vkdoom_m/src/polyrenderer/scene/poly_plane.cpp

/*
**  Polygon Doom software renderer
**  Copyright (c) 2016 Magnus Norddahl
**
**  This software is provided 'as-is', without any express or implied
**  warranty.  In no event will the authors be held liable for any damages
**  arising from the use of this software.
**
**  Permission is granted to anyone to use this software for any purpose,
**  including commercial applications, and to alter it and redistribute it
**  freely, subject to the following restrictions:
**
**  1. The origin of this software must not be misrepresented; you must not
**     claim that you wrote the original software. If you use this software
**     in a product, an acknowledgment in the product documentation would be
**     appreciated but is not required.
**  2. Altered source versions must be plainly marked as such, and must not be
**     misrepresented as being the original software.
**  3. This notice may not be removed or altered from any source distribution.
**
*/

#include <stdlib.h>
#include "templates.h"
#include "doomdef.h"
#include "sbar.h"
#include "r_data/r_translate.h"
#include "poly_plane.h"
#include "poly_portal.h"
#include "polyrenderer/poly_renderer.h"
#include "r_sky.h"
#include "polyrenderer/scene/poly_light.h"
#include "polyrenderer/poly_renderthread.h"
#include "p_lnspec.h"
#include "a_dynlight.h"

EXTERN_CVAR(Int, r_3dfloors)

void RenderPolyPlane::RenderPlanes(PolyRenderThread *thread, const TriMatrix &worldToClip, const PolyClipPlane &clipPlane, const PolyTransferHeights &fakeflat, uint32_t stencilValue, double skyCeilingHeight, double skyFloorHeight, std::vector<std::unique_ptr<PolyDrawSectorPortal>> &sectorPortals)
{
	if (fakeflat.FrontSector->CenterFloor() == fakeflat.FrontSector->CenterCeiling())
		return;

	RenderPolyPlane plane;
	plane.Render(thread, worldToClip, clipPlane, fakeflat, stencilValue, true, skyCeilingHeight, sectorPortals);
	plane.Render(thread, worldToClip, clipPlane, fakeflat, stencilValue, false, skyFloorHeight, sectorPortals);
}

void RenderPolyPlane::Render(PolyRenderThread *thread, const TriMatrix &worldToClip, const PolyClipPlane &clipPlane, const PolyTransferHeights &fakeflat, uint32_t stencilValue, bool ceiling, double skyHeight, std::vector<std::unique_ptr<PolyDrawSectorPortal>> &sectorPortals)
{
	FSectorPortal *portal = fakeflat.FrontSector->ValidatePortal(ceiling ? sector_t::ceiling : sector_t::floor);
	if (!portal || (portal->mFlags & PORTSF_INSKYBOX) == PORTSF_INSKYBOX) // Do not recurse into portals we already recursed into
	{
		RenderNormal(thread, worldToClip, clipPlane, fakeflat, stencilValue, ceiling, skyHeight);
	}
	else
	{
		RenderPortal(thread, worldToClip, clipPlane, fakeflat, stencilValue, ceiling, skyHeight, portal, sectorPortals);
	}
}

void RenderPolyPlane::RenderNormal(PolyRenderThread *thread, const TriMatrix &worldToClip, const PolyClipPlane &clipPlane, const PolyTransferHeights &fakeflat, uint32_t stencilValue, bool ceiling, double skyHeight)
{
	const auto &viewpoint = PolyRenderer::Instance()->Viewpoint;

	FTextureID picnum = fakeflat.FrontSector->GetTexture(ceiling ? sector_t::ceiling : sector_t::floor);
	if (picnum != skyflatnum)
	{
		FTexture *tex = TexMan(picnum);
		if (!tex || tex->UseType == FTexture::TEX_Null)
			return;

