added wall texture skewing.

This uses the same UDMF properties as Eternity recently introduced for the same feature.

src/gamedata/r_defs.h

@@ -1194,6 +1194,19 @@ struct side_t
 		walltop = 0,
 		wallbottom = 1,
 	};
+	enum ESkew
+	{
+		skew_none = 0,
+		skew_front = 1,
+		skew_back = 2,
+		// for mid textures there's 4 options
+		skew_front_floor = 1,
+		skew_front_ceiling = 2,
+		skew_back_floor = 3,
+		skew_back_ceiling = 4
+
+	};
+
 	struct part
 	{
 		enum EPartFlags
@@ -1209,7 +1222,8 @@ struct side_t
 		double xScale;
 		double yScale;
 		TObjPtr<DInterpolation*> interpolation;
-		int flags;
+		int16_t flags;
+		int8_t skew;
 		FTextureID texture;
 		TextureManipulation TextureFx;
 		PalEntry SpecialColors[2];

src/maploader/udmf.cpp

@@ -104,6 +104,24 @@ static char HexenSectorSpecialOk[256]={
 	1,1,1,1,1,
 };
 
+static const char* udmfsolidskewtypes[] =
+{
+   "none",
+   "front",
+   "back",
+   nullptr
+};
+
+static const char* udmfmaskedskewtypes[] =
+{
+   "none",
+   "front_floor",
+   "front_ceiling",
+   "back_floor",
+   "back_ceiling",
+   nullptr
+};
+
 static inline bool P_IsThingSpecial(int specnum)
 {
 	return (specnum >= Thing_Projectile && specnum <= Thing_SpawnNoFog) ||
@@ -282,6 +300,20 @@ const char *UDMFParserBase::CheckString(FName key)
 	return parsedString.GetChars();
 }
 
+int UDMFParserBase::MatchString(FName key, const char* const* strings, int defval)
+{
+	const char* string = CheckString(key);
+	for (int i = 0; *strings != nullptr; i++, strings++)
+	{
+		if (!stricmp(string, *strings))
+		{
+			return i;
+		}
+	}
+	sc.ScriptMessage("Unknown value %s for key '%s'", string, key.GetChars());
+	return defval;
+}
+
 //===========================================================================
 //
 // Storage of UDMF user properties
@@ -1484,6 +1516,22 @@ public:
 				CHECK_N(Zd | Zdt)
 					break;
 
+			case NAME_skew_top_type:
+				CHECK_N(Zd | Zdt)
+				sd->textures[side_t::top].skew = MatchString(key, udmfsolidskewtypes, 0);
+				break;
+
+			case NAME_skew_middle_type:
+				CHECK_N(Zd | Zdt)
+					sd->textures[side_t::mid].skew = MatchString(key, udmfmaskedskewtypes, 0);
+				break;
+
+			case NAME_skew_bottom_type:
+				CHECK_N(Zd | Zdt)
+					sd->textures[side_t::bottom].skew = MatchString(key, udmfsolidskewtypes, 0);
+				break;
+
+
 			default:
 				if (strnicmp("user_", key.GetChars(), 5))
 					DPrintf(DMSG_WARNING, "Unknown UDMF sidedef key %s\n", key.GetChars());
@@ -2200,6 +2248,17 @@ public:
 						sides[side].sector = &Level->sectors[intptr_t(sides[side].sector)];
 						lines[line].sidedef[sd] = &sides[side];
 
+						if (sd == 1)
+						{
+							// fix flags for backside. The definition is linedef relative, not sidedef relative.
+							static const uint8_t swaps[] = { 0, side_t::skew_back, side_t::skew_front };
+							static const uint8_t swapsm[] = {0, side_t::skew_back_floor, side_t::skew_back_ceiling, side_t::skew_front_floor, side_t::skew_front_ceiling};
+
+							sides[side].textures[side_t::top].skew = swaps[sides[side].textures[side_t::top].skew];
+							sides[side].textures[side_t::bottom].skew = swaps[sides[side].textures[side_t::bottom].skew];
+							sides[side].textures[side_t::mid].skew = swapsm[sides[side].textures[side_t::mid].skew];
+						}
+
 						loader->ProcessSideTextures(!isExtended, &sides[side], sides[side].sector, &ParsedSideTextures[mapside],
 							lines[line].special, lines[line].args[0], &tempalpha[sd], missingTex);
 

src/maploader/udmf.h

@@ -21,6 +21,7 @@ protected:
 	DAngle CheckAngle(FName key);
 	bool CheckBool(FName key);
 	const char *CheckString(FName key);
+	int MatchString(FName key, const char* const* strings, int defval);
 
 	template<typename T>
 	bool Flag(T &value, int mask, FName key)

src/namedef_custom.h

@@ -858,4 +858,8 @@ xx(lm_sampledist_ceiling)
 xx(lm_suncolor)
 xx(lm_sampledistance)
 
