Squashed commit of the following:

commit 6ecd831eb45a8258995c02664450c3ca8cfe5b48
Merge: a4fb1f61c afbd7f7a2
Author: Marisa Kirisame <marisa@sayachan.org>
Date:   Sun Jul 28 22:02:19 2019 +0200

    Merge branch 'master' of github.com:coelckers/gzdoom into f3dfloor_export

commit a4fb1f61c0532d3a6051d4c1fca4ac72ec33e060
Author: Marisa Kirisame <marisa@sayachan.org>
Date:   Fri Jul 12 15:43:25 2019 +0200

    Renamed EFFloorType enum in ZScript to the more descriptive EF3DFloorFlags

commit 9ad1c3b5625d53c06229be2a94d44fa0f36f41fd
Author: Marisa Kirisame <marisa@sayachan.org>
Date:   Sun Jul 7 20:25:31 2019 +0200

    Add bounds checks to Get3DFloor/GetAttached

commit dd2a7956a887b92ed24ce5e79f10b1a445664d6c
Author: Marisa Kirisame <marisa@sayachan.org>
Date:   Sun Jul 7 17:13:44 2019 +0200

    Correct handling of 3d floor plane texture getting.

commit 9b748287892c8fdee9ac67019bf1f66bc4b69eab
Author: Marisa Kirisame <marisa@sayachan.org>
Date:   Sun Jul 7 16:14:45 2019 +0200

    Implemented requested changes to F3DFloor exports.
    * Getters for ffloors/attached arrays.
    * Getter for 3D floor top/bottom texture.

commit 6a1482bb0637a70890629e4c13e8759c7a3673f3
Author: Marisa Kirisame <marisa@sayachan.org>
Date:   Sat Jul 6 13:42:52 2019 +0200

    Renamed exported extsector pointer in Sector struct to something more descriptive.

commit 7c6783d43b898cbd7a01fb2191fd401ed8e8c300
Merge: ff64e04b2 8d36f0a0c
Author: Marisa Kirisame <marisa@sayachan.org>
Date:   Mon Apr 29 12:40:44 2019 +0200

    Merge branch 'master' into f3dfloor_export

commit ff64e04b251f23325d2f72bc25c59f34b4cab6fa
Merge: a90947392 5b6bae409
Author: Marisa Kirisame <marisa@sayachan.org>
Date:   Sun Apr 21 16:56:18 2019 +0200

    Merge branch 'master' into f3dfloor_export

commit a90947392a27eb1c2dac7005614592ec2f410274
Author: Marisa Kirisame <marisa@sayachan.org>
Date:   Mon Feb 4 17:47:25 2019 +0100

    Export F3DFloor structure and related data.
    Small changes to Trace code to better use this struct.

src/playsim/p_trace.cpp

@@ -901,6 +901,41 @@ bool FTraceInfo::TraceTraverse (int ptflags)
 		Results->Distance = MaxDist;
 		Results->Fraction = 1.;
 	}
+
+	// [MK] set 3d floor on plane hits (if any)
+	// modders will need this to get accurate plane normals on slopes
+	if (Results->HitType == TRACE_HitFloor)
+	{
+		double secbottom = Results->Sector->floorplane.ZatPoint(Results->HitPos);
+		for (auto rover : Results->Sector->e->XFloor.ffloors)
+		{
+			if (!(rover->flags&FF_EXISTS))
+				continue;
+			double ff_top = rover->top.plane->ZatPoint(Results->HitPos);
+			if (fabs(ff_top-secbottom) < EQUAL_EPSILON)
+				continue;
+			if (fabs(ff_top-Results->HitPos.Z) > EQUAL_EPSILON)
+				continue;
+			Results->ffloor = rover;
+			break;
+		}
+	}
+	else if (Results->HitType == TRACE_HitCeiling)
+	{
+		double sectop = Results->Sector->ceilingplane.ZatPoint(Results->HitPos);
+		for (auto rover : Results->Sector->e->XFloor.ffloors)
+		{
+			if (!(rover->flags&FF_EXISTS))
+				continue;
+			double ff_bottom = rover->bottom.plane->ZatPoint(Results->HitPos);
+			if (fabs(ff_bottom-sectop) < EQUAL_EPSILON)
+				continue;
+			if (fabs(ff_bottom-Results->HitPos.Z) > EQUAL_EPSILON)
+				continue;
+			Results->ffloor = rover;
+			break;
+		}
+	}
 	return Results->HitType != TRACE_HitNone;
 }
 
