Merged in GZDB r2465.

Build/Compilers/ZDoom/zdefs.acs

@@ -969,6 +969,7 @@
 #define BLOCKF_USE 128
 #define BLOCKF_SIGHT 256
 #define BLOCKF_HITSCAN 512
+#define BLOCKF_SOUND 1024
 
 #define FOGP_DENSITY 0
 #define FOGP_OUTSIDEDENSITY 1

Build/Compilers/ZDoom/zspecial.acs

@@ -199,7 +199,7 @@ special
 //	211:Transfer_CeilingLight,
 	212:Sector_SetColor(4,5),
 	213:Sector_SetFade(4),
-	214:Sector_SetDamage(3),
+	214:Sector_SetDamage(3,5),
 	215:Teleport_Line(2),
 	216:Sector_SetGravity(3),
 	217:Stairs_BuildUpDoom(5),
@@ -302,7 +302,7 @@ special
 	-57:SetCVarString(2),
 	-58:GetUserCVarString(2),
 	-59:SetUserCVarString(3),
-	-60:LineAttack(4,8),
+	-60:LineAttack(4,9),
 	-61:PlaySound(2,6),
 	-62:StopSound(1,2),
 	-63:strcmp(2,3),
@@ -337,6 +337,7 @@ special
 	-91:QuakeEx(8,12),
 	-92:Warp(6,11),
 	-93:GetMaxInventory(2),
+	-94:SetSectorDamage(2,6),
 
 	// Zandronum's
 	-100:ResetMap(0),

Build/Configurations/Boom_DoomDoom.cfg

@@ -32,6 +32,15 @@ include("Includes\\Game_Doom.cfg");
 //mxd. No DECORATE support in vanilla
 decorategames = "";
 
+//mxd. Sky textures for vanilla maps
+defaultskytextures
+{
+	SKY1 = "E1M1,E1M2,E1M3,E1M4,E1M5,E1M6,E1M7,E1M8,E1M9";
+	SKY2 = "E2M1,E2M2,E2M3,E2M4,E2M5,E2M6,E2M7,E2M8,E2M9";
+	SKY3 = "E3M1,E3M2,E3M3,E3M4,E3M5,E3M6,E3M7,E3M8,E3M9";
+	SKY4 = "E4M1,E4M2,E4M3,E4M4,E4M5,E4M6,E4M7,E4M8,E4M9";
+}
+
 // Default thing filters
 // (these are not required, just useful for new users)
 thingsfilters

Build/Configurations/Doom_DoomDoom.cfg

@@ -32,6 +32,15 @@ include("Includes\\Game_Doom.cfg");
 //mxd. No DECORATE support in vanilla
 decorategames = "";
 
+//mxd. Sky textures for vanilla maps
+defaultskytextures
+{
+	SKY1 = "E1M1,E1M2,E1M3,E1M4,E1M5,E1M6,E1M7,E1M8,E1M9";
+	SKY2 = "E2M1,E2M2,E2M3,E2M4,E2M5,E2M6,E2M7,E2M8,E2M9";
+	SKY3 = "E3M1,E3M2,E3M3,E3M4,E3M5,E3M6,E3M7,E3M8,E3M9";
+	SKY4 = "E4M1,E4M2,E4M3,E4M4,E4M5,E4M6,E4M7,E4M8,E4M9";
+}
+
 // Default thing filters
 // (these are not required, just useful for new users)
 thingsfilters

Build/Configurations/Includes/Game_Doom.cfg

@@ -1,10 +1,18 @@
 // Default lump name for new map
 defaultlumpname = "MAP01";
-  basegame = 1; //mxd: 0 - UNKNOWN, 1 - DOOM, 2 - HERETIC, 3 - HEXEN, 4 - STRIFE, 
+basegame = 1; //mxd: 0 - UNKNOWN, 1 - DOOM, 2 - HERETIC, 3 - HEXEN, 4 - STRIFE
 
 // Decorate actors to include depending on actor game property
 decorategames = "doom";
 
+//mxd. Sky textures for vanilla maps
+defaultskytextures
+{
+	SKY1 = "MAP01,MAP02,MAP03,MAP04,MAP05,MAP06,MAP07,MAP08,MAP09,MAP10,MAP11";
+	SKY2 = "MAP12,MAP13,MAP14,MAP15,MAP16,MAP17,MAP18,MAP19,MAP20";
+	SKY3 = "MAP21,MAP22,MAP23,MAP24,MAP25,MAP26,MAP27,MAP28,MAP29,MAP30,MAP31,MAP32";
+}
+
 // Skill levels
 skills
 {

Build/Configurations/Includes/Game_Heretic.cfg

@@ -5,6 +5,14 @@
 // Decorate actors to include depending on actor game property
 decorategames = "heretic raven";
 
+//mxd. Sky textures for vanilla maps
+defaultskytextures
+{
+	SKY1 = "E1M1,E1M2,E1M3,E1M4,E1M5,E1M6,E1M7,E1M8,E1M9,E4M1,E4M2,E4M3,E4M4,E4M5,E4M6,E4M7,E4M8,E4M9,E6M1,E6M2,E6M3";
+	SKY2 = "E2M1,E2M2,E2M3,E2M4,E2M5,E2M6,E2M7,E2M8,E2M9";
+	SKY3 = "E3M1,E3M2,E3M3,E3M4,E3M5,E3M6,E3M7,E3M8,E3M9,E5M1,E5M2,E5M3,E5M4,E5M5,E5M6,E5M7,E5M8,E5M9";
+}
+
 // Skill levels
 skills
 {

Build/Configurations/Includes/Game_Strife.cfg

@@ -6,6 +6,13 @@
 // Decorate actors to include depending on actor game property
 decorategames = "strife";
 
+//mxd. Sky textures for vanilla maps
+defaultskytextures
+{
+	SKYMNT01 = "MAP10,MAP11,MAP12,MAP13,MAP14,MAP15,MAP16,MAP17,MAP18,MAP19,MAP20,MAP21,MAP22,MAP23,MAP24,MAP25,MAP26,MAP27,MAP28,MAP29,MAP30,MAP31";
+	SKYMNT02 = "MAP01,MAP02,MAP03,MAP04,MAP05,MAP06,MAP07,MAP08,MAP09,MAP32,MAP33,MAP34";
+}
+
 // Skill levels
 skills
 {

Build/Configurations/Includes/ZDoom_things.cfg

@@ -32,20 +32,6 @@ zdoom
 		}
 	}
 
-	obstacles
-	{
-		blocking = 2;
-		
-		5050
-		{
-			title = "Stalagmite";
-			sprite = "SMT2A0";
-			class = "Stalagmite";
-			width = 16;
-			height = 48;
-		}
-	}
-
 	lights
 	{
 		blocking = 2;
@@ -1397,6 +1383,20 @@ doom
 		}
 	}
 		
+	obstacles
+	{
+		blocking = 2;
+		
+		5050
+		{
+			title = "Stalagmite";
+			sprite = "SMT2A0";
+			class = "Stalagmite";
+			width = 16;
+			height = 48;
+		}
+	}
+
 	decoration
 	{
 		49	// Hanging victim, twitching (blocking)

Build/Configurations/Other Games/Action Doom/Includes/Game_Action2.cfg

@@ -4,6 +4,14 @@
 // Decorate actors to include depending on actor game property
 decorategames = "action2"; // Doesn't actually exist, but used to prevent loading Doom actors when loading zdoom.pk3
 
+//mxd. Sky textures for vanilla maps
+defaultskytextures
+{
+	SKY1 = "MAP01,MAP02,MAP03,MAP04,MAP05,MAP06,MAP07,MAP08,MAP09,MAP10,MAP11";
+	SKY2 = "MAP12,MAP13,MAP14,MAP15,MAP16,MAP17,MAP18,MAP19,MAP20";
+	SKY3 = "MAP21,MAP22,MAP23,MAP24,MAP25,MAP26,MAP27,MAP28,MAP29,MAP30,MAP31,MAP32";
+}
+
 // Skill levels
 skills
 {

Build/Configurations/Other Games/Chex Quest 3/Includes/Game_Chex3.cfg

@@ -4,6 +4,12 @@
 // Decorate actors to include depending on actor game property
 decorategames = "chex";
 
+//mxd. Sky textures for vanilla maps
+defaultskytextures
+{
+	SKY1 = "E1M1,E1M2,E1M3,E1M4,E1M5";
+}
+
 // Skill levels
 skills
 {

Build/Configurations/Other Games/Chex Quest/Includes/Game_Chex.cfg

@@ -4,6 +4,12 @@
 // Decorate actors to include depending on actor game property
 decorategames = "chex";
 
+//mxd. Sky textures for vanilla maps
+defaultskytextures
+{
+	SKY1 = "E1M1,E1M2,E1M3,E1M4,E1M5";
+}
+
 // Skill levels
 skills
 {

Build/Configurations/Other Games/Harmony/Includes/Game_Harmony.cfg

@@ -4,6 +4,14 @@
 // Decorate actors to include depending on actor game property
 decorategames = "harmony"; // Doesn't actually exist, but used to prevent loading Doom actors when loading zdoom.pk3
 
+//mxd. Sky textures for vanilla maps
+defaultskytextures
+{
+	SKY1 = "MAP01,MAP02,MAP03,MAP04,MAP05,MAP06,MAP07,MAP08,MAP09,MAP10,MAP11";
+	SKY2 = "MAP12,MAP13,MAP14,MAP15,MAP16,MAP17,MAP18,MAP19,MAP20";
+	SKY3 = "MAP21,MAP22,MAP23,MAP24,MAP25,MAP26,MAP27,MAP28,MAP29,MAP30,MAP31,MAP32";
+}
+
 // Skill levels
 skills
 {

Build/Scripting/ZDoom_ACS.cfg

@@ -121,7 +121,7 @@ keywords
 	Death = "Script expression Death";
 	Default = "default:";
 	Delay = "void Delay(int tics)";
-	Disconnect = "Disconnect script expression";
+	Disconnect = "Script expression Disconnect";
 	Do = "do";
 	Door_Animated = "Door_Animated(tag, speed, delay, lock)";
 	Door_Close = "Door_Close(tag, speed, lighttag)";
@@ -261,7 +261,7 @@ keywords
 	Light_Strobe = "Light_Strobe(tag, upper, lower, u-tics, l-tics)";
 	Light_StrobeDoom = "Light_StrobeDoom(tag, u-tics, l-tics)";
 	Lightning = "Script expression Lightning";
-	LineAttack = "LineAttack(int tid, fixed angle, fixed pitch, int damage[, str pufftype = 'BulletPuff'[, str damagetype = 'None'[, fixed range = 2048[, int flags = 0]]]])\nFires a hitscan attack. If tid is 0, the activator of the script is the source of the attack.";
+	LineAttack = "LineAttack(int tid, fixed angle, fixed pitch, int damage[, str pufftype = 'BulletPuff'[, str damagetype = 'None'[, fixed range = 2048[, int flags = 0[, int pufftid = 0]]]]])\nFires a hitscan attack. If tid is 0, the activator of the script is the source of the attack.";
 	Line_AlignCeiling = "Line_AlignCeiling(lineid, side)";
 	Line_AlignFloor = "Line_AlignFloor(lineid, side)";
 	Line_SetBlocking = "Line_SetBlocking(lineid, setflags, clearflags)";
@@ -390,6 +390,8 @@ keywords
 	SetPlayerProperty = "SetPlayerProperty(who, set, which)";
 	SetPointer = "bool SetPointer(int assign_slot, int tid[, int pointer_selector[, int flags]])\nSet the value of one of the caller's stored pointers.";
 	SetResultValue = "void SetResultValue(int value)";
+	SetSectorDamage = "fixed SetSectorDamage(int tag, int amount, str damagetype, int interval, int leaky)";
+	SetSectorTerrain = "fixed SetSectorTerrain(int tag, int plane, str terraintype)";
 	SetSkyScrollSpeed = "void SetSkyScrollSpeed(int sky, fixed skyspeed)\nChanges the scrolling speed of a sky.\nThis is useful in conjunction with ChangeSky.\nsky: either 1 or 2.\nskyspeed: the desired scrolling speed.";
 	SetActorTeleFog = "void SetActorTeleFog(int tid, str telefogsrcclass, str telefogdestclass";
 	SetThingSpecial = "void SetThingSpecial(int tid, int special[, int arg0[, int arg1[, int arg2[, int arg3[, int arg4]]]]])\nSets the special for any things with the same TID.\nThis is similar to Thing_SetSpecial, except it can only be used from ACS,\nand it can set all of a thing's special arguments.\nIf tid is 0, then the activator is used.";
@@ -547,11 +549,12 @@ constants
 	APROP_Mass;
 	APROP_MasterTID;
 	APROP_MeleeRange;
-	APROP_NameTag;
+	APROP_Nametag;
-	APROP_NoTarget;
+	APROP_Notarget;
-	APROP_NoTrigger;
+	APROP_Notrigger;
 	APROP_PainSound;
 	APROP_Radius;
+	APROP_Reactiontime;
 	APROP_RenderStyle;
 	APROP_ScaleX;
 	APROP_ScaleY;
@@ -566,12 +569,12 @@ constants
 	APROP_TracerTID;
 	APROP_ViewHeight;
 	APROP_Waterlevel;
-	ARMORINFO_CLASSNAME;
-	ARMORINFO_SAVEAMOUNT;
 	ARMORINFO_ACTUALSAVEAMOUNT;
-	ARMORINFO_SAVEPERCENT;
+	ARMORINFO_CLASSNAME;
 	ARMORINFO_MAXABSORB;
 	ARMORINFO_MAXFULLABSORB;
+	ARMORINFO_SAVEAMOUNT;
+	ARMORINFO_SAVEPERCENT;
 	ATTN_IDLE;
 	ATTN_NONE;
 	ATTN_NORM;
@@ -590,6 +593,7 @@ constants
 	BLOCKF_PROJECTILES;
 	BLOCKF_RAILING;
 	BLOCKF_SIGHT;
+	BLOCKF_SOUND;
 	BLOCKF_USE;
 	BT_ALTATTACK;
 	BT_ATTACK;
@@ -617,20 +621,19 @@ constants
 	BT_USER4;
 	BT_ZOOM;
 	CARRY;
-	CHAN_AREA;
+	CHAN_5;
+	CHAN_6;
+	CHAN_7;
 	CHAN_AUTO;
 	CHAN_BODY;
 	CHAN_ITEM;
 	CHAN_LISTENERZ;
-	CHAN_LOOP;
 	CHAN_MAYBE_LOCAL;
 	CHAN_NOPAUSE;
 	CHAN_UI;
 	CHAN_VOICE;
 	CHAN_WEAPON;
-	CHAN_5;
+	CHANGELEVEL_CHANGESKILL;
-	CHAN_6;
-	CHAN_7;
 	CHANGELEVEL_KEEPFACING;
 	CHANGELEVEL_NOINTERMISSION;
 	CHANGELEVEL_NOMONSTERS;
@@ -670,9 +673,27 @@ constants
 	DAMAGE_NONPLAYERS;
 	DAMAGE_PLAYERS;
 	DAMAGE_SUBCLASSES_PROTECT;
+	DB_ORDER_ASC;
+	DB_ORDER_DESC;
+	EV_Char;
+	EV_KeyDown;
+	EV_KeyRepeat;
+	EV_KeyUp;
+	EV_LButtonDblClick;
+	EV_LButtonDown;
+	EV_LButtonUp;
+	EV_MButtonDblClick;
+	EV_MButtonDown;
+	EV_MButtonUp;
+	EV_MouseMove;
+	EV_RButtonDblClick;
+	EV_RButtonDown;
+	EV_RButtonUp;
+	EV_WheelDown;
+	EV_WheelUp;
 	FALSE;
-	FHF_NORANDOMPUFFZ;
 	FHF_NOIMPACTDECAL;
+	FHF_NORANDOMPUFFZ;
 	FOGP_DENSITY;
 	FOGP_OUTSIDEDENSITY;
 	FOGP_SKYFOG;
@@ -680,6 +701,45 @@ constants
 	GAME_NET_DEATHMATCH;
 	GAME_SINGLE_PLAYER;
 	GAME_TITLE_MAP;
+	GK_ALERT;
+	GK_BACKSPACE;
+	GK_CESCAPE;
+	GK_DEL;
+	GK_DOWN;
+	GK_END;
+	GK_ESCAPE;
+	GK_F1;
+	GK_F10;
+	GK_F11;
+	GK_F12;
+	GK_F2;
+	GK_F3;
+	GK_F4;
+	GK_F5;
+	GK_F6;
+	GK_F7;
+	GK_F8;
+	GK_F9;
+	GK_FORMFEED;
+	GK_FREE1;
+	GK_FREE2;
+	GK_FREE3;
+	GK_HOME;
+	GK_LEFT;
+	GK_LINEFEED;
+	GK_PGDN;
+	GK_PGUP;
+	GK_RETURN;
+	GK_RIGHT;
+	GK_TAB;
+	GK_UP;
+	GK_VTAB;
+	GKM_ALT;
+	GKM_CTRL;
+	GKM_LBUTTON;
+	GKM_MBUTTON;
+	GKM_RBUTTON;
+	GKM_SHIFT;
 	HUDMSG_ADDBLEND;
 	HUDMSG_ALPHA;
 	HUDMSG_COLORSTRING;
@@ -733,66 +793,69 @@ constants
 	MARINEWEAPON_RocketLauncher;
 	MARINEWEAPON_Shotgun;
 	MARINEWEAPON_SuperShotgun;
-	MF_SPECIAL;
-	MF_SOLID;
-	MF_SHOOTABLE;
-	MF_NOSECTOR;
-	MF_NOBLOCKMAP;
 	MF_AMBUSH;
-	MF_JUSTHIT;
-	MF_JUSTATTACKED;
-	MF_SPAWNCEILING;
-	MF_NOGRAVITY;
-	MF_DROPOFF;
-	MF_PICKUP;
-	MF_NOCLIP;
-	MF_INCHASE;
-	MF_FLOAT;
-	MF_TELEPORT;
-	MF_MISSILE;
-	MF_DROPPED;
-	MF_SHADOW;
-	MF_NOBLOOD;
 	MF_CORPSE;
-	MF_INFLOAT;
-	MF_INBOUNCE;
-	MF_COUNTKILL;
 	MF_COUNTITEM;
-	MF_SKULLFLY;
+	MF_COUNTKILL;
-	MF_NOTDMATCH;
+	MF_DROPOFF;
-	MF_SPAWNSOUNDSOURCE;
+	MF_DROPPED;
+	MF_FLOAT;
 	MF_FRIENDLY;
-	MF_UNMORPHED;
-	MF_NOLIFTDROP;
-	MF_STEALTH;
 	MF_ICECORPSE;
-	ML_BLOCKING;
+	MF_INBOUNCE;
-	ML_BLOCKMONSTERS;
+	MF_INCHASE;
-	ML_TWOSIDED;
+	MF_INFLOAT;
-	ML_DONTPEGTOP;
+	MF_JUSTATTACKED;
-	ML_DONTPEGBOTTOM;
+	MF_JUSTHIT;
-	ML_SECRET;
+	MF_MISSILE;
-	ML_SOUNDBLOCK;
+	MF_NOBLOCKMAP;
-	ML_DONTDRAW;
+	MF_NOBLOOD;
-	ML_MAPPED;
+	MF_NOCLIP;
-	ML_REPEAT_SPECIAL;
+	MF_NOGRAVITY;
+	MF_NOLIFTDROP;
+	MF_NOSECTOR;
+	MF_NOTDMATCH;
+	MF_PICKUP;
+	MF_SHADOW;
+	MF_SHOOTABLE;
+	MF_SKULLFLY;
+	MF_SOLID;
+	MF_SPAWNCEILING;
+	MF_SPAWNSOUNDSOURCE;
+	MF_SPECIAL;
+	MF_STEALTH;
+	MF_TELEPORT;
+	MF_UNMORPHED;
+	ML_3DMIDTEX;
 	ML_ADDTRANS;
-	ML_MONSTERSCANACTIVATE;
+	ML_BLOCK_FLOATERS;
 	ML_BLOCK_PLAYERS;
 	ML_BLOCKEVERYTHING;
-	ML_ZONEBOUNDARY;
-	ML_RAILING;
-	ML_BLOCK_FLOATERS;
-	ML_CLIP_MIDTEX;
-	ML_WRAP_MIDTEX;
-	ML_3DMIDTEX;
-	ML_CHECKSWITCHRANGE;
-	ML_FIRSTSIDEONLY;
-	ML_BLOCKPROJECTILE;
-	ML_BLOCKUSE;
-	ML_BLOCKSIGHT;
 	ML_BLOCKHITSCAN;
+	ML_BLOCKING;
+	ML_BLOCKMONSTERS;
+	ML_BLOCKPROJECTILE;
+	ML_BLOCKSIGHT;
+	ML_BLOCKUSE;
+	ML_CHECKSWITCHRANGE;
+	ML_CLIP_MIDTEX;
+	ML_DONTDRAW;
+	ML_DONTPEGBOTTOM;
+	ML_DONTPEGTOP;
+	ML_FIRSTSIDEONLY;
+	ML_MAPPED;
+	ML_MONSTERSCANACTIVATE;
+	ML_RAILING;
+	ML_REPEAT_SPECIAL;
+	ML_SECRET;
+	ML_SOUNDBLOCK;
+	ML_TWOSIDED;
+	ML_WRAP_MIDTEX;
+	ML_ZONEBOUNDARY;
+	MOD_BARREL;
+	MOD_BFG_BOOM;
 	MOD_BFG_SPLASH;
+	MOD_CHAINSAW;
 	MOD_CRUSH;
 	MOD_DISINTEGRATE;
 	MOD_ELECTRIC;
@@ -801,9 +864,14 @@ constants
 	MOD_HIT;
 	MOD_ICE;
 	MOD_LAVA;
+	MOD_PLASMARIFLE;
 	MOD_POISON;
+	MOD_R_SPLASH;
 	MOD_RAILGUN;
+	MOD_ROCKET;
 	MOD_SLIME;
+	MOD_SPLASH;
+	MOD_SSHOTGUN;
 	MOD_SUICIDE;
 	MOD_TELEFRAG;
 	MOD_UNKNOWN;
@@ -835,6 +903,7 @@ constants
 	MRF_WHENINVULNERABLE;
 	NO;
 	NO_CHANGE;
+	NO_TEAM;
 	NOT_BOTTOM;
 	NOT_CEILING;
 	NOT_FLOOR;
@@ -875,11 +944,11 @@ constants
 	PTROP_NOSAFEGUARDS;
 	PTROP_UNSAFEMASTER;
 	PTROP_UNSAFETARGET;
+	QF_FULLINTENSITY;
+	QF_MAX;
 	QF_RELATIVE;
 	QF_SCALEDOWN;
 	QF_SCALEUP;
-	QF_MAX;
-	QF_FULLINTENSITY;
 	QF_WAVE;
 	SCROLL;
 	SCROLL_AND_CARRY;
@@ -900,21 +969,31 @@ constants
 	SKILL_NORMAL;
 	SKILL_VERY_EASY;
 	SKILL_VERY_HARD;
-	SPAC_None;
+	SOUND_Active;
-	SPAC_Cross;
+	SOUND_Attack;
-	SPAC_Use;
+	SOUND_Bounce;
-	SPAC_MCross;
+	SOUND_CrushPain;
-	SPAC_Impact;
+	SOUND_Death;
-	SPAC_Push;
+	SOUND_Howl;
-	SPAC_PCross;
+	SOUND_Pain;
-	SPAC_UseThrough;
+	SOUND_See;
+	SOUND_Use;
+	SOUND_WallBounce;
 	SPAC_AnyCross;
-	SPAC_MUse;
+	SPAC_Cross;
+	SPAC_Impact;
+	SPAC_MCross;
 	SPAC_MPush;
+	SPAC_MUse;
+	SPAC_None;
+	SPAC_PCross;
+	SPAC_Push;
+	SPAC_Use;
 	SPAC_UseBack;
+	SPAC_UseThrough;
 	STYLE_Add;
-	STYLE_AddStencil;
 	STYLE_AddShaded;
+	STYLE_AddStencil;
 	STYLE_Fuzzy;
 	STYLE_None;
 	STYLE_Normal;
@@ -1242,6 +1321,8 @@ constants
 	T_YELLOWKEYCARD;
 	T_YELLOWSKULLKEY;
 	T_ZOMBIE;
+	TEAM_BLUE;
+	TEAM_RED;
 	TEXFLAG_ADDOFFSET;
 	TEXFLAG_BOTTOM;
 	TEXFLAG_MIDDLE;
@@ -1249,22 +1330,41 @@ constants
 	TEXTURE_BOTTOM;
 	TEXTURE_MIDDLE;
 	TEXTURE_TOP;
-	WARPF_ABSOLUTEOFFSET;
+	TPROP_Assister;
+	TPROP_Carrier;
+	TPROP_DeathCount;
+	TPROP_FragCount;
+	TPROP_IsValid;
+	TPROP_LoserTheme;
+	TPROP_Name;
+	TPROP_NumLivePlayers;
+	TPROP_NumPlayers;
+	TPROP_PlayerStartNum;
+	TPROP_PointCount;
+	TPROP_ReturnTics;
+	TPROP_Score;
+	TPROP_Spread;
+	TPROP_TeamItem;
+	TPROP_TextColor;
+	TPROP_WinCount;
+	TPROP_WinnerTheme;
+	TRANSLATION_ICE;
+	TRUE;
 	WARPF_ABSOLUTEANGLE;
-	WARPF_USECALLERANGLE;
+	WARPF_ABSOLUTEOFFSET;
-	WARPF_NOCHECKPOSITION;
-	WARPF_INTERPOLATE;
-	WARPF_WARPINTERPOLATION;
-	WARPF_COPYINTERPOLATION;
-	WARPF_STOP;
-	WARPF_TOFLOOR;
-	WARPF_TESTONLY;
 	WARPF_ABSOLUTEPOSITION;
 	WARPF_BOB;
-	WARPF_MOVEPTR;
+	WARPF_COPYINTERPOLATION;
-	WARPF_USEPTR;
-	WARPF_COPYVELOCITY;
 	WARPF_COPYPITCH;
-	TRUE;
+	WARPF_COPYVELOCITY;
+	WARPF_INTERPOLATE;
+	WARPF_MOVEPTR;
+	WARPF_NOCHECKPOSITION;
+	WARPF_STOP;
+	WARPF_TESTONLY;
+	WARPF_TOFLOOR;
+	WARPF_USECALLERANGLE;
+	WARPF_USEPTR;
+	WARPF_WARPINTERPOLATION;
 	YES;
 }

