diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 564e019cf9..250abe03de 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -1043,7 +1043,6 @@ set (PCH_SOURCES
 	g_statusbar/sbar_mugshot.cpp
 	g_statusbar/shared_sbar.cpp
 	gl/compatibility/gl_20.cpp
-	gl/data/gl_data.cpp
 	gl/data/gl_portaldata.cpp
 	gl/data/gl_setup.cpp
 	gl/data/gl_vertexbuffer.cpp
diff --git a/src/g_level.cpp b/src/g_level.cpp
index 59ba0a07b3..c3ec833367 100644
--- a/src/g_level.cpp
+++ b/src/g_level.cpp
@@ -117,6 +117,31 @@ EXTERN_CVAR (String, playerclass)
 
 void G_VerifySkill();
 
+CUSTOM_CVAR(Bool, gl_brightfog, false, CVAR_ARCHIVE | CVAR_NOINITCALL)
+{
+	if (level.info->brightfog == -1) level.brightfog = self;
+}
+
+CUSTOM_CVAR(Bool, gl_lightadditivesurfaces, false, CVAR_ARCHIVE | CVAR_NOINITCALL)
+{
+	if (level.info->lightadditivesurfaces == -1) level.lightadditivesurfaces = self;
+}
+
+CUSTOM_CVAR(Bool, gl_notexturefill, false, CVAR_NOINITCALL)
+{
+	if (level.info->notexturefill == -1) level.notexturefill = self;
+}
+
+CUSTOM_CVAR(Int, gl_lightmode, 3, CVAR_ARCHIVE | CVAR_NOINITCALL)
+{
+	int newself = self;
+	if (newself > 4) newself = 8;	// use 8 for software lighting to avoid conflicts with the bit mask
+	if (newself < 0) newself = 0;
+	if (self != newself) self = newself;
+	else if (level.info->lightmode == -1) level.lightmode = self;
+}
+
+
 
 static FRandom pr_classchoice ("RandomPlayerClassChoice");
 
@@ -1491,6 +1516,12 @@ void G_InitLevelLocals ()
 	compatflags2.Callback();
 
 	level.DefaultEnvironment = info->DefaultEnvironment;
+
+	level.lightmode = info->lightmode < 0? gl_lightmode : info->lightmode;
+	level.brightfog = info->brightfog < 0? gl_brightfog : !!info->brightfog;
+	level.lightadditivesurfaces = info->lightadditivesurfaces < 0 ? gl_lightadditivesurfaces : !!info->lightadditivesurfaces;
+	level.notexturefill = info->notexturefill < 0 ? gl_notexturefill : !!info->notexturefill;
+
 }
 
 //==========================================================================
diff --git a/src/g_level.h b/src/g_level.h
index 78dcd55b11..b717bdbcfe 100644
--- a/src/g_level.h
+++ b/src/g_level.h
@@ -35,6 +35,7 @@
 #define __G_LEVEL_H__
 
 #include "doomtype.h"
+#include "vectors.h"
 #include "sc_man.h"
 #include "resourcefiles/file_zip.h"
 
@@ -395,6 +396,14 @@ struct level_info_t
 	
 	TArray<FString> EventHandlers;
 
+	int8_t		lightmode;
+	int8_t		brightfog;
+	int8_t		lightadditivesurfaces;
+	int8_t		notexturefill;
+	FVector3	skyrotatevector;
+	FVector3	skyrotatevector2;
+
+
 	level_info_t() 
 	{ 
 		Reset(); 
diff --git a/src/g_levellocals.h b/src/g_levellocals.h
index 868423491f..4a7a84b251 100644
--- a/src/g_levellocals.h
+++ b/src/g_levellocals.h
@@ -152,6 +152,12 @@ struct FLevelLocals
 	float		pixelstretch;
 	float		MusicVolume;
 
+	// Hardware render stuff that can either be set via CVAR or MAPINFO
+	int			lightmode;
+	bool		brightfog;
+	bool		lightadditivesurfaces;
+	bool		notexturefill;
+
 	bool		IsJumpingAllowed() const;
 	bool		IsCrouchingAllowed() const;
 	bool		IsFreelookAllowed() const;
diff --git a/src/g_mapinfo.cpp b/src/g_mapinfo.cpp
index 325f6c2d2a..914dad912f 100644
--- a/src/g_mapinfo.cpp
+++ b/src/g_mapinfo.cpp
@@ -283,6 +283,14 @@ void level_info_t::Reset()
 	specialactions.Clear();
 	DefaultEnvironment = 0;
 	PrecacheSounds.Clear();
+
+	brightfog = -1;
+	lightmode = -1;
+	notexturefill = -1;
+	lightadditivesurfaces = -1;
+	skyrotatevector = FVector3(0, 0, 1);
+	skyrotatevector2 = FVector3(0, 0, 1);
+
 }
 