+xx(skew_bottom_type)
+xx(skew_middle_type)
+xx(skew_top_type)
+
 xx(Corona)

src/p_saveg.cpp

@@ -140,6 +140,7 @@ FSerializer &Serialize(FSerializer &arc, const char *key, side_t::part &part, si
 			("texture", part.texture, def->texture)
 			("interpolation", part.interpolation)
 			("flags", part.flags, def->flags)
+			("skew", part.skew, def->skew)
 			("color1", part.SpecialColors[0], def->SpecialColors[0])
 			("color2", part.SpecialColors[1], def->SpecialColors[1])
 			("addcolor", part.AdditiveColor, def->AdditiveColor)

src/rendering/hwrenderer/scene/hw_drawstructs.h

@@ -237,19 +237,19 @@ public:
 	bool DoHorizon(HWWallDispatcher* di, seg_t* seg, sector_t* fs, vertex_t* v1, vertex_t* v2);
 
 	bool SetWallCoordinates(seg_t* seg, FTexCoordInfo* tci, float ceilingrefheight,
-		float topleft, float topright, float bottomleft, float bottomright, float t_ofs);
+		float topleft, float topright, float bottomleft, float bottomright, float t_ofs, float skew);
 
 	void DoTexture(HWWallDispatcher* di, int type, seg_t* seg, int peg,
 		float ceilingrefheight, float floorrefheight,
 		float CeilingHeightstart, float CeilingHeightend,
 		float FloorHeightstart, float FloorHeightend,
-		float v_offset);
+		float v_offset, float skew);
 
 	void DoMidTexture(HWWallDispatcher* di, seg_t* seg, bool drawfogboundary,
 		sector_t* front, sector_t* back,
 		sector_t* realfront, sector_t* realback,
 		float fch1, float fch2, float ffh1, float ffh2,
-		float bch1, float bch2, float bfh1, float bfh2, float zalign);
+		float bch1, float bch2, float bfh1, float bfh2, float zalign, float skew);
 
 	void GetPlanePos(F3DFloor::planeref* planeref, float& left, float& right);
 

src/rendering/hwrenderer/scene/hw_walls.cpp

@@ -1016,7 +1016,7 @@ static float ZeroLightmapUVs[8] = { 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.
 //
 //==========================================================================
 bool HWWall::SetWallCoordinates(seg_t * seg, FTexCoordInfo *tci, float texturetop,
-	float topleft, float topright, float bottomleft, float bottomright, float t_ofs)
+	float topleft, float topright, float bottomleft, float bottomright, float t_ofs, float skew)
 {
 	//
 	//
@@ -1109,8 +1109,8 @@ bool HWWall::SetWallCoordinates(seg_t * seg, FTexCoordInfo *tci, float textureto
 
 		if (tci)
 		{
-			tcs[UPRGT].v = tci->FloatToTexV(-ztop[1] + texturetop);
+			tcs[UPRGT].v = tci->FloatToTexV(-ztop[1] + texturetop + skew);
-			tcs[LORGT].v = tci->FloatToTexV(-zbottom[1] + texturetop);
+			tcs[LORGT].v = tci->FloatToTexV(-zbottom[1] + texturetop + skew);
 		}
 
 		lightuv[UPRGT].v = srclightuv[UPRGT].v;
@@ -1132,7 +1132,7 @@ bool HWWall::SetWallCoordinates(seg_t * seg, FTexCoordInfo *tci, float textureto
 		zbottom[1] = ztop[1] = inter_y;
 		if (tci)
 		{
-			tcs[LORGT].v = tcs[UPRGT].v = tci->FloatToTexV(-ztop[1] + texturetop);
+			tcs[LORGT].v = tcs[UPRGT].v = tci->FloatToTexV(-ztop[1] + texturetop + skew);
 		}
 