Help/gc_basicsettings.html

@@ -23,10 +23,11 @@
 		<br />
         <b class="fat">game</b> (string)<br />
 		The name that is displayed in Doom Buider for your Game Configuration.<br />
+        Default value is <b>"&lt;unnamed game&gt;"</b>.<br />
 		<br />
 		<b class="fat">enabledbydefault</b> (boolean) - <span class="red">GZDB only</span>.<br />
 		This game configuration is available by default. You can enable and disable game configurations using <a href="w_gameconfigurations.html">Game Configurations window</a>.<br />
-        The default value is <b>false</b>.<br />
+        Default value is <b>false</b>.<br />
 		<br />
         <b class="fat">actionspecialhelp</b> (string) - <span class="red">GZDB only</span>.<br />
 		The URL used to display action special help. &quot;<strong>%K</strong>&quot; wildcard is replaced by <strong>id</strong> property defined in <a href="gc_linedefsettings.html#actionid">action definition</a>.<br />
@@ -38,7 +39,7 @@
         <b class="fat">basegame</b>  (integer) [0 .. 4] - <span class="red">GZDB only</span>.<br />
 		Indicates which game the current configuration is based on. Used to load game-specific GLDEFS lumps (DOOMDEFS, HTICDEFS, HEXNDEFS or STRFDEFS).
         <br /><b>Possible values:</b> 1 (DOOM), 2 (HERETIC), 3 (HEXEN) or 4 (STRIFE).<br />
-        The default value is <b>0</b> (don't load game-specific lumps).<br />
+        Default value is <b>0</b> (don't load game-specific lumps).<br />
 
 		<br />
 		<b class="fat">engine</b> (string)<br />
@@ -52,7 +53,7 @@
 		<br />
 		<b class="fat">testshortpaths</b> (boolean)<br />
 		Set to <b>true</b> to use MSDOS 8.3 format paths and filenames by default. The user can still change this in the <a href="w_gameconfigurations.html">Game Configurations window</a>.<br />
-		The default value is <b>false</b>.<br />
+		Default value is <b>false</b>.<br />
 		<br />
 		<b class="fat">defaultsavecompiler</b> (string)<br />
 	  Name of the <a href="scriptingconfigs.html">Nodebuilder Compiler Configuration structure</a> to use as the default settings for the compiler that is used when saving the map. The user can still change this in the <a href="w_gameconfigurations.html">Game Configurations window</a>.<br />
@@ -79,7 +80,8 @@ skills
 </pre>
 		<br />
 		<b class="fat">linetagindicatesectors</b> (boolean)<br />
-		When <b>true</b>, Doom Builder will highlight sectors associated with the same tag number when a line is highlighted. This is only really useful for Doom format maps, because Hexen format and UDMF format has no single tag on linedefs (in those formats, the arguments of the linedef's action can be tags, which also works to highlight sectors).<br />The default is <b>false</b>.<br />
+		When <b>true</b>, Doom Builder will highlight sectors associated with the same tag number when a line is highlighted. This is only really useful for Doom format maps, because Hexen format and UDMF format has no single tag on linedefs (in those formats, the arguments of the linedef's action can be tags, which also works to highlight sectors).<br />
+Default value is <b>false</b>.<br />
 		<br />
 	  <b class="fat">singlesidedflag</b> (integer or string)<br />
 		This lets Doom Builder know the <a href="gc_linedefflags.html">linedef flag</a> that indicates a line with only one side. Doom Builder will set this flag value on a linedef when it changes a line to become single sided and removes the flag from a linedef when it becomes double sided. Plugins can also use this information to perform operations on linedefs. For map formats that use numeric flags (Doom and Hexen) this must be an integer flag value. For map formats that use named flags (UDMF), this must be a string indicating the name of the flag.<br />
@@ -92,21 +94,27 @@ skills
 		<br />
         <b class="fat">defaultwalltexture</b> (string) - <span class="red">GZDB only</span>.<br />
 		Name of a texture to use on sidedefs when creating a new sector.<br />
+<b>"STARTAN"</b>.<br />
         <br />
         <b class="fat">defaultfloortexture</b> (string) - <span class="red">GZDB only</span>.<br />
 		Name of a flat to use on the floor when creating a new sector.<br />
+      Default value is <b>"FLOOR0_1"</b>.<br />
         <br />
         <b class="fat">defaultceilingtexture</b> (string) - <span class="red">GZDB only</span>.<br />
 		Name of a flat to use on the ceiling when creating a new sector.<br />
+      Default value is <b>"CEIL1_1"</b>.<br />
         <br />
         <b class="fat">makedoortrack</b> (string)<br />
 		Name of a texture to use on the walls when making a door.<br />
+  Default value is <b>"-"</b> (no texture).<br />
         <br />
 		<b class="fat">makedoordoor</b> (string) - <span class="red">GZDB only</span>.<br />
 		Name of a texture to use as the door texture when making a door.<br />
+  Default value is <b>"-"</b> (no texture).<br />
 		<br />
         <b class="fat">makedoorceil</b> (string) - <span class="red">GZDB only</span>.<br />
 		Name of a texture to use as the door's ceiling texture when making a door.<br />
+  Default value is <b>"-"</b> (no texture).<br />
         <br />
 		<b class="fat">makedooraction</b> (integer)<br />
 		Linedef action number to put on the lines when making a door.<br />
@@ -115,13 +123,28 @@ skills
 		Arguments for the linedef action number to put on the lines when making a door.<br />
 		<br />
 		<b class="fat">doomlightlevels</b> (boolean)<br />
-		Set this to <b>false</b> to use linear lighting in Doom Builder. Normally Doom Builder uses a simulation of Doom's light levels.<br />Default value is <b>true</b>.<br />
+		Set this to <b>false</b> to use linear lighting in Doom Builder. Normally Doom Builder uses a simulation of Doom's light levels.
+<br />Default value is <b>true</b>.<br />
 		<br />
 		<b class="fat">start3dmode</b> (integer)<br />
 		Thing type number that Doom Builder will use to keep your Visual Mode camera position stored in the map. Doom Builder will place a single thing of this type in your map and move it along as you move in Visual Mode.<br />
 		<br />
 		<b class="fat">skyflatname</b> (string)<br />
-		Name of the flat that is interpreted as sky (meaning there is no ceiling). Doom Builder and plugins can use this information for various purposes.<br />
+		Name of the flat that is interpreted as sky (meaning there is no ceiling). Doom Builder and plugins can use this information for various purposes.
+  <br />Default value is <b>"F_SKY1"</b>.<br />
+		<br />
+        <b class="fat">defaultskytextures</b> (structure) - <span class="red">GZDB only</span>.<br />
+		Defines the relationship between map names and sky texture names used by vanilla maps.<br />
+		<br />
+        <strong>Example:</strong>
+        <pre>
+defaultskytextures
+{
+	SKY1 = "MAP01,MAP02,MAP03,MAP04,MAP05";
+	SKY2 = "MAP12,MAP13,MAP14,MAP15,MAP16";
+	SKY3 = "MAP21,MAP22,MAP23,MAP24,MAP25";
+}
+</pre>
 		<br />
 <b class="fat">longtexturenames</b> (boolean) - <span class="red">GZDB only</span>.<br />
 		Enables support for long (> 8 chars) texture names. This is used by GZDoom Builder to limit the input fields in the user interface and to check the validity of texture names in resources. This setting should only be enabled for UDMF game configurations. Enabling this setting will make maps incompatible with Doom Builder 2 and can lead to problems in Slade 3 This does NOT determine the actual limitation on the texture names in the map file format.<br />Default value is <b>false</b>.<br />

Help/gc_resourcesettings.html

@@ -21,7 +21,7 @@
 		<b class="fat">decorategames</b> (string)<br />
 		Fill this to the game names to support DECORATE actors from. Only the DECORATE actors who's game name is in this string will be loaded. If this setting is not set, DECORATE lumps are not loaded.<br />
 		<br />
-		Example:
+		<strong>Example:</strong>
 <pre>
 decorategames = "heretic raven";
 </pre>
@@ -41,7 +41,7 @@ decorategames = "heretic raven";
 		<b class="fat">textures</b> (structure)<br />
 		This lists the marker lump names that indicate the begin and end of a list of textures that Doom Builder should load. There must be a separate structure for each range, for which the structure name doesn't matter. The range must have a 'start' setting and an 'end' setting of which the values must be the names of the start and end lumps (strings). Please note that PNAMES, TEXTURE1 and TEXTURE2 lumps do not need to be in the game configuration, they are always loaded when available.<br />
 		<br />
-		Example:
+		<strong>Example:</strong>
 <pre>
 textures
 {
@@ -56,7 +56,7 @@ textures
 		<b class="fat">patches</b> (structure)<br />
 		This lists the marker lump names that indicate the begin and end of a list of patches that Doom Builder should load. There must be a separate structure for each range, for which the structure name doesn't matter. The range must have a 'start' setting and an 'end' setting of which the values must be the names of the start and end lumps (strings). Note that Doom Builder does not load all patches, only those that are used by the textures.<br />
 		<br />
-		Example:
+		<strong>Example:</strong>
 <pre>
 patches
 {
@@ -77,7 +77,7 @@ patches
 		<b class="fat">sprites</b> (structure)<br />
 		This lists the marker lump names that indicate the begin and end of a list of sprites that Doom Builder should load. There must be a separate structure for each range, for which the structure name doesn't matter. The range must have a 'start' setting and an 'end' setting of which the values must be the names of the start and end lumps (strings). Note that Doom Builder does not load all sprites, only those that are used by the <a href="gc_thingsettings.cfg">things</a>.<br />
 		<br />
-		Example:
+		<strong>Example:</strong>
 <pre>
 sprites
 {
@@ -92,7 +92,7 @@ sprites
 		<b class="fat">flats</b> (structure)<br />
 		This lists the marker lump names that indicate the begin and end of a list of flats that Doom Builder should load. There must be a separate structure for each range, for which the structure name doesn't matter. The range must have a 'start' setting and an 'end' setting of which the values must be the names of the start and end lumps (strings).<br />
 		<br />
-		Example:
+		<strong>Example:</strong>
 <pre>
 flats
 {
@@ -107,7 +107,7 @@ flats
 		<b class="fat">colormaps</b> (structure)<br />
 		This lists the marker lump names that indicate the begin and end of a list of colormaps that Doom Builder should load. There must be a separate structure for each range, for which the structure name doesn't matter. The range must have a 'start' setting and an 'end' setting of which the values must be the names of the start and end lumps (strings).<br />
 		<br />
-		Example:
+		<strong>Example:</strong>
 <pre>
 colormaps
 {

Source/Core/Builder.csproj

@@ -46,8 +46,9 @@
     <DocumentationFile>..\..\Build\Builder.xml</DocumentationFile>
     <DefineConstants>
     </DefineConstants>
-    <WarningLevel>3</WarningLevel>
+    <WarningLevel>4</WarningLevel>
     <DebugSymbols>true</DebugSymbols>
+    <NoWarn>1591</NoWarn>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug + Profiler|x86' ">
     <DebugSymbols>true</DebugSymbols>
@@ -875,6 +876,7 @@
     <Compile Include="GZBuilder\Data\ModelLoadState.cs" />
     <Compile Include="GZBuilder\Data\ScriptItem.cs" />
     <Compile Include="GZBuilder\Data\SharpCompressHelper.cs" />
+    <Compile Include="GZBuilder\Data\SkyboxInfo.cs" />
     <Compile Include="GZBuilder\Rendering\SizelessVisualThingCage.cs" />
     <Compile Include="GZBuilder\Rendering\ThingBoundingBox.cs" />
     <Compile Include="GZBuilder\Data\ThingCopyData.cs" />
@@ -1132,10 +1134,12 @@
     <None Include="Resources\MCrash.png" />
     <None Include="Resources\MixedThings.png" />
     <None Include="Resources\LinedefColorPresets.png" />
+    <EmbeddedResource Include="Resources\MissingSky3D.png" />
     <Content Include="Resources\Model.png" />
     <None Include="Resources\ModelDisabled.png" />
     <None Include="Resources\ModelFiltered.png" />
     <Content Include="Resources\Model_selected.png" />
+    <None Include="Resources\Sky.png" />
     <None Include="Resources\Update.png" />
     <None Include="Resources\Reload.png" />
     <None Include="Resources\Preferences.png" />

Source/Core/Config/GameConfiguration.cs

@@ -77,6 +77,7 @@ namespace CodeImp.DoomBuilder.Config
 		private readonly bool linetagindicatesectors;
 		private readonly string decorategames;
 		private string skyflatname;
+        private Dictionary<string, string> defaultskytextures; //mxd <map name, sky texture name>
         private readonly int maxtexturenamelength;
 		private readonly bool longtexturenames; //mxd
 		private readonly int leftboundary;
@@ -194,6 +195,7 @@ namespace CodeImp.DoomBuilder.Config
 		public bool LineTagIndicatesSectors { get { return linetagindicatesectors ; } }
 		public string DecorateGames { get { return decorategames; } }
 		public string SkyFlatName { get { return skyflatname; } internal set { skyflatname = value; } } //mxd. Added setter
+        public Dictionary<string, string> DefaultSkyTextures { get { return defaultskytextures; } } //mxd
         public int MaxTextureNameLength { get { return maxtexturenamelength; } }
 		public bool UseLongTextureNames { get { return longtexturenames; } } //mxd
 		public int LeftBoundary { get { return leftboundary; } }
@@ -309,6 +311,7 @@ namespace CodeImp.DoomBuilder.Config
 			this.linedefrenderstyles = new Dictionary<string, string>(StringComparer.Ordinal); //mxd
 			this.sectorrenderstyles = new Dictionary<string, string>(StringComparer.Ordinal); //mxd
 			this.thingrenderstyles = new Dictionary<string, string>(StringComparer.Ordinal); //mxd
+            this.defaultskytextures = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase); //mxd
 
             // Read general settings
             configname = cfg.ReadSetting("game", "<unnamed game>");
@@ -426,6 +429,9 @@ namespace CodeImp.DoomBuilder.Config
 			LoadTextureSets();
 			LoadThingFilters();
 
+            //mxd. Vanilla sky textures
+            LoadDefaultSkies();
+
             // Make door flags
             LoadMakeDoorFlags();
 		}
@@ -898,6 +904,40 @@ namespace CodeImp.DoomBuilder.Config
 			}
 		}
 
+        //mxd
+        private void LoadDefaultSkies()
+        {
+            IDictionary dic = cfg.ReadSetting("defaultskytextures", new Hashtable());
+            char[] separator = new[] { ',' };
+            foreach (DictionaryEntry de in dic)
+            {
+                string skytex = de.Key.ToString();
+                if (defaultskytextures.ContainsKey(skytex))
+                {
+                    General.ErrorLogger.Add(ErrorType.Warning, "Sky texture \"" + skytex + "\" is double-defined in the current game configuration!");
+                    continue;
+                }
+
+                string[] maps = de.Value.ToString().Split(separator, StringSplitOptions.RemoveEmptyEntries);
+                if (maps.Length == 0)
+                {
+                    General.ErrorLogger.Add(ErrorType.Warning, "Sky texture \"" + skytex + "\" has no map names defined in the current game configuration!");
+                    continue;
+                }
+
+                foreach (string map in maps)
+                {
+                    if (defaultskytextures.ContainsKey(map))
+                    {
+                        General.ErrorLogger.Add(ErrorType.Warning, "Map \"" + map + "\" is double-defined in the \"DefaultSkyTextures\" block of current game configuration!");
+                        continue;
+                    }
+
+                    defaultskytextures[map] = skytex;
+                }
+            }
+        }
+
         //mxd
         private void LoadStringDictionary(Dictionary<string, string> target, string settingname) 
 		{

