diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 8e06ff79c..da8e68db0 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -899,7 +899,6 @@ set (PCH_SOURCES
 	d_net.cpp
 	d_netinfo.cpp
 	d_protocol.cpp
-	decallib.cpp
 	dobject.cpp
 	dobjgc.cpp
 	dobjtype.cpp
@@ -911,10 +910,7 @@ set (PCH_SOURCES
 	g_game.cpp
 	g_hub.cpp
 	g_level.cpp
-	g_mapinfo.cpp
-	g_skill.cpp
 	gameconfigfile.cpp
-	gi.cpp
 	gitinfo.cpp
 	hu_scores.cpp
 	i_net.cpp
@@ -959,9 +955,7 @@ set (PCH_SOURCES
 	st_stuff.cpp
 	statistics.cpp
 	stats.cpp
-	stringtable.cpp
 	teaminfo.cpp
-	umapinfo.cpp
 	v_2ddrawer.cpp
 	v_blend.cpp
 	v_draw.cpp
@@ -971,13 +965,20 @@ set (PCH_SOURCES
 	v_pfx.cpp
 	v_text.cpp
 	v_video.cpp
-	w_wad.cpp
 	wi_stuff.cpp
 	gamedata/a_keys.cpp
 	gamedata/a_weapons.cpp
+	gamedata/decallib.cpp
+	gamedata/g_mapinfo.cpp
+	gamedata/g_skill.cpp
+	gamedata/gi.cpp
+	gamedata/stringtable.cpp
+	gamedata/umapinfo.cpp
+	gamedata/w_wad.cpp
 	g_shared/a_pickups.cpp
 	g_shared/a_action.cpp
 	g_shared/a_decals.cpp
+	g_shared/a_decalfx.cpp
 	g_shared/a_doors.cpp
 	g_shared/a_dynlight.cpp
 	g_shared/a_flashfader.cpp
diff --git a/src/g_level.h b/src/g_level.h
index 8b83ed043..5a8ca237c 100644
--- a/src/g_level.h
+++ b/src/g_level.h
@@ -1,450 +1,14 @@
-/*
-** g_level.h
-**
-**---------------------------------------------------------------------------
-** Copyright 1998-2006 Randy Heit
-** All rights reserved.
-**
-** Redistribution and use in source and binary forms, with or without
-** modification, are permitted provided that the following conditions
-** are met:
-**
-** 1. Redistributions of source code must retain the above copyright
-**    notice, this list of conditions and the following disclaimer.
-** 2. Redistributions in binary form must reproduce the above copyright
-**    notice, this list of conditions and the following disclaimer in the
-**    documentation and/or other materials provided with the distribution.
-** 3. The name of the author may not be used to endorse or promote products
-**    derived from this software without specific prior written permission.
-**
-** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
-** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
-** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
-** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
-** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
-** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-**---------------------------------------------------------------------------
-**
-*/
-
-#ifndef __G_LEVEL_H__
-#define __G_LEVEL_H__
+#pragma once
 
 #include "doomtype.h"
 #include "vectors.h"
 #include "sc_man.h"
 #include "resourcefiles/file_zip.h"
+#include "g_mapinfo.h"
 