 
@@ -1362,6 +1370,82 @@ DEFINE_MAP_OPTION(pixelratio, false)
 }
 
 
+DEFINE_MAP_OPTION(brightfog, false)
+{
+	parse.ParseAssign();
+	parse.sc.MustGetNumber();
+	info->brightfog = parse.sc.Number;
+}
+
+DEFINE_MAP_OPTION(lightmode, false)
+{
+	parse.ParseAssign();
+	parse.sc.MustGetNumber();
+
+	if ((parse.sc.Number >= 0 && parse.sc.Number <= 4) || parse.sc.Number == 8)
+	{
+		info->lightmode = uint8_t(parse.sc.Number);
+	}
+	else
+	{
+		parse.sc.ScriptMessage("Invalid light mode %d", parse.sc.Number);
+	}
+}
+
+DEFINE_MAP_OPTION(notexturefill, false)
+{
+	if (parse.CheckAssign())
+	{
+		parse.sc.MustGetNumber();
+		info->notexturefill = !!parse.sc.Number;
+	}
+	else
+	{
+		info->notexturefill = true;
+	}
+}
+
+DEFINE_MAP_OPTION(lightadditivesurfaces, false)
+{
+	if (parse.CheckAssign())
+	{
+		parse.sc.MustGetNumber();
+		info->lightadditivesurfaces = !!parse.sc.Number;
+	}
+	else
+	{
+		info->lightadditivesurfaces = true;
+	}
+}
+
+DEFINE_MAP_OPTION(skyrotate, false)
+{
+	parse.ParseAssign();
+	parse.sc.MustGetFloat();
+	info->skyrotatevector.X = (float)parse.sc.Float;
+	if (parse.format_type == FMapInfoParser::FMT_New) parse.sc.MustGetStringName(",");
+	parse.sc.MustGetFloat();
+	info->skyrotatevector.Y = (float)parse.sc.Float;
+	if (parse.format_type == FMapInfoParser::FMT_New) parse.sc.MustGetStringName(",");
+	parse.sc.MustGetFloat();
+	info->skyrotatevector.Z = (float)parse.sc.Float;
+	info->skyrotatevector.MakeUnit();
+}
+
+DEFINE_MAP_OPTION(skyrotate2, false)
+{
+	parse.ParseAssign();
+	parse.sc.MustGetFloat();
+	info->skyrotatevector2.X = (float)parse.sc.Float;
+	if (parse.format_type == FMapInfoParser::FMT_New) parse.sc.MustGetStringName(",");
+	parse.sc.MustGetFloat();
+	info->skyrotatevector2.Y = (float)parse.sc.Float;
+	if (parse.format_type == FMapInfoParser::FMT_New) parse.sc.MustGetStringName(",");
+	parse.sc.MustGetFloat();
+	info->skyrotatevector2.Z = (float)parse.sc.Float;
+	info->skyrotatevector2.MakeUnit();
+}
+
 //==========================================================================
 //
 // All flag based map options 
diff --git a/src/gl/compatibility/gl_20.cpp b/src/gl/compatibility/gl_20.cpp
index de9a957a88..afe9eb8672 100644
--- a/src/gl/compatibility/gl_20.cpp
+++ b/src/gl/compatibility/gl_20.cpp
@@ -485,7 +485,7 @@ static bool gl_CheckFog(FColormap *cm, int lightlevel)
 	{
 		frontfog = true;
 	}
-	else  if (level.fogdensity != 0 || (glset.lightmode & 4) || cm->FogDensity > 0)
+	else  if (level.fogdensity != 0 || (level.lightmode & 4) || cm->FogDensity > 0)
 	{
 		// case 3: level has fog density set
 		frontfog = true;
@@ -849,7 +849,7 @@ void GLSceneDrawer::RenderMultipassStuff()
 		{
 			gl_RenderState.BlendFunc(GL_ONE, GL_ONE);
 			glDepthFunc(GL_EQUAL);
-			if (glset.lightmode == 8) gl_RenderState.SetSoftLightLevel(255);
+			if (level.lightmode == 8) gl_RenderState.SetSoftLightLevel(255);
 			gl_drawinfo->dldrawlists[GLLDL_WALLS_PLAIN].DrawWalls(GLPASS_LIGHTTEX);
 			gl_drawinfo->dldrawlists[GLLDL_WALLS_MASKED].DrawWalls(GLPASS_LIGHTTEX);
 			gl_drawinfo->dldrawlists[GLLDL_FLATS_PLAIN].DrawFlats(GLPASS_LIGHTTEX);
diff --git a/src/gl/data/gl_data.cpp b/src/gl/data/gl_data.cpp
deleted file mode 100644
index effc5cbc78..0000000000
--- a/src/gl/data/gl_data.cpp
+++ /dev/null
@@ -1,323 +0,0 @@
-// 
-//---------------------------------------------------------------------------
-//
-// Copyright(C) 2005-2016 Christoph Oelckers
-// All rights reserved.
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU Lesser General Public License as published by
-// the Free Software Foundation, either version 3 of the License, or
-// (at your option) any later version.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU Lesser General Public License for more details.
-//
-// You should have received a copy of the GNU Lesser General Public License
-// along with this program.  If not, see http://www.gnu.org/licenses/
-//
-//--------------------------------------------------------------------------
-//
-/*
-** gl_data.cpp
-** Maintenance data for GL renderer (mostly to handle rendering hacks)
-**
-**/
-
-#include "gl/system/gl_system.h"
-
-#include "doomtype.h"
-#include "colormatcher.h"