Source/Core/Config/ProgramConfiguration.cs

@@ -98,6 +98,7 @@ namespace CodeImp.DoomBuilder.Config
 		private ModelRenderMode gzDrawModelsMode;
 		private LightRenderMode gzDrawLightsMode;
 		private bool gzDrawFog;
+        private bool gzDrawSky;
         private bool gzToolbarGZDoom;
 		private bool gzSynchCameras;
 		private bool gzShowEventLines;
@@ -112,6 +113,7 @@ namespace CodeImp.DoomBuilder.Config
 		private string lastUsedConfigName;
 		private string lastUsedMapFolder;
 		private bool gzMarkExtraFloors;
+        private bool gzdoomrenderingeffects = true; //mxd
         private bool drawFullCrosshair;
 		private int maxRecentFiles;
 		private bool autoClearSideTextures;
@@ -192,6 +194,7 @@ namespace CodeImp.DoomBuilder.Config
 		public ModelRenderMode GZDrawModelsMode { get { return gzDrawModelsMode; } internal set { gzDrawModelsMode = value; } }
 		public LightRenderMode GZDrawLightsMode { get { return gzDrawLightsMode; } internal set { gzDrawLightsMode = value; } }
 		public bool GZDrawFog { get { return gzDrawFog; } internal set { gzDrawFog = value; } }
+        public bool GZDrawSky { get { return gzDrawSky; } internal set { gzDrawSky = value; } }
         public bool GZToolbarGZDoom { get { return gzToolbarGZDoom; } internal set { gzToolbarGZDoom = value; } }
 		public bool GZSynchCameras { get { return gzSynchCameras; } internal set { gzSynchCameras = value; } }
 		public bool GZShowEventLines { get { return gzShowEventLines; } internal set { gzShowEventLines = value; } }
@@ -206,6 +209,7 @@ namespace CodeImp.DoomBuilder.Config
 		public string LastUsedConfigName { get { return lastUsedConfigName; } internal set { lastUsedConfigName = value; } }
 		public string LastUsedMapFolder { get { return lastUsedMapFolder; } internal set { lastUsedMapFolder = value; } }
 		public bool GZMarkExtraFloors { get { return gzMarkExtraFloors; } internal set { gzMarkExtraFloors = value; } }
+        public bool GZDoomRenderingEffects { get { return gzdoomrenderingeffects; } set { gzdoomrenderingeffects = value; } } //mxd
         public bool DrawFullCrosshair { get { return drawFullCrosshair; } internal set { drawFullCrosshair = value; } }
         public int MaxRecentFiles { get { return maxRecentFiles; } internal set { maxRecentFiles = General.Clamp(value, 8, 25); } }
 		public bool AutoClearSidedefTextures { get { return autoClearSideTextures; } internal set { autoClearSideTextures = value; } }
@@ -309,6 +313,7 @@ namespace CodeImp.DoomBuilder.Config
 				gzDrawModelsMode = (ModelRenderMode)cfg.ReadSetting("gzdrawmodels", (int)ModelRenderMode.ALL);
 				gzDrawLightsMode = (LightRenderMode)cfg.ReadSetting("gzdrawlights", (int)LightRenderMode.ALL);
 				gzDrawFog = cfg.ReadSetting("gzdrawfog", false);
+                gzDrawSky = cfg.ReadSetting("gzdrawsky", true);
                 gzToolbarGZDoom = cfg.ReadSetting("gztoolbargzdoom", true);
 				gzSynchCameras = cfg.ReadSetting("gzsynchcameras", true);
 				gzShowEventLines = cfg.ReadSetting("gzshoweventlines", true);
@@ -408,6 +413,7 @@ namespace CodeImp.DoomBuilder.Config
 			cfg.WriteSetting("gzdrawmodels", (int)gzDrawModelsMode);
 			cfg.WriteSetting("gzdrawlights", (int)gzDrawLightsMode);
 			cfg.WriteSetting("gzdrawfog", gzDrawFog);
+            cfg.WriteSetting("gzdrawsky", gzDrawSky);
             cfg.WriteSetting("gzsynchcameras", gzSynchCameras);
 			cfg.WriteSetting("gzshoweventlines", gzShowEventLines);
 			cfg.WriteSetting("gzoldhighlightmode", gzOldHighlightMode);

Source/Core/Controls/LinedefInfoPanel.cs

@@ -299,6 +299,16 @@ namespace CodeImp.DoomBuilder.Controls
 
 					//mxd. Sector index
 					frontpanel.Text += ". Sector " + l.Front.Sector.Index + " ";
+
+                    //visibility
+                    frontTopUDMFOffsetLabel.Visible = false;
+                    frontTopUDMFScaleLabel.Visible = false;
+
+                    frontMidUDMFOffsetLabel.Visible = false;
+                    frontMidUDMFScaleLabel.Visible = false;
+
+                    frontBottomUDMFOffsetLabel.Visible = false;
+                    frontBottomUDMFScaleLabel.Visible = false;
                 }
 
 				//mxd. Set texture names, update panel sizes

Source/Core/Controls/ScintillaControl.cs

@@ -135,10 +135,6 @@ namespace CodeImp.DoomBuilder.Controls
 		// on to the other controls on the parent form
 		private readonly Dictionary<int, int> ignoredkeys;
 				
-		// States
-		private ScriptMarginType indexmargintype;
-		private ScriptIndicatorStyle indexindicatorstyle;
-		
 		#endregion
 
 		#region ================== Properties
@@ -162,16 +158,6 @@ namespace CodeImp.DoomBuilder.Controls
 			set { EOLMode = (int)value; }
 		}
 
-		/// <summary>
-		/// The type of a margin.
-		/// </summary>
-		public ScriptMarginType MarginType { get { return indexmargintype; } }
-
-		/// <summary>
-		/// The type of a margin.
-		/// </summary>
-		public ScriptIndicatorStyle IndicatorStyle { get { return indexindicatorstyle; } }
-
 		/// <summary>
 		/// Are there any redoable actions in the undo history?
 		/// 

Source/Core/Data/DataManager.cs

@@ -18,6 +18,9 @@
 
 using System;
 using System.Collections.Generic;
+using System.Drawing;
+using System.Drawing.Drawing2D;
+using System.Drawing.Imaging;
 using System.IO;
 using System.Threading;
 using System.Windows.Forms;
@@ -29,6 +32,8 @@ using CodeImp.DoomBuilder.IO;
 using CodeImp.DoomBuilder.Map;
 using CodeImp.DoomBuilder.Windows;
 using CodeImp.DoomBuilder.ZDoom;
+using SlimDX;
+using SlimDX.Direct3D9;
 
 #endregion
 
@@ -70,6 +75,7 @@ namespace CodeImp.DoomBuilder.Data
 		private MapInfo mapinfo;
 		private Dictionary<string, KeyValuePair<int, int>> reverbs; //<name, <arg1, arg2> 
 		private Dictionary<long, GlowingFlatData> glowingflats; // Texture name hash, Glowing Flat Data
+        private Dictionary<string, SkyboxInfo> skyboxes;
         private List<string> soundsequences;
 		
 		// Background loading
@@ -92,6 +98,9 @@ namespace CodeImp.DoomBuilder.Data
 		private ImageData whitetexture;
 		private ImageData blacktexture; //mxd
 
+        //mxd. Sky textures
+        private CubeTexture skybox; // GZDoom skybox
+
         //mxd. Comment icons
         private ImageData[] commenttextures;
 		
@@ -139,6 +148,7 @@ namespace CodeImp.DoomBuilder.Data
 		public ImageData WhiteTexture { get { return whitetexture; } }
 		public ImageData BlackTexture { get { return blacktexture; } } //mxd
 		public ImageData[] CommentTextures { get { return commenttextures; } } //mxd
+        internal CubeTexture SkyBox { get { return skybox; } } //mxd
         public List<ThingCategory> ThingCategories { get { return thingcategories; } }
 		public ICollection<ThingTypeInfo> ThingTypes { get { return thingtypes.Values; } }
 		public DecorateParser Decorate { get { return decorate; } }
@@ -169,8 +179,10 @@ namespace CodeImp.DoomBuilder.Data
 			//mxd.
 			modeldefentries = new Dictionary<int, ModelData>();
 			gldefsentries = new Dictionary<int, DynamicLightData>();
-			reverbs = new Dictionary<string, KeyValuePair<int, int>>();
+            reverbs = new Dictionary<string, KeyValuePair<int, int>>(StringComparer.Ordinal);
             glowingflats = new Dictionary<long, GlowingFlatData>();
+            skyboxes = new Dictionary<string, SkyboxInfo>(StringComparer.Ordinal);
+
             soundsequences = new List<string>();
 
 			// Load special images (mxd: the rest is loaded in LoadInternalTextures())
@@ -224,8 +236,17 @@ namespace CodeImp.DoomBuilder.Data
 				blacktexture = null; //mxd
 				unknownimage.Dispose(); //mxd
 				unknownimage = null; //mxd
-				foreach(ImageData i in commenttextures) i.Dispose(); //mxd
+                for (int i = 0; i < commenttextures.Length; i++) //mxd
+                {
+                    commenttextures[i].Dispose();
+                    commenttextures[i] = null;
+                }
                 commenttextures = null;
+                if (skybox != null) //mxd
+                {
+                    skybox.Dispose();
+                    skybox = null;
+                }
 				
 				// Done
 				isdisposed = true;
@@ -252,7 +273,7 @@ namespace CodeImp.DoomBuilder.Data
 		}
 
         // This loads all data resources
-		internal void Load(DataLocationList locations)
+        private void Load(DataLocationList locations)
 		{
 			Dictionary<long, ImageData> texturesonly = new Dictionary<long, ImageData>();
 			Dictionary<long, ImageData> colormapsonly = new Dictionary<long, ImageData>();
@@ -475,6 +496,9 @@ namespace CodeImp.DoomBuilder.Data
 				alltextures.AddFlat(img.Value);
 			}
 
+            //mxd. Create skybox texture(s)
+            SetupSkybox();
+
             // Start background loading
             StartBackgroundLoader();
 			
@@ -483,7 +507,8 @@ namespace CodeImp.DoomBuilder.Data
 				colormapcount + " colormaps, " + spritecount + " sprites, " + 
 				thingcount + " decorate things, " + modeldefentries.Count + " model/voxel deinitions, " + 
 				gldefsentries.Count + " dynamic light definitions, " +
-				glowingflats.Count + " glowing flat definitions, " + reverbs.Count + " sound environment definitions");
+                glowingflats.Count + " glowing flat definitions, " + skyboxes.Count + " skybox definitions, " +
+                reverbs.Count + " sound environment definitions");
         }
 		
 		// This unloads all data
@@ -1730,7 +1755,7 @@ namespace CodeImp.DoomBuilder.Data
 		//mxd. This creates <Actor Class, Thing.Type> dictionary. Should be called after all DECORATE actors are parsed
 		private Dictionary<string, int> CreateActorsByClassList() 
 		{
-			Dictionary<string, int> actors = new Dictionary<string, int>(StringComparer.Ordinal);
+            Dictionary<string, int> actors = new Dictionary<string, int>(StringComparer.OrdinalIgnoreCase);
             if (string.IsNullOrEmpty(General.Map.Config.DecorateGames)) return actors;
 
 			//read our new shiny ClassNames for default game things
@@ -1738,11 +1763,9 @@ namespace CodeImp.DoomBuilder.Data
 			{
 				if(!string.IsNullOrEmpty(ti.Value.ClassName))
 				{
-					string classname = ti.Value.ClassName.ToLowerInvariant();
+                    if (actors.ContainsKey(ti.Value.ClassName) && actors[ti.Value.ClassName] != ti.Key)
-
-					if(actors.ContainsKey(classname) && actors[classname] != ti.Key)
                         General.ErrorLogger.Add(ErrorType.Warning, "actor '" + ti.Value.ClassName + "' has several editor numbers! Only the last one (" + ti.Key + ") will be used.");
-					actors[classname] = ti.Key;
+                    actors[ti.Value.ClassName] = ti.Key;
                 }
 			}
 
@@ -1772,7 +1795,10 @@ namespace CodeImp.DoomBuilder.Data
 
 			foreach(Thing t in General.Map.Map.Things) t.UpdateCache();
 
-			//rebuild geometry if in Visual mode
+            // Rebuild skybox texture
+            SetupSkybox();
+
+            // Rebuild geometry if in Visual mode
             if (General.Editing.Mode != null && General.Editing.Mode.GetType().Name == "BaseVisualMode") 
 			{
 				General.Editing.Mode.OnReloadResources();
@@ -1826,7 +1852,7 @@ namespace CodeImp.DoomBuilder.Data
 				foreach(KeyValuePair<string, Stream> group in streams) 
 				{
                     // Parse the data
-					if(parser.Parse(group.Value, currentreader.Location.location + "\\" + group.Key, true)) 
+                    if(parser.Parse(group.Value, Path.Combine(currentreader.Location.location, group.Key), true))
                     {
 						foreach(KeyValuePair<string, ModelData> g in parser.Entries) 
 						{
@@ -1952,7 +1978,7 @@ namespace CodeImp.DoomBuilder.Data
 		//mxd. This parses gldefs. Should be called after all DECORATE actors are parsed
 		private void LoadGldefs(Dictionary<string, int> actorsbyclass) 
 		{
-			//if no actors defined in DECORATE or game config...
+            // Skip if no actors defined in DECORATE or game config...
             if (actorsbyclass.Count == 0) return;
 
             GldefsParser parser = new GldefsParser { OnInclude = ParseFromLocation };
@@ -1977,10 +2003,10 @@ namespace CodeImp.DoomBuilder.Data
 				}
 			}
 
-			//create Gldefs Entries dictionary
+            // Create Gldefs Entries dictionary
             foreach (KeyValuePair<string, string> e in parser.Objects) //<ClassName, Light name>
             {
-				//if we have decorate actor and light definition for given ClassName...
+                //If we have decorate actor and light definition for given ClassName...
                 if (actorsbyclass.ContainsKey(e.Key) && parser.LightsByName.ContainsKey(e.Value)) 
 					gldefsentries[actorsbyclass[e.Key]] = parser.LightsByName[e.Value];
 				else if(!decorate.AllActorsByClass.ContainsKey(e.Key))
@@ -1989,6 +2015,9 @@ namespace CodeImp.DoomBuilder.Data
 
 			// Grab them glowy flats!
 			glowingflats = parser.GlowingFlats;
+
+            // And skyboxes
+            skyboxes = parser.Skyboxes;
         }
 
         //mxd. This loads (Z)MAPINFO
@@ -1996,6 +2025,7 @@ namespace CodeImp.DoomBuilder.Data
         {
             MapinfoParser parser = new MapinfoParser { OnInclude = ParseFromLocation };
 
+            // Parse mapinfo 
             foreach (DataReader dr in containers)
             {
                 currentreader = dr;
@@ -2004,30 +2034,33 @@ namespace CodeImp.DoomBuilder.Data
                 foreach (KeyValuePair<string, Stream> group in streams)
                 {
                     // Parse the data
-					parser.Parse(group.Value, Path.Combine(currentreader.Location.location, group.Key), General.Map.Options.LevelName, false);
+                    parser.Parse(group.Value, Path.Combine(dr.Location.location, group.Key), General.Map.Options.LevelName, false);
 
                     //MAPINFO lumps are interdependable. Can't carry on...
                     if (parser.HasError)
                     {
                         parser.LogError();
+                        break;
+                    }
+                }
+            }
 
+            if (!parser.HasError)
+            {
+                // Store parsed data
+                spawnnums = parser.SpawnNums;
+                doomednums = parser.DoomEdNums;
+                mapinfo = parser.MapInfo;
+            }
+            else
+            {
                 // No nulls allowed!
                 spawnnums = new Dictionary<int, string>();
                 doomednums = new Dictionary<int, string>();
                 mapinfo = new MapInfo();
-
-						return;
-					}
-				}
             }
 
-			// Set the output values
-			spawnnums = parser.SpawnNums;
-			doomednums = parser.DoomEdNums;
-
-			// Store to our MapInfo property
             currentreader = null;
-			mapinfo = parser.MapInfo ?? new MapInfo();
         }
 
         private void ParseFromLocation(ZDTextParser parser, string location, bool clearerrors)
@@ -2268,5 +2301,437 @@ namespace CodeImp.DoomBuilder.Data
 		}
 