-struct level_info_t;
-struct cluster_info_t;
-class FSerializer;
-
-#if defined(_MSC_VER)
-#pragma section(".yreg$u",read)
-#define MSVC_YSEG __declspec(allocate(".yreg$u"))
-#define GCC_YSEG
-#else
-#define MSVC_YSEG
-#define GCC_YSEG __attribute__((section(SECTION_YREG))) __attribute__((used))
-#endif
-
-// The structure used to control scripts between maps
-struct acsdefered_t
-{
-	enum EType
-	{
-		defexecute,
-		defexealways,
-		defsuspend,
-		defterminate
-	} type;
-	int script;
-	int args[3];
-	int playernum;
-};
-
-FSerializer &Serialize(FSerializer &arc, const char *key, acsdefered_t &defer, acsdefered_t *def);
-
-
-struct FIntermissionDescriptor;
-struct FIntermissionAction;
-
-struct FMapInfoParser
-{
-	enum EFormatType
-	{
-		FMT_Unknown,
-		FMT_Old,
-		FMT_New
-	};
-
-	FScanner sc;
-	int format_type;
-	bool HexenHack;
-
-	FMapInfoParser(int format = FMT_Unknown)
-	{
-		format_type = format;
-		HexenHack = false;
-	}
-
-	bool ParseLookupName(FString &dest);
-	void ParseMusic(FString &name, int &order);
-	//void ParseLumpOrTextureName(char *name);
-	void ParseLumpOrTextureName(FString &name);
-	void ParseExitText(FName formap, level_info_t *info);
-	void ParseExitMusic(FName formap, level_info_t *info);
-	void ParseExitBackdrop(FName formap, level_info_t *info, bool ispic);
-
-	void ParseCluster();
-	void ParseNextMap(FString &mapname);
-	level_info_t *ParseMapHeader(level_info_t &defaultinfo);
-	void ParseMapDefinition(level_info_t &leveldef);
-	void ParseGameInfo();
-	void ParseEpisodeInfo ();
-	void ParseSkill ();
-	void ParseMapInfo (int lump, level_info_t &gamedefaults, level_info_t &defaultinfo);
-
-	void ParseOpenBrace();
-	bool ParseCloseBrace();
-	bool CheckAssign();
-	void ParseAssign();
-	void MustParseAssign();
-	void ParseComma();
-	bool CheckNumber();
-	bool CheckFloat();
-	void SkipToNext();
-	void CheckEndOfFile(const char *block);
-
-	void ParseIntermissionAction(FIntermissionDescriptor *Desc);
-	void ParseIntermission();
-	void ParseDoomEdNums();
-	void ParseSpawnNums();
-	void ParseConversationIDs();
-	void ParseAMColors(bool);
-	FName CheckEndSequence();
-	FName ParseEndGame();
-	void ParseDamageDefinition();
-};
-
-#define DEFINE_MAP_OPTION(name, old) \
-	static void MapOptHandler_##name(FMapInfoParser &parse, level_info_t *info); \
-	static FMapOptInfo MapOpt_##name = \
-		{ #name, MapOptHandler_##name, old }; \
-	MSVC_YSEG FMapOptInfo *mapopt_##name GCC_YSEG = &MapOpt_##name; \
-	static void MapOptHandler_##name(FMapInfoParser &parse, level_info_t *info)
-
-
-struct FMapOptInfo
-{
-	const char *name;
-	void (*handler) (FMapInfoParser &parse, level_info_t *levelinfo);
-	bool old;
-};
-
-enum ELevelFlags : unsigned int
-{
-	LEVEL_NOINTERMISSION		= 0x00000001,
-	LEVEL_NOINVENTORYBAR		= 0x00000002,	// This effects Doom only, since it's the only one without a standard inventory bar.
-	LEVEL_DOUBLESKY				= 0x00000004,
-	LEVEL_HASFADETABLE			= 0x00000008,	// Level uses Hexen's fadetable mapinfo to get fog
-
-	LEVEL_MAP07SPECIAL			= 0x00000010,
-	LEVEL_BRUISERSPECIAL		= 0x00000020,
-	LEVEL_CYBORGSPECIAL			= 0x00000040,
-	LEVEL_SPIDERSPECIAL			= 0x00000080,
-
-	LEVEL_SPECLOWERFLOOR		= 0x00000100,
-	LEVEL_SPECOPENDOOR			= 0x00000200,
-	LEVEL_SPECLOWERFLOORTOHIGHEST=0x00000300,
-	LEVEL_SPECACTIONSMASK		= 0x00000300,
-
-	LEVEL_MONSTERSTELEFRAG		= 0x00000400,
-	LEVEL_ACTOWNSPECIAL			= 0x00000800,
-	LEVEL_SNDSEQTOTALCTRL		= 0x00001000,
-	LEVEL_FORCETILEDSKY		= 0x00002000,
-
-	LEVEL_CROUCH_NO				= 0x00004000,
-	LEVEL_JUMP_NO				= 0x00008000,
-	LEVEL_FREELOOK_NO			= 0x00010000,
-	LEVEL_FREELOOK_YES			= 0x00020000,
-
-	// The absence of both of the following bits means that this level does not
-	// use falling damage (though damage can be forced with dmflags,.
-	LEVEL_FALLDMG_ZD			= 0x00040000,	// Level uses ZDoom's falling damage
-	LEVEL_FALLDMG_HX			= 0x00080000,	// Level uses Hexen's falling damage
-
-	LEVEL_HEADSPECIAL			= 0x00100000,	// Heretic episode 1/4
-	LEVEL_MINOTAURSPECIAL		= 0x00200000,	// Heretic episode 2/5
-	LEVEL_SORCERER2SPECIAL		= 0x00400000,	// Heretic episode 3
-	LEVEL_SPECKILLMONSTERS		= 0x00800000,
-
-	LEVEL_STARTLIGHTNING		= 0x01000000,	// Automatically start lightning
-	LEVEL_FILTERSTARTS			= 0x02000000,	// Apply mapthing filtering to player starts
-	LEVEL_LOOKUPLEVELNAME		= 0x04000000,	// Level name is the name of a language string
-	LEVEL_USEPLAYERSTARTZ		= 0x08000000,	// Use the Z position of player starts
-
-	LEVEL_SWAPSKIES				= 0x10000000,	// Used by lightning
-	LEVEL_NOALLIES				= 0x20000000,	// i.e. Inside Strife's front base
-	LEVEL_CHANGEMAPCHEAT		= 0x40000000,	// Don't display cluster messages
-	LEVEL_VISITED				= 0x80000000,	// Used for intermission map
-
-	// The flags uint64_t is now split into 2 DWORDs 
-	LEVEL2_RANDOMPLAYERSTARTS	= 0x00000001,	// Select single player starts randomnly (no voodoo dolls)
-	LEVEL2_ALLMAP				= 0x00000002,	// The player picked up a map on this level
-
-	LEVEL2_LAXMONSTERACTIVATION	= 0x00000004,	// Monsters can open doors depending on the door speed
-	LEVEL2_LAXACTIVATIONMAPINFO	= 0x00000008,	// LEVEL_LAXMONSTERACTIVATION is not a default.
-
-	LEVEL2_MISSILESACTIVATEIMPACT=0x00000010,	// Missiles are the activators of SPAC_IMPACT events, not their shooters
-	LEVEL2_FROZEN				= 0x00000020,	// Game is frozen by a TimeFreezer
-
-	LEVEL2_KEEPFULLINVENTORY	= 0x00000040,	// doesn't reduce the amount of inventory items to 1
-
-	LEVEL2_PRERAISEWEAPON		= 0x00000080,	// players should spawn with their weapons fully raised (but not when respawning it multiplayer)
-	LEVEL2_MONSTERFALLINGDAMAGE	= 0x00000100,
-	LEVEL2_CLIPMIDTEX			= 0x00000200,
-	LEVEL2_WRAPMIDTEX			= 0x00000400,
-
-	LEVEL2_CHECKSWITCHRANGE		= 0x00000800,	
-
-	LEVEL2_PAUSE_MUSIC_IN_MENUS	= 0x00001000,
-	LEVEL2_TOTALINFIGHTING		= 0x00002000,
-	LEVEL2_NOINFIGHTING			= 0x00004000,
-
-	LEVEL2_NOMONSTERS			= 0x00008000,
-	LEVEL2_INFINITE_FLIGHT		= 0x00010000,
-
-	LEVEL2_ALLOWRESPAWN			= 0x00020000,
-
-	LEVEL2_FORCETEAMPLAYON		= 0x00040000,