-#include "i_system.h"
-#include "p_local.h"
-#include "p_tags.h"
-#include "p_lnspec.h"
-#include "c_dispatch.h"
-#include "r_sky.h"
-#include "sc_man.h"
-#include "w_wad.h"
-#include "gi.h"
-#include "g_level.h"
-#include "doomstat.h"
-#include "d_player.h"
-#include "g_levellocals.h"
-
-#include "gl/system/gl_interface.h"
-#include "gl/renderer/gl_renderer.h"
-#include "gl/renderer/gl_lightdata.h"
-#include "gl/data/gl_data.h"
-#include "gl/dynlights/gl_dynlight.h"
-#include "gl/dynlights/gl_glow.h"
-#include "gl/models/gl_models.h"
-#include "gl/utility/gl_clock.h"
-#include "gl/shaders/gl_shader.h"
-#include "gl/gl_functions.h"
-
-GLRenderSettings glset;
-
-EXTERN_CVAR(Int, gl_lightmode)
-EXTERN_CVAR(Bool, gl_brightfog)
-EXTERN_CVAR(Bool, gl_lightadditivesurfaces)
-
-
-CUSTOM_CVAR(Bool, gl_notexturefill, false, 0)
-{
-	glset.notexturefill = self;
-}
-
-
-void gl_CreateSections();
-
-
-//==========================================================================
-//
-// Portal identifier lists
-//
-//==========================================================================
-
-
-//==========================================================================
-//
-// MAPINFO stuff
-//
-//==========================================================================
-
-struct FGLROptions : public FOptionalMapinfoData
-{
-	FGLROptions()
-	{
-		identifier = "gl_renderer";
-		brightfog = false;
-		lightmode = -1;
-		notexturefill = -1;
-		skyrotatevector = FVector3(0,0,1);
-		skyrotatevector2 = FVector3(0,0,1);
-		lightadditivesurfaces = false;
-	}
-	virtual FOptionalMapinfoData *Clone() const
-	{
-		FGLROptions *newopt = new FGLROptions;
-		newopt->identifier = identifier;
-		newopt->lightmode = lightmode;
-		newopt->notexturefill = notexturefill;
-		newopt->skyrotatevector = skyrotatevector;
-		newopt->skyrotatevector2 = skyrotatevector2;
-		newopt->lightadditivesurfaces = lightadditivesurfaces;
-		return newopt;
-	}
-	int			lightmode;
-	int			brightfog;
-	int8_t		lightadditivesurfaces;
-	int8_t		notexturefill;
-	FVector3	skyrotatevector;
-	FVector3	skyrotatevector2;
-};
-
-DEFINE_MAP_OPTION(brightfog, false)
-{
-	FGLROptions *opt = info->GetOptData<FGLROptions>("gl_renderer");
-	parse.ParseAssign();
-	parse.sc.MustGetNumber();
-	opt->brightfog = parse.sc.Number;
-}
-
-DEFINE_MAP_OPTION(lightmode, false)
-{
-	FGLROptions *opt = info->GetOptData<FGLROptions>("gl_renderer");
-	parse.ParseAssign();
-	parse.sc.MustGetNumber();
-	opt->lightmode = uint8_t(parse.sc.Number);
-}
-
-DEFINE_MAP_OPTION(notexturefill, false)
-{
-	FGLROptions *opt = info->GetOptData<FGLROptions>("gl_renderer");
-	if (parse.CheckAssign())
-	{
-		parse.sc.MustGetNumber();
-		opt->notexturefill = !!parse.sc.Number;
-	}
-	else
-	{
-		opt->notexturefill = true;
-	}
-}
-
-DEFINE_MAP_OPTION(lightadditivesurfaces, false)
-{
-	FGLROptions *opt = info->GetOptData<FGLROptions>("gl_renderer");
-	if (parse.CheckAssign())
-	{
-		parse.sc.MustGetNumber();
-		opt->lightadditivesurfaces = !!parse.sc.Number;
-	}
-	else
-	{
-		opt->lightadditivesurfaces = true;
-	}
-}
-
-DEFINE_MAP_OPTION(skyrotate, false)
-{
-	FGLROptions *opt = info->GetOptData<FGLROptions>("gl_renderer");
-
-	parse.ParseAssign();
-	parse.sc.MustGetFloat();
-	opt->skyrotatevector.X = (float)parse.sc.Float;
-	if (parse.format_type == FMapInfoParser::FMT_New) parse.sc.MustGetStringName(","); 
-	parse.sc.MustGetFloat();
-	opt->skyrotatevector.Y = (float)parse.sc.Float;
-	if (parse.format_type == FMapInfoParser::FMT_New) parse.sc.MustGetStringName(","); 
-	parse.sc.MustGetFloat();
-	opt->skyrotatevector.Z = (float)parse.sc.Float;
-	opt->skyrotatevector.MakeUnit();
-}
-
-DEFINE_MAP_OPTION(skyrotate2, false)
-{
-	FGLROptions *opt = info->GetOptData<FGLROptions>("gl_renderer");
-
-	parse.ParseAssign();
-	parse.sc.MustGetFloat();
-	opt->skyrotatevector2.X = (float)parse.sc.Float;
-	if (parse.format_type == FMapInfoParser::FMT_New) parse.sc.MustGetStringName(","); 
-	parse.sc.MustGetFloat();
-	opt->skyrotatevector2.Y = (float)parse.sc.Float;
-	if (parse.format_type == FMapInfoParser::FMT_New) parse.sc.MustGetStringName(","); 
-	parse.sc.MustGetFloat();
-	opt->skyrotatevector2.Z = (float)parse.sc.Float;