         #endregion
+
+        #region ================== mxd. Skybox Making
+
+        private void SetupSkybox()
+        {
+            // Get rid of old texture
+            if (skybox != null) skybox.Dispose(); skybox = null;
+
+            // Determine which texture name to use
+            string skytex = string.Empty;
+            if (!string.IsNullOrEmpty(mapinfo.Sky1))
+            {
+                skytex = mapinfo.Sky1;
+            }
+            // Use vanilla sky only when current map doesn't have a MAPINFO entry
+            else if (!mapinfo.IsDefined)
+            {
+                if (General.Map.Config.DefaultSkyTextures.ContainsKey(General.Map.Options.CurrentName))
+                    skytex = General.Map.Config.DefaultSkyTextures[General.Map.Options.CurrentName];
+                else
+                    skytex = General.GetByIndex(General.Map.Config.DefaultSkyTextures, 0).Value;
+            }
+
+            // Create sky texture
+            if (!string.IsNullOrEmpty(skytex))
+            {
+                if (skyboxes.ContainsKey(skytex))
+                {
+                    // Create cubemap texture
+                    skybox = (skyboxes[skytex].Textures.Count == 6 ? MakeSkyBox6(skyboxes[skytex]) : MakeSkyBox3(skyboxes[skytex]));
+                }
+                else
+                {
+                    // Create classic texture
+                    ImageData tex = GetTextureImage(skytex);
+                    if (!(tex is UnknownImage))
+                    {
+                        if (!tex.IsImageLoaded) tex.LoadImage();
+                        if (!tex.LoadFailed)
+                        {
+                            skybox = MakeClassicSkyBox(new Bitmap(tex.GetBitmap()), true);
+                        }
+                    }
+                }
+            }
+
+            // Sky texture will be missing in ZDoom. Use internal texture
+            if (skybox == null)
+            {
+                ImageData tex = LoadInternalTexture("MissingSky3D.png");
+                tex.CreateTexture();
+                skybox = MakeClassicSkyBox(new Bitmap(tex.GetBitmap()), false);
+                tex.Dispose();
+            }
+        }
+
+        private static CubeTexture MakeClassicSkyBox(Bitmap img, bool dogradients)
+        {
+            // CubeTexture must be square with power of 2 sides
+            int targetwidth = General.NextPowerOf2(img.Width);
+            int targetheight = General.NextPowerOf2(img.Height);
+
+            // Get averaged top and bottom colors
+            Color topcolor, bottomcolor;
+            if (dogradients)
+            {
+                int tr = 0, tg = 0, tb = 0, br = 0, bg = 0, bb = 0;
+                for (int i = 0; i < img.Width; i++)
+                {
+                    Color c = img.GetPixel(i, 0);
+                    tr += c.R;
+                    tg += c.G;
+                    tb += c.B;
+
+                    c = img.GetPixel(i, img.Height - 1);
+                    br += c.R;
+                    bg += c.G;
+                    bb += c.B;
+                }
+
+                topcolor = Color.FromArgb(255, tr / img.Width, tg / img.Width, tb / img.Width);
+                bottomcolor = Color.FromArgb(255, br / img.Width, bg / img.Width, bb / img.Width);
+            }
+            else
+            {
+                // This should be built-in sky texture
+                Color c = img.GetPixel(img.Width / 2, 0);
+                topcolor = Color.FromArgb(255, c);
+
+                c = img.GetPixel(img.Width / 2, img.Height - 1);
+                bottomcolor = Color.FromArgb(255, c);
+            }
+
+            // Make it Po2
+            if (img.Width != targetwidth || img.Height != targetheight) img = ResizeImage(img, targetwidth, targetheight);
+
+            // Make it square
+            if (targetwidth > targetheight)
+            {
+                int c = targetwidth / targetheight;
+                Bitmap result = new Bitmap(targetwidth, targetwidth, img.PixelFormat);
+
+                // Tile vertically
+                using (Graphics g = Graphics.FromImage(result))
+                {
+                    for (int i = 0; i < c; i++) g.DrawImage(img, 0, targetheight * i);
+                }
+
+                img = result;
+            }
+            else if (targetwidth < targetheight)
+            {
+                int c = targetheight / targetwidth;
+                Bitmap result = new Bitmap(targetheight, targetheight);
+
+                // Tile horizontally
+                using (Graphics g = Graphics.FromImage(result))
+                {
+                    for (int i = 0; i < c; i++) g.DrawImage(img, targetwidth * i, 0);
+                }
+
+                img = result;
+            }
+
+            // Make top and bottom images
+            Bitmap top = new Bitmap(img.Width, img.Height);
+            using (Graphics g = Graphics.FromImage(top))
+            {
+                using (SolidBrush b = new SolidBrush(topcolor))
+                {
+                    g.FillRectangle(b, 0, 0, img.Width, img.Height);
+                }
+            }
+
+            Bitmap bottom = new Bitmap(img.Width, img.Height);
+            using (Graphics g = Graphics.FromImage(bottom))
+            {
+                using (SolidBrush b = new SolidBrush(bottomcolor))
+                {
+                    g.FillRectangle(b, 0, 0, img.Width, img.Height);
+                }
+            }
+
+            // Apply top/bottom gradients
+            if (dogradients)
+            {
+                using (Graphics g = Graphics.FromImage(img))
+                {
+                    int gradientheight = img.Height / 6;
+                    Rectangle area = new Rectangle(0, 0, img.Width, gradientheight);
+                    using (LinearGradientBrush b = new LinearGradientBrush(area, topcolor, Color.FromArgb(0, topcolor), 90f))
+                    {
+                        g.FillRectangle(b, area);
+                    }
+
+                    area = new Rectangle(0, img.Height - gradientheight, img.Width, gradientheight);
+                    using (LinearGradientBrush b = new LinearGradientBrush(area, Color.FromArgb(0, bottomcolor), bottomcolor, 90f))
+                    {
+                        area.Y += 1;
+                        g.FillRectangle(b, area);
+                    }
+                }
+            }
+
+            // Make cubemap texture
+            CubeTexture cubemap = new CubeTexture(General.Map.Graphics.Device, img.Width, 1, Usage.None, Format.A8R8G8B8, Pool.Managed);
+
+            // Draw faces
+            img.RotateFlip(RotateFlipType.Rotate180FlipX);
+            DrawCubemapFace(cubemap, CubeMapFace.NegativeX, img);
+
+            img.RotateFlip(RotateFlipType.Rotate90FlipNone);
+            DrawCubemapFace(cubemap, CubeMapFace.NegativeY, img);
+
+            img.RotateFlip(RotateFlipType.Rotate90FlipNone);
+            DrawCubemapFace(cubemap, CubeMapFace.PositiveX, img);
+
+            img.RotateFlip(RotateFlipType.Rotate90FlipNone);
+            DrawCubemapFace(cubemap, CubeMapFace.PositiveY, img);
+
+            DrawCubemapFace(cubemap, CubeMapFace.PositiveZ, top);
+            DrawCubemapFace(cubemap, CubeMapFace.NegativeZ, bottom);
+
+            // All done...
+            return cubemap;
+        }
+
+        // Makes CubeTexture from 6 images
+        private CubeTexture MakeSkyBox6(SkyboxInfo info)
+        {
+            // Gather images. They should be defined in this order: North, East, South, West, Top, Bottom
+            Bitmap[] sides = new Bitmap[6];
+            int targetsize = 0;
+            for (int i = 0; i < info.Textures.Count; i++)
+            {
+                ImageData tex = GetTextureImage(info.Textures[i]);
+                if (!(tex is UnknownImage))
+                {
+                    if (!tex.IsImageLoaded) tex.LoadImage();
+                    if (!tex.LoadFailed)
+                    {
+                        sides[i] = new Bitmap(tex.GetBitmap());
+                        targetsize = Math.Max(targetsize, Math.Max(sides[i].Width, sides[i].Height));
+                    }
+                }
+
+                if (sides[i] == null)
+                {
+                    General.ErrorLogger.Add(ErrorType.Error, "Unable to create \"" + info.Name + "\" skybox: unable to find \"" + info.Textures[i] + "\" texture");
+                    return null;
+                }
+            }
+
+            // All images must be square and have the same size
+            if (targetsize == 0)
+            {
+                General.ErrorLogger.Add(ErrorType.Error, "Unable to create \"" + info.Name + "\" skybox: invalid texture size");
+                return null;
+            }
+
+            // Make it Po2
+            targetsize = General.NextPowerOf2(targetsize);
+
+            for (int i = 0; i < sides.Length; i++)
+            {
+                if (sides[i].Width != targetsize || sides[i].Height != targetsize)
+                    sides[i] = ResizeImage(sides[i], targetsize, targetsize);
+            }
+
+            // Return cubemap texture
+            return MakeSkyBox(sides, targetsize, info.FlipTop);
+        }
+
+        // Makes CubeTexture from 3 images
+        private CubeTexture MakeSkyBox3(SkyboxInfo info)
+        {
+            // Gather images. They should be defined in this order: Sides, Top, Bottom
+            Bitmap[] sides = new Bitmap[6];
+            int targetsize = 0;
+
+            // Create NWSE images from the side texture
+            ImageData side = GetTextureImage(info.Textures[0]);
+            if (!(side is UnknownImage))
+            {
+                if (!side.IsImageLoaded) side.LoadImage();
+                if (!side.LoadFailed)
+                {
+                    // This should be 4x1 format image. If it's not, resize it
+                    Bitmap sideimg = new Bitmap(side.GetBitmap());
+                    targetsize = Math.Max(sideimg.Width / 4, sideimg.Height);
+
+                    if (targetsize == 0)
+                    {
+                        General.ErrorLogger.Add(ErrorType.Error, "Unable to create \"" + info.Name + "\" skybox: invalid texture size");
+                        return null;
+                    }
+
+                    // Make it Po2
+                    targetsize = General.NextPowerOf2(targetsize);
+
+                    // Resize if needed
+                    if (sideimg.Width != targetsize * 4 || sideimg.Height != targetsize)
+                    {
+                        sideimg = ResizeImage(sideimg, targetsize * 4, targetsize);
+                    }
+
+                    // Chop into tiny pieces
+                    for (int i = 0; i < 4; i++)
+                    {
+                        // Create square image
+                        Bitmap img = new Bitmap(targetsize, targetsize);
+                        using (Graphics g = Graphics.FromImage(img))
+                        {
+                            // Copy area from the side image
+                            g.DrawImage(sideimg, 0, 0, new Rectangle(targetsize * i, 0, targetsize, targetsize), GraphicsUnit.Pixel);
+                        }
+
+                        // Add to collection
+                        sides[i] = img;
+                    }
+                }
+            }
+
+            // Sanity check...
+            if (sides[0] == null || sides[1] == null || sides[2] == null || sides[3] == null)
+            {
+                General.ErrorLogger.Add(ErrorType.Error, "Unable to create \"" + info.Name + "\" skybox: unable to find \"" + info.Textures[0] + "\" texture");
+                return null;
+            }
+
+            // Create top
+            ImageData top = GetTextureImage(info.Textures[1]);
+            if (!(top is UnknownImage))
+            {
+                if (!top.IsImageLoaded) top.LoadImage();
+                if (!top.LoadFailed)
+                {
+                    // Copy bitmap 
+                    Bitmap topimg = new Bitmap(top.GetBitmap());
+
+                    // Resize if needed
+                    if (topimg.Width != targetsize || topimg.Height != targetsize)
+                        topimg = ResizeImage(topimg, targetsize, targetsize);
+
+                    // Add to collection
+                    sides[4] = topimg;
+                }
+            }
+
+            // Sanity check...
+            if (sides[4] == null)
+            {
+                General.ErrorLogger.Add(ErrorType.Error, "Unable to create \"" + info.Name + "\" skybox: unable to find \"" + info.Textures[1] + "\" texture");
+                return null;
+            }
+
+            // Create bottom
+            ImageData bottom = GetTextureImage(info.Textures[2]);
+            if (!(bottom is UnknownImage))
+            {
+                if (!bottom.IsImageLoaded) bottom.LoadImage();
+                if (!bottom.LoadFailed)
+                {
+                    // Copy bitmap 
+                    Bitmap bottomimg = new Bitmap(bottom.GetBitmap());
+
+                    // Resize if needed
+                    if (bottomimg.Width != targetsize || bottomimg.Height != targetsize)
+                        bottomimg = ResizeImage(bottomimg, targetsize, targetsize);
+
+                    // Add to collection
+                    sides[5] = bottomimg;
+                }
+            }
+
+            // Sanity check...
+            if (sides[5] == null)
+            {
+                General.ErrorLogger.Add(ErrorType.Error, "Unable to create \"" + info.Name + "\" skybox: unable to find \"" + info.Textures[2] + "\" texture");
+                return null;
+            }
+
+            // Return cubemap texture
+            return MakeSkyBox(sides, targetsize, info.FlipTop);
+        }
+
+        // Makes CubeTexture from 6 images.
+        // sides[] must contain 6 square Po2 images in this order: North, East, South, West, Top, Bottom
+        private static CubeTexture MakeSkyBox(Bitmap[] sides, int targetsize, bool fliptop)
+        {
+            CubeTexture cubemap = new CubeTexture(General.Map.Graphics.Device, targetsize, 1, Usage.None, Format.A8R8G8B8, Pool.Managed);
+
+            // Draw faces
+            sides[3].RotateFlip(RotateFlipType.Rotate180FlipX);
+            DrawCubemapFace(cubemap, CubeMapFace.NegativeX, sides[3]); // West
+
+            sides[0].RotateFlip(RotateFlipType.Rotate90FlipX);
+            DrawCubemapFace(cubemap, CubeMapFace.NegativeY, sides[0]); // North
+
+            sides[1].RotateFlip(RotateFlipType.RotateNoneFlipX);
+            DrawCubemapFace(cubemap, CubeMapFace.PositiveX, sides[1]); // East
+
+            sides[2].RotateFlip(RotateFlipType.Rotate270FlipX);
+            DrawCubemapFace(cubemap, CubeMapFace.PositiveY, sides[2]); // South
+
+            sides[4].RotateFlip(fliptop ? RotateFlipType.Rotate90FlipX : RotateFlipType.Rotate90FlipNone);
+            DrawCubemapFace(cubemap, CubeMapFace.PositiveZ, sides[4]); // Top
+
+            sides[5].RotateFlip(RotateFlipType.Rotate270FlipX);
+            DrawCubemapFace(cubemap, CubeMapFace.NegativeZ, sides[5]); // Bottom
+
+            // All done...
+            return cubemap;
+        }
+
+        private static void DrawCubemapFace(CubeTexture texture, CubeMapFace face, Bitmap image)
+        {
+            DataRectangle rect = texture.LockRectangle(face, 0, LockFlags.NoSystemLock);
+            SurfaceDescription desc = texture.GetLevelDescription(0);
+
+            if (rect.Data.CanWrite)
+            {
+                for (int row = 0; row < desc.Height; row++)
+                {
+                    int rowstart = row * rect.Pitch;
+                    rect.Data.Seek(rowstart, SeekOrigin.Begin);
+
+                    for (int col = 0; col < desc.Width; col++)
+                    {
+                        Color color = image.GetPixel(row, col);
+
+                        rect.Data.WriteByte(color.B);
+                        rect.Data.WriteByte(color.G);
+                        rect.Data.WriteByte(color.R);
+                        rect.Data.WriteByte(color.A);
+                    }
+                }
+            }
+            else
+            {
+                General.ErrorLogger.Add(ErrorType.Error, "Skybox creation failed: CubeTexture is unwritable...");
+            }
+
+            texture.UnlockRectangle(face, 0);
+        }
+
+        private static Bitmap ResizeImage(Image image, int width, int height)
+        {
+            var destrect = new Rectangle(0, 0, width, height);
+            var destimage = new Bitmap(width, height);
+
+            destimage.SetResolution(image.HorizontalResolution, image.VerticalResolution);
+
+            using (var graphics = Graphics.FromImage(destimage))
+            {
+                graphics.CompositingMode = CompositingMode.SourceCopy;
+                graphics.CompositingQuality = CompositingQuality.HighQuality;
+                graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;
+                graphics.SmoothingMode = SmoothingMode.HighQuality;
+                graphics.PixelOffsetMode = PixelOffsetMode.HighQuality;
+
+                using (var wrapmode = new ImageAttributes())
+                {
+                    wrapmode.SetWrapMode(WrapMode.TileFlipXY);
+                    graphics.DrawImage(image, destrect, 0, 0, image.Width, image.Height, GraphicsUnit.Pixel, wrapmode);
+                }
+            }
+
+            return destimage;
+        }
+
+        #endregion
     }
 }

Source/Core/Data/PK3StructuredReader.cs

@@ -531,16 +531,16 @@ namespace CodeImp.DoomBuilder.Data
 			// Error when suspended
 			if(issuspended) throw new Exception("Data reader is suspended");
 
-			//mapinfo should be in root folder
+			// Mapinfo should be in root folder
 			Dictionary<string, Stream> streams = new Dictionary<string, Stream>(StringComparer.Ordinal);
-			string[] files = GetAllFiles("", false);
 
             //try to find (z)mapinfo
+            string[] files = GetAllFiles("", false);
 			foreach(string s in files)
 			{
 				string filename = Path.GetFileNameWithoutExtension(s.ToLowerInvariant());
 				if(filename == "zmapinfo" || filename == "mapinfo")
-					streams.Add(s, LoadFile(s));
+                    streams[s] = LoadFile(s);
             }
 
 			return streams;

Source/Core/Data/SpriteImage.cs

@@ -30,8 +30,8 @@ namespace CodeImp.DoomBuilder.Data
 	{
 		#region ================== Variables
 
-		protected int offsetx;
+		private int offsetx;
-		protected int offsety;
+        private int offsety;
         protected bool flipped;
 		
 		#endregion

Source/Core/GZBuilder/Data/MapInfo.cs

@@ -1,30 +1,69 @@
-using SlimDX;
+#region ================== Namespaces
+
+using SlimDX;
+
+#endregion
 
 namespace CodeImp.DoomBuilder.GZBuilder.Data
 {
     public sealed class MapInfo
     {
-		public string Sky1;
+        #region ================== Variables
-		public float Sky1ScrollSpeed;
-		public string Sky2;
-		public float Sky2ScrollSpeed;
-		public bool DoubleSky;
-		public bool HasFadeColor;
-		public Color4 FadeColor;
-		public bool HasOutsideFogColor;
-		public Color4 OutsideFogColor;
-		public int FogDensity;
-		public int OutsideFogDensity;
 
-		public bool EvenLighting;
+        private bool isdefined;
-		public bool SmoothLighting;
+
-		public int VertWallShade;
+        private string title;
-		public int HorizWallShade;
+        private string sky1;
+        private float sky1scrollspeed;
+        private string sky2;
+        private float sky2scrollspeed;
+        private bool doublesky;
+        private bool hasfadecolor;
+        private Color4 fadecolor;
+        private bool hasoutsidefogcolor;
+        private Color4 outsidefogcolor;
+        private int fogdensity;
+        private int outsidefogdensity;
+
+        private bool evenlighting;
+        private bool smoothlighting;
+        private int vertwallshade;
+        private int horizwallshade;
+
+        #endregion
+
+        #region ================== Properties
+
+        public bool IsDefined { get { return isdefined; } }
+
+        public string Title { get { return title; } internal set { title = value; isdefined = true; } }
+        public string Sky1 { get { return sky1; } internal set { sky1 = value; isdefined = true; } }
+        public float Sky1ScrollSpeed { get { return sky1scrollspeed; } internal set { sky1scrollspeed = value; isdefined = true; } }
+        public string Sky2 { get { return sky2; } internal set { sky2 = value; isdefined = true; } }
+        public float Sky2ScrollSpeed { get { return sky2scrollspeed; } internal set { sky2scrollspeed = value; isdefined = true; } }
+        public bool DoubleSky { get { return doublesky; } internal set { doublesky = value; isdefined = true; } }
+        public bool HasFadeColor { get { return hasfadecolor; } internal set { hasfadecolor = value; isdefined = true; } }
+        public Color4 FadeColor { get { return fadecolor; } internal set { fadecolor = value; isdefined = true; } }
+        public bool HasOutsideFogColor { get { return hasoutsidefogcolor; } internal set { hasoutsidefogcolor = value; isdefined = true; } }
+        public Color4 OutsideFogColor { get { return outsidefogcolor; } internal set { outsidefogcolor = value; isdefined = true; } }
+        public int FogDensity { get { return fogdensity; } internal set { fogdensity = value; isdefined = true; } }
+        public int OutsideFogDensity { get { return outsidefogdensity; } internal set { outsidefogdensity = value; isdefined = true; } }
+
+        public bool EvenLighting { get { return evenlighting; } internal set { evenlighting = value; isdefined = true; } }
+        public bool SmoothLighting { get { return smoothlighting; } internal set { smoothlighting = value; isdefined = true; } }
+        public int VertWallShade { get { return vertwallshade; } internal set { vertwallshade = value; isdefined = true; } }
+        public int HorizWallShade { get { return horizwallshade; } internal set { horizwallshade = value; isdefined = true; } }
+
+        #endregion
+
+        #region ================== Constructor
 
         public MapInfo()
         {
-			VertWallShade = 16;
+            vertwallshade = 16;
-			HorizWallShade = -16;
+            horizwallshade = -16;
-		}
+        }
+
+        #endregion
     }
 }

Source/Core/GZBuilder/Data/SkyboxInfo.cs

@@ -0,0 +1,18 @@
+using System.Collections.Generic;
+
+namespace CodeImp.DoomBuilder.GZBuilder.Data
+{
+	public sealed class SkyboxInfo
+	{
+		private readonly string name;
+		public string Name { get { return name; } }
+		public readonly List<string> Textures;
+		public bool FlipTop;
+
+		public SkyboxInfo(string name)
+		{
+			this.name = name;
+			Textures = new List<string>();
+		}
+	}
+}

Source/Core/GZBuilder/GZDoom/GldefsParser.cs

@@ -46,18 +46,20 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
 
         #region ================== Variables
 
-		private readonly Dictionary<string, DynamicLightData> lightsByName; //LightName, light definition
+        private readonly Dictionary<string, DynamicLightData> lightsbyname; //LightName, light definition
         private readonly Dictionary<string, string> objects; //ClassName, LightName
         private readonly Dictionary<long, GlowingFlatData> glowingflats;
+        private readonly Dictionary<string, SkyboxInfo> skyboxes;
         private readonly HashSet<string> parsedlumps;
 
         #endregion
 
         #region ================== Properties
 
-		public Dictionary<string, DynamicLightData> LightsByName { get { return lightsByName; } }
+        internal Dictionary<string, DynamicLightData> LightsByName { get { return lightsbyname; } }
-		public Dictionary<string, string> Objects { get { return objects; } }
+        internal Dictionary<string, string> Objects { get { return objects; } }
         internal Dictionary<long, GlowingFlatData> GlowingFlats { get { return glowingflats; } }
+        internal Dictionary<string, SkyboxInfo> Skyboxes { get { return skyboxes; } }
 
         #endregion
 
@@ -70,9 +72,10 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
             specialtokens = ",{}\n";
 
             parsedlumps = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
-			lightsByName = new Dictionary<string, DynamicLightData>(StringComparer.Ordinal); //LightName, Light params
+            lightsbyname = new Dictionary<string, DynamicLightData>(StringComparer.OrdinalIgnoreCase); //LightName, Light params
-			objects = new Dictionary<string, string>(StringComparer.Ordinal); //ClassName, LightName
+            objects = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase); //ClassName, LightName
             glowingflats = new Dictionary<long, GlowingFlatData>(); // Texture name hash, Glowing Flat Data
+            skyboxes = new Dictionary<string, SkyboxInfo>(StringComparer.OrdinalIgnoreCase);
         }
 
         #endregion
@@ -94,41 +97,81 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                 string token = StripTokenQuotes(ReadToken()).ToLowerInvariant(); // Quotes can be anywhere! ANYWHERE!!! And GZDoom will still parse data correctly
                 if (string.IsNullOrEmpty(token)) break;
 
-				//got light structure
+                switch (token)
-				if(token == GldefsLightType.POINT || token == GldefsLightType.PULSE || token == GldefsLightType.FLICKER 
-					|| token == GldefsLightType.FLICKER2 || token == GldefsLightType.SECTOR) 
                 {
-					string lightType = token;
+                    case GldefsLightType.POINT:
-					DynamicLightData light = new DynamicLightData { Type = GldefsLightType.GLDEFS_TO_GZDOOM_LIGHT_TYPE[lightType] };
+                    case GldefsLightType.PULSE:
+                    case GldefsLightType.SECTOR:
+                    case GldefsLightType.FLICKER:
+                    case GldefsLightType.FLICKER2:
+                        if (!ParseLight(token)) return false;
+                        break;
 
-					//find classname
+                    case "object":
+                        if (!ParseObject()) return false;
+                        break;
+
+                    case "glow":
+                        if (!ParseGlowingFlats()) return false;
+                        break;
+
+                    case "skybox":
+                        if (!ParseSkybox()) return false;
+                        break;
+
+                    case "#include":
+                        if (!ParseInclude(clearerrors)) return false;
+
+                        // Set our buffers back to continue parsing
+                        datastream = localstream;
+                        datareader = localreader;
+                        sourcename = localsourcename;
+                        break;
+
+                    case "$gzdb_skip": return !this.HasError;
+
+                    default:
+                        // Unknown structure!
+                        SkipStructure();
+                        break;
+                }
+            }
+
+            // All done
+            return !this.HasError;
+        }
+
+        private bool ParseLight(string lighttype)
+        {
+            DynamicLightData light = new DynamicLightData { Type = GldefsLightType.GLDEFS_TO_GZDOOM_LIGHT_TYPE[lighttype] };
+
+            // Find classname
             SkipWhitespace(true);
-					string lightName = StripTokenQuotes(ReadToken()).ToLowerInvariant();
+            string lightname = StripTokenQuotes(ReadToken()).ToLowerInvariant();
 
-					if(string.IsNullOrEmpty(lightName))
+            if (string.IsNullOrEmpty(lightname))
             {
-						ReportError("Expected " + token + " name");
+                ReportError("Expected " + lighttype + " name");
                 return false;
             }
 
-					//now find opening brace
+            // Now find opening brace
             if (!NextTokenIs("{", false))
             {
                 ReportError("Expected opening brace");
                 return false;
             }
 
-					//read gldefs light structure
+            // Read gldefs light structure
             while (SkipWhitespace(true))
             {
-						token = ReadToken().ToLowerInvariant();
+                string token = ReadToken().ToLowerInvariant();
-						if(!string.IsNullOrEmpty(token)) 
+                if (string.IsNullOrEmpty(token)) continue;
-						{
-//color
-							if(token == "color") 
-							{
-								SkipWhitespace(true);
 
+                switch (token)
+                {
+                    case "color":
+                        SkipWhitespace(true);
                         token = StripTokenQuotes(ReadToken());
                         if (!float.TryParse(token, NumberStyles.Float, CultureInfo.InvariantCulture, out light.Color.Red))
                         {
@@ -138,7 +181,6 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                         }
 
                         SkipWhitespace(true);
-
                         token = StripTokenQuotes(ReadToken());
                         if (!float.TryParse(token, NumberStyles.Float, CultureInfo.InvariantCulture, out light.Color.Green))
                         {
@@ -148,7 +190,6 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                         }
 
                         SkipWhitespace(true);
-
                         token = StripTokenQuotes(ReadToken());
                         if (!float.TryParse(token, NumberStyles.Float, CultureInfo.InvariantCulture, out light.Color.Blue))
                         {
@@ -156,11 +197,10 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                             ReportError("Expected Blue color value, but got '" + token + "'");
                             return false;
                         }
-//size
+                        break;
-							} 
+
-							else if(token == "size") 
+                    case "size":
-							{
+                        if (lighttype != GldefsLightType.SECTOR)
-								if(lightType != GldefsLightType.SECTOR) 
                         {
                             SkipWhitespace(true);
 