 		lightuv[UPRGT].v = srclightuv[UPRGT].v + inter_x * (srclightuv[UPRGT].v - srclightuv[UPLFT].v);
@@ -1258,7 +1258,7 @@ void HWWall::DoTexture(HWWallDispatcher *di, int _type,seg_t * seg, int peg,
 					   float ceilingrefheight,float floorrefheight,
 					   float topleft,float topright,
 					   float bottomleft,float bottomright,
-					   float v_offset)
+					   float v_offset, float skew)
 {
 	if (topleft<=bottomleft && topright<=bottomright) return;
 
@@ -1300,7 +1300,7 @@ void HWWall::DoTexture(HWWallDispatcher *di, int _type,seg_t * seg, int peg,
 	if (peg) floatceilingref += tci.mRenderHeight - flh - v_offset;
 
 	if (!SetWallCoordinates(seg, &tci, floatceilingref, topleft, topright, bottomleft, bottomright, 
-							seg->sidedef->GetTextureXOffset(texpos))) return;
+							seg->sidedef->GetTextureXOffset(texpos), skew)) return;
 
 	if (seg->linedef->special == Line_Mirror && _type == RENDERWALL_M1S && gl_mirrors && !(di->Level->ib_compatflags & BCOMPATF_NOMIRRORS))
 	{
@@ -1332,7 +1332,7 @@ void HWWall::DoMidTexture(HWWallDispatcher *di, seg_t * seg, bool drawfogboundar
 						  sector_t * front, sector_t * back,
 						  sector_t * realfront, sector_t * realback,
 						  float fch1, float fch2, float ffh1, float ffh2,
-						  float bch1, float bch2, float bfh1, float bfh2, float zalign)
+						  float bch1, float bch2, float bfh1, float bfh2, float zalign, float skew)
 								
 {
 	FTexCoordInfo tci;
@@ -1449,10 +1449,10 @@ void HWWall::DoMidTexture(HWWallDispatcher *di, seg_t * seg, bool drawfogboundar
 		// if we don't need a fog sheet let's clip away some unnecessary parts of the polygon
 		//
 		//
-		if (!drawfogboundary && !wrap)
+		if (!drawfogboundary && !wrap && skew == 0)
 		{
-			if (texturetop<topleft && texturetop<topright) topleft=topright=texturetop;
+			if (texturetop < topleft && texturetop < topright) topleft = topright = texturetop;
-			if (texturebottom>bottomleft && texturebottom>bottomright) bottomleft=bottomright=texturebottom;
+			if (texturebottom > bottomleft && texturebottom > bottomright) bottomleft = bottomright = texturebottom;
 		}
 	}
 	else
@@ -1465,8 +1465,10 @@ void HWWall::DoMidTexture(HWWallDispatcher *di, seg_t * seg, bool drawfogboundar
 		// unwanted side effects.
 		//
 		//
-		topleft=topright=texturetop;
+		topleft = texturetop;
-		bottomleft=bottomright=texturebottom;
+		topright = texturetop + skew;
+		bottomleft = texturebottom;
+		bottomright = texturebottom + skew;
 	}
 
 	// nothing visible - skip the rest
@@ -1529,7 +1531,7 @@ void HWWall::DoMidTexture(HWWallDispatcher *di, seg_t * seg, bool drawfogboundar
 		// mid textures on portal lines need the same offsetting as mid textures on sky lines
 		flags |= HWF_SKYHACK;
 	}
-	SetWallCoordinates(seg, &tci, texturetop, topleft, topright, bottomleft, bottomright, t_ofs);
+	SetWallCoordinates(seg, &tci, texturetop, topleft, topright, bottomleft, bottomright, t_ofs, skew);
 
 	//
 	//
@@ -1588,7 +1590,7 @@ void HWWall::DoMidTexture(HWWallDispatcher *di, seg_t * seg, bool drawfogboundar
 		FloatRect *splitrect;
 		int v = texture->GetAreas(&splitrect);
 		if (seg->frontsector == seg->backsector) flags |= HWF_NOSPLIT;	// we don't need to do vertex splits if a line has both sides in the same sector
-		if (v>0 && !drawfogboundary && !(seg->linedef->flags&ML_WRAP_MIDTEX) && !(flags & HWF_NOSLICE))
+		if (v>0 && !drawfogboundary && !(seg->linedef->flags&ML_WRAP_MIDTEX) && !(flags & HWF_NOSLICE) && skew == 0)
 		{
 			// split the poly!
 			int i,t=0;
@@ -2042,6 +2044,10 @@ inline int CalcRelLight(int lightlevel, int orglightlevel, int rel)
 	}
 }
 
