Merged https://github.com/coelckers/gzdoom/pull/1176 (ViewPos)

src/playsim/actor.h

@@ -414,7 +414,8 @@ enum ActorFlag8
 	MF8_STOPRAILS		= 0x00000200,	// [MC] Prevent rails from going further if an actor has this flag.
 	MF8_ABSVIEWANGLES	= 0x00000400,	// [MC] By default view angle/pitch/roll is an offset. This will make it absolute instead.
 	MF8_FALLDAMAGE		= 0x00000800,	// Monster will take fall damage regardless of map settings.
-
+	MF8_VIEWPOSNOANGLES	= 0x00001000,	// [MC] View position takes no angles into account
+	MF8_ABSVIEWPOS		= 0x00002000,	// [MC] Absolute position, so the actor must update it manually.
 };
 
 // --- mobj.renderflags ---
@@ -968,7 +969,8 @@ public:
 	DAngle			SpriteAngle;
 	DAngle			SpriteRotation;
 	DRotator		Angles;
-	DRotator		ViewAngles;			// Offsets for cameras
+	DRotator		ViewAngles;			// Angle offsets for cameras
+	DVector3		ViewPos;			// Position offsets for cameras
 	DVector2		Scale;				// Scaling values; 1 is normal size
 	double			Alpha;				// Since P_CheckSight makes an alpha check this can't be a float. It has to be a double.
 

src/playsim/p_local.h

@@ -394,6 +394,9 @@ void	P_PlaySpawnSound(AActor *missile, AActor *spawner);
 // [RH] Position the chasecam
 void	P_AimCamera (AActor *t1, DVector3 &, DAngle &, sector_t *&sec, bool &unlinked);
 
+// [MC] Aiming for viewpos.
+void	P_AdjustViewPos(AActor *t1, DVector3 orig, DVector3 &, sector_t *&sec, bool &unlinked);
+
 // [RH] Means of death
 enum
 {

src/playsim/p_map.cpp

@@ -5384,6 +5384,27 @@ void P_AimCamera(AActor *t1, DVector3 &campos, DAngle &camangle, sector_t *&Came
 	camangle = trace.SrcAngleFromTarget - 180.;
 }
 
+void P_AdjustViewPos(AActor *t1, DVector3 orig, DVector3 &campos, sector_t *&CameraSector, bool &unlinked)
+{
+	FTraceResults trace;
+	DVector3 vvec = campos - orig;
+	double distance = vvec.Length();
+
+	// Trace handles all of the portal crossing, which is why there is no usage of Vec#Offset(Z).
+	if (Trace(orig, t1->Sector, vvec.Unit(), distance, 0, 0, t1, trace) &&
+		trace.Distance > 5)
+	{
+		// Position camera slightly in front of hit thing
+		campos = orig + vvec.Unit() * (trace.Distance - 5);
+	}
+	else
+	{
+		campos = trace.HitPos - trace.HitVector * 1 / 256.;
+	}
+	CameraSector = trace.Sector;
+	unlinked = trace.unlinked;
+}
+
 
 //==========================================================================
 //

src/playsim/p_mobj.cpp

@@ -368,7 +368,8 @@ void AActor::Serialize(FSerializer &arc)
 		A("spawnorder", SpawnOrder)
 		A("friction", Friction)
 		A("SpriteOffset", SpriteOffset)
-		A("userlights", UserLights);
+		A("userlights", UserLights)
+		A("viewpos", ViewPos);
 
 		SerializeTerrain(arc, "floorterrain", floorterrain, &def->floorterrain);
 		SerializeArgs(arc, "args", args, def->args, special);

src/rendering/hwrenderer/scene/hw_sprites.cpp

@@ -725,7 +725,7 @@ void HWSprite::Process(HWDrawInfo *di, AActor* thing, sector_t * sector, area_t
 	if (thing == camera && !vp.showviewer)
 	{
 		DVector3 thingorigin = thing->Pos();
-		if (thruportal == 1) thingorigin += di->Level->Displacements.getOffset(thing->Sector->PortalGroup, sector->PortalGroup);
+		if (thruportal == 1) 	thingorigin += di->Level->Displacements.getOffset(thing->Sector->PortalGroup, sector->PortalGroup);
 		if (fabs(thingorigin.X - vp.ActorPos.X) < 2 && fabs(thingorigin.Y - vp.ActorPos.Y) < 2) return;
 	}
 	// Thing is invisible if close to the camera.

src/rendering/r_utility.cpp

@@ -129,6 +129,7 @@ FRenderViewpoint::FRenderViewpoint()
 	FrameTime = 0;
 	extralight = 0;
 	showviewer = false;
+	NoPortalPath = false;
 }
 