-	opt->skyrotatevector2.MakeUnit();
-}
-
-bool IsLightmodeValid()
-{
-	return (glset.map_lightmode >= 0 && glset.map_lightmode <= 4) || glset.map_lightmode == 8;
-}
-
-static void ResetOpts()
-{
-	if (!IsLightmodeValid()) glset.lightmode = gl_lightmode;
-	else glset.lightmode = glset.map_lightmode;
-	if (glset.map_notexturefill == -1) glset.notexturefill = gl_notexturefill;
-	else glset.notexturefill = !!glset.map_notexturefill;
-	if (glset.map_brightfog == -1) glset.brightfog = gl_brightfog;
-	else glset.brightfog = !!glset.map_brightfog;
-	if (glset.map_lightadditivesurfaces == -1) glset.lightadditivesurfaces = gl_lightadditivesurfaces;
-	else glset.lightadditivesurfaces = !!glset.map_lightadditivesurfaces;
-}
-
-void InitGLRMapinfoData()
-{
-	FGLROptions *opt = level.info->GetOptData<FGLROptions>("gl_renderer", false);
-
-	if (opt != NULL)
-	{
-		glset.map_lightmode = opt->lightmode;
-		glset.map_lightadditivesurfaces = opt->lightadditivesurfaces;
-		glset.map_brightfog = opt->brightfog;
-		glset.map_notexturefill = opt->notexturefill;
-		glset.skyrotatevector = opt->skyrotatevector;
-		glset.skyrotatevector2 = opt->skyrotatevector2;
-	}
-	else
-	{
-		glset.map_lightmode = -1;
-		glset.map_lightadditivesurfaces = -1;
-		glset.map_brightfog = -1;
-		glset.map_notexturefill = -1;
-		glset.skyrotatevector = FVector3(0, 0, 1);
-		glset.skyrotatevector2 = FVector3(0, 0, 1);
-	}
-	ResetOpts();
-}
-CCMD(gl_resetmap)
-{
-	ResetOpts();
-}
-
-
-//==========================================================================
-//
-// Recalculate all heights affecting this vertex.
-//
-//==========================================================================
-void gl_RecalcVertexHeights(vertex_t * v)
-{
-	int i,j,k;
-	float height;
-
-	v->numheights=0;
-	for(i=0;i<v->numsectors;i++)
-	{
-		for(j=0;j<2;j++)
-		{
-			if (j==0) height=v->sectors[i]->ceilingplane.ZatPoint(v);
-			else height=v->sectors[i]->floorplane.ZatPoint(v);
-
-			for(k=0;k<v->numheights;k++)
-			{
-				if (height == v->heightlist[k]) break;
-				if (height < v->heightlist[k])
-				{
-					memmove(&v->heightlist[k+1], &v->heightlist[k], sizeof(float) * (v->numheights-k));
-					v->heightlist[k]=height;
-					v->numheights++;
-					break;
-				}
-			}
-			if (k==v->numheights) v->heightlist[v->numheights++]=height;
-		}
-	}
-	if (v->numheights<=2) v->numheights=0;	// is not in need of any special attention
-	v->dirty = false;
-}
-
-
-
-
-//==========================================================================
-//
-// dumpgeometry
-//
-//==========================================================================
-
-CCMD(dumpgeometry)
-{
-	for(auto &sector : level.sectors)
-	{
-		Printf(PRINT_LOG, "Sector %d\n", sector.sectornum);
-		for(int j=0;j<sector.subsectorcount;j++)
-		{
-			subsector_t * sub = sector.subsectors[j];
-
-			Printf(PRINT_LOG, "    Subsector %d - real sector = %d - %s\n", int(sub->Index()), sub->sector->sectornum, sub->hacked&1? "hacked":"");
-			for(uint32_t k=0;k<sub->numlines;k++)
-			{
-				seg_t * seg = sub->firstline + k;
-				if (seg->linedef)
-				{
-				Printf(PRINT_LOG, "      (%4.4f, %4.4f), (%4.4f, %4.4f) - seg %d, linedef %d, side %d", 
-					seg->v1->fX(), seg->v1->fY(), seg->v2->fX(), seg->v2->fY(),
-					seg->Index(), seg->linedef->Index(), seg->sidedef != seg->linedef->sidedef[0]);
-				}
-				else
-				{
-					Printf(PRINT_LOG, "      (%4.4f, %4.4f), (%4.4f, %4.4f) - seg %d, miniseg", 
-						seg->v1->fX(), seg->v1->fY(), seg->v2->fX(), seg->v2->fY(), seg->Index());
-				}
-				if (seg->PartnerSeg) 
-				{
-					subsector_t * sub2 = seg->PartnerSeg->Subsector;
-					Printf(PRINT_LOG, ", back sector = %d, real back sector = %d", sub2->render_sector->sectornum, seg->PartnerSeg->frontsector->sectornum);
-				}
-				else if (seg->backsector)
-			{
-					Printf(PRINT_LOG, ", back sector = %d (no partnerseg)", seg->backsector->sectornum);
-				}
-
-				Printf(PRINT_LOG, "\n");
-			}
-		}
-	}
-}
diff --git a/src/gl/data/gl_data.h b/src/gl/data/gl_data.h
index 96ee070cb2..75f248b072 100644
--- a/src/gl/data/gl_data.h
+++ b/src/gl/data/gl_data.h
@@ -6,24 +6,6 @@
 #include "vectors.h"
 #include "r_utility.h"
 