		PolyPlaneUVTransform transform = PolyPlaneUVTransform(ceiling ? fakeflat.FrontSector->planes[sector_t::ceiling].xform : fakeflat.FrontSector->planes[sector_t::floor].xform, tex);
		TriVertex *vertices = CreatePlaneVertices(thread, fakeflat.Subsector, transform, ceiling ? fakeflat.FrontSector->ceilingplane : fakeflat.FrontSector->floorplane);

		PolyDrawArgs args;
		SetLightLevel(thread, args, fakeflat, ceiling);
		SetDynLights(thread, args, fakeflat.Subsector, ceiling);
		args.SetTransform(&worldToClip);
		args.SetFaceCullCCW(true);
		args.SetStencilTestValue(stencilValue);
		args.SetWriteStencil(true, stencilValue + 1);
		args.SetClipPlane(0, clipPlane);
		args.SetTexture(tex);
		args.SetStyle(TriBlendMode::TextureOpaque);
		args.DrawArray(thread, vertices, fakeflat.Subsector->numlines, PolyDrawMode::TriangleFan);
	}
	else
	{
		TriVertex *vertices = CreateSkyPlaneVertices(thread, fakeflat.Subsector, skyHeight);

		PolyDrawArgs args;
		args.SetTransform(&worldToClip);
		args.SetFaceCullCCW(true);
		args.SetStencilTestValue(stencilValue);
		args.SetWriteStencil(true, stencilValue + 1);
		args.SetClipPlane(0, clipPlane);
		args.SetWriteStencil(true, 255);
		args.SetWriteColor(false);
		args.SetWriteDepth(false);
		args.DrawArray(thread, vertices, fakeflat.Subsector->numlines, PolyDrawMode::TriangleFan);

		RenderSkyWalls(thread, args, fakeflat.Subsector, nullptr, ceiling, skyHeight);
	}
}

void RenderPolyPlane::RenderPortal(PolyRenderThread *thread, const TriMatrix &worldToClip, const PolyClipPlane &clipPlane, const PolyTransferHeights &fakeflat, uint32_t stencilValue, bool ceiling, double skyHeight, FSectorPortal *portal, std::vector<std::unique_ptr<PolyDrawSectorPortal>> &sectorPortals)
{
	const auto &viewpoint = PolyRenderer::Instance()->Viewpoint;

	PolyDrawSectorPortal *polyportal = nullptr;
	std::vector<PolyPortalSegment> portalSegments;

	// Skip portals not facing the camera
	if ((ceiling && fakeflat.FrontSector->ceilingplane.PointOnSide(viewpoint.Pos) < 0) ||
		(!ceiling && fakeflat.FrontSector->floorplane.PointOnSide(viewpoint.Pos) < 0))
	{
		return;
	}

	for (auto &p : sectorPortals)
	{
		if (p->Portal == portal) // To do: what other criteria do we need to check for?
		{
			polyportal = p.get();
			break;
		}
	}
	if (!polyportal)
	{
		sectorPortals.push_back(std::unique_ptr<PolyDrawSectorPortal>(new PolyDrawSectorPortal(portal, ceiling)));
		polyportal = sectorPortals.back().get();
	}

#if 0
	// Calculate portal clipping
	portalSegments.reserve(sub->numlines);
	for (uint32_t i = 0; i < sub->numlines; i++)
	{
		seg_t *line = &sub->firstline[i];

		DVector2 pt1 = line->v1->fPos() - viewpoint.Pos;
		DVector2 pt2 = line->v2->fPos() - viewpoint.Pos;
		bool backside = pt1.Y * (pt1.X - pt2.X) + pt1.X * (pt2.Y - pt1.Y) >= 0;
		if (!backside)
		{
			angle_t angle1, angle2;
			if (cull.GetAnglesForLine(line->v1->fX(), line->v1->fY(), line->v2->fX(), line->v2->fY(), angle1, angle2))
				portalSegments.push_back({ angle1, angle2 });
		}
		else
		{
			angle_t angle1, angle2;
			if (cull.GetAnglesForLine(line->v2->fX(), line->v2->fY(), line->v1->fX(), line->v1->fY(), angle1, angle2))
				portalSegments.push_back({ angle1, angle2 });
		}
	}
#endif