 FRenderViewpoint r_viewpoint;
@@ -435,7 +436,7 @@ void R_InterpolateView (FRenderViewpoint &viewpoint, player_t *player, double Fr
 			// What needs be done is to store the portal transitions of the camera actor as waypoints
 			// and then find out on which part of the path the current view lies.
 			// Needless to say, this doesn't work for chasecam mode.
-			if (!viewpoint.showviewer)
+			if (!viewpoint.showviewer && !viewpoint.NoPortalPath)
 			{
 				double pathlen = 0;
 				double zdiff = 0;
@@ -775,34 +776,107 @@ void R_SetupFrame (FRenderViewpoint &viewpoint, FViewWindow &viewwindow, AActor
 		iview->Old = iview->New;
 	}
 
-	if (player != NULL && gamestate != GS_TITLELEVEL &&
-		((player->cheats & CF_CHASECAM) || (r_deathcamera && viewpoint.camera->health <= 0)))
+	//==============================================================================================
+	// Handles offsetting the camera with ChaseCam and/or viewpos.
+	{
+	AActor *mo = viewpoint.camera;
+	const DVector3 orig = { mo->Pos().XY(), mo->player ? mo->player->viewz : mo->Z() + mo->GetCameraHeight() };
+	viewpoint.ActorPos = orig;
+
+	if (player && gamestate != GS_TITLELEVEL)
 	{
 		sector_t *oldsector = viewpoint.ViewLevel->PointInRenderSubsector(iview->Old.Pos)->sector;
-		// [RH] Use chasecam view
-		DVector3 campos;
-		DAngle camangle;
-		P_AimCamera (viewpoint.camera, campos, camangle, viewpoint.sector, unlinked);	// fixme: This needs to translate the angle, too.
-		iview->New.Pos = campos;
-		iview->New.Angles.Yaw = camangle;
-		
-		viewpoint.showviewer = true;
-		// Interpolating this is a very complicated thing because nothing keeps track of the aim camera's movement, so whenever we detect a portal transition
-		// it's probably best to just reset the interpolation for this move.
-		// Note that this can still cause problems with unusually linked portals
-		if (viewpoint.sector->PortalGroup != oldsector->PortalGroup || (unlinked && ((iview->New.Pos.XY() - iview->Old.Pos.XY()).LengthSquared()) > 256*256))
+		if ((player->cheats & CF_CHASECAM) || (r_deathcamera && viewpoint.camera->health <= 0))
 		{
-			iview->otic = nowtic;
-			iview->Old = iview->New;
-			r_NoInterpolate = true;
+			// [RH] Use chasecam view
+			DVector3 campos;
+			DAngle camangle;
+			P_AimCamera (viewpoint.camera, campos, camangle, viewpoint.sector, unlinked);	// fixme: This needs to translate the angle, too.
+			iview->New.Pos = campos;
+			iview->New.Angles.Yaw = camangle;
+		
+			viewpoint.showviewer = true;
+			// Interpolating this is a very complicated thing because nothing keeps track of the aim camera's movement, so whenever we detect a portal transition
+			// it's probably best to just reset the interpolation for this move.
+			// Note that this can still cause problems with unusually linked portals
+			if (viewpoint.sector->PortalGroup != oldsector->PortalGroup || (unlinked && ((iview->New.Pos.XY() - iview->Old.Pos.XY()).LengthSquared()) > 256*256))
+			{
+				iview->otic = nowtic;
+				iview->Old = iview->New;
+				r_NoInterpolate = true;
+			}
+			viewpoint.ActorPos = campos;
+		}
+		else // No chase/death cam and player is alive.
+		{
+			viewpoint.sector = viewpoint.ViewLevel->PointInRenderSubsector(iview->New.Pos.XY())->sector;
+			viewpoint.showviewer = false;
+			// [MC] Ignores all portal portal transitions since it's meant to be absolute.
+			// It'll be down to the modder to handle performing offsetting with the appropriate functions.
+			if (mo->flags8 & MF8_ABSVIEWPOS)
+			{
+				iview->New.Pos = mo->ViewPos;
+			}
+			else
+			{
+				
+				DVector3 next = orig;
+
+				if (mo->ViewPos.isZero())
+				{
+					// Since viewpos isn't being used, it's safe to enable path interpolation
+					viewpoint.NoPortalPath = false;
+				}
+				else if ((mo->flags8 & MF8_VIEWPOSNOANGLES))
+				{
+					// No relativity added from angles.
+					next += mo->ViewPos;
+				}
+				else
+				{
+					// [MC] Do NOT handle portals here! Trace must have the unportaled (absolute) position to
+					// get the correct angle and distance. Trace automatically handles portals by itself.
+					// Also, viewpos must use the original angles, not the view angles to position the camera
+
+					DAngle yaw = mo->Angles.Yaw;
+					DAngle pitch = mo->Angles.Pitch;
+					DAngle roll = mo->Angles.Roll;
+					DVector3 relx, rely, relz, Off = mo->ViewPos;
+					DMatrix3x3 rot =
+						DMatrix3x3(DVector3(0., 0., 1.), yaw.Cos(), yaw.Sin()) *
+						DMatrix3x3(DVector3(0., 1., 0.), pitch.Cos(), pitch.Sin()) *
+						DMatrix3x3(DVector3(1., 0., 0.), roll.Cos(), roll.Sin());
+					relx = DVector3(1., 0., 0.)*rot;
+					rely = DVector3(0., 1., 0.)*rot;
+					relz = DVector3(0., 0., 1.)*rot;
+					next += relx * Off.X + rely * Off.Y + relz * Off.Z;
+				}
+
+				if (next != orig)
+				{
+					// [MC] Disable interpolation if the camera view is crossing through a portal.
+					// Also, disable the portal interpolation pathing entirely when using the viewpos feature.
+					// Interpolation still happens with everything else though and seems to work fine.
+					viewpoint.NoPortalPath = true;
+					P_AdjustViewPos(mo, orig, next, viewpoint.sector, unlinked);
+					
+					if (viewpoint.sector->PortalGroup != oldsector->PortalGroup || (unlinked && ((iview->New.Pos.XY() - iview->Old.Pos.XY()).LengthSquared()) > 256 * 256))
+					{
+						iview->otic = nowtic;
+						iview->Old = iview->New;
+						r_NoInterpolate = true;
+					}
+				}
+				iview->New.Pos = next;
+			}
 		}
-		viewpoint.ActorPos = campos;
 	}
 	else
 	{
-		viewpoint.ActorPos = iview->New.Pos = { viewpoint.camera->Pos().XY(), viewpoint.camera->player ? viewpoint.camera->player->viewz : viewpoint.camera->Z() + viewpoint.camera->GetCameraHeight() };
+		iview->New.Pos = orig;
 		viewpoint.sector = viewpoint.camera->Sector;
-		viewpoint.showviewer = false;
+		viewpoint.showviewer = viewpoint.NoPortalPath = false;
+	}
 	}
 