@@ -176,15 +216,13 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                         }
                         else
                         {
-									ReportError("'" + token + "' is not valid property for " + lightType);
+                            ReportError("'" + token + "' is not valid property for " + lighttype);
                             return false;
                         }
-//offset
+                        break;
-							} 
-							else if(token == "offset") 
-							{
-								SkipWhitespace(true);
 
+                    case "offset":
+                        SkipWhitespace(true);
                         token = StripTokenQuotes(ReadToken());
                         if (!ReadSignedFloat(token, ref light.Offset.X))
                         {
@@ -194,7 +232,6 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                         }
 
                         SkipWhitespace(true);
-
                         token = StripTokenQuotes(ReadToken());
                         if (!ReadSignedFloat(token, ref light.Offset.Z))
                         {
@@ -204,7 +241,6 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                         }
 
                         SkipWhitespace(true);
-
                         token = StripTokenQuotes(ReadToken());
                         if (!ReadSignedFloat(token, ref light.Offset.Y))
                         {
@@ -212,9 +248,9 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                             ReportError("Expected Offset Z value, but got '" + token + "'");
                             return false;
                         }
-//subtractive
+                        break;
-							} 
+
-							else if(token == "subtractive") 
+                    case "subtractive":
                         {
                             SkipWhitespace(true);
 
@@ -227,10 +263,11 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                                 return false;
                             }
 
-								light.Subtractive = i == 1;
+                            light.Subtractive = (i == 1);
-//dontlightself
                         }
-							else if(token == "dontlightself") 
+                        break;
+
+                    case "dontlightself":
                         {
                             SkipWhitespace(true);
 
@@ -244,11 +281,11 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                             }
 
                             light.DontLightSelf = (i == 1);
-//interval
                         }
-							else if(token == "interval") 
+                        break;
-							{
+
-								if(lightType == GldefsLightType.PULSE || lightType == GldefsLightType.FLICKER2) 
+                    case "interval":
+                        if (lighttype == GldefsLightType.PULSE || lighttype == GldefsLightType.FLICKER2)
                         {
                             SkipWhitespace(true);
 
@@ -264,7 +301,7 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                             if (interval == 0) LogWarning("Interval value should be greater than zero");
 
                             //I wrote logic for dynamic lights animation first, so here I modify gldefs settings to fit in existing logic
-									if(lightType == GldefsLightType.PULSE) 
+                            if (lighttype == GldefsLightType.PULSE)
                             {
                                 light.Interval = (int)(interval * 35); //measured in tics (35 per second) in PointLightPulse, measured in seconds in gldefs' PulseLight
                             }
@@ -275,14 +312,13 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                         }
                         else
                         {
-									ReportError("'" + token + "' is not valid property for " + lightType);
+                            ReportError("'" + token + "' is not valid property for " + lighttype);
                             return false;
                         }
-//secondarysize
+                        break;
-							} 
+
-							else if(token == "secondarysize") 
+                    case "secondarysize":
-							{
+                        if (lighttype == GldefsLightType.PULSE || lighttype == GldefsLightType.FLICKER || lighttype == GldefsLightType.FLICKER2)
-								if(lightType == GldefsLightType.PULSE || lightType == GldefsLightType.FLICKER || lightType == GldefsLightType.FLICKER2) 
                         {
                             SkipWhitespace(true);
 
@@ -293,18 +329,18 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                                 ReportError("Expected SecondarySize value, but got '" + token + "'");
                                 return false;
                             }
+
                             light.SecondaryRadius *= 2;
                         }
                         else
                         {
-									ReportError("'" + token + "' is not valid property for " + lightType);
+                            ReportError("'" + token + "' is not valid property for " + lighttype);
                             return false;
                         }
-//chance
+                        break;
-							} 
+
-							else if(token == "chance") 
+                    case "chance":
-							{
+                        if (lighttype == GldefsLightType.FLICKER)
-								if(lightType == GldefsLightType.FLICKER) 
                         {
                             SkipWhitespace(true);
 
@@ -317,19 +353,18 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                                 return false;
                             }
 
-									//transforming from 0.0 .. 1.0 to 0 .. 359 to fit in existing logic
+                            // Transforming from 0.0 .. 1.0 to 0 .. 359 to fit in existing logic
                             light.Interval = (int)(chance * 359.0f);
                         }
                         else
                         {
-									ReportError("'" + token + "' is not valid property for " + lightType);
+                            ReportError("'" + token + "' is not valid property for " + lighttype);
                             return false;
                         }
-//scale
+                        break;
-							} 
+
-							else if(token == "scale") 
+                    case "scale":
-							{
+                        if (lighttype == GldefsLightType.SECTOR)
-								if(lightType == GldefsLightType.SECTOR) 
                         {
                             SkipWhitespace(true);
 
@@ -354,26 +389,26 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                         }
                         else
                         {
-									ReportError("'" + token + "' is not valid property for " + lightType);
+                            ReportError("'" + token + "' is not valid property for " + lighttype);
                             return false;
                         }
-							} 
+                        break;
-							//end of structure
+
-							else if(token == "}") 
+                    case "}":
                         {
                             bool skip = false;
 
-								//general checks
+                            // General checks
                             if (light.Color.Red == 0.0f && light.Color.Green == 0.0f && light.Color.Blue == 0.0f)
                             {
-									LogWarning("'" + lightName + "' light Color is " + light.Color.Red + "," + light.Color.Green + "," + light.Color.Blue + ". It won't be shown in GZDoom");
+                                LogWarning("'" + lightname + "' light Color is " + light.Color.Red + "," + light.Color.Green + "," + light.Color.Blue + ". It won't be shown in GZDoom");
                                 skip = true;
                             }
 
-								//light-type specific checks
+                            // Light-type specific checks
                             if (light.Type == DynamicLightType.NORMAL && light.PrimaryRadius == 0)
                             {
-									LogWarning("'" + lightName + "' light Size is 0. It won't be shown in GZDoom");
+                                LogWarning("'" + lightname + "' light Size is 0. It won't be shown in GZDoom");
                                 skip = true;
                             }
 
@@ -381,73 +416,77 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                             {
                                 if (light.PrimaryRadius == 0 && light.SecondaryRadius == 0)
                                 {
-										LogWarning("'" + lightName + "' light Size and SecondarySize are 0. This light won't be shown in GZDoom");
+                                    LogWarning("'" + lightname + "' light Size and SecondarySize are 0. This light won't be shown in GZDoom");
                                     skip = true;
                                 }
                             }
 
-								//offset it slightly to avoid shading glitches
+                            // Offset it slightly to avoid shading glitches
                             if (light.Offset.Z == 0.0f) light.Offset.Z = 0.1f;
 
                             // Add to the collection?
-								if(!skip) lightsByName[lightName] = light;
+                            if (!skip) lightsbyname[lightname] = light;
 
-								//break out of this parsing loop
+                            // Break out of this parsing loop
-								break; 
+                            return true;
                         }
                 }
             }
+
+            // All done here
+            return true;
         }
-				else if(token == "object") 
+
+        private bool ParseObject()
         {
             SkipWhitespace(true);
 
-					//read object class
+            // Read object class
-					string objectClass = StripTokenQuotes(ReadToken()).ToLowerInvariant();
+            string objectclass = StripTokenQuotes(ReadToken()).ToLowerInvariant();
 
-					if(string.IsNullOrEmpty(objectClass))
+            if (string.IsNullOrEmpty(objectclass))
             {
                 ReportError("Expected object class");
                 return false;
             }
 
-					//now find opening brace
+            // Now find opening brace
             if (!NextTokenIs("{", false))
             {
                 ReportError("Expected opening brace");
                 return false;
             }
 
-					int bracesCount = 1;
+            int bracescount = 1;
-					bool foundLight = false;
+            bool foundlight = false;
-					bool foundFrame = false;
+            bool foundframe = false;
 
-					//read frames structure
+            // Read frames structure
             while (SkipWhitespace(true))
             {
-						token = ReadToken();
+                string token = ReadToken();
-						if(!string.IsNullOrEmpty(token)) 
+                if (string.IsNullOrEmpty(token)) continue;
-						{
+
                 token = StripTokenQuotes(token).ToLowerInvariant();
-							if(!foundLight && !foundFrame && token == "frame") 
+                if (!foundlight && !foundframe && token == "frame")
                 {
                     SkipWhitespace(true);
-								token = ReadToken().ToLowerInvariant(); //should be frame name
+                    token = ReadToken().ToLowerInvariant(); // Should be frame name
 
-								//use this frame if it's 4 characters long or it's the first frame
+                    // Use this frame if it's 4 characters long or it's the first frame
-								foundFrame = (token.Length == 4 || (token.Length > 4 && token[4] == 'a'));
+                    foundframe = (token.Length == 4 || (token.Length > 4 && token[4] == 'a'));
                 }
-							else if(!foundLight && foundFrame && token == "light") //just use first light and be done with it
+                else if (!foundlight && foundframe && token == "light") // Just use first light and be done with it
                 {
                     SkipWhitespace(true);
-								token = ReadToken().ToLowerInvariant(); //should be light name
+                    token = ReadToken().ToLowerInvariant(); // Should be light name
 
                     if (!string.IsNullOrEmpty(token))
                     {
-									if(lightsByName.ContainsKey(token)) 
+                        if (lightsbyname.ContainsKey(token))
                         {
-										objects[objectClass] = token;
+                            objects[objectclass] = token;
-										foundLight = true;
+                            foundlight = true;
                         }
                         else
                         {
@@ -455,19 +494,21 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                         }
                     }
                 }
-							else if(token == "{") //continue in this loop until object structure ends
+                else if (token == "{") // Continue in this loop until object structure ends
                 {
-								bracesCount++;
+                    bracescount++;
                 }
                 else if (token == "}")
                 {
-								if(--bracesCount < 1) break; //This was Cave Johnson. And we are done here.
+                    if (--bracescount < 1) break; // This was Cave Johnson. And we are done here.
                 }
             }
+
+            // All done here
+            return true;
         }
-				}
+
-				//Glowing flats block start
+        private bool ParseGlowingFlats()
-				else if(token == "glow")
         {
             // Next sould be opening brace
             if (!NextTokenIs("{", false))
@@ -479,54 +520,53 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
             // Parse inner blocks
             while (SkipWhitespace(true))
             {
-						token = ReadToken().ToLowerInvariant();
+                string token = ReadToken().ToLowerInvariant();
-						if(token == "}")
+                if (token == "}") break; // End of Glow structure
+
+                switch (token)
                 {
-							// End of Glow structure
+                    case "walls":
-							break;
+                    case "flats":
-						}
-						else if(token == "flats" || token == "walls") 
-						{
-							// Next sould be opening brace
                         if (!NextTokenIs("{", false))
                         {
                             ReportError("Expected opening brace");
                             return false;
                         }
 
-							// Read flat names
                         while (SkipWhitespace(true))
                         {
                             token = ReadToken();
                             if (token == "}") break;
 
                             // Add glow data
-								glowingflats[General.Map.Data.GetFullLongFlatName(Lump.MakeLongName(token, General.Map.Options.UseLongTextureNames))] = new GlowingFlatData {
+                            long flatnamehash = General.Map.Data.GetFullLongFlatName(Lump.MakeLongName(token, General.Map.Options.UseLongTextureNames));
+                            glowingflats[flatnamehash] = new GlowingFlatData
+                            {
                                 Height = DEFAULT_GLOW_HEIGHT * 2,
                                 Fullbright = true,
                                 Color = new PixelColor(255, 255, 255, 255),
                                 CalculateTextureColor = true
                             };
                         }
-						} 
+                        break;
-						// GLOOME subtractive flats
+
-						else if(token == "subflats" || token == "subwalls")
+                    case "subwalls":
-						{
+                    case "subflats":
-							// Next sould be opening brace
                         if (!NextTokenIs("{", false))
                         {
                             ReportError("Expected opening brace");
                             return false;
                         }
 
-							// Read flat names
                         while (SkipWhitespace(true))
                         {
                             token = ReadToken();
                             if (token == "}") break;
 
                             // Add glow data
-								glowingflats[General.Map.Data.GetFullLongFlatName(Lump.MakeLongName(token, General.Map.Options.UseLongTextureNames))] = new GlowingFlatData {
+                            long flatnamehash = General.Map.Data.GetFullLongFlatName(Lump.MakeLongName(token, General.Map.Options.UseLongTextureNames));
+                            glowingflats[flatnamehash] = new GlowingFlatData
+                            {
                                 Height = DEFAULT_GLOW_HEIGHT * 2,
                                 Fullblack = true,
                                 Subtractive = true,
@@ -534,8 +574,10 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                                 CalculateTextureColor = false
                             };
                         }
-						}
+                        break;
-						else if(token == "texture" || token == "subtexture")
+
+                    case "subtexture":
+                    case "texture":
                         {
                             int color;
                             int glowheight = DEFAULT_GLOW_HEIGHT;
@@ -581,13 +623,13 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                             if (!NextTokenIs(",", false))
                             {
                                 // Add glow data
-								glowingflats[texturehash] = new GlowingFlatData {
+                                glowingflats[texturehash] = new GlowingFlatData
+                                {
                                     Height = glowheight * 2,
                                     Subtractive = subtractivetexture,
                                     Color = PixelColor.FromInt(color).WithAlpha(255),
                                     CalculateTextureColor = false
                                 };
-
                                 continue;
                             }
 
@@ -605,13 +647,13 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                                 if (!NextTokenIs(",", false))
                                 {
                                     // Add glow data
-									glowingflats[texturehash] = new GlowingFlatData {
+                                    glowingflats[texturehash] = new GlowingFlatData
+                                    {
                                         Height = glowheight * 2,
                                         Subtractive = subtractivetexture,
                                         Color = PixelColor.FromInt(color).WithAlpha(255),
                                         CalculateTextureColor = false
                                     };
-
                                     continue;
                                 }
 
@@ -632,7 +674,8 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                             }
 
                             // Add glow data
-							glowingflats[texturehash] = new GlowingFlatData {
+                            glowingflats[texturehash] = new GlowingFlatData
+                            {
                                 Height = glowheight * 2,
                                 Fullbright = fullbright,
                                 Fullblack = fullblack,
@@ -641,11 +684,68 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                                 CalculateTextureColor = false
                             };
                         }
+                        break;
                 }
             }
-				else if(token == "#include") 
+
+            // All done here
+            return true;
+        }
+
+        private bool ParseSkybox()
         {
-					//INFO: ZDoom GLDEFS include paths can't be relative ("../glstuff.txt") 
+            SkipWhitespace(true);
+            string name = StripTokenQuotes(ReadToken());
+
+            if (string.IsNullOrEmpty(name))
+            {
+                ReportError("Expected skybox name");
+                return false;
+            }
+
+            if (skyboxes.ContainsKey(name)) LogWarning("Skybox \"" + name + "\" is double-defined");
+
+            SkyboxInfo info = new SkyboxInfo(name.ToUpperInvariant());
+
+            // FlipTop / opening brace
+            SkipWhitespace(true);
+            string token = ReadToken();
+            if (token.ToLowerInvariant() == "fliptop")
+            {
+                info.FlipTop = true;
+                if (!NextTokenIs("{")) return false;
+            }
+            else if (token != "{")
+            {
+                ReportError("Expected opening brace or \"fliptop\" keyword");
+                return false;
+            }
+
+            // Read skybox texture names
+            while (SkipWhitespace(true))
+            {
+                token = ReadToken();
+                if (token == "}") break;
+                info.Textures.Add(token);
+            }
+
+            // Sanity check. Should have 3 or 6 textrues
+            if (info.Textures.Count != 3 && info.Textures.Count != 6)
+            {
+                ReportError("Expected 3 or 6 skybox textures");
+                return false;
+            }
+
+            // Add to collection
+            skyboxes[name] = info;
+
+            // All done here
+            return true;
+        }
+
+        private bool ParseInclude(bool clearerrors)
+        {
+            //INFO: GZDoom GLDEFS include paths can't be relative ("../glstuff.txt") 
             //or absolute ("d:/project/glstuff.txt") 
             //or have backward slashes ("info\glstuff.txt")
             //include paths are relative to the first parsed entry, not the current one 
@@ -661,12 +761,12 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
             }
 
             // Check invalid path chars
-                    if (!CheckInvalidPathChars(token)) return false;
+            if (!CheckInvalidPathChars(includelump)) return false;
 
             // Absolute paths are not supported...
             if (Path.IsPathRooted(includelump))
             {
-						ReportError("Absolute include paths are not supported by ZDoom");
+                ReportError("Absolute include paths are not supported by GZDoom");
                 return false;
             }
 
@@ -674,14 +774,14 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
             if (includelump.StartsWith(RELATIVE_PATH_MARKER) || includelump.StartsWith(CURRENT_FOLDER_PATH_MARKER) ||
                includelump.StartsWith(ALT_RELATIVE_PATH_MARKER) || includelump.StartsWith(ALT_CURRENT_FOLDER_PATH_MARKER))
             {
-						ReportError("Relative include paths are not supported by ZDoom");
+                ReportError("Relative include paths are not supported by GZDoom");
                 return false;
             }
 
             // Backward slashes are not supported
             if (includelump.Contains(Path.DirectorySeparatorChar.ToString(CultureInfo.InvariantCulture)))
             {
-						ReportError("Only forward slashes are supported by ZDoom");
+                ReportError("Only forward slashes are supported by GZDoom");
                 return false;
             }
 
@@ -698,42 +798,7 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
             // Callback to parse this file
             if (OnInclude != null) OnInclude(this, includelump, clearerrors);
 
-					// Bail out on error
+            // All done here
-					if(this.HasError) return false;
-
-					// Set our buffers back to continue parsing
-					datastream = localstream;
-					datareader = localreader;
-					sourcename = localsourcename;
-				} 
-				else if(token == "$gzdb_skip") //mxd
-				{
-					break;
-				}
-				else 
-				{
-					// Unknown structure!
-					string token2;
-					do 
-					{
-						if(!SkipWhitespace(true)) break;
-						token2 = ReadToken();
-						if(string.IsNullOrEmpty(token2)) break;
-					}
-					while(token2 != "{");
-					int scopelevel = 1;
-					do 
-					{
-						if(!SkipWhitespace(true)) break;
-						token2 = ReadToken();
-						if(string.IsNullOrEmpty(token2)) break;
-						if(token2 == "{") scopelevel++;
-						if(token2 == "}") scopelevel--;
-					}
-					while(scopelevel > 0);
-				}
-			}
-
             return !this.HasError;
         }
 

Source/Core/GZBuilder/GZDoom/MapinfoParser.cs

@@ -61,7 +61,7 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
 
         override public bool Parse(Stream stream, string sourcefilename, bool clearerrors)
         {
-			if(string.IsNullOrEmpty(mapname)) throw new NotSupportedException("MapName is required!");
+            if (string.IsNullOrEmpty(mapname)) throw new NotSupportedException("Map name required!");
             return Parse(stream, sourcefilename, mapname, clearerrors);
         }
 
@@ -70,289 +70,115 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
             this.mapname = mapname.ToLowerInvariant();
             if (!base.Parse(stream, sourcefilename, clearerrors)) return false;
 
+            // Keep local data
+            Stream localstream = datastream;
+            string localsourcename = sourcename;
+            BinaryReader localreader = datareader;
+
+            // Classic format skip stoppers...
+            HashSet<string> breakat = new HashSet<string> { "map", "defaultmap", "adddefaultmap" };
+
             while (SkipWhitespace(true))
             {
-				string token = ReadToken();
+                string token = ReadToken().ToLowerInvariant();
-				if(!string.IsNullOrEmpty(token)) 
+                if (string.IsNullOrEmpty(token)) break;
+                bool stopparsing = false;
+
+                switch (token)
                 {
-					token = token.ToLowerInvariant();
+                    case "adddefaultmap":
-					if(ParseBlock(token, clearerrors)) break;
+                        // Parse properties
+                        if (!ParseMapBlock()) return false;
+                        break;
+
+                    case "defaultmap":
+                        // Reset MapInfo
+                        mapinfo = new MapInfo();
+
+                        // Parse properties
+                        if (!ParseMapBlock()) return false;
+                        break;
+
+                    case "map":
+                        // Get map lump name
+                        SkipWhitespace(true);
+                        token = ReadToken().ToLowerInvariant();
+                        if (token != this.mapname)
+                        {
+                            // Map number? Try to build map name from it...
+                            int n;
+                            if (int.TryParse(token, NumberStyles.Integer, CultureInfo.InvariantCulture, out n))
+                            {
+                                token = ((n > 0 && n < 10) ? "map0" + n : "map" + n);
+                            }
+
+                            // Still no dice?
+                            if (token != this.mapname)
+                            {
+                                SkipStructure(breakat);
+                                continue; // Not finished, search for next "map", "defaultmap" or "adddefaultmap" block
                             }
                         }
 