-	LEVEL2_FORCETEAMPLAYOFF		= 0x00080000,
-
-	LEVEL2_CONV_SINGLE_UNFREEZE	= 0x00100000,
-	LEVEL2_RAILINGHACK			= 0x00200000,	// but UDMF requires them to be separate to have more control
-	LEVEL2_DUMMYSWITCHES		= 0x00400000,
-	LEVEL2_HEXENHACK			= 0x00800000,	// Level was defined in a Hexen style MAPINFO
-
-	LEVEL2_SMOOTHLIGHTING		= 0x01000000,	// Level uses the smooth lighting feature.
-	LEVEL2_POLYGRIND			= 0x02000000,	// Polyobjects grind corpses to gibs.
-	LEVEL2_RESETINVENTORY		= 0x04000000,	// Resets player inventory when starting this level (unless in a hub)
-	LEVEL2_RESETHEALTH			= 0x08000000,	// Resets player health when starting this level (unless in a hub)
-
-	LEVEL2_NOSTATISTICS			= 0x10000000,	// This level should not have statistics collected
-	LEVEL2_ENDGAME				= 0x20000000,	// This is an epilogue level that cannot be quit.
-	LEVEL2_NOAUTOSAVEHINT		= 0x40000000,	// tell the game that an autosave for this level does not need to be kept
-	LEVEL2_FORGETSTATE			= 0x80000000,	// forget this map's state in a hub
-	
-	// More flags!
-	LEVEL3_FORCEFAKECONTRAST	= 0x00000001,	// forces fake contrast even with fog enabled
-	LEVEL3_REMOVEITEMS			= 0x00000002,	// kills all INVBAR items on map change.
-	LEVEL3_ATTENUATE			= 0x00000004,	// attenuate lights?
-	LEVEL3_NOLIGHTFADE			= 0x00000008,	// no light fading to black.
-	LEVEL3_NOCOLOREDSPRITELIGHTING = 0x00000010,	// draw sprites only with color-less light
-	LEVEL3_EXITNORMALUSED		= 0x00000020,
-	LEVEL3_EXITSECRETUSED		= 0x00000040,
-	LEVEL3_FORCEWORLDPANNING	= 0x00000080,	// Forces the world panning flag for all textures, even those without it explicitly set.
-};
-
-
-struct FSpecialAction
-{
-	FName Type;					// this is initialized before the actors...
-	int Action;
-	int Args[5];
-};
-
-class DScroller;
-
-class FScanner;
-struct level_info_t;
-
-typedef TMap<int, FName> FMusicMap;
-
-enum EMapType : int
-{
-	MAPTYPE_UNKNOWN = 0,
-	MAPTYPE_DOOM,
-	MAPTYPE_HEXEN,
-	MAPTYPE_BUILD,
-	MAPTYPE_UDMF	// This does not distinguish between namespaces.
-};
-
-struct FExitText
-{
-	enum EDefined
-	{
-		DEF_TEXT = 1,
-		DEF_MUSIC = 2,
-		DEF_BACKDROP = 4,
-		DEF_LOOKUP = 8,
-		DEF_PIC = 16
-	};
-	int16_t mDefined = 0;
-	int16_t mOrder = -1;
-	FString mText;
-	FString mMusic;
-	FString mBackdrop;
-
-	FExitText(int def = 0, int order = -1, const FString &text = "", const FString &backdrop = "", const FString &music = "")
-		: mDefined(int16_t(def)), mOrder(int16_t(order)), mText(text), mMusic(music), mBackdrop(backdrop)
-	{
-	}
-};
-
-
-struct level_info_t
-{
-	int			levelnum;
-	
-	FString		MapName;
-	FString		NextMap;
-	FString		NextSecretMap;
-	FString		PName;
-	FString		SkyPic1;
-	FString		SkyPic2;
-	FString		FadeTable;
-	FString		F1Pic;
-	FString		BorderTexture;
-	FString		MapBackground;
-
-	TMap<FName, FExitText> ExitMapTexts;
-
-	int			cluster;
-	int			partime;
-	int			sucktime;
-	int32_t		flags;
-	uint32_t	flags2;
-	uint32_t	flags3;
-
-	FString		Music;
-	FString		LevelName;
-	int8_t		WallVertLight, WallHorizLight;
-	int			musicorder;
-	FCompressedBuffer	Snapshot;
-	TArray<acsdefered_t> deferred;
-	float		skyspeed1;
-	float		skyspeed2;
-	uint32_t	fadeto;
-	uint32_t	outsidefog;
-	int			cdtrack;
-	unsigned int cdid;
-	double		gravity;
-	double		aircontrol;
-	int			WarpTrans;
-	int			airsupply;
-	uint32_t	compatflags, compatflags2;
-	uint32_t	compatmask, compatmask2;
-	FString		Translator;	// for converting Doom-format linedef and sector types.
-	int			DefaultEnvironment;	// Default sound environment for the map.
-	FName		Intermission;
-	FName		deathsequence;
-	FName		slideshow;
-	uint32_t	hazardcolor;
-	uint32_t	hazardflash;
-	int			fogdensity;
-	int			outsidefogdensity;
-	int			skyfog;
-	float		pixelstretch;
-
-	// Redirection: If any player is carrying the specified item, then
-	// you go to the RedirectMap instead of this one.
-	FName		RedirectType;
-	FString		RedirectMapName;
-
-	FString		EnterPic;
-	FString		ExitPic;
-	FString 	InterMusic;
-	int			intermusicorder;
-	TMap <FName, std::pair<FString, int> > MapInterMusic;
-
-	FString		SoundInfo;
-	FString		SndSeq;
-
-	double		teamdamage;
-
-	FMusicMap	MusicMap;
-
-	TArray<FSpecialAction> specialactions;
-
-	TArray<int> PrecacheSounds;
-	TArray<FString> PrecacheTextures;
-	TArray<FName> PrecacheClasses;
-	
-	TArray<FString> EventHandlers;
-
-	ELightMode	lightmode;
-	int8_t		brightfog;
-	int8_t		lightadditivesurfaces;
-	int8_t		notexturefill;
-	FVector3	skyrotatevector;
-	FVector3	skyrotatevector2;
-
-	FString		EDName;
-	FString		acsName;
-	bool		fs_nocheckposition;
-
-
-	level_info_t() 
-	{ 
-		Reset(); 
-	}
-	~level_info_t()
-	{
-		Snapshot.Clean();
-		ClearDefered();
-	}
-	void Reset();
-	bool isValid();
-	FString LookupLevelName ();
-	void ClearDefered()
-	{
-		deferred.Clear();
-	}
-	level_info_t *CheckLevelRedirect ();
-};
-
-
-struct cluster_info_t
-{
-	int			cluster;
-	FString		FinaleFlat;
-	FString		ExitText;
-	FString		EnterText;
-	FString		MessageMusic;
-	int			musicorder;
-	int			flags;
-	int			cdtrack;
-	FString		ClusterName;
-	unsigned int cdid;
-
-	void Reset();
-
-};
-
-// Cluster flags
-#define CLUSTER_HUB				0x00000001	// Cluster uses hub behavior
-#define CLUSTER_EXITTEXTINLUMP	0x00000002	// Exit text is the name of a lump
-#define CLUSTER_ENTERTEXTINLUMP	0x00000004	// Enter text is the name of a lump
-#define CLUSTER_FINALEPIC		0x00000008	// Finale "flat" is actually a full-sized image
-#define CLUSTER_LOOKUPEXITTEXT	0x00000010	// Exit text is the name of a language string
-#define CLUSTER_LOOKUPENTERTEXT	0x00000020	// Enter text is the name of a language string
-#define CLUSTER_LOOKUPNAME		0x00000040	// Name is the name of a language string
-#define CLUSTER_LOOKUPCLUSTERNAME 0x00000080	// Cluster name is the name of a language string
-#define CLUSTER_ALLOWINTERMISSION 0x00000100  // Allow intermissions between levels in a hub.
-
-extern TArray<level_info_t> wadlevelinfos;
-extern TArray<cluster_info_t> wadclusterinfos;
 
