOBJ)) ||
+		(port->mDestination->backsector == NULL && !(port->mOrigin->sidedef[0]->Flags & WALLF_POLYOBJ)))
+	{
+		// disable teleporting capability if a portal is or links to a one-sided wall (unless part of a polyobject.)
+		port->mFlags = PORTF_VISIBLE;
+	}
 	else if (port->mDestination->getPortalDestination() != port->mOrigin)
 	{
 		//portal doesn't link back. This will be a simple teleporter portal.
@@ -387,6 +393,7 @@ void P_FinalizePortals()
 	}
 	P_CollectLinkedPortals();
 	BuildBlockmap();
+	P_CreateLinkedPortals();
 }
 
 //============================================================================

src/r_utility.cpp

@@ -81,7 +81,7 @@ static TArray<InterpolationViewer> PastViewers;
 static FRandom pr_torchflicker ("TorchFlicker");
 static FRandom pr_hom;
 static bool NoInterpolateView;
-static TArray<fixedvec3> InterpolationPath;
+static TArray<fixedvec3a> InterpolationPath;
 
 // PUBLIC DATA DEFINITIONS -------------------------------------------------
 
@@ -586,6 +586,8 @@ void R_InterpolateView (player_t *player, fixed_t frac, InterpolationViewer *ivi
 	int oldgroup = R_PointInSubsector(iview->oviewx, iview->oviewy)->sector->PortalGroup;
 	int newgroup = R_PointInSubsector(iview->nviewx, iview->nviewy)->sector->PortalGroup;
 
+	fixed_t oviewangle = iview->oviewangle;
+	fixed_t nviewangle = iview->nviewangle;
 	if ((iview->oviewx != iview->nviewx || iview->oviewy != iview->nviewy) && InterpolationPath.Size() > 0)
 	{
 		viewx = iview->nviewx;
@@ -601,27 +603,31 @@ void R_InterpolateView (player_t *player, fixed_t frac, InterpolationViewer *ivi
 			fixed_t pathlen = 0;
 			fixed_t zdiff = 0;
 			fixed_t totalzdiff = 0;
+			angle_t adiff = 0;
+			angle_t totaladiff = 0;
 			fixed_t oviewz = iview->oviewz;
 			fixed_t nviewz = iview->nviewz;
-			fixedvec3 oldpos = { iview->oviewx, iview->oviewy, 0 };
-			fixedvec3 newpos = { iview->nviewx, iview->nviewy, 0 };
+			fixedvec3a oldpos = { iview->oviewx, iview->oviewy, 0, 0 };
+			fixedvec3a newpos = { iview->nviewx, iview->nviewy, 0, 0 };
 			InterpolationPath.Push(newpos);	// add this to  the array to simplify the loops below
 
 			for (unsigned i = 0; i < InterpolationPath.Size(); i += 2)
 			{
-				fixedvec3 &start = i == 0 ? oldpos : InterpolationPath[i - 1];
-				fixedvec3 &end = InterpolationPath[i];
+				fixedvec3a &start = i == 0 ? oldpos : InterpolationPath[i - 1];
+				fixedvec3a &end = InterpolationPath[i];
 				pathlen += xs_CRoundToInt(TVector2<double>(end.x - start.x, end.y - start.y).Length());
 				totalzdiff += start.z;
+				totaladiff += start.angle;
 			}
 			fixed_t interpolatedlen = FixedMul(frac, pathlen);
 
 			for (unsigned i = 0; i < InterpolationPath.Size(); i += 2)
 			{
-				fixedvec3 &start = i == 0 ? oldpos : InterpolationPath[i - 1];
-				fixedvec3 &end = InterpolationPath[i];
+				fixedvec3a &start = i == 0 ? oldpos : InterpolationPath[i - 1];
+				fixedvec3a &end = InterpolationPath[i];
 				fixed_t fraglen = xs_CRoundToInt(TVector2<double>(end.x - start.x, end.y - start.y).Length());
 				zdiff += start.z;
+				adiff += start.angle;
 				if (fraglen <= interpolatedlen)
 				{
 					interpolatedlen -= fraglen;
@@ -631,9 +637,12 @@ void R_InterpolateView (player_t *player, fixed_t frac, InterpolationViewer *ivi
 					fixed_t fragfrac = FixedDiv(interpolatedlen, fraglen);
 					oviewz += zdiff;
 					nviewz -= totalzdiff - zdiff;
+					oviewangle += adiff;
+					nviewangle -= totaladiff - adiff;
 					viewx = start.x + FixedMul(fragfrac, end.x - start.x);
 					viewy = start.y + FixedMul(fragfrac, end.y - start.y);
 					viewz = oviewz + FixedMul(frac, nviewz - oviewz);
+					break;
 				}
 			}
 			InterpolationPath.Pop();
@@ -661,7 +670,7 @@ void R_InterpolateView (player_t *player, fixed_t frac, InterpolationViewer *ivi
 		(!netgame || !cl_noprediction) &&
 		!LocalKeyboardTurner)
 	{
-		viewangle = iview->nviewangle + (LocalViewAngle & 0xFFFF0000);
+		viewangle = nviewangle + (LocalViewAngle & 0xFFFF0000);
 
 		fixed_t delta = player->centering ? 0 : -(signed)(LocalViewPitch & 0xFFFF0000);
 
@@ -694,7 +703,7 @@ void R_InterpolateView (player_t *player, fixed_t frac, InterpolationViewer *ivi
 	else
 	{
 		viewpitch = iview->oviewpitch + FixedMul (frac, iview->nviewpitch - iview->oviewpitch);
-		viewangle = iview->oviewangle + FixedMul (frac, iview->nviewangle - iview->oviewangle);
+		viewangle = oviewangle + FixedMul (frac, nviewangle - oviewangle);
 	}
 	
 	// Due to interpolation this is not necessarily the same as the sector the camera is in.
@@ -876,7 +885,7 @@ void R_ClearInterpolationPath()
 //
 //==========================================================================
 
-void R_AddInterpolationPoint(const fixedvec3 &vec)
+void R_AddInterpolationPoint(const fixedvec3a &vec)
 {
 	InterpolationPath.Push(vec);
 }

src/r_utility.h

@@ -63,13 +63,21 @@ inline angle_t R_PointToAnglePrecise (fixed_t viewx, fixed_t viewy, fixed_t x, f
 	return xs_RoundToUInt(atan2(double(y-viewy), double(x-viewx)) * (ANGLE_180/M_PI));
 }
 
+// Used for interpolation waypoints.
+struct fixedvec3a
+{
+	fixed_t x, y, z;
+	angle_t angle;
+};
+
+
 subsector_t *R_PointInSubsector (fixed_t x, fixed_t y);
 fixed_t R_PointToDist2 (fixed_t dx, fixed_t dy);
 void R_ResetViewInterpolation ();
 void R_RebuildViewInterpolation(player_t *player);
 bool R_GetViewInterpolationStatus();
 void R_ClearInterpolationPath();
-void R_AddInterpolationPoint(const fixedvec3 &vec);
+void R_AddInterpolationPoint(const fixedvec3a &vec);
 void R_SetViewSize (int blocks);
 void R_SetFOV (float fov);
 float R_GetFOV ();