	TriVertex *vertices = CreateSkyPlaneVertices(thread, fakeflat.Subsector, skyHeight);

	PolyDrawArgs args;
	args.SetTransform(&worldToClip);
	args.SetFaceCullCCW(true);
	args.SetStencilTestValue(stencilValue);
	args.SetWriteStencil(true, stencilValue + 1);
	args.SetClipPlane(0, clipPlane);
	args.SetWriteStencil(true, polyportal->StencilValue);
	args.SetWriteColor(false);
	args.SetWriteDepth(false);
	args.DrawArray(thread, vertices, fakeflat.Subsector->numlines, PolyDrawMode::TriangleFan);

	RenderSkyWalls(thread, args, fakeflat.Subsector, polyportal, ceiling, skyHeight);

	polyportal->Shape.push_back({ vertices, (int)fakeflat.Subsector->numlines, true });
}

void RenderPolyPlane::RenderSkyWalls(PolyRenderThread *thread, PolyDrawArgs &args, subsector_t *sub, PolyDrawSectorPortal *polyportal, bool ceiling, double skyHeight)
{
	sector_t *frontsector = sub->sector;
	for (uint32_t i = 0; i < sub->numlines; i++)
	{
		seg_t *line = &sub->firstline[i];

		double skyBottomz1 = frontsector->ceilingplane.ZatPoint(line->v1);
		double skyBottomz2 = frontsector->ceilingplane.ZatPoint(line->v2);
		if (line->backsector)
		{
			sector_t *backsector = line->backsector;

			double backceilz1 = backsector->ceilingplane.ZatPoint(line->v1);
			double backfloorz1 = backsector->floorplane.ZatPoint(line->v1);
			double backceilz2 = backsector->ceilingplane.ZatPoint(line->v2);
			double backfloorz2 = backsector->floorplane.ZatPoint(line->v2);

			bool bothSkyCeiling = frontsector->GetTexture(sector_t::ceiling) == skyflatnum && backsector->GetTexture(sector_t::ceiling) == skyflatnum;

			bool closedSector = backceilz1 == backfloorz1 && backceilz2 == backfloorz2;
			if (ceiling && bothSkyCeiling && closedSector)
			{
				double frontceilz1 = frontsector->ceilingplane.ZatPoint(line->v1);
				double frontfloorz1 = frontsector->floorplane.ZatPoint(line->v1);
				double frontceilz2 = frontsector->ceilingplane.ZatPoint(line->v2);
				double frontfloorz2 = frontsector->floorplane.ZatPoint(line->v2);

				double topceilz1 = frontceilz1;
				double topceilz2 = frontceilz2;
				double topfloorz1 = MIN(backceilz1, frontceilz1);
				double topfloorz2 = MIN(backceilz2, frontceilz2);
				double bottomceilz1 = MAX(frontfloorz1, backfloorz1);
				double bottomceilz2 = MAX(frontfloorz2, backfloorz2);
				double middleceilz1 = topfloorz1;
				double middleceilz2 = topfloorz2;
				double middlefloorz1 = MIN(bottomceilz1, middleceilz1);
				double middlefloorz2 = MIN(bottomceilz2, middleceilz2);

				skyBottomz1 = middlefloorz1;
				skyBottomz2 = middlefloorz2;
			}
			else if (bothSkyCeiling)
			{
				continue;
			}
		}
		else if (polyportal && line->linedef && line->linedef->special == Line_Horizon)
		{
			// Not entirely correct as this closes the line horizon rather than allowing the floor to continue to infinity
			skyBottomz1 = frontsector->floorplane.ZatPoint(line->v1);
			skyBottomz2 = frontsector->floorplane.ZatPoint(line->v2);
		}