 extern bool savegamerestore;
 
-// mapname will be changed if it is a valid warptrans
-bool CheckWarpTransMap (FString &mapname, bool substitute);
-
 void G_InitNew (const char *mapname, bool bTitleLevel);
 
 // Can be called by the startup code or M_Responder.
@@ -467,15 +31,6 @@ enum
 
 void G_DoLoadLevel (const FString &MapName, int position, bool autosave, bool newGame);
 
-cluster_info_t *FindClusterInfo (int cluster);
-level_info_t *FindLevelInfo (const char *mapname, bool allowdefault=true);
-level_info_t *FindLevelByNum (int num);
-level_info_t *CheckLevelRedirect (level_info_t *info);
-
-FString CalcMapName (int episode, int level);
-
-void G_ParseMapInfo (FString basemapinfo);
-
 void G_ClearSnapshots (void);
 void P_RemoveDefereds ();
 void G_ReadSnapshots (FResourceFile *);
@@ -484,110 +39,3 @@ void G_WriteVisited(FSerializer &arc);
 void G_ReadVisited(FSerializer &arc);
 void G_ClearHubInfo();
 
-enum ESkillProperty
-{
-	SKILLP_FastMonsters,
-	SKILLP_Respawn,
-	SKILLP_RespawnLimit,
-	SKILLP_DisableCheats,
-	SKILLP_AutoUseHealth,
-	SKILLP_SpawnFilter,
-	SKILLP_EasyBossBrain,
-	SKILLP_ACSReturn,
-	SKILLP_NoPain,
-	SKILLP_EasyKey,
-	SKILLP_SlowMonsters,
-	SKILLP_Infight,
-	SKILLP_PlayerRespawn,
-};
-enum EFSkillProperty	// floating point properties
-{
-	SKILLP_AmmoFactor,
-	SKILLP_DropAmmoFactor,
-	SKILLP_ArmorFactor,
-	SKILLP_HealthFactor,
-	SKILLP_DamageFactor,
-	SKILLP_Aggressiveness,
-	SKILLP_MonsterHealth,
-	SKILLP_FriendlyHealth,
-	SKILLP_KickbackFactor,
-};
-
-int G_SkillProperty(ESkillProperty prop);
-double G_SkillProperty(EFSkillProperty prop);
-const char * G_SkillName();
-
-typedef TMap<FName, FString> SkillMenuNames;
-
-typedef TMap<FName, FName> SkillActorReplacement;
-
-struct FSkillInfo
-{
-	FName Name = NAME_None;
-	double AmmoFactor, DoubleAmmoFactor, DropAmmoFactor;
-	double DamageFactor;
-	double ArmorFactor;
-	double HealthFactor;
-	double KickbackFactor;
-
-	bool FastMonsters;
-	bool SlowMonsters;
-	bool DisableCheats;
-	bool AutoUseHealth;
-
-	bool EasyBossBrain;
-	bool EasyKey;
-	bool NoMenu;
-	int RespawnCounter;
-	int RespawnLimit;
-	double Aggressiveness;
-	int SpawnFilter;
-	int ACSReturn;
-	FString MenuName;
-	FString PicName;
-	SkillMenuNames MenuNamesForPlayerClass;
-	bool MustConfirm;
-	FString MustConfirmText;
-	char Shortcut;
-	FString TextColor;
-	SkillActorReplacement Replace;
-	SkillActorReplacement Replaced;
-	double MonsterHealth;
-	double FriendlyHealth;
-	bool NoPain;
-	int Infighting;
-	bool PlayerRespawn;
-
-	FSkillInfo() {}
-	FSkillInfo(const FSkillInfo &other)
-	{
-		operator=(other);
-	}
-	FSkillInfo &operator=(const FSkillInfo &other);
-	int GetTextColor() const;
-
-	void SetReplacement(FName a, FName b);
-	FName GetReplacement(FName a);
-	void SetReplacedBy(FName b, FName a);
-	FName GetReplacedBy(FName b);
-};
-
-extern TArray<FSkillInfo> AllSkills;
-extern int DefaultSkill;
-
-struct FEpisode
-{
-	FString mEpisodeName;
-	FString mEpisodeMap;
-	FString mPicName;
-	char mShortcut;
-	bool mNoSkill;
-};
-
-extern TArray<FEpisode> AllEpisodes;
-
-int ParseUMapInfo(int lumpnum);
-void CommitUMapinfo(level_info_t *defaultinfo);
-
-
-#endif //__G_LEVEL_H__
diff --git a/src/g_shared/a_decalfx.cpp b/src/g_shared/a_decalfx.cpp
new file mode 100644
index 000000000..16ebca74b
--- /dev/null
+++ b/src/g_shared/a_decalfx.cpp
@@ -0,0 +1,246 @@
+/*
+** a_decalfx.h
+** Decal animation thinkers
+**
+**---------------------------------------------------------------------------
+** Copyright 1998-2006 Randy Heit
+** All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions
+** are met:
+**
+** 1. Redistributions of source code must retain the above copyright
+**    notice, this list of conditions and the following disclaimer.
+** 2. Redistributions in binary form must reproduce the above copyright
+**    notice, this list of conditions and the following disclaimer in the
+**    documentation and/or other materials provided with the distribution.
+** 3. The name of the author may not be used to endorse or promote products
+**    derived from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**---------------------------------------------------------------------------
+**
+*/
+
+#include "decallib.h"
+#include "a_decalfx.h"
+#include "serializer.h"
+#include "a_sharedglobal.h"
+#include "g_levellocals.h"
+#include "m_fixed.h"
+
+
+IMPLEMENT_CLASS(DDecalThinker, false, true)
+
+IMPLEMENT_POINTERS_START(DDecalThinker)
+	IMPLEMENT_POINTER(TheDecal)
+IMPLEMENT_POINTERS_END
+
+void DDecalThinker::Serialize(FSerializer &arc)
+{
+	Super::Serialize (arc);
+	arc("thedecal", TheDecal);
+}
+
+IMPLEMENT_CLASS(DDecalFader, false, false)
+
+void DDecalFader::Serialize(FSerializer &arc)
+{
+	Super::Serialize (arc);
+	arc("starttime", TimeToStartDecay)
+		("endtime", TimeToEndDecay)
+		("starttrans", StartTrans);
+}
+
+void DDecalFader::Tick ()
+{
+	if (TheDecal == nullptr)
+	{
+		Destroy ();
+	}
+	else
+	{
+		if (Level->maptime < TimeToStartDecay || Level->isFrozen())
+		{
+			return;
+		}
+		else if (Level->maptime >= TimeToEndDecay)
+		{
+			TheDecal->Destroy ();		// remove the decal
+			Destroy ();					// remove myself
+			return;
+		}
+		if (StartTrans == -1)
+		{
+			StartTrans = TheDecal->Alpha;
+		}
+
+		int distanceToEnd = TimeToEndDecay - Level->maptime;
+		int fadeDistance = TimeToEndDecay - TimeToStartDecay;
+		TheDecal->Alpha = StartTrans * distanceToEnd / fadeDistance;
+	}
+}
+
+IMPLEMENT_CLASS(DDecalStretcher, false, false)
+
+void DDecalStretcher::Serialize(FSerializer &arc)
+{
+	Super::Serialize (arc);
+	arc("starttime", TimeToStart)
+		("endtime", TimeToStop)
+		("goalx", GoalX)
+		("startx", StartX)
+		("stretchx", bStretchX)
+		("goaly", GoalY)
+		("starty", StartY)
+		("stretchy", bStretchY)
+		("started", bStarted);
+}
+
+void DDecalStretcher::Tick ()
+{
+	if (TheDecal == nullptr)
+	{
+		Destroy ();
+		return;
+	}
+	if (Level->maptime < TimeToStart || Level->isFrozen())
+	{
+		return;
+	}
+	if (Level->maptime >= TimeToStop)
+	{
+		if (bStretchX)
+		{
+			TheDecal->ScaleX = GoalX;
+		}
+		if (bStretchY)
+		{
+			TheDecal->ScaleY = GoalY;
+		}
+		Destroy ();
+		return;
+	}
+	if (!bStarted)
+	{
+		bStarted = true;
+		StartX = TheDecal->ScaleX;
+		StartY = TheDecal->ScaleY;
+	}
+
+	int distance = Level->maptime - TimeToStart;
+	int maxDistance = TimeToStop - TimeToStart;
+	if (bStretchX)
+	{
+		TheDecal->ScaleX = StartX + (GoalX - StartX) * distance / maxDistance;
+	}
+	if (bStretchY)
+	{
+		TheDecal->ScaleY = StartY + (GoalY - StartY) * distance / maxDistance;
+	}
+}
+
+IMPLEMENT_CLASS(DDecalSlider, false, false)
+
+void DDecalSlider::Serialize(FSerializer &arc)
+{
+	Super::Serialize (arc);
+	arc("starttime", TimeToStart)
+		("endtime", TimeToStop)
+		("disty", DistY)
+		("starty", StartY)
+		("started", bStarted);
+}
+
+void DDecalSlider::Tick ()
+{
+	if (TheDecal == nullptr)
+	{
+		Destroy ();
+		return;
+	}
+	if (Level->maptime < TimeToStart || Level->isFrozen())
+	{
+		return;
+	}
+	if (!bStarted)
+	{
+		bStarted = true;
+		/*StartX = TheDecal->LeftDistance;*/
+		StartY = TheDecal->Z;
+	}
+	if (Level->maptime >= TimeToStop)
+	{
+		/*TheDecal->LeftDistance = StartX + DistX;*/
+		TheDecal->Z = StartY + DistY;
+		Destroy ();
+		return;
+	}
+
+	int distance = Level->maptime - TimeToStart;
+	int maxDistance = TimeToStop - TimeToStart;
+	/*TheDecal->LeftDistance = StartX + DistX * distance / maxDistance);*/
+	TheDecal->Z = StartY + DistY * distance / maxDistance;
+}
+
+IMPLEMENT_CLASS(DDecalColorer, false, false)
+
+void DDecalColorer::Serialize(FSerializer &arc)
+{
+	Super::Serialize (arc);
+	arc("starttime", TimeToStartDecay)
+		("endtime", TimeToEndDecay)
+		("startcolor", StartColor)
+		("goalcolor", GoalColor);
+}
+
+void DDecalColorer::Tick ()
+{
+	if (TheDecal == nullptr || !(TheDecal->RenderStyle.Flags & STYLEF_ColorIsFixed))
+	{
+		Destroy ();
+	}
+	else
+	{
+		if (Level->maptime < TimeToStartDecay || Level->isFrozen())
+		{
+			return;
+		}
+		else if (Level->maptime >= TimeToEndDecay)
+		{
+			TheDecal->SetShade (GoalColor);
+			Destroy ();					// remove myself
+		}
+		if (StartColor.a == 255)
+		{
+			StartColor = TheDecal->AlphaColor & 0xffffff;
+			if (StartColor == GoalColor)
+			{
+				Destroy ();
+				return;
+			}
+		}
+		if (Level->maptime & 0)
+		{ // Changing the shade can be expensive, so don't do it too often.
+			return;
+		}
+
+		int distance = Level->maptime - TimeToStartDecay;
+		int maxDistance = TimeToEndDecay - TimeToStartDecay;
+		int r = StartColor.r + Scale (GoalColor.r - StartColor.r, distance, maxDistance);
+		int g = StartColor.g + Scale (GoalColor.g - StartColor.g, distance, maxDistance);
+		int b = StartColor.b + Scale (GoalColor.b - StartColor.b, distance, maxDistance);
+		TheDecal->SetShade (r, g, b);
+	}
+}
+
diff --git a/src/g_shared/a_decalfx.h b/src/g_shared/a_decalfx.h
new file mode 100644
index 000000000..a25192b01
--- /dev/null
+++ b/src/g_shared/a_decalfx.h
@@ -0,0 +1,93 @@
+#pragma once
+
+#include "dthinker.h"
+
+struct DDecalThinker : public DThinker
+{
+	DECLARE_CLASS (DDecalThinker, DThinker)
+	HAS_OBJECT_POINTERS
+public:
+	static const int DEFAULT_STAT = STAT_DECALTHINKER;
+	void Construct(DBaseDecal *decal)
+	{
+		TheDecal = decal;
+	}
+	void Serialize(FSerializer &arc);
+	TObjPtr<DBaseDecal*> TheDecal;
+};
+
+class DDecalFader : public DDecalThinker
+{
+	DECLARE_CLASS (DDecalFader, DDecalThinker)
+public:
+	void Construct(DBaseDecal *decal)
+	{
+		Super::Construct(decal);
+	}
+	void Serialize(FSerializer &arc);
+	void Tick ();
+
+	int TimeToStartDecay;
+	int TimeToEndDecay;
+	double StartTrans;
+};
+
+class DDecalColorer : public DDecalThinker
+{
+	DECLARE_CLASS (DDecalColorer, DDecalThinker)
+public:
+	void Construct(DBaseDecal *decal)
+	{
+		Super::Construct(decal);
+	}
+	void Serialize(FSerializer &arc);
+	void Tick ();
+
+	int TimeToStartDecay;
+	int TimeToEndDecay;
+	PalEntry StartColor;
+	PalEntry GoalColor;
+};
+
+class DDecalStretcher : public DDecalThinker
+{
+	DECLARE_CLASS (DDecalStretcher, DDecalThinker)
+public:
+	void Construct(DBaseDecal *decal)
+	{
+		Super::Construct(decal);
+	}
+	void Serialize(FSerializer &arc);
+	void Tick ();
+
+	int TimeToStart;
+	int TimeToStop;
+	double GoalX;
+	double StartX;
+	double GoalY;
+	double StartY;
+	bool bStretchX;
+	bool bStretchY;
+	bool bStarted;
+};
+
+class DDecalSlider : public DDecalThinker
+{
+	DECLARE_CLASS (DDecalSlider, DDecalThinker)
+public:
+	void Construct(DBaseDecal *decal)
+	{
+		Super::Construct(decal);
+	}
+	void Serialize(FSerializer &arc);
+	void Tick ();
+
+	int TimeToStart;
+	int TimeToStop;
+/*	double DistX; */
+	double DistY;
+	double StartX;
+	double StartY;
+	bool bStarted;
+};
+
diff --git a/src/decallib.cpp b/src/gamedata/decallib.cpp
similarity index 81%
rename from src/decallib.cpp
rename to src/gamedata/decallib.cpp
index 18c1c7cfd..6b471492a 100644
--- a/src/decallib.cpp
+++ b/src/gamedata/decallib.cpp
@@ -46,6 +46,7 @@
 #include "b_bot.h"
 #include "serializer.h"
 #include "g_levellocals.h"
+#include "a_decalfx.h"
 
 FDecalLib DecalLibrary;
 
@@ -102,34 +103,6 @@ struct FDecalAnimator
 	FName Name;
 };
 