@@ -1008,6 +1043,7 @@ DEFINE_FIELD_X(TraceResults, FTraceResults, Side)
 DEFINE_FIELD_X(TraceResults, FTraceResults, Tier)
 DEFINE_FIELD_X(TraceResults, FTraceResults, unlinked)
 DEFINE_FIELD_X(TraceResults, FTraceResults, HitType)
+DEFINE_FIELD_X(TraceResults, FTraceResults, ffloor)
 DEFINE_FIELD_X(TraceResults, FTraceResults, CrossedWater)
 DEFINE_FIELD_X(TraceResults, FTraceResults, CrossedWaterPos)
 DEFINE_FIELD_X(TraceResults, FTraceResults, Crossed3DWater)

src/scripting/vmthunks.cpp

@@ -1340,6 +1340,72 @@ DEFINE_ACTION_FUNCTION_NATIVE(_Sector, SetXOffset, SetXOffset)
 	 return 0;
  }
 
+ static F3DFloor* Get3DFloor(sector_t *self, int index)
+ {
+ 	 if ((index < 0) || (index >= self->e->XFloor.ffloors.Size()))
+ 	 	return nullptr;
+	 return self->e->XFloor.ffloors[index];
+ }
+
+ DEFINE_ACTION_FUNCTION_NATIVE(_Sector, Get3DFloor, Get3DFloor)
+ {
+	 PARAM_SELF_STRUCT_PROLOGUE(sector_t);
+	 PARAM_INT(index);
+	 ACTION_RETURN_POINTER(Get3DFloor(self,index));
+ }
+
+ static int Get3DFloorCount(sector_t *self)
+ {
+	 return self->e->XFloor.ffloors.Size();
+ }
+
+ DEFINE_ACTION_FUNCTION_NATIVE(_Sector, Get3DFloorCount, Get3DFloorCount)
+ {
+	 PARAM_SELF_STRUCT_PROLOGUE(sector_t);
+	 ACTION_RETURN_INT(self->e->XFloor.ffloors.Size());
+ }
+
+ static sector_t* GetAttached(sector_t *self, int index)
+ {
+ 	 if ((index < 0) || (index >= self->e->XFloor.attached.Size()))
+ 	 	return nullptr;
+	 return self->e->XFloor.attached[index];
+ }
+
+ DEFINE_ACTION_FUNCTION_NATIVE(_Sector, GetAttached, GetAttached)
+ {
+	 PARAM_SELF_STRUCT_PROLOGUE(sector_t);
+	 PARAM_INT(index);
+	 ACTION_RETURN_POINTER(GetAttached(self,index));
+ }
+
+ static int GetAttachedCount(sector_t *self)
+ {
+	 return self->e->XFloor.attached.Size();
+ }
+
+ DEFINE_ACTION_FUNCTION_NATIVE(_Sector, GetAttachedCount, GetAttachedCount)
+ {
+	 PARAM_SELF_STRUCT_PROLOGUE(sector_t);
+	 ACTION_RETURN_INT(self->e->XFloor.attached.Size());
+ }
+
+ static int Get3DFloorTexture(F3DFloor *self, int pos)
+ {
+ 	 if ( pos )
+ 		 return self->bottom.texture->GetIndex();
+ 	 return self->top.texture->GetIndex();
+ }
+
+ DEFINE_ACTION_FUNCTION_NATIVE(_F3DFloor, GetTexture, Get3DFloorTexture)
+ {
+	 PARAM_SELF_STRUCT_PROLOGUE(F3DFloor);
+	 PARAM_INT(pos);
+	 if ( pos )
+		 ACTION_RETURN_INT(self->bottom.texture->GetIndex());
+	 ACTION_RETURN_INT(self->top.texture->GetIndex());
+ }
+
  //===========================================================================
  //
  //  line_t exports
@@ -3183,6 +3249,14 @@ DEFINE_FIELD_X(Secplane, secplane_t, normal)
 DEFINE_FIELD_X(Secplane, secplane_t, D)
 DEFINE_FIELD_X(Secplane, secplane_t, negiC)
 
+DEFINE_FIELD_NAMED_X(F3DFloor, F3DFloor, bottom.plane, bottom);
+DEFINE_FIELD_NAMED_X(F3DFloor, F3DFloor, top.plane, top);
+DEFINE_FIELD_X(F3DFloor, F3DFloor, flags);
+DEFINE_FIELD_X(F3DFloor, F3DFloor, master);
+DEFINE_FIELD_X(F3DFloor, F3DFloor, model);
+DEFINE_FIELD_X(F3DFloor, F3DFloor, target);
+DEFINE_FIELD_X(F3DFloor, F3DFloor, alpha);
+
 DEFINE_FIELD_X(Vertex, vertex_t, p)
 