		TriVertex *wallvert = thread->FrameMemory->AllocMemory<TriVertex>(4);

		if (ceiling)
		{
			wallvert[0] = GetSkyVertex(line->v1, skyHeight);
			wallvert[1] = GetSkyVertex(line->v2, skyHeight);
			wallvert[2] = GetSkyVertex(line->v2, skyBottomz2);
			wallvert[3] = GetSkyVertex(line->v1, skyBottomz1);
		}
		else
		{
			wallvert[0] = GetSkyVertex(line->v1, frontsector->floorplane.ZatPoint(line->v1));
			wallvert[1] = GetSkyVertex(line->v2, frontsector->floorplane.ZatPoint(line->v2));
			wallvert[2] = GetSkyVertex(line->v2, skyHeight);
			wallvert[3] = GetSkyVertex(line->v1, skyHeight);
		}

		args.DrawArray(thread, wallvert, 4, PolyDrawMode::TriangleFan);

		if (polyportal)
		{
			polyportal->Shape.push_back({ wallvert, 4, args.FaceCullCCW() });
		}
	}
}

void RenderPolyPlane::SetLightLevel(PolyRenderThread *thread, PolyDrawArgs &args, const PolyTransferHeights &fakeflat, bool ceiling)
{
	bool foggy = level.fadeto || fakeflat.FrontSector->Colormap.FadeColor || (level.flags & LEVEL_HASFADETABLE);

	int lightlevel = ceiling ? fakeflat.CeilingLightLevel : fakeflat.FloorLightLevel;
	int actualextralight = foggy ? 0 : PolyRenderer::Instance()->Viewpoint.extralight << 4;
	lightlevel = clamp(lightlevel + actualextralight, 0, 255);

	PolyCameraLight *cameraLight = PolyCameraLight::Instance();
	FDynamicColormap *basecolormap = GetColorTable(fakeflat.FrontSector->Colormap, fakeflat.FrontSector->SpecialColors[ceiling ? sector_t::ceiling : sector_t::floor]);
	if (cameraLight->FixedLightLevel() < 0 && fakeflat.FrontSector->e && fakeflat.FrontSector->e->XFloor.lightlist.Size())
	{
		lightlist_t *light = P_GetPlaneLight(fakeflat.FrontSector, ceiling ? &fakeflat.FrontSector->ceilingplane : &fakeflat.FrontSector->floorplane, false);
		basecolormap = GetColorTable(light->extra_colormap, fakeflat.FrontSector->SpecialColors[ceiling ? sector_t::ceiling : sector_t::floor]);
		if (light->p_lightlevel != &fakeflat.FrontSector->lightlevel) // If this is the real ceiling, don't discard plane lighting R_FakeFlat() accounted for.
		{
			lightlevel = *light->p_lightlevel;
		}
	}

	args.SetLight(basecolormap, lightlevel, PolyRenderer::Instance()->Light.WallGlobVis(foggy), false);
}

void RenderPolyPlane::SetDynLights(PolyRenderThread *thread, PolyDrawArgs &args, subsector_t *sub, bool ceiling)
{
	FLightNode *light_list = sub->lighthead;

	auto cameraLight = PolyCameraLight::Instance();
	if ((cameraLight->FixedLightLevel() >= 0) || (cameraLight->FixedColormap() != nullptr))
	{
		args.SetLights(nullptr, 0); // [SP] Don't draw dynlights if invul/lightamp active
		return;
	}

	// Calculate max lights that can touch the wall so we can allocate memory for the list
	int max_lights = 0;
	FLightNode *cur_node = light_list;
	while (cur_node)
	{
		if (!(cur_node->lightsource->flags2&MF2_DORMANT))
			max_lights++;
		cur_node = cur_node->nextLight;
	}

	if (max_lights == 0)
	{
		args.SetLights(nullptr, 0);
		return;
	}

	int dc_num_lights = 0;
	PolyLight *dc_lights = thread->FrameMemory->AllocMemory<PolyLight>(max_lights);