-TDeletingArray<FDecalAnimator *> Animators;
-
-struct DDecalThinker : public DThinker
-{
-	DECLARE_CLASS (DDecalThinker, DThinker)
-	HAS_OBJECT_POINTERS
-public:
-	static const int DEFAULT_STAT = STAT_DECALTHINKER;
-	void Construct(DBaseDecal *decal)
-	{
-		TheDecal = decal;
-	}
-	void Serialize(FSerializer &arc);
-	TObjPtr<DBaseDecal*> TheDecal;
-};
-
-IMPLEMENT_CLASS(DDecalThinker, false, true)
-
-IMPLEMENT_POINTERS_START(DDecalThinker)
-	IMPLEMENT_POINTER(TheDecal)
-IMPLEMENT_POINTERS_END
-
-void DDecalThinker::Serialize(FSerializer &arc)
-{
-	Super::Serialize (arc);
-	arc("thedecal", TheDecal);
-}
-
 struct FDecalFaderAnim : public FDecalAnimator
 {
 	FDecalFaderAnim (const char *name) : FDecalAnimator (name) {}
@@ -139,22 +112,6 @@ struct FDecalFaderAnim : public FDecalAnimator
 	int DecayTime;
 };
 
-class DDecalFader : public DDecalThinker
-{
-	DECLARE_CLASS (DDecalFader, DDecalThinker)
-public:
-	void Construct(DBaseDecal *decal)
-	{
-		Super::Construct(decal);
-	}
-	void Serialize(FSerializer &arc);
-	void Tick ();
-
-	int TimeToStartDecay;
-	int TimeToEndDecay;
-	double StartTrans;
-};
-
 struct FDecalColorerAnim : public FDecalAnimator
 {
 	FDecalColorerAnim (const char *name) : FDecalAnimator (name) {}
@@ -165,23 +122,6 @@ struct FDecalColorerAnim : public FDecalAnimator
 	PalEntry GoalColor;
 };
 
-class DDecalColorer : public DDecalThinker
-{
-	DECLARE_CLASS (DDecalColorer, DDecalThinker)
-public:
-	void Construct(DBaseDecal *decal)
-	{
-		Super::Construct(decal);
-	}
-	void Serialize(FSerializer &arc);
-	void Tick ();
-
-	int TimeToStartDecay;
-	int TimeToEndDecay;
-	PalEntry StartColor;
-	PalEntry GoalColor;
-};
-
 struct FDecalStretcherAnim : public FDecalAnimator
 {
 	FDecalStretcherAnim (const char *name) : FDecalAnimator (name) {}
@@ -192,28 +132,6 @@ struct FDecalStretcherAnim : public FDecalAnimator
 	double GoalX, GoalY;
 };
 
-class DDecalStretcher : public DDecalThinker
-{
-	DECLARE_CLASS (DDecalStretcher, DDecalThinker)
-public:
-	void Construct(DBaseDecal *decal)
-	{
-		Super::Construct(decal);
-	}
-	void Serialize(FSerializer &arc);
-	void Tick ();
-
-	int TimeToStart;
-	int TimeToStop;
-	double GoalX;
-	double StartX;
-	double GoalY;
-	double StartY;
-	bool bStretchX;
-	bool bStretchY;
-	bool bStarted;
-};
-
 struct FDecalSliderAnim : public FDecalAnimator
 {
 	FDecalSliderAnim (const char *name) : FDecalAnimator (name) {}
@@ -224,26 +142,6 @@ struct FDecalSliderAnim : public FDecalAnimator
 	double /*DistX,*/ DistY;
 };
 
-class DDecalSlider : public DDecalThinker
-{
-	DECLARE_CLASS (DDecalSlider, DDecalThinker)
-public:
-	void Construct(DBaseDecal *decal)
-	{
-		Super::Construct(decal);
-	}
-	void Serialize(FSerializer &arc);
-	void Tick ();
-
-	int TimeToStart;
-	int TimeToStop;
-/*	double DistX; */
-	double DistY;
-	double StartX;
-	double StartY;
-	bool bStarted;
-};
-
 struct FDecalCombinerAnim : public FDecalAnimator
 {
 	FDecalCombinerAnim (const char *name) : FDecalAnimator (name) {}
@@ -255,6 +153,7 @@ struct FDecalCombinerAnim : public FDecalAnimator
 	static TArray<FDecalAnimator *> AnimatorList;
 };
 
+TDeletingArray<FDecalAnimator *> Animators;
 TArray<FDecalAnimator *> FDecalCombinerAnim::AnimatorList;
 
 static const char *DecalKeywords[] =
@@ -1166,45 +1065,6 @@ FDecalAnimator::~FDecalAnimator ()
 {
 }
 
-IMPLEMENT_CLASS(DDecalFader, false, false)
-
-void DDecalFader::Serialize(FSerializer &arc)
-{
-	Super::Serialize (arc);
-	arc("starttime", TimeToStartDecay)
-		("endtime", TimeToEndDecay)
-		("starttrans", StartTrans);
-}
-
-void DDecalFader::Tick ()
-{
-	if (TheDecal == NULL)
-	{
-		Destroy ();
-	}
-	else
-	{
-		if (Level->maptime < TimeToStartDecay || Level->isFrozen())
-		{
-			return;
-		}
-		else if (Level->maptime >= TimeToEndDecay)
-		{
-			TheDecal->Destroy ();		// remove the decal
-			Destroy ();					// remove myself
-			return;
-		}
-		if (StartTrans == -1)
-		{
-			StartTrans = TheDecal->Alpha;
-		}
-
-		int distanceToEnd = TimeToEndDecay - Level->maptime;
-		int fadeDistance = TimeToEndDecay - TimeToStartDecay;
-		TheDecal->Alpha = StartTrans * distanceToEnd / fadeDistance;
-	}
-}
-
 DThinker *FDecalFaderAnim::CreateThinker (DBaseDecal *actor, side_t *wall) const
 {
 	auto Level = actor->Level;
@@ -1216,22 +1076,6 @@ DThinker *FDecalFaderAnim::CreateThinker (DBaseDecal *actor, side_t *wall) const
 	return fader;
 }
 
-IMPLEMENT_CLASS(DDecalStretcher, false, false)
-
-void DDecalStretcher::Serialize(FSerializer &arc)
-{
-	Super::Serialize (arc);
-	arc("starttime", TimeToStart)
-		("endtime", TimeToStop)
-		("goalx", GoalX)
-		("startx", StartX)
-		("stretchx", bStretchX)
-		("goaly", GoalY)
-		("starty", StartY)
-		("stretchy", bStretchY)
-		("started", bStarted);
-}
-
 DThinker *FDecalStretcherAnim::CreateThinker (DBaseDecal *actor, side_t *wall) const
 {
 	auto Level = actor->Level;
@@ -1264,61 +1108,6 @@ DThinker *FDecalStretcherAnim::CreateThinker (DBaseDecal *actor, side_t *wall) c
 	return thinker;
 }
 
-void DDecalStretcher::Tick ()
-{
-	if (TheDecal == NULL)
-	{
-		Destroy ();
-		return;
-	}
-	if (Level->maptime < TimeToStart || Level->isFrozen())
-	{
-		return;
-	}
-	if (Level->maptime >= TimeToStop)
-	{
-		if (bStretchX)
-		{
-			TheDecal->ScaleX = GoalX;
-		}
-		if (bStretchY)
-		{
-			TheDecal->ScaleY = GoalY;
-		}
-		Destroy ();
-		return;
-	}
-	if (!bStarted)
-	{
-		bStarted = true;
-		StartX = TheDecal->ScaleX;
-		StartY = TheDecal->ScaleY;
-	}
-
-	int distance = Level->maptime - TimeToStart;
-	int maxDistance = TimeToStop - TimeToStart;
-	if (bStretchX)
-	{
-		TheDecal->ScaleX = StartX + (GoalX - StartX) * distance / maxDistance;
-	}
-	if (bStretchY)
-	{
-		TheDecal->ScaleY = StartY + (GoalY - StartY) * distance / maxDistance;
-	}
-}
-
-IMPLEMENT_CLASS(DDecalSlider, false, false)
-
-void DDecalSlider::Serialize(FSerializer &arc)
-{
-	Super::Serialize (arc);
-	arc("starttime", TimeToStart)
-		("endtime", TimeToStop)
-		("disty", DistY)
-		("starty", StartY)
-		("started", bStarted);
-}
-
 DThinker *FDecalSliderAnim::CreateThinker (DBaseDecal *actor, side_t *wall) const
 {
 	auto Level = actor->Level;
@@ -1332,37 +1121,6 @@ DThinker *FDecalSliderAnim::CreateThinker (DBaseDecal *actor, side_t *wall) cons
 	return thinker;
 }
 