-struct GLRenderSettings
-{
-	int8_t lightmode;
-	bool notexturefill;
-	bool brightfog;
-	bool lightadditivesurfaces;
-
-	int8_t map_lightmode;
-	int8_t map_notexturefill;
-	int8_t map_brightfog;
-	int8_t map_lightadditivesurfaces;
-
-	FVector3 skyrotatevector;
-	FVector3 skyrotatevector2;
-};
-
-extern GLRenderSettings glset;
-
 #include "r_defs.h"
 #include "a_sharedglobal.h"
 #include "c_cvars.h"
@@ -35,7 +17,6 @@ inline	int getExtraLight()
 	return r_viewpoint.extralight * gl_weaponlight;
 }
 
-void gl_RecalcVertexHeights(vertex_t * v);
 
 struct GLSectorStackPortal;
 
diff --git a/src/gl/data/gl_setup.cpp b/src/gl/data/gl_setup.cpp
index 35c33199ae..6c12991267 100644
--- a/src/gl/data/gl_setup.cpp
+++ b/src/gl/data/gl_setup.cpp
@@ -50,8 +50,6 @@
 #include "gl/utility/gl_clock.h"
 #include "gl/gl_functions.h"
 
-void InitGLRMapinfoData();
-
 //==========================================================================
 //
 // 
@@ -580,8 +578,6 @@ void gl_PreprocessLevel()
 #if 0
 	gl_CreateSections();
 #endif
-
-	InitGLRMapinfoData();
 }
 
 
diff --git a/src/gl/renderer/gl_lightdata.cpp b/src/gl/renderer/gl_lightdata.cpp
index 542b6a5886..586221b33f 100644
--- a/src/gl/renderer/gl_lightdata.cpp
+++ b/src/gl/renderer/gl_lightdata.cpp
@@ -53,8 +53,6 @@ CUSTOM_CVAR(Bool, gl_enhanced_nightvision, true, CVAR_ARCHIVE|CVAR_NOINITCALL)
 		GLRenderer->mShaderManager->ResetFixedColormap();
 	}
 }
-CVAR(Bool, gl_brightfog, false, CVAR_ARCHIVE);
-CVAR(Bool, gl_lightadditivesurfaces, false, CVAR_ARCHIVE);
 
 
 
@@ -97,14 +95,6 @@ CUSTOM_CVAR(Int,gl_fogmode,1,CVAR_ARCHIVE|CVAR_NOINITCALL)
 	if (self<0) self=0;
 }
 
-CUSTOM_CVAR(Int, gl_lightmode, 3 ,CVAR_ARCHIVE|CVAR_NOINITCALL)
-{
-	int newself = self;
-	if (newself > 4) newself=8;	// use 8 for software lighting to avoid conflicts with the bit mask
-	if (newself < 0) newself=0;
-	if (self != newself) self = newself;
-	glset.lightmode = newself;
-}
 
 
 
@@ -172,7 +162,7 @@ int gl_CalcLightLevel(int lightlevel, int rellight, bool weapon)
 
 	if (lightlevel == 0) return 0;
 
-	if ((glset.lightmode & 2) && lightlevel < 192 && !weapon) 
+	if ((level.lightmode & 2) && lightlevel < 192 && !weapon) 
 	{
 		if (lightlevel > 100)
 		{
@@ -210,7 +200,7 @@ static PalEntry gl_CalcLightColor(int light, PalEntry pe, int blendfactor)
 {
 	int r,g,b;
 
-	if (glset.lightmode == 8)
+	if (level.lightmode == 8)
 	{
 		return pe;
 	}
@@ -276,7 +266,7 @@ float gl_GetFogDensity(int lightlevel, PalEntry fogcolor, int sectorfogdensity)
 {
 	float density;
 
-	if (glset.lightmode & 4)
+	if (level.lightmode & 4)
 	{
 		// uses approximations of Legacy's default settings.
 		density = level.fogdensity ? level.fogdensity : 18;
@@ -289,9 +279,9 @@ float gl_GetFogDensity(int lightlevel, PalEntry fogcolor, int sectorfogdensity)
 	else if ((fogcolor.d & 0xffffff) == 0)
 	{
 		// case 2: black fog
-		if (glset.lightmode != 8 && !(level.flags3 & LEVEL3_NOLIGHTFADE))
+		if (level.lightmode != 8 && !(level.flags3 & LEVEL3_NOLIGHTFADE))
 		{
-			density = distfogtable[glset.lightmode != 0][gl_ClampLight(lightlevel)];
+			density = distfogtable[level.lightmode != 0][gl_ClampLight(lightlevel)];
 		}
 		else
 		{
@@ -350,7 +340,7 @@ bool gl_CheckFog(sector_t *frontsector, sector_t *backsector)
 	else if (level.outsidefogdensity != 0 && APART(level.info->outsidefog) != 0xff && (fogcolor.d & 0xffffff) == (level.info->outsidefog & 0xffffff))
 	{
 	}
-	else  if (level.fogdensity!=0 || (glset.lightmode & 4))
+	else  if (level.fogdensity!=0 || (level.lightmode & 4))
 	{
 		// case 3: level has fog density set
 	}
@@ -369,7 +359,7 @@ bool gl_CheckFog(sector_t *frontsector, sector_t *backsector)
 	{
 		return false;
 	}
-	else  if (level.fogdensity!=0 || (glset.lightmode & 4))
+	else  if (level.fogdensity!=0 || (level.lightmode & 4))
 	{
 		// case 3: level has fog density set
 		return false;
@@ -459,7 +449,7 @@ void gl_SetFog(int lightlevel, int rellight, bool fullbright, const FColormap *c
 	}
 	else
 	{
-		if (glset.lightmode == 2 && fogcolor == 0)
+		if (level.lightmode == 2 && fogcolor == 0)
 		{
 			float light = gl_CalcLightLevel(lightlevel, rellight, false);
 			gl_SetShaderLight(light, lightlevel);
@@ -480,7 +470,7 @@ void gl_SetFog(int lightlevel, int rellight, bool fullbright, const FColormap *c
 		gl_RenderState.SetFog(fogcolor, fogdensity);
 