 DEFINE_FIELD(DBaseStatusBar, RelTop);

wadsrc/static/zscript/base.zs

@@ -618,7 +618,7 @@ struct TraceResults native
 	native bool unlinked;		// passed through a portal without static offset.
 
 	native ETraceResult HitType;
-	// F3DFloor *ffloor;
+	native F3DFloor ffloor;
 
 	native Sector CrossedWater;		// For Boom-style, Transfer_Heights-based deep water
 	native vector3 CrossedWaterPos;	// remember the position so that we can use it for spawning the splash
@@ -835,10 +835,6 @@ struct State native
 	native bool InStateSequence(State base);
 }
 
-struct F3DFloor native
-{
-}
-
 struct Wads
 {
 	enum WadNamespace

wadsrc/static/zscript/mapdata.zs

@@ -212,6 +212,55 @@ struct SecPlane native play
 	native double PointToDist(Vector2 xy, double z) const;
 }
 
+struct F3DFloor native play
+{
+	enum EF3DFloorFlags
+	{
+		FF_EXISTS        = 0x1,    //MAKE SURE IT'S VALID
+		FF_SOLID         = 0x2,    //Does it clip things?
+		FF_RENDERSIDES   = 0x4,    //Render the sides?
+		FF_RENDERPLANES  = 0x8,    //Render the floor/ceiling?
+		FF_RENDERALL     = 0xC,    //Render everything?
+		FF_SWIMMABLE     = 0x10,   //Can we swim?
+		FF_NOSHADE       = 0x20,   //Does it mess with the lighting?
+		FF_BOTHPLANES    = 0x200,  //Render both planes all the time?
+		FF_TRANSLUCENT   = 0x800,  //See through!
+		FF_FOG           = 0x1000, //Fog "brush"?
+		FF_INVERTPLANES  = 0x2000, //Reverse the plane visibility rules?
+		FF_ALLSIDES      = 0x4000, //Render inside and outside sides?
+		FF_INVERTSIDES   = 0x8000, //Only render inside sides?
+		FF_DOUBLESHADOW  = 0x10000,//Make two lightlist entries to reset light?
+		FF_UPPERTEXTURE	 = 0x20000,
+		FF_LOWERTEXTURE  = 0x40000,
+		FF_THINFLOOR     = 0x80000,	// EDGE
+		FF_SCROLLY       = 0x100000,  // EDGE - not yet implemented!!!
+		FF_FIX           = 0x200000,  // use floor of model sector as floor and floor of real sector as ceiling
+		FF_INVERTSECTOR  = 0x400000,	// swap meaning of sector planes
+		FF_DYNAMIC       = 0x800000,	// created by partitioning another 3D-floor due to overlap
+		FF_CLIPPED       = 0x1000000,	// split into several dynamic ffloors
+		FF_SEETHROUGH    = 0x2000000,
+		FF_SHOOTTHROUGH  = 0x4000000,
+		FF_FADEWALLS     = 0x8000000,	// Applies real fog to walls and doesn't blend the view		
+		FF_ADDITIVETRANS = 0x10000000, // Render this floor with additive translucency
+		FF_FLOOD         = 0x20000000, // extends towards the next lowest flooding or solid 3D floor or the bottom of the sector
+		FF_THISINSIDE    = 0x40000000, // hack for software 3D with FF_BOTHPLANES
+		FF_RESET         = 0x80000000, // light effect is completely reset, once interrupted  
+	};
+
+	native readonly secplane bottom;
+	native readonly secplane top;
+
+	native readonly uint flags;
+	native readonly Line master;
+
+	native readonly Sector model;
+	native readonly Sector target;
+
+	native readonly int alpha;
+
+	native TextureID GetTexture(int pos);
+}
+
 // This encapsulates all info Doom's original 'special' field contained - for saving and transferring.
 struct SecSpecial play
 {
@@ -367,6 +416,11 @@ struct Sector native play
 	native double, Sector, F3DFloor NextHighestCeilingAt(double x, double y, double bottomz, double topz, int flags = 0);
 	native double, Sector, F3DFloor NextLowestFloorAt(double x, double y, double z, int flags = 0, double steph = 0);
 
+	native F3DFloor Get3DFloor(int index);
+	native int Get3DFloorCount();
+	native Sector GetAttached(int index);
+	native int GetAttachedCount();
+
 	native void RemoveForceField();
 	deprecated("3.8") static clearscope Sector PointInSector(Vector2 pt)
 	{