-void DDecalSlider::Tick ()
-{
-	if (TheDecal == NULL)
-	{
-		Destroy ();
-		return;
-	}
-	if (Level->maptime < TimeToStart || Level->isFrozen())
-	{
-		return;
-	}
-	if (!bStarted)
-	{
-		bStarted = true;
-		/*StartX = TheDecal->LeftDistance;*/
-		StartY = TheDecal->Z;
-	}
-	if (Level->maptime >= TimeToStop)
-	{
-		/*TheDecal->LeftDistance = StartX + DistX;*/
-		TheDecal->Z = StartY + DistY;
-		Destroy ();
-		return;
-	}
-
-	int distance = Level->maptime - TimeToStart;
-	int maxDistance = TimeToStop - TimeToStart;
-	/*TheDecal->LeftDistance = StartX + DistX * distance / maxDistance);*/
-	TheDecal->Z = StartY + DistY * distance / maxDistance;
-}
-
 DThinker *FDecalCombinerAnim::CreateThinker (DBaseDecal *actor, side_t *wall) const
 {
 	DThinker *thinker = NULL;
@@ -1388,57 +1146,6 @@ FDecalAnimator *FDecalLib::FindAnimator (const char *name)
 	return NULL;
 }
 
-IMPLEMENT_CLASS(DDecalColorer, false, false)
-
-void DDecalColorer::Serialize(FSerializer &arc)
-{
-	Super::Serialize (arc);
-	arc("starttime", TimeToStartDecay)
-		("endtime", TimeToEndDecay)
-		("startcolor", StartColor)
-		("goalcolor", GoalColor);
-}
-
-void DDecalColorer::Tick ()
-{
-	if (TheDecal == NULL || !(TheDecal->RenderStyle.Flags & STYLEF_ColorIsFixed))
-	{
-		Destroy ();
-	}
-	else
-	{
-		if (Level->maptime < TimeToStartDecay || Level->isFrozen())
-		{
-			return;
-		}
-		else if (Level->maptime >= TimeToEndDecay)
-		{
-			TheDecal->SetShade (GoalColor);
-			Destroy ();					// remove myself
-		}
-		if (StartColor.a == 255)
-		{
-			StartColor = TheDecal->AlphaColor & 0xffffff;
-			if (StartColor == GoalColor)
-			{
-				Destroy ();
-				return;
-			}
-		}
-		if (Level->maptime & 0)
-		{ // Changing the shade can be expensive, so don't do it too often.
-			return;
-		}
-
-		int distance = Level->maptime - TimeToStartDecay;
-		int maxDistance = TimeToEndDecay - TimeToStartDecay;
-		int r = StartColor.r + Scale (GoalColor.r - StartColor.r, distance, maxDistance);
-		int g = StartColor.g + Scale (GoalColor.g - StartColor.g, distance, maxDistance);
-		int b = StartColor.b + Scale (GoalColor.b - StartColor.b, distance, maxDistance);
-		TheDecal->SetShade (r, g, b);
-	}
-}
-
 DThinker *FDecalColorerAnim::CreateThinker (DBaseDecal *actor, side_t *wall) const
 {
 	auto Level = actor->Level;
diff --git a/src/decallib.h b/src/gamedata/decallib.h
similarity index 100%
rename from src/decallib.h
rename to src/gamedata/decallib.h
diff --git a/src/g_mapinfo.cpp b/src/gamedata/g_mapinfo.cpp
similarity index 100%
rename from src/g_mapinfo.cpp
rename to src/gamedata/g_mapinfo.cpp
diff --git a/src/gamedata/g_mapinfo.h b/src/gamedata/g_mapinfo.h
new file mode 100644
index 000000000..e7e31deb2
--- /dev/null
+++ b/src/gamedata/g_mapinfo.h
@@ -0,0 +1,561 @@
+/*
+** g_level.h
+**
+**---------------------------------------------------------------------------
+** Copyright 1998-2006 Randy Heit
+** All rights reserved.
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions
+** are met:
+**
+** 1. Redistributions of source code must retain the above copyright
+**    notice, this list of conditions and the following disclaimer.
+** 2. Redistributions in binary form must reproduce the above copyright
+**    notice, this list of conditions and the following disclaimer in the
+**    documentation and/or other materials provided with the distribution.
+** 3. The name of the author may not be used to endorse or promote products
+**    derived from this software without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+**---------------------------------------------------------------------------
+**
+*/
+
+#ifndef __G_LEVEL_H__
+#define __G_LEVEL_H__
+
+#include "doomtype.h"
+#include "vectors.h"
+#include "sc_man.h"
+#include "resourcefiles/file_zip.h"
+
+struct level_info_t;
+struct cluster_info_t;
+class FSerializer;
+
+#if defined(_MSC_VER)
+#pragma section(".yreg$u",read)
+#define MSVC_YSEG __declspec(allocate(".yreg$u"))
+#define GCC_YSEG
+#else
+#define MSVC_YSEG
+#define GCC_YSEG __attribute__((section(SECTION_YREG))) __attribute__((used))
+#endif
+
+// The structure used to control scripts between maps
+struct acsdefered_t
+{
+	enum EType
+	{
+		defexecute,
+		defexealways,
+		defsuspend,
+		defterminate
+	} type;
+	int script;
+	int args[3];
+	int playernum;
+};
+
+FSerializer &Serialize(FSerializer &arc, const char *key, acsdefered_t &defer, acsdefered_t *def);
+
+
+struct FIntermissionDescriptor;
+struct FIntermissionAction;
+
+struct FMapInfoParser
+{
+	enum EFormatType
+	{
+		FMT_Unknown,
+		FMT_Old,
+		FMT_New
+	};
+
+	FScanner sc;
+	int format_type;
+	bool HexenHack;
+
+	FMapInfoParser(int format = FMT_Unknown)
+	{
+		format_type = format;
+		HexenHack = false;
+	}
+
+	bool ParseLookupName(FString &dest);
+	void ParseMusic(FString &name, int &order);
+	//void ParseLumpOrTextureName(char *name);
+	void ParseLumpOrTextureName(FString &name);
+	void ParseExitText(FName formap, level_info_t *info);
+	void ParseExitMusic(FName formap, level_info_t *info);
+	void ParseExitBackdrop(FName formap, level_info_t *info, bool ispic);
+
+	void ParseCluster();
+	void ParseNextMap(FString &mapname);
+	level_info_t *ParseMapHeader(level_info_t &defaultinfo);
+	void ParseMapDefinition(level_info_t &leveldef);
+	void ParseGameInfo();
+	void ParseEpisodeInfo ();
+	void ParseSkill ();
+	void ParseMapInfo (int lump, level_info_t &gamedefaults, level_info_t &defaultinfo);
+
+	void ParseOpenBrace();
+	bool ParseCloseBrace();
+	bool CheckAssign();
+	void ParseAssign();
+	void MustParseAssign();
+	void ParseComma();
+	bool CheckNumber();
+	bool CheckFloat();
+	void SkipToNext();
+	void CheckEndOfFile(const char *block);
+
+	void ParseIntermissionAction(FIntermissionDescriptor *Desc);
+	void ParseIntermission();
+	void ParseDoomEdNums();
+	void ParseSpawnNums();
+	void ParseConversationIDs();
+	void ParseAMColors(bool);
+	FName CheckEndSequence();
+	FName ParseEndGame();
+	void ParseDamageDefinition();
+};
+
+#define DEFINE_MAP_OPTION(name, old) \
+	static void MapOptHandler_##name(FMapInfoParser &parse, level_info_t *info); \
+	static FMapOptInfo MapOpt_##name = \
+		{ #name, MapOptHandler_##name, old }; \
+	MSVC_YSEG FMapOptInfo *mapopt_##name GCC_YSEG = &MapOpt_##name; \
+	static void MapOptHandler_##name(FMapInfoParser &parse, level_info_t *info)
+
+
+struct FMapOptInfo
+{
+	const char *name;
+	void (*handler) (FMapInfoParser &parse, level_info_t *levelinfo);
+	bool old;
+};
+
+enum ELevelFlags : unsigned int
+{
+	LEVEL_NOINTERMISSION		= 0x00000001,
+	LEVEL_NOINVENTORYBAR		= 0x00000002,	// This effects Doom only, since it's the only one without a standard inventory bar.