 		// Korshun: fullbright fog like in software renderer.
-		if (glset.lightmode == 8 && glset.brightfog && fogdensity != 0 && fogcolor != 0)
+		if (level.lightmode == 8 && level.brightfog && fogdensity != 0 && fogcolor != 0)
 		{
 			gl_RenderState.SetSoftLightLevel(255);
 		}
diff --git a/src/gl/renderer/gl_renderstate.h b/src/gl/renderer/gl_renderstate.h
index 74df2a0749..0a1012d919 100644
--- a/src/gl/renderer/gl_renderstate.h
+++ b/src/gl/renderer/gl_renderstate.h
@@ -31,6 +31,7 @@
 #include "c_cvars.h"
 #include "r_defs.h"
 #include "r_data/r_translate.h"
+#include "g_levellocals.h"
 
 class FVertexBuffer;
 class FShader;
@@ -356,9 +357,9 @@ public:
 		mGlowBottom.Set(b[0], b[1], b[2], b[3]);
 	}
 
-	void SetSoftLightLevel(int level)
+	void SetSoftLightLevel(int llevel)
 	{
-		if (glset.lightmode == 8) mLightParms[3] = level / 255.f;
+		if (level.lightmode == 8) mLightParms[3] = llevel / 255.f;
 		else mLightParms[3] = -1.f;
 	}
 
diff --git a/src/gl/scene/gl_flats.cpp b/src/gl/scene/gl_flats.cpp
index 04569e2855..163d7a00a8 100644
--- a/src/gl/scene/gl_flats.cpp
+++ b/src/gl/scene/gl_flats.cpp
@@ -110,7 +110,7 @@ void GLFlat::SetupSubsectorLights(int pass, subsector_t * sub, int *dli)
 {
 	Plane p;
 
-	if (renderstyle == STYLE_Add && !glset.lightadditivesurfaces) return;	// no lights on additively blended surfaces.
+	if (renderstyle == STYLE_Add && !level.lightadditivesurfaces) return;	// no lights on additively blended surfaces.
 
 	if (dli != NULL && *dli != -1)
 	{
diff --git a/src/gl/scene/gl_renderhacks.cpp b/src/gl/scene/gl_renderhacks.cpp
index 605d6bfd35..f121a26053 100644
--- a/src/gl/scene/gl_renderhacks.cpp
+++ b/src/gl/scene/gl_renderhacks.cpp
@@ -661,7 +661,7 @@ void FDrawInfo::DrawUnhandledMissingTextures()
 		if (seg->backsector->GetTexture(sector_t::ceiling) == skyflatnum) continue;
 		if (seg->backsector->ValidatePortal(sector_t::ceiling) != NULL) continue;
 
-		if (!glset.notexturefill) FloodUpperGap(seg);
+		if (!level.notexturefill) FloodUpperGap(seg);
 	}
 
 	validcount++;
@@ -680,7 +680,7 @@ void FDrawInfo::DrawUnhandledMissingTextures()
 		if (seg->backsector->GetTexture(sector_t::floor) == skyflatnum) continue;
 		if (seg->backsector->ValidatePortal(sector_t::floor) != NULL) continue;
 
-		if (!glset.notexturefill) FloodLowerGap(seg);
+		if (!level.notexturefill) FloodLowerGap(seg);
 	}
 	MissingUpperTextures.Clear();
 	MissingLowerTextures.Clear();
diff --git a/src/gl/scene/gl_skydome.cpp b/src/gl/scene/gl_skydome.cpp
index ded02561c6..a6eda805be 100644
--- a/src/gl/scene/gl_skydome.cpp
+++ b/src/gl/scene/gl_skydome.cpp
@@ -435,9 +435,9 @@ static void RenderBox(FTextureID texno, FMaterial * gltex, float x_offset, bool
 	gl_RenderState.mModelMatrix.loadIdentity();
 
 	if (!sky2)
-		gl_RenderState.mModelMatrix.rotate(-180.0f+x_offset, glset.skyrotatevector.X, glset.skyrotatevector.Z, glset.skyrotatevector.Y);
+		gl_RenderState.mModelMatrix.rotate(-180.0f+x_offset, level.info->skyrotatevector.X, level.info->skyrotatevector.Z, level.info->skyrotatevector.Y);
 	else
-		gl_RenderState.mModelMatrix.rotate(-180.0f+x_offset, glset.skyrotatevector2.X, glset.skyrotatevector2.Z, glset.skyrotatevector2.Y);
+		gl_RenderState.mModelMatrix.rotate(-180.0f+x_offset, level.info->skyrotatevector2.X, level.info->skyrotatevector2.Z, level.info->skyrotatevector2.Y);
 
 	if (sb->faces[5]) 
 	{
@@ -501,10 +501,10 @@ void GLSkyPortal::DrawContents()
 	bool drawBoth = false;
 
 	// We have no use for Doom lighting special handling here, so disable it for this function.
-	int oldlightmode = glset.lightmode;
-	if (glset.lightmode == 8)
+	int oldlightmode = ::level.lightmode;
+	if (::level.lightmode == 8)
 	{
-		glset.lightmode = 2;
+		::level.lightmode = 2;
 		gl_RenderState.SetSoftLightLevel(-1);
 	}
 