-			//check values
+                        // Try to get map name
+                        SkipWhitespace(true);
+                        token = ReadToken();
+                        if (token.ToLowerInvariant() == "lookup")
+                        {
+                            // No dice...
+                            SkipWhitespace(true);
+                            ReadToken();
+                        }
+                        else
+                        {
+                            mapinfo.Title = StripTokenQuotes(token);
+                        }
+
+                        // Parse properties
+                        if (!ParseMapBlock()) return false;
+                        break;
+
+                    case "include":
+                        if (!ParseInclude(clearerrors)) return false;
+
+                        // Set our buffers back to continue parsing
+                        datastream = localstream;
+                        datareader = localreader;
+                        sourcename = localsourcename;
+                        break;
+
+                    case "gameinfo":
+                        if (!ParseGameInfo()) return false;
+                        break;
+
+                    case "doomednums":
+                        if (!ParseDoomEdNums()) return false;
+                        break;
+
+                    case "spawnnums":
+                        if (!ParseSpawnNums()) return false;
+                        break;
+
+                    case "$gzdb_skip":
+                        stopparsing = true; // Finished with this file
+                        break;
+                }
+
+                if (stopparsing) break;
+            }
+
+            // Check values
             if (mapinfo.FadeColor.Red > 0 || mapinfo.FadeColor.Green > 0 || mapinfo.FadeColor.Blue > 0)
                 mapinfo.HasFadeColor = true;
 
             if (mapinfo.OutsideFogColor.Red > 0 || mapinfo.OutsideFogColor.Green > 0 || mapinfo.OutsideFogColor.Blue > 0)
                 mapinfo.HasOutsideFogColor = true;
 
-			//Cannot fail here
+            // All done
-			return true;
+            return !this.HasError;
         }
 
-		//returns true if parsing is finished
+        private bool ParseInclude(bool clearerrors)
-		private bool ParseBlock(string token, bool clearerrors) 
-		{
-			// Keep local data
-			Stream localstream = datastream;
-			string localsourcename = sourcename;
-			BinaryReader localreader = datareader;
-			
-			if(token == "map" || token == "defaultmap" || token == "adddefaultmap") 
-			{
-				switch(token)
-				{
-					case "map":
-						//get map name
-						SkipWhitespace(true);
-						token = ReadToken().ToLowerInvariant();
-						if(token != mapname) return false; //not finished, search for next "map", "defaultmap" or "adddefaultmap" block
-						break;
-
-					case "defaultmap":
-						//reset MapInfo
-						mapinfo = new MapInfo();
-						break;
-				}
-
-				// Track brace level
-				int bracelevel = 0;
-
-				//search for required keys
-				while(SkipWhitespace(true)) 
-				{
-					token = ReadToken().ToLowerInvariant();
-//sky1 or sky2
-					if(token == "sky1" || token == "sky2") 
-					{
-						string skyType = token;
-						SkipWhitespace(true);
-						token = StripTokenQuotes(ReadToken()).ToLowerInvariant();
-
-						//new format
-						if(token == "=") 
-						{
-							SkipWhitespace(true);
-
-							//should be sky texture name
-							token = StripTokenQuotes(ReadToken());
-							bool gotComma = (token.IndexOf(",", StringComparison.Ordinal) != -1);
-							if(gotComma) token = token.Replace(",", "");
-							string skyTexture = StripTokenQuotes(token).ToLowerInvariant();
-
-							if(!string.IsNullOrEmpty(skyTexture)) 
-							{
-								if(skyType == "sky1")
-									mapinfo.Sky1 = skyTexture;
-								else
-									mapinfo.Sky2 = skyTexture;
-
-								//check if we have scrollspeed
-								SkipWhitespace(true);
-								token = StripTokenQuotes(ReadToken());
-
-								if(!gotComma && token == ",") 
-								{
-									gotComma = true;
-									SkipWhitespace(true);
-									token = ReadToken();
-								}
-
-								if(gotComma) 
-								{
-									float scrollSpeed = 0;
-									if(!ReadSignedFloat(token, ref scrollSpeed)) 
-									{
-										// Not numeric!
-										ReportError("Expected " + skyType + " scroll speed value, but got '" + token + "'");
-										return false;
-									}
-
-									if(skyType == "sky1")
-										mapinfo.Sky1ScrollSpeed = scrollSpeed;
-									else
-										mapinfo.Sky2ScrollSpeed = scrollSpeed;
-								} 
-								else 
-								{
-									datastream.Seek(-token.Length - 1, SeekOrigin.Current); //step back and try parsing this token again
-								}
-							} 
-							else 
-							{
-								ReportError("Expected " + skyType + " texture name");
-								return false;
-							}
-						}
-						//old format
-						else 
-						{
-							//token should be sky1/2 name
-							if(!string.IsNullOrEmpty(token)) 
-							{
-								if(skyType == "sky1")
-									mapinfo.Sky1 = token;
-								else
-									mapinfo.Sky2 = token;
-
-								//try to read scroll speed
-								SkipWhitespace(true);
-								token = StripTokenQuotes(ReadToken());
-
-								float scrollSpeed = 0;
-								if(!ReadSignedFloat(token, ref scrollSpeed)) 
-								{
-									// Not numeric!
-									datastream.Seek(-token.Length - 1, SeekOrigin.Current); //step back and try parsing this token again
-									continue;
-								}
-
-								if(skyType == "sky1")
-									mapinfo.Sky1ScrollSpeed = scrollSpeed;
-								else
-									mapinfo.Sky2ScrollSpeed = scrollSpeed;
-
-							} 
-							else 
-							{
-								ReportError("Expected " + skyType + " texture name");
-								return false;
-							}
-						}
-					}
-//fade or outsidefog
-					else if(token == "fade" || token == "outsidefog") 
-					{
-						string fadeType = token;
-						SkipWhitespace(true);
-						token = StripTokenQuotes(ReadToken()).ToLowerInvariant();
-
-						//new format?
-						if(token == "=") 
-						{
-							SkipWhitespace(true);
-							token = ReadToken();
-						}
-
-						//get the color value
-						string colorVal = StripTokenQuotes(token).ToLowerInvariant().Replace(" ", "");
-						if(!string.IsNullOrEmpty(colorVal)) 
-						{
-							Color4 color = new Color4();
-							//try to get the color...
-							if(GetColor(colorVal, ref color)) 
-							{
-								if(fadeType == "fade")
-									mapinfo.FadeColor = color;
-								else
-									mapinfo.OutsideFogColor = color;
-							} 
-							else //...or not
-							{ 
-								ReportError("Failed to parse " + fadeType + " value from string '" + colorVal + "'");
-								return false;
-							}
-						} 
-						else 
-						{
-							ReportError("Expected " + fadeType + " color value");
-							return false;
-						}
-					}
-//vertwallshade or horizwallshade
-					else if(token == "vertwallshade" || token == "horizwallshade") 
-					{
-						string shadeType = token;
-						SkipWhitespace(true);
-						token = StripTokenQuotes(ReadToken());
-
-						//new format
-						if(token == "=") 
-						{
-							SkipWhitespace(true);
-							token = StripTokenQuotes(ReadToken());
-						}
-
-						int val = 0;
-						if(!ReadSignedInt(token, ref val)) 
-						{
-							// Not numeric!
-							ReportError("Expected " + shadeType + " value, but got '" + token + "'");
-							return false;
-						}
-
-						if(shadeType == "vertwallshade")
-							mapinfo.VertWallShade = General.Clamp(val, -255, 255);
-						else
-							mapinfo.HorizWallShade = General.Clamp(val, -255, 255);
-					}
-//fogdensity or outsidefogdensity
-					else if(token == "fogdensity" || token == "outsidefogdensity") 
-					{
-						string densityType = token;
-						SkipWhitespace(true);
-						token = StripTokenQuotes(ReadToken());
-
-						//new format
-						if(token == "=") 
-						{
-							SkipWhitespace(true);
-							token = StripTokenQuotes(ReadToken());
-						}
-
-						int val;
-						if(!int.TryParse(token, NumberStyles.Integer, CultureInfo.InvariantCulture, out val)) 
-						{
-							// Not numeric!
-							ReportError("Expected " + densityType + " value, but got '" + token + "'");
-							return false;
-						}
-
-						if(densityType == "fogdensity")
-							mapinfo.FogDensity = (int)(1024 * (256.0f / val));
-						else
-							mapinfo.OutsideFogDensity = (int)(1024 * (256.0f / val));
-					}
-//doublesky
-					else if(token == "doublesky") 
-					{
-						mapinfo.DoubleSky = true;
-					}
-//evenlighting
-					else if(token == "evenlighting") 
-					{
-						mapinfo.EvenLighting = true;
-					}
-//smoothlighting
-					else if(token == "smoothlighting") 
-					{
-						mapinfo.SmoothLighting = true;
-					}
-//block end
-					else if(token == "}") 
-					{
-						return ParseBlock(token, clearerrors);
-					}
-//child block
-					else if(token == "{")
-					{
-						// Skip inner properties
-						bracelevel++;
-						if(bracelevel > 1)
-						{
-							do
-							{
-								SkipWhitespace(true);
-								token = ReadToken();
-								if(token == "{") bracelevel++;
-								else if(token == "}") bracelevel--;
-							} while(!string.IsNullOrEmpty(token) && bracelevel > 1);
-						}
-					}
-				}
-			}
-			else if(token == "include") // It's "include", not "#include". Cause fuck consistency.
         {
             SkipWhitespace(true);
             string includelump = StripTokenQuotes(ReadToken(false)); // Don't skip newline
@@ -386,6 +212,9 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                     return false;
                 }
 
+                // Check invalid path chars
+                if (!CheckInvalidPathChars(includelump)) return false;
+
                 // Already parsed?
                 if (parsedlumps.Contains(includelump))
                 {
@@ -397,37 +226,40 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                 parsedlumps.Add(includelump);
 
                 // Callback to parse this file
-					if(OnInclude != null) OnInclude(this, includelump, clearerrors);
+                if (OnInclude != null)
+                {
+                    OnInclude(this, includelump, clearerrors);
 
                     // Bail out on error
                     if (this.HasError) return false;
-
+                }
-					// Set our buffers back to continue parsing
-					datastream = localstream;
-					datareader = localreader;
-					sourcename = localsourcename;
             }
             else
             {
                 ReportError("Expected filename to include");
                 return false;
             }
+
+            // All done here
+            return true;
         }
-			else if(token == "gameinfo")
+
+        private bool ParseGameInfo()
         {
             if (!NextTokenIs("{")) return false; // Finished with this file
 
             while (SkipWhitespace(true))
             {
-					token = ReadToken();
+                string token = ReadToken();
                 if (string.IsNullOrEmpty(token))
                 {
                     ReportError("Failed to find the end of GameInfo block");
                     return false; // Finished with this file
                 }
+
                 if (token == "}") break;
 
-					if(token == "skyflatname")
+                if (token.ToLowerInvariant() == "skyflatname")
                 {
                     if (!NextTokenIs("=")) return false; // Finished with this file
                     SkipWhitespace(true);
@@ -441,19 +273,24 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                     General.Map.Config.SkyFlatName = skyflatname.ToUpperInvariant();
                 }
             }
+
+            // All done here
+            return true;
         }
-			else if(token == "doomednums")
+
+        private bool ParseDoomEdNums()
         {
             if (!NextTokenIs("{")) return false; // Finished with this file
 
             while (SkipWhitespace(true))
             {
-					token = ReadToken();
+                string token = ReadToken();
                 if (string.IsNullOrEmpty(token))
                 {
                     ReportError("Failed to find the end of DoomEdNums block");
                     return false; // Finished with this file
                 }
+
                 if (token == "}") break;
 
                 // First must be a number
@@ -489,19 +326,24 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                 // Add to collection?
                 if (id != 0) doomednums[id] = classname.ToLowerInvariant();
             }
+
+            // All done here
+            return true;
         }
-			else if(token == "spawnnums")
+
+        private bool ParseSpawnNums()
         {
             if (!NextTokenIs("{")) return false; // Finished with this file
 
             while (SkipWhitespace(true))
             {
-					token = ReadToken();
+                string token = ReadToken();
                 if (string.IsNullOrEmpty(token))
                 {
                     ReportError("Failed to find the end of SpawnNums block");
                     return false; // Finished with this file
                 }
+
                 if (token == "}") break;
 
                 // First must be a number
@@ -528,13 +370,292 @@ namespace CodeImp.DoomBuilder.GZBuilder.GZDoom
                 // Add to collection
                 spawnnums[id] = token.ToLowerInvariant();
             }
-			} 
+
-			else if(token == "$gzdb_skip")
+            // All done here
-			{
+            return true;
-				return true; // Finished with this file
         }
 
-			return false; // Not done yet
+        #endregion
+
+        #region ================== Map block parsing
+
+        private bool ParseMapBlock()
+        {
+            bool classicformat = !NextTokenIs("{", false);
+
+            // Track brace level
+            int bracelevel = 0;
+
+            // Parse required values
+            while (SkipWhitespace(true))
+            {
+                string token = ReadToken().ToLowerInvariant();
+                switch (token)
+                {
+                    //TODO: are there any other blocks available in the classic format?..
+                    case "map":
+                    case "defaultmap":
+                    case "adddefaultmap":
+                        if (classicformat)
+                        {
+                            // We parsed too greadily, step back
+                            DataStream.Seek(-token.Length - 1, SeekOrigin.Current);
+
+                            // Finished with this block
+                            return true;
+                        }
+                        else
+                        {
+                            ReportError("Unexpected token \"" + token + "\"");
+                            return false;
+                        }
+
+                    case "sky2":
+                    case "sky1":
+                        if (!ParseSky(token)) return false;
+                        break;
+
+                    case "outsidefog":
+                    case "fade":
+                        if (!ParseFade(token)) return false;
+                        break;
+
+                    case "horizwallshade":
+                    case "vertwallshade":
+                        if (!ParseWallShade(token)) return false;
+                        break;
+
+                    case "outsidefogdensity":
+                    case "fogdensity":
+                        if (!ParseFogDensity(token)) return false;
+                        break;
+
+                    case "doublesky":
+                        mapinfo.DoubleSky = true;
+                        break;
+
+                    case "evenlighting":
+                        mapinfo.EvenLighting = true;
+                        break;
+
+                    case "smoothlighting":
+                        mapinfo.SmoothLighting = true;
+                        break;
+
+                    case "}": return true; // Block end
+
+                    case "{": // Skip inner blocks
+                        bracelevel++;
+                        if (bracelevel > 1)
+                        {
+                            do
+                            {
+                                SkipWhitespace(true);
+                                token = ReadToken();
+                                if (token == "{") bracelevel++;
+                                else if (token == "}") bracelevel--;
+                            } while (!string.IsNullOrEmpty(token) && bracelevel > 1);
+                        }
+                        break;
+                }
+            }
+
+            // All done here
+            return true;
+        }
+
+        private bool ParseSky(string skytype)
+        {
+            SkipWhitespace(true);
+            string token = StripTokenQuotes(ReadToken());
+
+            // New format
+            if (token == "=")
+            {
+                SkipWhitespace(true);
+
+                // Should be sky texture name
+                token = StripTokenQuotes(ReadToken());
+                bool gotcomma = (token.IndexOf(",", StringComparison.Ordinal) != -1);
+                if (gotcomma) token = token.Replace(",", "");
+                string skytexture = token.ToUpperInvariant();
+
+                if (string.IsNullOrEmpty(skytexture))
+                {
+                    ReportError("Expected " + skytype + " texture name");
+                    return false;
+                }
+
+                if (skytype == "sky1")
+                    mapinfo.Sky1 = skytexture;
+                else
+                    mapinfo.Sky2 = skytexture;
+
+                // Check if we have scrollspeed
+                SkipWhitespace(true);
+                token = StripTokenQuotes(ReadToken());
+
+                if (!gotcomma && token == ",")
+                {
+                    gotcomma = true;
+                    SkipWhitespace(true);
+                    token = StripTokenQuotes(ReadToken());
+                }
+
+                if (gotcomma)
+                {
+                    float scrollspeed = 0;
+                    if (!ReadSignedFloat(token, ref scrollspeed))
+                    {
+                        // Not numeric!
+                        ReportError("Expected " + skytype + " scroll speed value, but got '" + token + "'");
+                        return false;
+                    }
+
+                    if (skytype == "sky1")
+                        mapinfo.Sky1ScrollSpeed = scrollspeed;
+                    else
+                        mapinfo.Sky2ScrollSpeed = scrollspeed;
+                }
+                else
+                {
+                    datastream.Seek(-token.Length - 1, SeekOrigin.Current); // Step back and try parsing this token again
+                }
+            }
+            // Old format
+            else
+            {
+                // Token should be sky1/2 name
+                if (string.IsNullOrEmpty(token))
+                {
+                    ReportError("Expected " + skytype + " texture name");
+                    return false;
+                }
+
+                if (skytype == "sky1")
+                    mapinfo.Sky1 = token.ToUpperInvariant();
+                else
+                    mapinfo.Sky2 = token.ToUpperInvariant();
+
+                // Try to read scroll speed
+                SkipWhitespace(true);
+                token = StripTokenQuotes(ReadToken());
+
+                float scrollspeed = 0;
+                if (!ReadSignedFloat(token, ref scrollspeed))
+                {
+                    // Not numeric!
+                    datastream.Seek(-token.Length - 1, SeekOrigin.Current); // Step back and try parsing this token again
+                    return true;
+                }
+
+                if (skytype == "sky1")
+                    mapinfo.Sky1ScrollSpeed = scrollspeed;
+                else
+                    mapinfo.Sky2ScrollSpeed = scrollspeed;
+            }
+
+            // All done here
+            return true;
+        }
+
+        private bool ParseFade(string fadetype)
+        {
+            SkipWhitespace(true);
+            string token = StripTokenQuotes(ReadToken());
+
+            // New format?
+            if (token == "=")
+            {
+                SkipWhitespace(true);
+                token = StripTokenQuotes(ReadToken());
+            }
+
+            // Get the color value
+            string colorval = StripTokenQuotes(token).ToLowerInvariant().Replace(" ", "");
+
+            if (string.IsNullOrEmpty(colorval))
+            {
+                ReportError("Expected " + fadetype + " color value");
+                return false;
+            }
+
+            Color4 color = new Color4();
+
+            // Try to get the color...
+            if (GetColor(colorval, ref color))
+            {
+                if (fadetype == "fade")
+                    mapinfo.FadeColor = color;
+                else
+                    mapinfo.OutsideFogColor = color;
+            }
+            else //...or not
+            {
+                ReportError("Failed to parse " + fadetype + " value from string '" + colorval + "'");
+                return false;
+            }
+
+            // All done here
+            return true;
+        }
+
+        private bool ParseWallShade(string shadetype)
+        {
+            SkipWhitespace(true);
+            string token = StripTokenQuotes(ReadToken());
+
+            // New format
+            if (token == "=")
+            {
+                SkipWhitespace(true);
+                token = StripTokenQuotes(ReadToken());
+            }
+
+            int val = 0;
+            if (!ReadSignedInt(token, ref val))
+            {
+                // Not numeric!
+                ReportError("Expected " + shadetype + " value, but got '" + token + "'");
+                return false;
+            }
+
+            if (shadetype == "vertwallshade")
+                mapinfo.VertWallShade = General.Clamp(val, -255, 255);
+            else
+                mapinfo.HorizWallShade = General.Clamp(val, -255, 255);
+
+            // All done here
+            return true;
+        }
+
+        private bool ParseFogDensity(string densitytype)
+        {
+            SkipWhitespace(true);
+            string token = StripTokenQuotes(ReadToken());
+
+            // New format
+            if (token == "=")
+            {
+                SkipWhitespace(true);
+                token = StripTokenQuotes(ReadToken());
+            }
+
+            int val;
+            if (!int.TryParse(token, NumberStyles.Integer, CultureInfo.InvariantCulture, out val))
+            {
+                // Not numeric!
+                ReportError("Expected " + densitytype + " value, but got '" + token + "'");
+                return false;
+            }
+
+            if (densitytype == "fogdensity")
+                mapinfo.FogDensity = (int)(1024 * (256.0f / val));
+            else
+                mapinfo.OutsideFogDensity = (int)(1024 * (256.0f / val));
+
+            // All done here
+            return true;
         }
 
         #endregion

Source/Core/GZBuilder/GZGeneral.cs

@@ -2,6 +2,7 @@
 
 using CodeImp.DoomBuilder.Actions;
 using CodeImp.DoomBuilder.Config;
+using CodeImp.DoomBuilder.Editing;
 using CodeImp.DoomBuilder.Windows;
 using CodeImp.DoomBuilder.GZBuilder.Data;
 
@@ -72,6 +73,23 @@ namespace CodeImp.DoomBuilder.GZBuilder
 
 		[BeginAction("gztogglelights")]
 		private static void ToggleLightsRenderingMode() 
+		{
+            if (General.Editing.Mode is ClassicMode)
+            {
+                switch (General.Settings.GZDrawLightsMode)
+                {
+                    case LightRenderMode.NONE:
+                        General.Settings.GZDrawLightsMode = LightRenderMode.ALL;
+                        General.MainWindow.DisplayStatus(StatusType.Action, "Dynamic lights rendering mode: ALL");
+                        break;
+
+                    default:
+                        General.Settings.GZDrawLightsMode = LightRenderMode.NONE;
+                        General.MainWindow.DisplayStatus(StatusType.Action, "Dynamic lights rendering mode: NONE");
+                        break;
+                }
+            }
+            else
             {
                 switch (General.Settings.GZDrawLightsMode)
                 {
@@ -82,14 +100,15 @@ namespace CodeImp.DoomBuilder.GZBuilder
 
                     case LightRenderMode.ALL:
                         General.Settings.GZDrawLightsMode = LightRenderMode.ALL_ANIMATED;
-					General.MainWindow.DisplayStatus(StatusType.Action, "Models rendering mode: ANIMATED");
+                        General.MainWindow.DisplayStatus(StatusType.Action, "Dynamic lights rendering mode: ANIMATED");
                         break;
 
                     case LightRenderMode.ALL_ANIMATED:
                         General.Settings.GZDrawLightsMode = LightRenderMode.NONE;
-					General.MainWindow.DisplayStatus(StatusType.Action, "Models rendering mode: NONE");
+                        General.MainWindow.DisplayStatus(StatusType.Action, "Dynamic lights rendering mode: NONE");
                         break;
                 }
+            }
 