 	// [MC] Apply the view angles first, which is the offsets. If the absolute isn't desired,

src/rendering/r_utility.h

@@ -44,6 +44,7 @@ struct FRenderViewpoint
 	int				extralight;		// extralight to be added to this viewpoint
 	bool			showviewer;		// show the camera actor?
 
+	bool			NoPortalPath;	// Disable portal interpolation path for actor viewpos.
 
 	void SetViewAngle(const FViewWindow &viewwindow);
 

src/scripting/thingdef_data.cpp

@@ -327,6 +327,8 @@ static FFlagDef ActorFlagDefs[]=
 	DEFINE_FLAG(MF8, STOPRAILS, AActor, flags8),
 	DEFINE_FLAG(MF8, FALLDAMAGE, AActor, flags8),
 	DEFINE_FLAG(MF8, ABSVIEWANGLES, AActor, flags8),
+	DEFINE_FLAG(MF8, VIEWPOSNOANGLES, AActor, flags8),
+	DEFINE_FLAG(MF8, ABSVIEWPOS, AActor, flags8),
 
 	// Effect flags
 	DEFINE_FLAG(FX, VISIBILITYPULSE, AActor, effects),

src/scripting/vmthunks_actors.cpp

@@ -1948,6 +1948,7 @@ DEFINE_FIELD(AActor, InventoryID)
 DEFINE_FIELD_NAMED(AActor, ViewAngles.Yaw, viewangle)
 DEFINE_FIELD_NAMED(AActor, ViewAngles.Pitch, viewpitch)
 DEFINE_FIELD_NAMED(AActor, ViewAngles.Roll, viewroll)
+DEFINE_FIELD(AActor, ViewPos)
 
 DEFINE_FIELD_X(FCheckPosition, FCheckPosition, thing);
 DEFINE_FIELD_X(FCheckPosition, FCheckPosition, pos);

wadsrc/static/zscript/actors/actor.zs

@@ -235,6 +235,7 @@ class Actor : Thinker native
 	native double CameraHeight;	// Height of camera when used as such
 	native double CameraFOV;
 	native double ViewAngle, ViewPitch, ViewRoll;
+	native Vector3 ViewPos;
 	native double RadiusDamageFactor;		// Radius damage factor
 	native double SelfDamageFactor;
 	native double StealthAlpha;