Add WorldOffset field

Adjusts the thing's 3D position on render side. This allows for adjusting a thing's visual position without impacting their hitbox.

# Conflicts:
#	src/playsim/p_mobj.cpp

src/playsim/actor.h

@@ -1049,6 +1049,7 @@ public:
 	DVector3		OldRenderPos;
 	DVector3		Vel;
 	DVector2		SpriteOffset;
+	DVector3		WorldOffset;
 	double			Speed;
 	double			FloatSpeed;
 

src/playsim/p_mobj.cpp

@@ -371,7 +371,8 @@ void AActor::Serialize(FSerializer &arc)
 		A("friction", Friction)
 		A("SpriteOffset", SpriteOffset)
 		("viewpos", ViewPos)
-		A("userlights", UserLights);
+		A("userlights", UserLights)
+		A("WorldOffset", WorldOffset);
 
 		SerializeTerrain(arc, "floorterrain", floorterrain, &def->floorterrain);
 		SerializeArgs(arc, "args", args, def->args, special);

src/rendering/hwrenderer/scene/hw_sprites.cpp

@@ -797,9 +797,9 @@ void HWSprite::Process(HWDrawInfo *di, AActor* thing, sector_t * sector, area_t
 	bottomclip = rendersector->PortalBlocksMovement(sector_t::floor) ? -LARGE_VALUE : rendersector->GetPortalPlaneZ(sector_t::floor);
 
 	uint32_t spritetype = (thing->renderflags & RF_SPRITETYPEMASK);
-	x = thingpos.X;
+	x = thingpos.X + thing->WorldOffset.X;
-	z = thingpos.Z;
+	z = thingpos.Z + thing->WorldOffset.Z;
-	y = thingpos.Y;
+	y = thingpos.Y + thing->WorldOffset.Y;
 	if (spritetype == RF_FACESPRITE) z -= thing->Floorclip; // wall and flat sprites are to be considered di->Level-> geometry so this may not apply.
 
 	// snap shadow Z to the floor

src/rendering/swrenderer/scene/r_opaque_pass.cpp

@@ -1027,6 +1027,7 @@ namespace swrenderer
 	{
 		// The X offsetting (SpriteOffset.X) is performed in r_sprite.cpp, in RenderSprite::Project().
 		sprite.pos = thing->InterpolatedPosition(Thread->Viewport->viewpoint.TicFrac);
+		sprite.pos += thing->WorldOffset;
 		sprite.pos.Z += thing->GetBobOffset(Thread->Viewport->viewpoint.TicFrac) - thing->SpriteOffset.Y;
 		sprite.spritenum = thing->sprite;
 		sprite.tex = nullptr;

src/scripting/vmthunks_actors.cpp

@@ -1851,6 +1851,7 @@ DEFINE_FIELD_NAMED(AActor, __Pos.X, x)
 DEFINE_FIELD_NAMED(AActor, __Pos.Y, y)
 DEFINE_FIELD_NAMED(AActor, __Pos.Z, z)
 DEFINE_FIELD(AActor, SpriteOffset)
+DEFINE_FIELD(AActor, WorldOffset)
 DEFINE_FIELD(AActor, Prev)
 DEFINE_FIELD(AActor, SpriteAngle)
 DEFINE_FIELD(AActor, SpriteRotation)

wadsrc/static/zscript/actors/actor.zs

@@ -100,6 +100,7 @@ class Actor : Thinker native
 	native vector3 Prev;
 	native uint ThruBits;
 	native vector2 SpriteOffset;
+	native vector3 WorldOffset;
 	native double spriteAngle;
 	native double spriteRotation;
 	native float VisibleStartAngle;