             General.MainWindow.RedrawDisplay();
 			General.MainWindow.UpdateGZDoomPanel();
@@ -104,17 +123,28 @@ namespace CodeImp.DoomBuilder.GZBuilder
 			General.MainWindow.UpdateGZDoomPanel();
 		}
 
+        [BeginAction("gztogglesky")]
+        private static void ToggleSky()
+        {
+            General.Settings.GZDrawSky = !General.Settings.GZDrawSky;
+            General.MainWindow.DisplayStatus(StatusType.Action, "Sky rendering is " + (General.Settings.GZDrawSky ? "ENABLED" : "DISABLED"));
+            General.MainWindow.RedrawDisplay();
+            General.MainWindow.UpdateGZDoomPanel();
+        }
+
         [BeginAction("gztogglefx")]
 		private static void ToggleFx() 
 		{
 			int on = 0;
 			on += General.Settings.GZDrawFog ? 1 : -1;
+            on += General.Settings.GZDrawSky ? 1 : -1;
             on += General.Settings.GZDrawLightsMode != LightRenderMode.NONE ? 1 : -1;
 			on += General.Settings.GZDrawModelsMode != ModelRenderMode.NONE ? 1 : -1;
 
 			bool enable = (on < 0);
 
 			General.Settings.GZDrawFog = enable;
+            General.Settings.GZDrawSky = enable;
             General.Settings.GZDrawLightsMode = (enable ? LightRenderMode.ALL : LightRenderMode.NONE);
 			General.Settings.GZDrawModelsMode = (enable ? ModelRenderMode.ALL : ModelRenderMode.NONE);
 			General.MainWindow.DisplayStatus(StatusType.Action, "Advanced effects are " + (enable ? "ENABLED" : "DISABLED") );

Source/Core/General/General.cs

@@ -1808,7 +1808,7 @@ namespace CodeImp.DoomBuilder
 		}
 
         // This returns the next power of 2
-		public static int NextPowerOf2(int v)
+        /*public static int NextPowerOf2(int v)
 		{
 			int p = 0;
 
@@ -1817,6 +1817,20 @@ namespace CodeImp.DoomBuilder
 
 			// Return power
 			return (int)Math.Pow(2, p);
+		}*/
+
+        //mxd. This returns the next power of 2. Taken from http://bits.stephan-brumme.com/roundUpToNextPowerOfTwo.html
+        public static int NextPowerOf2(int x)
+        {
+            x--;
+            x |= x >> 1;  // handle  2 bit numbers
+            x |= x >> 2;  // handle  4 bit numbers
+            x |= x >> 4;  // handle  8 bit numbers
+            x |= x >> 8;  // handle 16 bit numbers
+            x |= x >> 16; // handle 32 bit numbers
+            x++;
+
+            return x;
         }
 
         // Convert bool to integer

Source/Core/Geometry/Tools.cs

@@ -2127,6 +2127,7 @@ namespace CodeImp.DoomBuilder.Geometry
 		public static List<Line3D> GetDynamicLightShapes()
 		{
 			List<Line3D> circles = new List<Line3D>();
+            const int linealpha = 128;
             foreach (Thing t in General.Map.Map.Things)
 			{
 				int lightid = Array.IndexOf(GZBuilder.GZGeneral.GZ_LIGHTS, t.Type);
@@ -2171,15 +2172,15 @@ namespace CodeImp.DoomBuilder.Geometry
 				switch(t.Type)
 				{
 					case 1502: // Vavoom light
-						color = new PixelColor(255, 255, 255, 255);
+						color = new PixelColor(linealpha, 255, 255, 255);
 						break;
 
 					case 1503: // Vavoom colored light
-						color = new PixelColor(255, (byte)t.Args[1], (byte)t.Args[2], (byte)t.Args[3]);
+						color = new PixelColor(linealpha, (byte)t.Args[1], (byte)t.Args[2], (byte)t.Args[3]);
 						break;
 
 					default:
-						color = new PixelColor(255, (byte)t.Args[0], (byte)t.Args[1], (byte)t.Args[2]);
+						color = new PixelColor(linealpha, (byte)t.Args[0], (byte)t.Args[1], (byte)t.Args[2]);
 						break;
 				}
 

Source/Core/Map/Linedef.cs

@@ -305,7 +305,7 @@ namespace CodeImp.DoomBuilder.Map
 		}
 		
 		// This copies all properties to another line
-		new public void CopyPropertiesTo(Linedef l)
+		public void CopyPropertiesTo(Linedef l)
 		{
 			l.BeforePropsChange();
 			

Source/Core/Properties/Resources.Designer.cs

@@ -1180,6 +1180,15 @@ namespace CodeImp.DoomBuilder.Properties {
             }
         }
 
+        internal static System.Drawing.Bitmap Sky
+        {
+            get
+            {
+                object obj = ResourceManager.GetObject("Sky", resourceCulture);
+                return ((System.Drawing.Bitmap)(obj));
+            }
+        }
+
         /// <summary>
         ///   Sucht eine lokalisierte Ressource vom Typ System.Drawing.Bitmap.
         /// </summary>

Source/Core/Properties/Resources.resx

@@ -544,6 +544,9 @@
   <data name="GridIncrease" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>..\Resources\GridIncrease.png;System.Drawing.Bitmap, System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
   </data>
+  <data name="Sky" type="System.Resources.ResXFileRef, System.Windows.Forms">
+    <value>..\Resources\Sky.png;System.Drawing.Bitmap, System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
+  </data>
   <data name="zonebuilder" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>..\Resources\zonebuilder.png;System.Drawing.Bitmap, System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a</value>
   </data>

Source/Core/Rendering/Display2DShader.cs

@@ -113,10 +113,10 @@ namespace CodeImp.DoomBuilder.Rendering
 		// This sets up the render pipeline
 		public override void BeginPass(int index)
 		{
-			Device device = manager.D3DDevice.Device;
-
 			if(!manager.Enabled)
 			{
+                Device device = manager.D3DDevice.Device;
+
                 // Sampler settings
                 if (General.Settings.ClassicBilinear)
 				{

Source/Core/Rendering/Renderer3D.cs

@@ -44,6 +44,9 @@ namespace CodeImp.DoomBuilder.Rendering
 		internal const float GZDOOM_VERTICAL_VIEW_STRETCH = 1.2f;
 		internal const float GZDOOM_INVERTED_VERTICAL_VIEW_STRETCH = 1.0f / GZDOOM_VERTICAL_VIEW_STRETCH;
 
+        private const int SHADERPASS_LIGHT = 17; //mxd
+        private const int SHADERPASS_SKYBOX = 5; //mxd
+
         #endregion
 
         #region ================== Variables
@@ -92,6 +95,9 @@ namespace CodeImp.DoomBuilder.Rendering
 		//mxd. Translucent geometry to be rendered. Must be sorted by camera distance.
 		private List<VisualGeometry> translucentgeo;
 
+        //mxd. Geometry to be rendered as skybox.
+        private List<VisualGeometry> skygeo;
+
         //mxd. Solid things to be rendered (currently(?) there won't be any). Must be sorted by sector.
         private Dictionary<ImageData, List<VisualThing>> solidthings;
 
@@ -400,6 +406,7 @@ namespace CodeImp.DoomBuilder.Rendering
 			solidgeo = new Dictionary<ImageData, List<VisualGeometry>>(); //mxd
 			maskedgeo = new Dictionary<ImageData, List<VisualGeometry>>(); //mxd
 			translucentgeo = new List<VisualGeometry>(); //mxd
+            skygeo = new List<VisualGeometry>(); //mxd
 
             solidthings = new Dictionary<ImageData, List<VisualThing>>(); //mxd
 			maskedthings = new Dictionary<ImageData, List<VisualThing>>(); //mxd
@@ -427,6 +434,14 @@ namespace CodeImp.DoomBuilder.Rendering
 			graphics.Device.SetRenderState(RenderState.TextureFactor, -1);
 			graphics.Shaders.World3D.Begin();
 
+            //mxd. SKY PASS
+            if (skygeo.Count > 0)
+            {
+                world = Matrix.Identity;
+                ApplyMatrices3D();
+                RenderSky(skygeo);
+            }
+
             // SOLID PASS
             world = Matrix.Identity;
 			ApplyMatrices3D();
@@ -510,6 +525,7 @@ namespace CodeImp.DoomBuilder.Rendering
 			solidgeo = null;
 			maskedgeo = null;
 			translucentgeo = null;
+            skygeo = null;
 
             solidthings = null;
 			maskedthings = null;
@@ -951,6 +967,7 @@ namespace CodeImp.DoomBuilder.Rendering
 				// If the camera is inside a sector, compare z coordinates
 				translucentgeo.Sort(delegate(VisualGeometry vg1, VisualGeometry vg2)
 				{
+                    if (vg1 == vg2) return 0;
                     float camdist1, camdist2;
 
 					if((vg1.GeometryType == VisualGeometryType.FLOOR || vg1.GeometryType == VisualGeometryType.CEILING)
@@ -978,8 +995,12 @@ namespace CodeImp.DoomBuilder.Rendering
 			}
 			else
 			{
-				translucentgeo.Sort((vg1, vg2) => (int)((General.Map.VisualCamera.Position - vg2.BoundingBox[0]).GetLengthSq()
+                translucentgeo.Sort(delegate (VisualGeometry vg1, VisualGeometry vg2)
-													  - (General.Map.VisualCamera.Position - vg1.BoundingBox[0]).GetLengthSq()));
+                {
+                    if (vg1 == vg2) return 0;
+                    return (int)((General.Map.VisualCamera.Position - vg2.BoundingBox[0]).GetLengthSq()
+                               - (General.Map.VisualCamera.Position - vg1.BoundingBox[0]).GetLengthSq());
+                });
             }
 
 			ImageData curtexture;
@@ -1105,8 +1126,12 @@ namespace CodeImp.DoomBuilder.Rendering
 				graphics.Device.SetRenderState(RenderState.CullMode, Cull.None); //mxd. Disable backside culling, because otherwise sprites with positive ScaleY and negative ScaleX will be facing away from the camera...
 
                 // Sort geometry by camera distance. First vertex of the BoundingBox is it's center
-				thingspass.Sort((vt1, vt2) => (int)((General.Map.VisualCamera.Position - vt2.BoundingBox[0]).GetLengthSq()
+                thingspass.Sort(delegate (VisualThing vt1, VisualThing vt2)
-												  - (General.Map.VisualCamera.Position - vt1.BoundingBox[0]).GetLengthSq()));
+                {
+                    if (vt1 == vt2) return 0;
+                    return (int)((General.Map.VisualCamera.Position - vt2.BoundingBox[0]).GetLengthSq()
+                               - (General.Map.VisualCamera.Position - vt1.BoundingBox[0]).GetLengthSq());
+                });
 
                 // Reset vars
                 currentpass = RenderPass.Solid;
@@ -1279,7 +1304,7 @@ namespace CodeImp.DoomBuilder.Rendering
 			if(geometrytolit.Count == 0) return;
 			
 			graphics.Shaders.World3D.World = Matrix.Identity;
-			graphics.Shaders.World3D.BeginPass(17);
+			graphics.Shaders.World3D.BeginPass(SHADERPASS_LIGHT);
 
 			VisualSector sector = null;
 
@@ -1565,6 +1590,57 @@ namespace CodeImp.DoomBuilder.Rendering
 			graphics.Shaders.World3D.EndPass();
 		}
 
+        //mxd
+        private void RenderSky(IEnumerable<VisualGeometry> geo)
+        {
+            VisualSector sector = null;
+
+            // Set render settings
+            graphics.Shaders.World3D.BeginPass(SHADERPASS_SKYBOX);
+            graphics.Shaders.World3D.Texture1 = General.Map.Data.SkyBox;
+            graphics.Shaders.World3D.World = world;
+            graphics.Shaders.World3D.CameraPosition = new Vector4(cameraposition.x, cameraposition.y, cameraposition.z, 0f);
+
+            foreach (VisualGeometry g in geo)
+            {
+                // Changing sector?
+                if (!object.ReferenceEquals(g.Sector, sector))
+                {
+                    // Update the sector if needed
+                    if (g.Sector.NeedsUpdateGeo) g.Sector.Update();
+
+                    // Only do this sector when a vertexbuffer is created
+                    //mxd. No Map means that sector was deleted recently, I suppose
+                    if (g.Sector.GeometryBuffer != null && g.Sector.Sector.Map != null)
+                    {
+                        // Change current sector
+                        sector = g.Sector;
+
+                        // Set stream source
+                        graphics.Device.SetStreamSource(0, sector.GeometryBuffer, 0, WorldVertex.Stride);
+                    }
+                    else
+                    {
+                        sector = null;
+                    }
+                }
+
+                if (sector != null)
+                {
+                    // Set the colors to use
+                    graphics.Shaders.World3D.HighlightColor = CalculateHighlightColor((g == highlighted) && showhighlight, (g.Selected && showselection));
+
+                    // Apply changes
+                    graphics.Shaders.World3D.ApplySettings();
+
+                    // Render!
+                    graphics.Device.DrawPrimitives(PrimitiveType.TriangleList, g.VertexOffset, g.Triangles);
+                }
+            }
+
+            graphics.Shaders.World3D.EndPass();
+        }
+
         //mxd. This gets color from dynamic lights based on distance to thing. 
         //thing position must be in absolute cordinates 
         //(thing.Position.Z value is relative to floor of the sector the thing is in)
@@ -1595,6 +1671,7 @@ namespace CodeImp.DoomBuilder.Rendering
 		// This calculates the highlight/selection color
 		private Color4 CalculateHighlightColor(bool ishighlighted, bool isselected)
 		{
+            if (!ishighlighted && !isselected) return new Color4(); //mxd
             Color4 highlightcolor = isselected ? General.Colors.Selection.ToColorValue() : General.Colors.Highlight.ToColorValue();
 			highlightcolor.Alpha = ishighlighted ? highlightglowinv : highlightglow;
 			return highlightcolor;
@@ -1627,19 +1704,28 @@ namespace CodeImp.DoomBuilder.Rendering
 			// Must have a texture and vertices
 			if(g.Texture != null && g.Triangles > 0)
 			{
+                if (g.RenderAsSky && General.Settings.GZDrawSky)
+                {
+                    skygeo.Add(g);
+                }
+                else
+                {
                     switch (g.RenderPass)
                     {
                         case RenderPass.Solid:
-						if(!solidgeo.ContainsKey(g.Texture)) solidgeo.Add(g.Texture, new List<VisualGeometry>());
+                            if (!solidgeo.ContainsKey(g.Texture))
+                                solidgeo.Add(g.Texture, new List<VisualGeometry>());
                             solidgeo[g.Texture].Add(g);
                             break;
 
                         case RenderPass.Mask:
-						if(!maskedgeo.ContainsKey(g.Texture)) maskedgeo.Add(g.Texture, new List<VisualGeometry>());
+                            if (!maskedgeo.ContainsKey(g.Texture))
+                                maskedgeo.Add(g.Texture, new List<VisualGeometry>());
                             maskedgeo[g.Texture].Add(g);
                             break;
 
-					case RenderPass.Additive: case RenderPass.Alpha:
+                        case RenderPass.Additive:
+                        case RenderPass.Alpha:
                             translucentgeo.Add(g);
                             break;
 
@@ -1647,6 +1733,7 @@ namespace CodeImp.DoomBuilder.Rendering
                             throw new NotImplementedException("Geometry rendering of " + g.RenderPass + " render pass is not implemented!");
                     }
                 }
+            }
 		}
 
 		// This collects a visual sector's geometry for rendering

Source/Core/Rendering/Things2DShader.cs

@@ -137,10 +137,10 @@ namespace CodeImp.DoomBuilder.Rendering
 		// This sets up the render pipeline
 		public override void BeginPass(int index)
 		{
-			Device device = manager.D3DDevice.Device;
-
 			if(!manager.Enabled)
 			{
+                Device device = manager.D3DDevice.Device;
+
                 // Sampler settings
                 if (General.Settings.ClassicBilinear)
 				{

Source/Core/Rendering/World3DShader.cs

@@ -67,7 +67,7 @@ namespace CodeImp.DoomBuilder.Rendering
 			}
 		}
 
-		public Texture Texture1 { set { if(manager.Enabled) effect.SetTexture(texture1, value); settingschanged = true; } }
+		public BaseTexture Texture1 { set { if(manager.Enabled) effect.SetTexture(texture1, value); settingschanged = true; } }
 
 		//mxd
 		private Color4 vertexcolor;
@@ -184,7 +184,7 @@ namespace CodeImp.DoomBuilder.Rendering
 				lightPositionAndRadiusHandle = effect.GetParameter(null, "lightPosAndRadius");
 				lightColorHandle = effect.GetParameter(null, "lightColor");
 				//fog
-				camPosHandle = effect.GetParameter(null, "cameraPos");
+				camPosHandle = effect.GetParameter(null, "campos");
 
 				world = effect.GetParameter(null, "world");
 			}
@@ -285,10 +285,10 @@ namespace CodeImp.DoomBuilder.Rendering
 		// This sets up the render pipeline
 		public override void BeginPass(int index)
 		{
-			Device device = manager.D3DDevice.Device;
-
 			if(!manager.Enabled)
 			{
+                Device device = manager.D3DDevice.Device;
+
                 // Sampler settings
                 if (General.Settings.VisualBilinear)
 				{

Source/Core/Resources/Actions.cfg

@@ -1166,6 +1166,16 @@ gztogglefog
 	allowscroll = false;
 }
 
+gztogglesky
+{
+	title = "Toggle sky rendering";
+	category = "gzdoombuilder";
+	description = "Toggles sky rendering in Visual mode.";
+	allowkeys = true;
+	allowmouse = true;
+	allowscroll = false;
+}
+
 gztogglefx
 {
 	title = "Toggle models, dynamic lights and fog rendering";

Source/Core/Resources/world3d.fx

@@ -18,8 +18,21 @@ struct PixelData
 	float2 uv		  : TEXCOORD0;
 };
 
-//mxd
+//mxd. Vertex input data for sky rendering
-// Pixel input data for light pass
+struct SkyVertexData
+{
+	float3 pos		: POSITION;
+	float2 uv			: TEXCOORD0;
+};
+
+//mxd. Pixel input data for sky rendering
+struct SkyPixelData
+{
+	float4 pos		: POSITION;
+	float3 tex		: TEXCOORD0;
+};
+
+//mxd. Pixel input data for light pass
 struct LitPixelData
 {
 	float4 pos		  : POSITION;
@@ -44,7 +57,10 @@ float4 lightPosAndRadius;
 float4 lightColor; //also used as fog color
 
 //fog
-const float4 cameraPos;  //w is set to fade factor (distance, at wich fog color completely overrides pixel color)
+const float4 campos;  //w is set to fade factor (distance, at wich fog color completely overrides pixel color)
+
+//sky
+static const float4 skynormal = float4(0.0f, 1.0f, 0.0f, 0.0f);
 
 // Texture input
 const texture texture1;
@@ -66,6 +82,17 @@ sampler2D texturesamp = sampler_state
 	MaxAnisotropy = maxanisotropysetting;
 };
 
+//mxd. Skybox texture sampler settings
+samplerCUBE skysamp = sampler_state
+{
+	Texture = <texture1>;
+	MagFilter = magfiltersettings;
+	MinFilter = minfiltersettings;
+	MipFilter = mipfiltersettings;
+	MipMapLodBias = 0.0f;
+	MaxAnisotropy = maxanisotropysetting;
+};
+
 // Vertex shader
 PixelData vs_main(VertexData vd) 
 {
@@ -100,7 +127,7 @@ LitPixelData vs_customvertexcolor_fog(VertexData vd)
 	
 	// Fill pixel data input
 	pd.pos = mul(float4(vd.pos, 1.0f), worldviewproj);
-	pd.pos_w = mul(float4(vd.pos, 1.0f), world);
+	pd.pos_w = mul(float4(vd.pos, 1.0f), world).xyz;
 	pd.color = vertexColor;
 	pd.uv = vd.uv;
 	pd.normal = vd.normal;
@@ -114,7 +141,7 @@ LitPixelData vs_lightpass(VertexData vd)
 {
 	LitPixelData pd;
 	pd.pos = mul(float4(vd.pos, 1.0f), worldviewproj);
-	pd.pos_w = mul(float4(vd.pos, 1.0f), world);
+	pd.pos_w = mul(float4(vd.pos, 1.0f), world).xyz;
 	pd.color = vd.color;
 	pd.uv = vd.uv;
 	pd.normal = vd.normal;
@@ -165,8 +192,8 @@ float4 ps_fullbright_highlight(PixelData pd) : COLOR
 //mxd. This adds fog color to current pixel color
 float4 getFogColor(LitPixelData pd, float4 color)
 {
-	float fogdist = max(16.0f, distance(pd.pos_w, cameraPos.xyz));
+	float fogdist = max(16.0f, distance(pd.pos_w, campos.xyz));
-	float fogfactor = exp2(cameraPos.w * fogdist);
+	float fogfactor = exp2(campos.w * fogdist);
 
 	color.rgb = lerp(lightColor.rgb, color.rgb, fogfactor);
 	return color;
@@ -238,6 +265,23 @@ float4 ps_lightpass(LitPixelData pd) : COLOR
 	return lightColorMod; //should never get here
 }
 