+	LEVEL_DOUBLESKY				= 0x00000004,
+	LEVEL_HASFADETABLE			= 0x00000008,	// Level uses Hexen's fadetable mapinfo to get fog
+
+	LEVEL_MAP07SPECIAL			= 0x00000010,
+	LEVEL_BRUISERSPECIAL		= 0x00000020,
+	LEVEL_CYBORGSPECIAL			= 0x00000040,
+	LEVEL_SPIDERSPECIAL			= 0x00000080,
+
+	LEVEL_SPECLOWERFLOOR		= 0x00000100,
+	LEVEL_SPECOPENDOOR			= 0x00000200,
+	LEVEL_SPECLOWERFLOORTOHIGHEST=0x00000300,
+	LEVEL_SPECACTIONSMASK		= 0x00000300,
+
+	LEVEL_MONSTERSTELEFRAG		= 0x00000400,
+	LEVEL_ACTOWNSPECIAL			= 0x00000800,
+	LEVEL_SNDSEQTOTALCTRL		= 0x00001000,
+	LEVEL_FORCETILEDSKY		= 0x00002000,
+
+	LEVEL_CROUCH_NO				= 0x00004000,
+	LEVEL_JUMP_NO				= 0x00008000,
+	LEVEL_FREELOOK_NO			= 0x00010000,
+	LEVEL_FREELOOK_YES			= 0x00020000,
+
+	// The absence of both of the following bits means that this level does not
+	// use falling damage (though damage can be forced with dmflags,.
+	LEVEL_FALLDMG_ZD			= 0x00040000,	// Level uses ZDoom's falling damage
+	LEVEL_FALLDMG_HX			= 0x00080000,	// Level uses Hexen's falling damage
+
+	LEVEL_HEADSPECIAL			= 0x00100000,	// Heretic episode 1/4
+	LEVEL_MINOTAURSPECIAL		= 0x00200000,	// Heretic episode 2/5
+	LEVEL_SORCERER2SPECIAL		= 0x00400000,	// Heretic episode 3
+	LEVEL_SPECKILLMONSTERS		= 0x00800000,
+
+	LEVEL_STARTLIGHTNING		= 0x01000000,	// Automatically start lightning
+	LEVEL_FILTERSTARTS			= 0x02000000,	// Apply mapthing filtering to player starts
+	LEVEL_LOOKUPLEVELNAME		= 0x04000000,	// Level name is the name of a language string
+	LEVEL_USEPLAYERSTARTZ		= 0x08000000,	// Use the Z position of player starts
+
+	LEVEL_SWAPSKIES				= 0x10000000,	// Used by lightning
+	LEVEL_NOALLIES				= 0x20000000,	// i.e. Inside Strife's front base
+	LEVEL_CHANGEMAPCHEAT		= 0x40000000,	// Don't display cluster messages
+	LEVEL_VISITED				= 0x80000000,	// Used for intermission map
+
+	// The flags uint64_t is now split into 2 DWORDs 
+	LEVEL2_RANDOMPLAYERSTARTS	= 0x00000001,	// Select single player starts randomnly (no voodoo dolls)
+	LEVEL2_ALLMAP				= 0x00000002,	// The player picked up a map on this level
+
+	LEVEL2_LAXMONSTERACTIVATION	= 0x00000004,	// Monsters can open doors depending on the door speed
+	LEVEL2_LAXACTIVATIONMAPINFO	= 0x00000008,	// LEVEL_LAXMONSTERACTIVATION is not a default.
+
+	LEVEL2_MISSILESACTIVATEIMPACT=0x00000010,	// Missiles are the activators of SPAC_IMPACT events, not their shooters
+	LEVEL2_FROZEN				= 0x00000020,	// Game is frozen by a TimeFreezer
+
+	LEVEL2_KEEPFULLINVENTORY	= 0x00000040,	// doesn't reduce the amount of inventory items to 1
+
+	LEVEL2_PRERAISEWEAPON		= 0x00000080,	// players should spawn with their weapons fully raised (but not when respawning it multiplayer)
+	LEVEL2_MONSTERFALLINGDAMAGE	= 0x00000100,
+	LEVEL2_CLIPMIDTEX			= 0x00000200,
+	LEVEL2_WRAPMIDTEX			= 0x00000400,
+
+	LEVEL2_CHECKSWITCHRANGE		= 0x00000800,	
+
+	LEVEL2_PAUSE_MUSIC_IN_MENUS	= 0x00001000,
+	LEVEL2_TOTALINFIGHTING		= 0x00002000,
+	LEVEL2_NOINFIGHTING			= 0x00004000,
+
+	LEVEL2_NOMONSTERS			= 0x00008000,
+	LEVEL2_INFINITE_FLIGHT		= 0x00010000,
+
+	LEVEL2_ALLOWRESPAWN			= 0x00020000,
+
+	LEVEL2_FORCETEAMPLAYON		= 0x00040000,
+	LEVEL2_FORCETEAMPLAYOFF		= 0x00080000,
+
+	LEVEL2_CONV_SINGLE_UNFREEZE	= 0x00100000,
+	LEVEL2_RAILINGHACK			= 0x00200000,	// but UDMF requires them to be separate to have more control
+	LEVEL2_DUMMYSWITCHES		= 0x00400000,
+	LEVEL2_HEXENHACK			= 0x00800000,	// Level was defined in a Hexen style MAPINFO
+
+	LEVEL2_SMOOTHLIGHTING		= 0x01000000,	// Level uses the smooth lighting feature.
+	LEVEL2_POLYGRIND			= 0x02000000,	// Polyobjects grind corpses to gibs.
+	LEVEL2_RESETINVENTORY		= 0x04000000,	// Resets player inventory when starting this level (unless in a hub)
+	LEVEL2_RESETHEALTH			= 0x08000000,	// Resets player health when starting this level (unless in a hub)
+
+	LEVEL2_NOSTATISTICS			= 0x10000000,	// This level should not have statistics collected
+	LEVEL2_ENDGAME				= 0x20000000,	// This is an epilogue level that cannot be quit.
+	LEVEL2_NOAUTOSAVEHINT		= 0x40000000,	// tell the game that an autosave for this level does not need to be kept
+	LEVEL2_FORGETSTATE			= 0x80000000,	// forget this map's state in a hub
+	
+	// More flags!
+	LEVEL3_FORCEFAKECONTRAST	= 0x00000001,	// forces fake contrast even with fog enabled
+	LEVEL3_REMOVEITEMS			= 0x00000002,	// kills all INVBAR items on map change.
+	LEVEL3_ATTENUATE			= 0x00000004,	// attenuate lights?
+	LEVEL3_NOLIGHTFADE			= 0x00000008,	// no light fading to black.
+	LEVEL3_NOCOLOREDSPRITELIGHTING = 0x00000010,	// draw sprites only with color-less light
+	LEVEL3_EXITNORMALUSED		= 0x00000020,
+	LEVEL3_EXITSECRETUSED		= 0x00000040,
+	LEVEL3_FORCEWORLDPANNING	= 0x00000080,	// Forces the world panning flag for all textures, even those without it explicitly set.
+};
+
+
+struct FSpecialAction
+{
+	FName Type;					// this is initialized before the actors...
+	int Action;
+	int Args[5];
+};
+
+class DScroller;
+
+class FScanner;
+struct level_info_t;
+
+typedef TMap<int, FName> FMusicMap;
+
+enum EMapType : int
+{
+	MAPTYPE_UNKNOWN = 0,
+	MAPTYPE_DOOM,
+	MAPTYPE_HEXEN,
+	MAPTYPE_BUILD,
+	MAPTYPE_UDMF	// This does not distinguish between namespaces.
+};
+
+struct FExitText
+{
+	enum EDefined
+	{
+		DEF_TEXT = 1,
+		DEF_MUSIC = 2,
+		DEF_BACKDROP = 4,
+		DEF_LOOKUP = 8,
+		DEF_PIC = 16
+	};
+	int16_t mDefined = 0;
+	int16_t mOrder = -1;
+	FString mText;
+	FString mMusic;
+	FString mBackdrop;
+
+	FExitText(int def = 0, int order = -1, const FString &text = "", const FString &backdrop = "", const FString &music = "")
+		: mDefined(int16_t(def)), mOrder(int16_t(order)), mText(text), mMusic(music), mBackdrop(backdrop)
+	{
+	}
+};
+
+
+struct level_info_t
+{
+	int			levelnum;
+	
+	FString		MapName;
+	FString		NextMap;
+	FString		NextSecretMap;
+	FString		PName;
+	FString		SkyPic1;
+	FString		SkyPic2;
+	FString		FadeTable;
+	FString		F1Pic;
+	FString		BorderTexture;
+	FString		MapBackground;
+
+	TMap<FName, FExitText> ExitMapTexts;
+
+	int			cluster;
+	int			partime;
+	int			sucktime;
+	int32_t		flags;
+	uint32_t	flags2;
+	uint32_t	flags3;
+
+	FString		Music;
+	FString		LevelName;
+	int8_t		WallVertLight, WallHorizLight;
+	int			musicorder;
+	FCompressedBuffer	Snapshot;
+	TArray<acsdefered_t> deferred;
+	float		skyspeed1;
+	float		skyspeed2;
+	uint32_t	fadeto;
+	uint32_t	outsidefog;
+	int			cdtrack;
+	unsigned int cdid;
+	double		gravity;
+	double		aircontrol;
+	int			WarpTrans;
+	int			airsupply;
+	uint32_t	compatflags, compatflags2;
+	uint32_t	compatmask, compatmask2;