	// Setup lights
	cur_node = light_list;
	while (cur_node)
	{
		if (!(cur_node->lightsource->flags2&MF2_DORMANT))
		{
			bool is_point_light = (cur_node->lightsource->lightflags & LF_ATTENUATE) != 0;

			// To do: cull lights not touching subsector

			uint32_t red = cur_node->lightsource->GetRed();
			uint32_t green = cur_node->lightsource->GetGreen();
			uint32_t blue = cur_node->lightsource->GetBlue();

			auto &light = dc_lights[dc_num_lights++];
			light.x = (float)cur_node->lightsource->X();
			light.y = (float)cur_node->lightsource->Y();
			light.z = (float)cur_node->lightsource->Z();
			light.radius = 256.0f / cur_node->lightsource->GetRadius();
			light.color = (red << 16) | (green << 8) | blue;
			if (is_point_light)
				light.radius = -light.radius;
		}

		cur_node = cur_node->nextLight;
	}

	args.SetLights(dc_lights, dc_num_lights);

	DVector3 normal = ceiling ? sub->sector->ceilingplane.Normal() : sub->sector->floorplane.Normal();
	args.SetNormal({ (float)normal.X, (float)normal.Y, (float)normal.Z });
}

TriVertex *RenderPolyPlane::CreatePlaneVertices(PolyRenderThread *thread, subsector_t *sub, const PolyPlaneUVTransform &transform, const secplane_t &plane)
{
	TriVertex *vertices = thread->FrameMemory->AllocMemory<TriVertex>(sub->numlines);

	const auto &viewpoint = PolyRenderer::Instance()->Viewpoint;
	double planeZ = plane.ZatPoint(viewpoint.Pos.XY());
	if (viewpoint.Pos.Z < planeZ)
	{
		for (uint32_t i = 0; i < sub->numlines; i++)
		{
			seg_t *line = &sub->firstline[sub->numlines - 1 - i];
			vertices[i] = transform.GetVertex(line->v1, plane.ZatPoint(line->v1));
		}
	}
	else
	{
		for (uint32_t i = 0; i < sub->numlines; i++)
		{
			seg_t *line = &sub->firstline[i];
			vertices[i] = transform.GetVertex(line->v1, plane.ZatPoint(line->v1));
		}
	}

	return vertices;
}

TriVertex *RenderPolyPlane::CreateSkyPlaneVertices(PolyRenderThread *thread, subsector_t *sub, double skyHeight)
{
	TriVertex *vertices = thread->FrameMemory->AllocMemory<TriVertex>(sub->numlines);

	const auto &viewpoint = PolyRenderer::Instance()->Viewpoint;
	if (viewpoint.Pos.Z < skyHeight)
	{
		for (uint32_t i = 0; i < sub->numlines; i++)
		{
			seg_t *line = &sub->firstline[sub->numlines - 1 - i];
			vertices[i] = GetSkyVertex(line->v1, skyHeight);
		}
	}
	else
	{
		for (uint32_t i = 0; i < sub->numlines; i++)
		{
			seg_t *line = &sub->firstline[i];
			vertices[i] = GetSkyVertex(line->v1, skyHeight);
		}
	}

	return vertices;
}

/////////////////////////////////////////////////////////////////////////////

PolyPlaneUVTransform::PolyPlaneUVTransform(const FTransform &transform, FTexture *tex)
{
	if (tex)
	{
		xscale = (float)(transform.xScale * tex->Scale.X / tex->GetWidth());
		yscale = (float)(transform.yScale * tex->Scale.Y / tex->GetHeight());

		double planeang = (transform.Angle + transform.baseAngle).Radians();
		cosine = (float)cos(planeang);
		sine = (float)sin(planeang);

		xOffs = (float)transform.xOffs;
		yOffs = (float)transform.yOffs;
	}
	else
	{
		xscale = 1.0f / 64.0f;
		yscale = 1.0f / 64.0f;
		cosine = 1.0f;
		sine = 0.0f;
		xOffs = 0.0f;
		yOffs = 0.0f;
	}
}