@@ -557,7 +557,7 @@ void GLSkyPortal::DrawContents()
 	gl_RenderState.SetVertexBuffer(GLRenderer->mVBO);
 	gl_MatrixStack.Pop(gl_RenderState.mViewMatrix);
 	gl_RenderState.ApplyMatrices();
-	glset.lightmode = oldlightmode;
+	::level.lightmode = oldlightmode;
 	gl_RenderState.SetDepthClamp(oldClamp);
 }
 
diff --git a/src/gl/scene/gl_walls.cpp b/src/gl/scene/gl_walls.cpp
index 92ff6c59fd..9b99d76cc5 100644
--- a/src/gl/scene/gl_walls.cpp
+++ b/src/gl/scene/gl_walls.cpp
@@ -1482,8 +1482,8 @@ void GLWall::Process(seg_t *seg, sector_t * frontsector, sector_t * backsector)
 		glseg.fracright = 1;
 		if (gl_seamless)
 		{
-			if (v1->dirty) gl_RecalcVertexHeights(v1);
-			if (v2->dirty) gl_RecalcVertexHeights(v2);
+			if (v1->dirty) v1->RecalcVertexHeights();
+			if (v2->dirty) v2->RecalcVertexHeights();
 		}
 	}
 	else	// polyobjects must be rendered per seg.
diff --git a/src/gl/scene/gl_walls_draw.cpp b/src/gl/scene/gl_walls_draw.cpp
index e22d352104..6bb0e7d2fb 100644
--- a/src/gl/scene/gl_walls_draw.cpp
+++ b/src/gl/scene/gl_walls_draw.cpp
@@ -59,7 +59,7 @@ FDynLightData lightdata;
 
 void GLWall::SetupLights()
 {
-	if (RenderStyle == STYLE_Add && !glset.lightadditivesurfaces) return;	// no lights on additively blended surfaces.
+	if (RenderStyle == STYLE_Add && !level.lightadditivesurfaces) return;	// no lights on additively blended surfaces.
 
 	// check for wall types which cannot have dynamic lights on them (portal types never get here so they don't need to be checked.)
 	switch (type)
diff --git a/src/gl/scene/gl_weapon.cpp b/src/gl/scene/gl_weapon.cpp
index 6daefd88cd..e8c555ea4f 100644
--- a/src/gl/scene/gl_weapon.cpp
+++ b/src/gl/scene/gl_weapon.cpp
@@ -315,7 +315,7 @@ void GLSceneDrawer::DrawPlayerSprites(sector_t * viewsector, bool hudModelStep)
 
 		lightlevel = gl_CalcLightLevel(lightlevel, getExtraLight(), true);
 
-		if (glset.lightmode == 8 || lightlevel < 92)
+		if (level.lightmode == 8 || lightlevel < 92)
 		{
 			// Korshun: the way based on max possible light level for sector like in software renderer.
 			float min_L = 36.0 / 31.0 - ((lightlevel / 255.0) * (63.0 / 31.0)); // Lightlevel in range 0-63
@@ -335,7 +335,7 @@ void GLSceneDrawer::DrawPlayerSprites(sector_t * viewsector, bool hudModelStep)
 	}
 	
 	// Korshun: fullbright fog in opengl, render weapon sprites fullbright (but don't cancel out the light color!)
-	if (glset.brightfog && ((level.flags&LEVEL_HASFADETABLE) || cm.FadeColor != 0))
+	if (level.brightfog && ((level.flags&LEVEL_HASFADETABLE) || cm.FadeColor != 0))
 	{
 		lightlevel = 255;
 	}
@@ -344,8 +344,8 @@ void GLSceneDrawer::DrawPlayerSprites(sector_t * viewsector, bool hudModelStep)
 
 	// hack alert! Rather than changing everything in the underlying lighting code let's just temporarily change
 	// light mode here to draw the weapon sprite.
-	int oldlightmode = glset.lightmode;
-	if (glset.lightmode == 8) glset.lightmode = 2;
+	int oldlightmode = level.lightmode;
+	if (level.lightmode == 8) level.lightmode = 2;
 
 	for(DPSprite *psp = player->psprites; psp != nullptr && psp->GetID() < PSP_TARGETCENTER; psp = psp->GetNext())
 	{
@@ -491,7 +491,7 @@ void GLSceneDrawer::DrawPlayerSprites(sector_t * viewsector, bool hudModelStep)
 	gl_RenderState.SetObjectColor(0xffffffff);
 	gl_RenderState.SetDynLight(0, 0, 0);
 	gl_RenderState.EnableBrightmap(false);
-	glset.lightmode = oldlightmode;
+	level.lightmode = oldlightmode;
 }
 
 //==========================================================================
diff --git a/src/p_sectors.cpp b/src/p_sectors.cpp
index f26c7e229a..9b01a0f1a6 100644
--- a/src/p_sectors.cpp
+++ b/src/p_sectors.cpp
@@ -2395,6 +2395,46 @@ int side_t::GetLightLevel (bool foggy, int baselight, bool is3dlight, int *pfake
 	return baselight;
 }
 