+CVAR(Int, topskew, 0, 0)
+CVAR(Int, midskew, 0, 0)
+CVAR(Int, bottomskew, 0, 0)
+
 //==========================================================================
 //
 // 
@@ -2198,9 +2204,14 @@ void HWWall::Process(HWWallDispatcher *di, seg_t *seg, sector_t * frontsector, s
 			texture = TexMan.GetGameTexture(seg->sidedef->GetTexture(side_t::mid), true);
 			if (texture && texture->isValid())
 			{
+				int skewflag = seg->sidedef->textures[side_t::mid].skew;
+				if (skewflag == 0) skewflag = midskew;
+				float skew = 
+					skewflag == side_t::skew_front_ceiling ? fch2 - fch1 :
+					skewflag == side_t::skew_front_floor ? ffh2 - ffh1 : 0.;
 				DoTexture(di, RENDERWALL_M1S, seg, (seg->linedef->flags & ML_DONTPEGBOTTOM) > 0,
 					crefz, frefz,	// must come from the original!
-					fch1, fch2, ffh1, ffh2, 0);
+					fch1, fch2, ffh1, ffh2, 0, skew);
 			}
 		}
 	}
@@ -2268,9 +2279,15 @@ void HWWall::Process(HWWallDispatcher *di, seg_t *seg, sector_t * frontsector, s
 				texture = TexMan.GetGameTexture(seg->sidedef->GetTexture(side_t::top), true);
 				if (texture && texture->isValid())
 				{
+					int skewflag = seg->sidedef->textures[side_t::top].skew;
+					if (skewflag == 0) skewflag = topskew;
+					float skew =
+						skewflag == side_t::skew_front ? fch2 - fch1 :
+						skewflag == side_t::skew_back ? bch2 - bch1 : 0.;
+
 					DoTexture(di, RENDERWALL_TOP, seg, (seg->linedef->flags & (ML_DONTPEGTOP)) == 0,
 						crefz, realback->GetPlaneTexZ(sector_t::ceiling),
-						fch1, fch2, bch1a, bch2a, 0);
+						fch1, fch2, bch1a, bch2a, 0, skew);
 				}
 				else if (!(seg->sidedef->Flags & WALLF_POLYOBJ))
 				{
@@ -2283,7 +2300,7 @@ void HWWall::Process(HWWallDispatcher *di, seg_t *seg, sector_t * frontsector, s
 						{
 							DoTexture(di, RENDERWALL_TOP, seg, (seg->linedef->flags & (ML_DONTPEGTOP)) == 0,
 								crefz, realback->GetPlaneTexZ(sector_t::ceiling),
-								fch1, fch2, bch1a, bch2a, 0);
+								fch1, fch2, bch1a, bch2a, 0, 0);
 						}
 					}
 					else
@@ -2318,6 +2335,28 @@ void HWWall::Process(HWWallDispatcher *di, seg_t *seg, sector_t * frontsector, s
 		lightlevel = hw_ClampLight(seg->sidedef->GetLightLevel(foggy, orglightlevel, side_t::mid, false, &rel));
 		rellight = CalcRelLight(lightlevel, orglightlevel, rel);
 