/////////////////////////////////////////////////////////////////////////////

void Render3DFloorPlane::RenderPlanes(PolyRenderThread *thread, const TriMatrix &worldToClip, const PolyClipPlane &clipPlane, subsector_t *sub, uint32_t stencilValue, uint32_t subsectorDepth, std::vector<PolyTranslucentObject *> &translucentObjects)
{
	if (!r_3dfloors || sub->sector->CenterFloor() == sub->sector->CenterCeiling())
		return;

	const auto &viewpoint = PolyRenderer::Instance()->Viewpoint;

	auto frontsector = sub->sector;
	auto &ffloors = frontsector->e->XFloor.ffloors;

	// 3D floor floors
	for (int i = 0; i < (int)ffloors.Size(); i++)
	{
		F3DFloor *fakeFloor = ffloors[i];
		if (!(fakeFloor->flags & FF_EXISTS)) continue;
		if (!fakeFloor->model) continue;
		//if (!(fakeFloor->flags & FF_NOSHADE) || (fakeFloor->flags & (FF_RENDERPLANES | FF_RENDERSIDES)))
		//	R_3D_AddHeight(fakeFloor->top.plane, frontsector);
		if (!(fakeFloor->flags & FF_RENDERPLANES)) continue;
		if (fakeFloor->alpha == 0) continue;
		if (fakeFloor->flags & FF_THISINSIDE && fakeFloor->flags & FF_INVERTSECTOR) continue;
		//fakeFloor->alpha

		double fakeHeight = fakeFloor->top.plane->ZatPoint(frontsector->centerspot);
		if (fakeFloor->bottom.plane->isSlope() || (fakeHeight < viewpoint.Pos.Z && fakeHeight > frontsector->floorplane.ZatPoint(frontsector->centerspot)))
		{
			Render3DFloorPlane plane;
			plane.sub = sub;
			plane.stencilValue = stencilValue;
			plane.ceiling = false;
			plane.fakeFloor = fakeFloor;
			plane.Additive = !!(fakeFloor->flags & FF_ADDITIVETRANS);
			if (!plane.Additive && fakeFloor->alpha == 255)
			{
				plane.Masked = false;
				plane.Alpha = 1.0;
			}
			else
			{
				plane.Masked = true;
				plane.Alpha = fakeFloor->alpha / 255.0;
			}

			if (!plane.Masked)
				plane.Render(thread, worldToClip, clipPlane);
			else
				translucentObjects.push_back(thread->FrameMemory->NewObject<PolyTranslucent3DFloorPlane>(plane, subsectorDepth));
		}
	}

	// 3D floor ceilings
	for (int i = 0; i < (int)ffloors.Size(); i++)
	{
		F3DFloor *fakeFloor = ffloors[i];
		if (!(fakeFloor->flags & FF_EXISTS)) continue;
		if (!fakeFloor->model) continue;
		//if (!(fakeFloor->flags & FF_NOSHADE) || (fakeFloor->flags & (FF_RENDERPLANES | FF_RENDERSIDES)))
		//	R_3D_AddHeight(fakeFloor->bottom.plane, frontsector);
		if (!(fakeFloor->flags & FF_RENDERPLANES)) continue;
		if (fakeFloor->alpha == 0) continue;
		if (!(fakeFloor->flags & FF_THISINSIDE) && (fakeFloor->flags & (FF_SWIMMABLE | FF_INVERTSECTOR)) == (FF_SWIMMABLE | FF_INVERTSECTOR)) continue;
		//fakeFloor->alpha