+//==========================================================================
+//
+// Recalculate all heights affecting this vertex.
+//
+//==========================================================================
+
+void vertex_t::RecalcVertexHeights()
+{
+	int i, j, k;
+	float height;
+
+	numheights = 0;
+	for (i = 0; i < numsectors; i++)
+	{
+		for (j = 0; j<2; j++)
+		{
+			if (j == 0) height = (float)sectors[i]->ceilingplane.ZatPoint(this);
+			else height = (float)sectors[i]->floorplane.ZatPoint(this);
+
+			for (k = 0; k < numheights; k++)
+			{
+				if (height == heightlist[k]) break;
+				if (height < heightlist[k])
+				{
+					memmove(&heightlist[k + 1], &heightlist[k], sizeof(float) * (numheights - k));
+					heightlist[k] = height;
+					numheights++;
+					break;
+				}
+			}
+			if (k == numheights) heightlist[numheights++] = height;
+		}
+	}
+	if (numheights <= 2) numheights = 0;	// is not in need of any special attention
+	dirty = false;
+}
+
+
+
+
 DEFINE_ACTION_FUNCTION(_Secplane, isSlope)
 {
 	PARAM_SELF_STRUCT_PROLOGUE(secplane_t);
diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index 030ae1cbbc..0320aca07f 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -110,6 +110,7 @@
 #include "p_spec.h"
 #include "p_saveg.h"
 #include "g_levellocals.h"
+#include "c_dispatch.h"
 #ifndef NO_EDATA
 #include "edata.h"
 #endif
@@ -4294,3 +4295,48 @@ CCMD (lineloc)
 }
 #endif
 
+//==========================================================================
+//
+// dumpgeometry
+//
+//==========================================================================
+
+CCMD(dumpgeometry)
+{
+	for (auto &sector : level.sectors)
+	{
+		Printf(PRINT_LOG, "Sector %d\n", sector.sectornum);
+		for (int j = 0; j<sector.subsectorcount; j++)
+		{
+			subsector_t * sub = sector.subsectors[j];
+
+			Printf(PRINT_LOG, "    Subsector %d - real sector = %d - %s\n", int(sub->Index()), sub->sector->sectornum, sub->hacked & 1 ? "hacked" : "");
+			for (uint32_t k = 0; k<sub->numlines; k++)
+			{
+				seg_t * seg = sub->firstline + k;
+				if (seg->linedef)
+				{
+					Printf(PRINT_LOG, "      (%4.4f, %4.4f), (%4.4f, %4.4f) - seg %d, linedef %d, side %d",
+						seg->v1->fX(), seg->v1->fY(), seg->v2->fX(), seg->v2->fY(),
+						seg->Index(), seg->linedef->Index(), seg->sidedef != seg->linedef->sidedef[0]);
+				}
+				else
+				{
+					Printf(PRINT_LOG, "      (%4.4f, %4.4f), (%4.4f, %4.4f) - seg %d, miniseg",
+						seg->v1->fX(), seg->v1->fY(), seg->v2->fX(), seg->v2->fY(), seg->Index());
+				}
+				if (seg->PartnerSeg)
+				{
+					subsector_t * sub2 = seg->PartnerSeg->Subsector;
+					Printf(PRINT_LOG, ", back sector = %d, real back sector = %d", sub2->render_sector->sectornum, seg->PartnerSeg->frontsector->sectornum);
+				}
+				else if (seg->backsector)
+				{
+					Printf(PRINT_LOG, ", back sector = %d (no partnerseg)", seg->backsector->sectornum);
+				}
+
+				Printf(PRINT_LOG, "\n");
+			}
+		}
+	}
+}
\ No newline at end of file
diff --git a/src/polyrenderer/poly_renderer.cpp b/src/polyrenderer/poly_renderer.cpp
index 0a32e7d90f..6c6c8e460c 100644
--- a/src/polyrenderer/poly_renderer.cpp
+++ b/src/polyrenderer/poly_renderer.cpp
@@ -41,7 +41,6 @@
 
 EXTERN_CVAR(Int, screenblocks)
 EXTERN_CVAR(Float, r_visibility)
-void InitGLRMapinfoData();
 
 /////////////////////////////////////////////////////////////////////////////
 
@@ -183,7 +182,6 @@ void PolyRenderer::SetupPerspectiveMatrix()
 
 	if (!bDidSetup)
 	{
-		InitGLRMapinfoData();
 		bDidSetup = true;
 	}
 
diff --git a/src/r_defs.h b/src/r_defs.h
index 6a3dfac762..76a0e1e44b 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -138,6 +138,7 @@ struct vertex_t
 	}
 
 	int Index() const;
+	void RecalcVertexHeights();
 
 
 	angle_t viewangle;	// precalculated angle for clipping
diff --git a/src/textures/texture.cpp b/src/textures/texture.cpp
index 6f91b33b0b..aeb631e494 100644
--- a/src/textures/texture.cpp
+++ b/src/textures/texture.cpp
@@ -1381,7 +1381,7 @@ unsigned char * FTexture::CreateTexBuffer(int translation, int & w, int & h, int
 		{
 			inf.blend = (EBlend)(BLEND_DESATURATE1 + translation - STRange_Desaturate);
 		}
-		else if (translation >= STRange_Specialcolormap && translation < STRange_Specialcolormap + SpecialColormaps.Size())
+		else if (translation >= STRange_Specialcolormap && translation < STRange_Specialcolormap + (int)SpecialColormaps.Size())
 		{
 			inf.blend = (EBlend)(BLEND_SPECIALCOLORMAP1 + translation - STRange_Specialcolormap);
 		}