+		float skew;
+		int skewflag = seg->sidedef->textures[side_t::mid].skew;
+		if (skewflag == 0) skewflag = midskew;
+		switch (skewflag)
+		{
+		default:
+			skew = 0;
+			break;
+		case side_t::skew_front_ceiling:
+			skew = fch2 - fch1;
+			break;
+		case side_t::skew_back_ceiling:
+			skew = bch2 - bch1;
+			break;
+		case side_t::skew_front_floor:
+			skew = bfh2 - bfh1;
+			break;
+		case side_t::skew_back_floor:
+			skew = ffh2 - ffh1;
+			break;
+		}
+
 		if (isportal)
 		{
 			lineportal = seg->linedef->getPortal()->mGroup;
@@ -2330,7 +2369,7 @@ void HWWall::Process(HWWallDispatcher *di, seg_t *seg, sector_t * frontsector, s
 			if (texture && seg->backsector != nullptr)
 			{
 				DoMidTexture(di, seg, drawfogboundary, frontsector, backsector, realfront, realback,
-					fch1, fch2, ffh1, ffh2, bch1, bch2, bfh1, bfh2, zalign);
+					fch1, fch2, ffh1, ffh2, bch1, bch2, bfh1, bfh2, zalign, skew);
 			}
 		}
 		else
@@ -2339,7 +2378,7 @@ void HWWall::Process(HWWallDispatcher *di, seg_t *seg, sector_t * frontsector, s
 			if (texture || drawfogboundary)
 			{
 				DoMidTexture(di, seg, drawfogboundary, frontsector, backsector, realfront, realback,
-					fch1, fch2, ffh1, ffh2, bch1, bch2, bfh1, bfh2, zalign);
+					fch1, fch2, ffh1, ffh2, bch1, bch2, bfh1, bfh2, zalign, skew);
 			}
 
 			if (backsector->e->XFloor.ffloors.Size() || frontsector->e->XFloor.ffloors.Size())
@@ -2352,6 +2391,7 @@ void HWWall::Process(HWWallDispatcher *di, seg_t *seg, sector_t * frontsector, s
 
 		/* bottom texture */
 		// the back sector's ceiling obstructs part of this wall (specially important for sky sectors)
+		float bfh1a = bch1, bfh2a = bch2;
 		if (fch1 < bfh1 && fch2 < bfh2 && (seg->linedef->flags & ML_DRAWFULLHEIGHT) == 0)
 		{
 			bfh1 = fch1;
@@ -2365,12 +2405,18 @@ void HWWall::Process(HWWallDispatcher *di, seg_t *seg, sector_t * frontsector, s
 			texture = TexMan.GetGameTexture(seg->sidedef->GetTexture(side_t::bottom), true);
 			if (texture && texture->isValid())
 			{
+				int skewflag = seg->sidedef->textures[side_t::bottom].skew;
+				if (skewflag == 0) skewflag = bottomskew;
+				float skew =
+					skewflag == side_t::skew_back ? bfh2a - bfh1a :
+					skewflag == side_t::skew_front ? ffh2 - ffh1 : 0.;
+
 				DoTexture(di, RENDERWALL_BOTTOM, seg, (seg->linedef->flags & ML_DONTPEGBOTTOM) > 0,
 					realback->GetPlaneTexZ(sector_t::floor), frefz,
 					bfh1, bfh2, ffh1, ffh2,
 					frontsector->GetTexture(sector_t::ceiling) == skyflatnum && backsector->GetTexture(sector_t::ceiling) == skyflatnum ?
 					frefz - realback->GetPlaneTexZ(sector_t::ceiling) :
-					frefz - crefz);
+					frefz - crefz, skew);
 			}
 			else if (!(seg->sidedef->Flags & WALLF_POLYOBJ))
 			{
@@ -2386,7 +2432,7 @@ void HWWall::Process(HWWallDispatcher *di, seg_t *seg, sector_t * frontsector, s
 					{
 						DoTexture(di, RENDERWALL_BOTTOM, seg, (seg->linedef->flags & ML_DONTPEGBOTTOM) > 0,
 							realback->GetPlaneTexZ(sector_t::floor), frefz,
-							bfh1, bfh2, ffh1, ffh2, frefz - crefz);
+							bfh1, bfh2, ffh1, ffh2, frefz - crefz, 0);
 					}
 				}
 				else if (backsector->GetTexture(sector_t::floor) != skyflatnum)
@@ -2458,7 +2504,7 @@ void HWWall::ProcessLowerMiniseg(HWWallDispatcher *di, seg_t *seg, sector_t * fr
 			FTexCoordInfo tci;
 			type = RENDERWALL_BOTTOM;
 			tci.GetFromTexture(texture, 1, 1, false);
-			SetWallCoordinates(seg, &tci, bfh, bfh, bfh, ffh, ffh, 0);
+			SetWallCoordinates(seg, &tci, bfh, bfh, bfh, ffh, ffh, 0, 0);
 			PutWall(di, false);
 		}
 	}