		double fakeHeight = fakeFloor->bottom.plane->ZatPoint(frontsector->centerspot);
		if (fakeFloor->bottom.plane->isSlope() || (fakeHeight > viewpoint.Pos.Z && fakeHeight < frontsector->ceilingplane.ZatPoint(frontsector->centerspot)))
		{
			Render3DFloorPlane plane;
			plane.sub = sub;
			plane.stencilValue = stencilValue;
			plane.ceiling = true;
			plane.fakeFloor = fakeFloor;
			plane.Additive = !!(fakeFloor->flags & FF_ADDITIVETRANS);
			if (!plane.Additive && fakeFloor->alpha == 255)
			{
				plane.Masked = false;
				plane.Alpha = 1.0;
			}
			else
			{
				plane.Masked = true;
				plane.Alpha = fakeFloor->alpha / 255.0;
			}

			if (!plane.Masked)
				plane.Render(thread, worldToClip, clipPlane);
			else
				translucentObjects.push_back(thread->FrameMemory->NewObject<PolyTranslucent3DFloorPlane>(plane, subsectorDepth));
		}
	}
}

void Render3DFloorPlane::Render(PolyRenderThread *thread, const TriMatrix &worldToClip, const PolyClipPlane &clipPlane)
{
	FTextureID picnum = ceiling ? *fakeFloor->bottom.texture : *fakeFloor->top.texture;
	FTexture *tex = TexMan(picnum);
	if (tex->UseType == FTexture::TEX_Null)
		return;

	PolyCameraLight *cameraLight = PolyCameraLight::Instance();

	int lightlevel = 255;
	bool foggy = false;
	if (cameraLight->FixedLightLevel() < 0 && sub->sector->e->XFloor.lightlist.Size())
	{
		lightlist_t *light = P_GetPlaneLight(sub->sector, &sub->sector->ceilingplane, false);
		//basecolormap = light->extra_colormap;
		lightlevel = *light->p_lightlevel;
	}

	int actualextralight = foggy ? 0 : PolyRenderer::Instance()->Viewpoint.extralight << 4;
	lightlevel = clamp(lightlevel + actualextralight, 0, 255);

	PolyPlaneUVTransform xform(ceiling ? fakeFloor->top.model->planes[sector_t::ceiling].xform : fakeFloor->top.model->planes[sector_t::floor].xform, tex);

	TriVertex *vertices = thread->FrameMemory->AllocMemory<TriVertex>(sub->numlines);
	if (ceiling)
	{
		for (uint32_t i = 0; i < sub->numlines; i++)
		{
			seg_t *line = &sub->firstline[i];
			vertices[sub->numlines - 1 - i] = xform.GetVertex(line->v1, fakeFloor->bottom.plane->ZatPoint(line->v1));
		}
	}
	else
	{
		for (uint32_t i = 0; i < sub->numlines; i++)
		{
			seg_t *line = &sub->firstline[i];
			vertices[i] = xform.GetVertex(line->v1, fakeFloor->top.plane->ZatPoint(line->v1));
		}
	}

	PolyDrawArgs args;
	args.SetLight(GetColorTable(sub->sector->Colormap), lightlevel, PolyRenderer::Instance()->Light.WallGlobVis(foggy), false);
	args.SetTransform(&worldToClip);
	if (!Masked)
	{
		args.SetStyle(TriBlendMode::TextureOpaque);
	}
	else
	{
		double srcalpha = MIN(Alpha, 1.0);
		double destalpha = Additive ? 1.0 : 1.0 - srcalpha;
		args.SetStyle(TriBlendMode::TextureAdd, srcalpha, destalpha);
		args.SetDepthTest(true);
		args.SetWriteDepth(true);
		args.SetWriteStencil(false);
	}
	args.SetFaceCullCCW(true);
	args.SetStencilTestValue(stencilValue);
	args.SetWriteStencil(true, stencilValue + 1);
	args.SetTexture(tex);
	args.SetClipPlane(0, clipPlane);
	args.DrawArray(thread, vertices, sub->numlines, PolyDrawMode::TriangleFan);
}