+//mxd. Vertex skybox shader
+SkyPixelData vs_skybox(SkyVertexData vd)
+{
+	SkyPixelData pd;
+	pd.pos = mul(float4(vd.pos, 1.0f), worldviewproj);
+	float3 worldpos = mul(float4(vd.pos, 1.0f), world).xyz;
+	pd.tex = reflect(worldpos - campos.xyz, normalize(mul(skynormal, world).xyz));
+	return pd;
+}
+
+//mxd. Pixel skybox shader
+float4 ps_skybox(SkyPixelData pd) : COLOR
+{
+	float4 ncolor = texCUBE(skysamp, pd.tex);
+	return float4(highlightcolor.rgb * highlightcolor.a + (ncolor.rgb - 0.4f * highlightcolor.a), 1.0f);
+}
+
 // Technique for shader model 2.0
 technique SM20 
 {
@@ -277,7 +321,12 @@ technique SM20
 		PixelShader = compile ps_2_0 ps_main();
 	}
 	
-	pass p5 {} //mxd. need this only to maintain offset
+	//mxd. Skybox shader
+	pass p5
+	{
+		VertexShader = compile vs_2_0 vs_skybox();
+		PixelShader = compile ps_2_0 ps_skybox();
+	}
 
 	// Normal with highlight
 	pass p6 

Source/Core/VisualModes/VisualGeometry.cs

@@ -75,6 +75,7 @@ namespace CodeImp.DoomBuilder.VisualModes
 		private Vector3D[] boundingBox;
 		protected VisualGeometryType geometrytype;
 		protected string partname; //UDMF part name
+        protected bool renderassky;
 
         #endregion
 
@@ -89,6 +90,7 @@ namespace CodeImp.DoomBuilder.VisualModes
 		public Vector3D[] BoundingBox { get { return boundingBox; } }
 		public VisualGeometryType GeometryType { get { return geometrytype; } }
 		public float FogFactor { get { return fogfactor; } set { fogfactor = value; } }
+        public bool RenderAsSky { get { return renderassky; } }
 
         /// <summary>
         /// Render pass in which this geometry must be rendered. Default is Solid.
@@ -131,7 +133,6 @@ namespace CodeImp.DoomBuilder.VisualModes
 		/// <summary>
 		/// This creates visual geometry that is bound to a sidedef. This geometry is only visible when the sidedef is visible. It is automatically back-face culled during rendering and automatically XY intersection tested as well as back-face culled during object picking.
 		/// </summary>
-		/// <param name="sd"></param>
 		protected VisualGeometry(VisualSector vs, Sidedef sd)
 		{
 			this.sector = vs;

Source/Core/VisualModes/VisualVertex.cs

@@ -1,14 +1,14 @@
 using System;
+using CodeImp.DoomBuilder.Geometry;
 using CodeImp.DoomBuilder.Map;
 using SlimDX;
-using CodeImp.DoomBuilder.Geometry;
 
 namespace CodeImp.DoomBuilder.VisualModes
 {
 	public class VisualVertexPair
 	{
-		private VisualVertex floorvert;
+		private readonly VisualVertex floorvert;
-		private VisualVertex ceilvert;
+		private readonly VisualVertex ceilvert;
 
 		public VisualVertex[] Vertices { get { return new[] { floorvert, ceilvert }; } }
 		public VisualVertex FloorVertex { get { return floorvert; } }
@@ -37,18 +37,17 @@ namespace CodeImp.DoomBuilder.VisualModes
 		}
 	}
 
-	public abstract class VisualVertex : IVisualPickable, IComparable<VisualVertex>
+	public abstract class VisualVertex : IVisualPickable
 	{
 		//Constants
 		public const float DEFAULT_SIZE = 6.0f;
 		
 		//Variables
-		protected Vertex vertex;
+		protected readonly Vertex vertex;
 		private Matrix position;
-		private float cameradistance;
 		protected bool selected;
 		protected bool changed;
-		protected bool ceilingVertex;
+		protected readonly bool ceilingVertex;
 		protected bool haveOffset;
 
 		//Properties
@@ -90,13 +89,5 @@ namespace CodeImp.DoomBuilder.VisualModes
 		{
 			return false;
 		}
-
-		/// <summary>
-		/// This sorts things by distance from the camera. Farthest first.
-		/// </summary>
-		public int CompareTo(VisualVertex other) 
-		{
-			return Math.Sign(other.cameradistance - this.cameradistance);
-		}
 	}
 }

Source/Core/Windows/MainForm.Designer.cs

@@ -197,6 +197,7 @@ namespace CodeImp.DoomBuilder.Windows
 			this.modelsshowfiltered = new System.Windows.Forms.ToolStripMenuItem();
 			this.modelsshowall = new System.Windows.Forms.ToolStripMenuItem();
 			this.buttontogglefog = new System.Windows.Forms.ToolStripButton();
+            this.buttontogglesky = new System.Windows.Forms.ToolStripButton();
             this.buttontoggleeventlines = new System.Windows.Forms.ToolStripButton();
 			this.buttontogglevisualvertices = new System.Windows.Forms.ToolStripButton();
 			this.separatorgzmodes = new System.Windows.Forms.ToolStripSeparator();
@@ -1262,6 +1263,7 @@ namespace CodeImp.DoomBuilder.Windows
             this.dynamiclightmode,
             this.modelrendermode,
             this.buttontogglefog,
+            this.buttontogglesky,
             this.buttontoggleeventlines,
             this.buttontogglevisualvertices,
             this.separatorgzmodes,
@@ -1844,6 +1846,18 @@ namespace CodeImp.DoomBuilder.Windows
 			this.buttontogglefog.Text = "Toggle Fog Rendering";
 			this.buttontogglefog.Click += new System.EventHandler(this.InvokeTaggedAction);
             // 
+            // buttontogglesky
+            // 
+            this.buttontogglesky.CheckOnClick = true;
+            this.buttontogglesky.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
+            this.buttontogglesky.Image = global::CodeImp.DoomBuilder.Properties.Resources.Sky;
+            this.buttontogglesky.ImageTransparentColor = System.Drawing.Color.Magenta;
+            this.buttontogglesky.Name = "buttontogglesky";
+            this.buttontogglesky.Size = new System.Drawing.Size(23, 20);
+            this.buttontogglesky.Tag = "builder_gztogglesky";
+            this.buttontogglesky.Text = "Toggle Sky Rendering";
+            this.buttontogglesky.Click += new System.EventHandler(this.InvokeTaggedAction);
+            // 
             // buttontoggleeventlines
             // 
             this.buttontoggleeventlines.DisplayStyle = System.Windows.Forms.ToolStripItemDisplayStyle.Image;
@@ -2647,6 +2661,7 @@ namespace CodeImp.DoomBuilder.Windows
 		private System.Windows.Forms.ToolStripSeparator seperatorgeometry;
 		private System.Windows.Forms.ToolStripButton buttontogglefx;
 		private System.Windows.Forms.ToolStripButton buttontogglefog;
+        private System.Windows.Forms.ToolStripButton buttontogglesky;
         private System.Windows.Forms.ToolStripStatusLabel warnsLabel;
 		private System.Windows.Forms.ToolStripMenuItem itemReloadModedef;
 		private System.Windows.Forms.ToolStripMenuItem itemReloadGldefs;

Source/Core/Windows/MainForm.cs

@@ -420,6 +420,9 @@ namespace CodeImp.DoomBuilder.Windows
 			// Map opened?
 			if(General.Map != null)
 			{
+                // Get nice name
+                string maptitle = (!string.IsNullOrEmpty(General.Map.Data.MapInfo.Title) ? ": " + General.Map.Data.MapInfo.Title : "");
+
                 // Show map name and filename in caption
                 this.Text = (mapchanged ? "\u25CF " : "") + General.Map.FileTitle + " (" + General.Map.Options.CurrentName + ") - " + Application.ProductName;
 			}
@@ -2039,6 +2042,7 @@ namespace CodeImp.DoomBuilder.Windows
 			dynamiclightmode.Visible = General.Settings.GZToolbarGZDoom && maploaded;
 			buttontogglefx.Visible = General.Settings.GZToolbarGZDoom && maploaded;
 			buttontogglefog.Visible = General.Settings.GZToolbarGZDoom && maploaded;
+            buttontogglesky.Visible = General.Settings.GZToolbarGZDoom && maploaded;
             buttontoggleeventlines.Visible = General.Settings.GZToolbarGZDoom && maploaded;
 			buttontogglevisualvertices.Visible = General.Settings.GZToolbarGZDoom && maploaded;
 			separatorgzmodes.Visible = General.Settings.GZToolbarGZDoom && maploaded;
@@ -2192,6 +2196,7 @@ namespace CodeImp.DoomBuilder.Windows
 				}
 				
 				buttontogglefog.Checked = General.Settings.GZDrawFog;
+                buttontogglesky.Checked = General.Settings.GZDrawSky;
                 buttontoggleeventlines.Checked = General.Settings.GZShowEventLines;
 				buttontogglevisualvertices.Visible = General.Map.UDMF;
 				buttontogglevisualvertices.Checked = General.Settings.GZShowVisualVertices;

Source/Core/ZDoom/ZDTextParser.cs

@@ -17,6 +17,7 @@
 #region ================== Namespaces
 
 using System;
+using System.Collections.Generic;
 using System.Globalization;
 using System.Text;
 using System.IO;
@@ -87,13 +88,22 @@ namespace CodeImp.DoomBuilder.ZDoom
 			//mxd. Clear error status?
 			if(clearerrors) ClearError();
 
-			//mxd. Integrity check
+            //mxd. Integrity checks
-			if(stream == null || stream.Length == 0)
+            if (stream == null)
             {
-				ReportError("Unable to load '" + sourcefilename + "'");
+                ReportError("Unable to load \"" + sourcefilename + "\"");
                 return false;
             }
 
+            if (stream.Length == 0)
+            {
+                if (!string.IsNullOrEmpty(sourcename))
+                    LogWarning("Include file \"" + sourcefilename + "\" is empty");
+                else
+                    LogWarning("File is empty");
+                return true;
+            }
+
             datastream = stream;
 			datareader = new BinaryReader(stream, Encoding.ASCII);
 			sourcename = sourcefilename;
@@ -471,6 +481,35 @@ namespace CodeImp.DoomBuilder.ZDoom
 			return success;
 		}
 
+        //mxd
+        protected void SkipStructure() { SkipStructure(new HashSet<string>()); }
+        protected void SkipStructure(HashSet<string> breakat)
+        {
+            string token;
+            do
+            {
+                if (!SkipWhitespace(true)) break;
+                token = ReadToken();
+                if (string.IsNullOrEmpty(token)) break;
+                if (breakat.Contains(token))
+                {
+                    DataStream.Seek(-token.Length - 1, SeekOrigin.Current);
+                    return;
+                }
+            }
+            while (token != "{");
+            int scopelevel = 1;
+            do
+            {
+                if (!SkipWhitespace(true)) break;
+                token = ReadToken();
+                if (string.IsNullOrEmpty(token)) break;
+                if (token == "{") scopelevel++;
+                if (token == "}") scopelevel--;
+            }
+            while (scopelevel > 0);
+        }
+
         // This reports an error
         protected internal void ReportError(string message)
 		{
@@ -606,7 +645,7 @@ namespace CodeImp.DoomBuilder.ZDoom
                     case 60:
                     case 62:
                     case 124:
-                        ReportError("unsupported character \"" + c + "\" in path \"" + path + "\".");
+                        ReportError("Unsupported character \"" + c + "\" in path \"" + path + "\".");
                         return false;
 
                     default:

Source/Plugins/BuilderModes/IO/WavefrontExporter.cs

@@ -197,7 +197,7 @@ namespace CodeImp.DoomBuilder.BuilderModes.IO
 			BaseVisualMode mode = new BaseVisualMode();
 			bool renderingEffectsDisabled = false;
 
-			if(!BaseVisualMode.GZDoomRenderingEffects) 
+			if(!General.Settings.GZDoomRenderingEffects) 
 			{
 				renderingEffectsDisabled = true;
 				mode.ToggleGZDoomRenderingEffects();

Source/Plugins/BuilderModes/VisualModes/BaseVisualMode.cs

@@ -95,8 +95,6 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		private readonly List<ThingCopyData> copybuffer;
 		private Type lasthighlighttype;
 
-		private static bool gzdoomRenderingEffects = true; //mxd
-
         private BSP bsp;
 
         //mxd. Moved here from Tools
@@ -161,7 +159,6 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		}
 
 		public object HighlightedTarget { get { return target.picked; } } //mxd
-		public static bool GZDoomRenderingEffects { get { return gzdoomRenderingEffects; } } //mxd
 		public bool UseSelectionFromClassicMode { get { return useSelectionFromClassicMode; } } //mxd
 
 		new public IRenderer3D Renderer { get { return renderer; } }
@@ -785,7 +782,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			Sector[] sectorsWithEffects = null;
             bsp.Update();
 
-			if(!gzdoomRenderingEffects) 
+            if (!General.Settings.GZDoomRenderingEffects)
             {
 				//store all sectors with effects
 				if(sectordata != null && sectordata.Count > 0) 
@@ -828,7 +825,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				vertices.Clear();
 			}
 
-			if(!gzdoomRenderingEffects) return; //mxd
+            if (!General.Settings.GZDoomRenderingEffects) return; //mxd
 
             // Find all sector who's tag is not 0 and hash them so that we can find them quicly
             foreach (Sector s in General.Map.Map.Sectors)
@@ -1592,7 +1589,7 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			base.OnUndoEnd();
 
             //mxd. Effects may've become invalid
-			if(gzdoomRenderingEffects && sectordata != null && sectordata.Count > 0)
+            if (General.Settings.GZDoomRenderingEffects && sectordata != null && sectordata.Count > 0)
                 RebuildElementData();
 
 			//mxd. As well as geometry...
@@ -3532,10 +3529,10 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		[BeginAction("togglegzdoomgeometryeffects")]
 		public void ToggleGZDoomRenderingEffects() 
 		{
-			gzdoomRenderingEffects = !gzdoomRenderingEffects;
+            General.Settings.GZDoomRenderingEffects = !General.Settings.GZDoomRenderingEffects;
             RebuildElementData();
 			UpdateChangedObjects();
-			General.Interface.DisplayStatus(StatusType.Info, "(G)ZDoom geometry effects are " + (gzdoomRenderingEffects ? "ENABLED" : "DISABLED"));
+            General.Interface.DisplayStatus(StatusType.Info, "(G)ZDoom geometry effects are " + (General.Settings.GZDoomRenderingEffects ? "ENABLED" : "DISABLED"));
         }
 
 		//mxd

Source/Plugins/BuilderModes/VisualModes/SectorData.cs

@@ -339,9 +339,6 @@ namespace CodeImp.DoomBuilder.BuilderModes
 					SectorLevel l = lightlevels[i];
 					SectorLevel pl = lightlevels[i + 1];
 
-					// Glow levels should not affect light transfer
-					if(l.type == SectorLevelType.Glow) continue;
-
 					// Glow levels don't cast light
 					if(pl.type == SectorLevelType.Glow && lightlevels.Count > i + 2) pl = lightlevels[i + 2];
 

Source/Plugins/BuilderModes/VisualModes/VisualCeiling.cs

@@ -117,16 +117,8 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			else
 				texscale = new Vector2D(1.0f / 64.0f, 1.0f / 64.0f);
 
-			//mxd. Sky is always bright
+            // Determine brightness
-			int color;
+            int color = PixelColor.FromInt(level.color).WithAlpha((byte)General.Clamp(level.alpha, 0, 255)).ToInt();
-			if(s.CeilTexture == General.Map.Config.SkyFlatName)
-			{
-				color = -1; // That's white. With alpha. Not very impressive, eh?
-				fogfactor = 0; // No fog
-			}
-			else
-			{
-				color = PixelColor.FromInt(level.color).WithAlpha((byte)General.Clamp(level.alpha, 0, 255)).ToInt();
 
             //mxd. Top extrafloor level should calculate fogdensity
             //from the brightness of the level above it
@@ -149,11 +141,11 @@ namespace CodeImp.DoomBuilder.BuilderModes
                 targetbrightness = level.brightnessbelow;
             }
 
+            //mxd. Determine fog density
             fogfactor = CalculateFogDensity(targetbrightness);
-			}
 
             // Make vertices
-			ReadOnlyCollection<Vector2D> triverts = base.Sector.Sector.Triangles.Vertices;
+            ReadOnlyCollection<Vector2D> triverts = Sector.Sector.Triangles.Vertices;
 			WorldVertex[] verts = new WorldVertex[triverts.Count];
 			for(int i = 0; i < triverts.Count; i++)
 			{
@@ -197,11 +189,31 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				this.RenderPass = RenderPass.Solid;
 			}
 
+            //mxd. Update sky render flag
+            UpdateSkyRenderFlag();
+
             // Apply vertices
             base.SetVertices(verts);
 			return (verts.Length > 0);
 		}
 
+        //mxd
+        private void UpdateSkyRenderFlag()
+        {
+            bool isrenderedassky = renderassky;
+            renderassky = (level.sector.CeilTexture == General.Map.Config.SkyFlatName);
+            if (isrenderedassky != renderassky && Sector.Sides != null)
+            {
+                // Upper/middle geometry may need updating...
+                foreach (Sidedef side in level.sector.Sidedefs)
+                {
+                    VisualSidedefParts parts = Sector.GetSidedefParts(side);
+                    if (parts.upper != null) parts.upper.UpdateSkyRenderFlag();
+                    else if (parts.middlesingle != null) parts.middlesingle.UpdateSkyRenderFlag();
+                }
+            }
+        }
+
         #endregion
 
         #region ================== Methods

Source/Plugins/BuilderModes/VisualModes/VisualFloor.cs

@@ -119,16 +119,8 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			else
 				texscale = new Vector2D(1.0f / 64.0f, 1.0f / 64.0f);
 
-			//mxd. Sky is always bright
+            // Determine brightness
-			int color;
+            int color = PixelColor.FromInt(level.color).WithAlpha((byte)General.Clamp(level.alpha, 0, 255)).ToInt();
-			if(s.FloorTexture == General.Map.Config.SkyFlatName)
-			{
-				color = -1; // That's white. With alpha. Not very impressive, eh?
-				fogfactor = 0; // No fog
-			}
-			else
-			{
-				color = PixelColor.FromInt(level.color).WithAlpha((byte)General.Clamp(level.alpha, 0, 255)).ToInt();
 
             //mxd. Top extrafloor level should calculate fogdensity
             //from the brightness of the level above it
@@ -151,11 +143,11 @@ namespace CodeImp.DoomBuilder.BuilderModes
                 targetbrightness = level.brightnessbelow;
             }
 
+            //mxd. Determine fog density
             fogfactor = CalculateFogDensity(targetbrightness);
-			}
 
             // Make vertices
-			ReadOnlyCollection<Vector2D> triverts = base.Sector.Sector.Triangles.Vertices;
+            ReadOnlyCollection<Vector2D> triverts = Sector.Sector.Triangles.Vertices;
 			WorldVertex[] verts = new WorldVertex[triverts.Count];
 			for(int i = 0; i < triverts.Count; i++)
 			{
@@ -199,11 +191,30 @@ namespace CodeImp.DoomBuilder.BuilderModes
 				this.RenderPass = RenderPass.Solid;
 			}
             
+            //mxd. Update sky render flag
+            UpdateSkyRenderFlag();
+
             // Apply vertices
             base.SetVertices(verts);
 			return (verts.Length > 0);
 		}
 
+        //mxd
+        private void UpdateSkyRenderFlag()
+        {
+            bool isrenderedassky = renderassky;
+            renderassky = (level.sector.FloorTexture == General.Map.Config.SkyFlatName || level.sector.LongFloorTexture == MapSet.EmptyLongName);
+            if (isrenderedassky != renderassky && Sector.Sides != null)
+            {
+                // Middle geometry may need updating...
+                foreach (Sidedef side in level.sector.Sidedefs)
+                {
+                    VisualSidedefParts parts = Sector.GetSidedefParts(side);
+                    if (parts.middlesingle != null) parts.middlesingle.UpdateSkyRenderFlag();
+                }
+            }
+        }
+
         #endregion
 
         #region ================== Methods

Source/Plugins/BuilderModes/VisualModes/VisualMiddleSingle.cs

@@ -62,6 +62,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		{
 			Vector2D vl, vr;
 
+            //mxd. Apply sky hack?
+            UpdateSkyRenderFlag();
+
             //mxd. lightfog flag support
             int lightvalue;
 			bool lightabsolute;
@@ -202,6 +205,12 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			return false;
 		}
 
+        //mxd
+        internal void UpdateSkyRenderFlag()
+        {
+            renderassky = (Sidedef.LongMiddleTexture == MapSet.EmptyLongName && Sidedef.Sector != null && Sidedef.Sector.CeilTexture == General.Map.Config.SkyFlatName);
+        }
+
         #endregion
 
         #region ================== Methods

Source/Plugins/BuilderModes/VisualModes/VisualUpper.cs

@@ -62,6 +62,9 @@ namespace CodeImp.DoomBuilder.BuilderModes
 		{
 			Vector2D vl, vr;
 
+            //mxd. Apply sky hack?
+            UpdateSkyRenderFlag();
+
             //mxd. lightfog flag support
             int lightvalue;
 			bool lightabsolute;
@@ -197,6 +200,14 @@ namespace CodeImp.DoomBuilder.BuilderModes
 			return false;
 		}
 
+        //mxd
+        internal void UpdateSkyRenderFlag()
+        {
+            renderassky = (Sidedef.Other != null && Sidedef.Sector != null && Sidedef.Other.Sector != null &&
+                           Sidedef.Sector.CeilTexture == General.Map.Config.SkyFlatName &&
+                           Sidedef.Other.Sector.CeilTexture == General.Map.Config.SkyFlatName);
+        }
+
         #endregion
 
         #region ================== Methods