+	FString		Translator;	// for converting Doom-format linedef and sector types.
+	int			DefaultEnvironment;	// Default sound environment for the map.
+	FName		Intermission;
+	FName		deathsequence;
+	FName		slideshow;
+	uint32_t	hazardcolor;
+	uint32_t	hazardflash;
+	int			fogdensity;
+	int			outsidefogdensity;
+	int			skyfog;
+	float		pixelstretch;
+
+	// Redirection: If any player is carrying the specified item, then
+	// you go to the RedirectMap instead of this one.
+	FName		RedirectType;
+	FString		RedirectMapName;
+
+	FString		EnterPic;
+	FString		ExitPic;
+	FString 	InterMusic;
+	int			intermusicorder;
+	TMap <FName, std::pair<FString, int> > MapInterMusic;
+
+	FString		SoundInfo;
+	FString		SndSeq;
+
+	double		teamdamage;
+
+	FMusicMap	MusicMap;
+
+	TArray<FSpecialAction> specialactions;
+
+	TArray<int> PrecacheSounds;
+	TArray<FString> PrecacheTextures;
+	TArray<FName> PrecacheClasses;
+	
+	TArray<FString> EventHandlers;
+
+	ELightMode	lightmode;
+	int8_t		brightfog;
+	int8_t		lightadditivesurfaces;
+	int8_t		notexturefill;
+	FVector3	skyrotatevector;
+	FVector3	skyrotatevector2;
+
+	FString		EDName;
+	FString		acsName;
+	bool		fs_nocheckposition;
+
+
+	level_info_t() 
+	{ 
+		Reset(); 
+	}
+	~level_info_t()
+	{
+		Snapshot.Clean();
+		ClearDefered();
+	}
+	void Reset();
+	bool isValid();
+	FString LookupLevelName ();
+	void ClearDefered()
+	{
+		deferred.Clear();
+	}
+	level_info_t *CheckLevelRedirect ();
+};
+
+
+struct cluster_info_t
+{
+	int			cluster;
+	FString		FinaleFlat;
+	FString		ExitText;
+	FString		EnterText;
+	FString		MessageMusic;
+	int			musicorder;
+	int			flags;
+	int			cdtrack;
+	FString		ClusterName;
+	unsigned int cdid;
+
+	void Reset();
+
+};
+
+// Cluster flags
+#define CLUSTER_HUB				0x00000001	// Cluster uses hub behavior
+#define CLUSTER_EXITTEXTINLUMP	0x00000002	// Exit text is the name of a lump
+#define CLUSTER_ENTERTEXTINLUMP	0x00000004	// Enter text is the name of a lump
+#define CLUSTER_FINALEPIC		0x00000008	// Finale "flat" is actually a full-sized image
+#define CLUSTER_LOOKUPEXITTEXT	0x00000010	// Exit text is the name of a language string
+#define CLUSTER_LOOKUPENTERTEXT	0x00000020	// Enter text is the name of a language string
+#define CLUSTER_LOOKUPNAME		0x00000040	// Name is the name of a language string
+#define CLUSTER_LOOKUPCLUSTERNAME 0x00000080	// Cluster name is the name of a language string
+#define CLUSTER_ALLOWINTERMISSION 0x00000100  // Allow intermissions between levels in a hub.
+
+extern TArray<level_info_t> wadlevelinfos;
+extern TArray<cluster_info_t> wadclusterinfos;
+
+// mapname will be changed if it is a valid warptrans
+bool CheckWarpTransMap (FString &mapname, bool substitute);
+
+cluster_info_t *FindClusterInfo (int cluster);
+level_info_t *FindLevelInfo (const char *mapname, bool allowdefault=true);
+level_info_t *FindLevelByNum (int num);
+level_info_t *CheckLevelRedirect (level_info_t *info);
+
+FString CalcMapName (int episode, int level);
+
+void G_ParseMapInfo (FString basemapinfo);
+
+enum ESkillProperty
+{
+	SKILLP_FastMonsters,
+	SKILLP_Respawn,
+	SKILLP_RespawnLimit,
+	SKILLP_DisableCheats,
+	SKILLP_AutoUseHealth,
+	SKILLP_SpawnFilter,
+	SKILLP_EasyBossBrain,
+	SKILLP_ACSReturn,
+	SKILLP_NoPain,
+	SKILLP_EasyKey,
+	SKILLP_SlowMonsters,
+	SKILLP_Infight,
+	SKILLP_PlayerRespawn,
+};
+enum EFSkillProperty	// floating point properties
+{
+	SKILLP_AmmoFactor,
+	SKILLP_DropAmmoFactor,
+	SKILLP_ArmorFactor,
+	SKILLP_HealthFactor,
+	SKILLP_DamageFactor,
+	SKILLP_Aggressiveness,
+	SKILLP_MonsterHealth,
+	SKILLP_FriendlyHealth,
+	SKILLP_KickbackFactor,
+};
+
+int G_SkillProperty(ESkillProperty prop);
+double G_SkillProperty(EFSkillProperty prop);
+const char * G_SkillName();
+
+typedef TMap<FName, FString> SkillMenuNames;
+
+typedef TMap<FName, FName> SkillActorReplacement;
+
+struct FSkillInfo
+{
+	FName Name = NAME_None;
+	double AmmoFactor, DoubleAmmoFactor, DropAmmoFactor;
+	double DamageFactor;
+	double ArmorFactor;
+	double HealthFactor;
+	double KickbackFactor;
+
+	bool FastMonsters;
+	bool SlowMonsters;
+	bool DisableCheats;
+	bool AutoUseHealth;
+
+	bool EasyBossBrain;
+	bool EasyKey;
+	bool NoMenu;
+	int RespawnCounter;
+	int RespawnLimit;
+	double Aggressiveness;
+	int SpawnFilter;
+	int ACSReturn;
+	FString MenuName;
+	FString PicName;
+	SkillMenuNames MenuNamesForPlayerClass;
+	bool MustConfirm;
+	FString MustConfirmText;
+	char Shortcut;
+	FString TextColor;
+	SkillActorReplacement Replace;
+	SkillActorReplacement Replaced;
+	double MonsterHealth;
+	double FriendlyHealth;
+	bool NoPain;
+	int Infighting;
+	bool PlayerRespawn;
+
+	FSkillInfo() {}
+	FSkillInfo(const FSkillInfo &other)
+	{
+		operator=(other);
+	}
+	FSkillInfo &operator=(const FSkillInfo &other);
+	int GetTextColor() const;
+
+	void SetReplacement(FName a, FName b);
+	FName GetReplacement(FName a);
+	void SetReplacedBy(FName b, FName a);
+	FName GetReplacedBy(FName b);
+};
+
+extern TArray<FSkillInfo> AllSkills;
+extern int DefaultSkill;
+
+struct FEpisode
+{
+	FString mEpisodeName;
+	FString mEpisodeMap;
+	FString mPicName;
+	char mShortcut;
+	bool mNoSkill;
+};
+
+extern TArray<FEpisode> AllEpisodes;
+
+int ParseUMapInfo(int lumpnum);
+void CommitUMapinfo(level_info_t *defaultinfo);
+
+
+#endif //__G_LEVEL_H__
diff --git a/src/g_skill.cpp b/src/gamedata/g_skill.cpp
similarity index 100%
rename from src/g_skill.cpp
rename to src/gamedata/g_skill.cpp
diff --git a/src/gi.cpp b/src/gamedata/gi.cpp
similarity index 100%
rename from src/gi.cpp
rename to src/gamedata/gi.cpp
diff --git a/src/gi.h b/src/gamedata/gi.h
similarity index 100%
rename from src/gi.h
rename to src/gamedata/gi.h
diff --git a/src/gstrings.h b/src/gamedata/gstrings.h
similarity index 100%
rename from src/gstrings.h
rename to src/gamedata/gstrings.h
diff --git a/src/stringtable.cpp b/src/gamedata/stringtable.cpp
similarity index 100%
rename from src/stringtable.cpp
rename to src/gamedata/stringtable.cpp
diff --git a/src/stringtable.h b/src/gamedata/stringtable.h
similarity index 100%
rename from src/stringtable.h
rename to src/gamedata/stringtable.h
diff --git a/src/umapinfo.cpp b/src/gamedata/umapinfo.cpp
similarity index 100%
rename from src/umapinfo.cpp
rename to src/gamedata/umapinfo.cpp
diff --git a/src/w_wad.cpp b/src/gamedata/w_wad.cpp
similarity index 100%
rename from src/w_wad.cpp
rename to src/gamedata/w_wad.cpp
diff --git a/src/w_wad.h b/src/gamedata/w_wad.h
similarity index 100%
rename from src/w_wad.h
rename to src/gamedata/w_wad.h
diff --git a/src/w_zip.h b/src/gamedata/w_zip.h
similarity index 100%
rename from src/w_zip.h
rename to src/gamedata/w_zip.h