Use TRUE and FALSE enums for setlevel.

Also simplify if conditions to make
use of boolean values.

(If the cleanup4 PR ends up increasing
inserts/deletions, then this commit is
probably at fault.)

Source/diablo.cpp

@@ -376,7 +376,7 @@ void diablo_parse_flags(char *args)
 			*/
 				break;
 			case 'l':
-				setlevel = 0;
+				setlevel = FALSE;
 				leveldebug = 1;
 				while (isspace(*args)) {
 					args++;
@@ -440,7 +440,7 @@ void diablo_parse_flags(char *args)
 				break;
 			case 't':
 				leveldebug = 1;
-				setlevel = 1;
+				setlevel = TRUE;
 				while (isspace(*args)) {
 					args++;
 				}
@@ -1834,7 +1834,6 @@ void LoadGameLevel(BOOL firstflag, int lvldir)
 		PlaySFX(USFX_SKING1);
 }
 // 525738: using guessed type int setseed;
-// 5CF31D: using guessed type char setlevel;
 // 679660: using guessed type char gbMaxPlayers;
 
 void game_loop(BOOL bStartup)

Source/gendung.cpp

@@ -950,6 +950,6 @@ void InitLevels()
 	if (!leveldebug) {
 		currlevel = 0;
 		leveltype = DTYPE_TOWN;
-		setlevel = 0;
+		setlevel = FALSE;
 	}
 }

Source/loadsave.cpp

@@ -595,7 +595,7 @@ void SaveLevel()
 	pfile_write_save_file(szName, SaveBuff, tbuff - SaveBuff, dwLen);
 	mem_free_dbg(SaveBuff);
 
-	if (setlevel == 0)
+	if (!setlevel)
 		plr[myplr]._pLvlVisited[currlevel] = TRUE;
 	else
 		plr[myplr]._pSLvlVisited[setlvlnum] = TRUE;

Source/missiles.cpp

@@ -1299,7 +1299,7 @@ void AddRndTeleport(int mi, int sx, int sy, int dx, int dy, int midir, char mien
 
 	missile[mi]._miVar1 = 0;
 	missile[mi]._mirange = 2;
-	if (setlevel == 0 || setlvlnum != SL_VILEBETRAYER) {
+	if (!setlevel || setlvlnum != SL_VILEBETRAYER) {
 		missile[mi]._mix = sx + r1;
 		missile[mi]._miy = sy + r2;
 		if (!mienemy)

Source/multi.cpp

@@ -772,7 +772,7 @@ void SetupLocalCoords()
 	if (!leveldebug || gbMaxPlayers > 1) {
 		currlevel = 0;
 		leveltype = DTYPE_TOWN;
-		setlevel = 0;
+		setlevel = FALSE;
 	}
 	x = 75;
 	y = 68;

Source/objects.cpp

@@ -2462,7 +2462,7 @@ void OperateBook(int pnum, int i)
 	}
 	object[i]._oAnimFrame++;
 	object[i]._oSelFlag = 0;
-	if (setlevel == 0)
+	if (!setlevel)
 		return;
 
 	if (setlvlnum == SL_BONECHAMB) {
@@ -2485,7 +2485,7 @@ void OperateBook(int pnum, int i)
 		    0,
 		    0);
 	}
-	if (setlevel != 0 && setlvlnum == SL_VILEBETRAYER) {
+	if (setlevel && setlvlnum == SL_VILEBETRAYER) {
 		ObjChangeMapResync(
 		    object[i]._oVar1,
 		    object[i]._oVar2,

Source/portal.cpp

@@ -121,19 +121,19 @@ void SetCurrentPortal(int p)
 void GetPortalLevel()
 {
 	if (currlevel) {
-		setlevel = 0;
+		setlevel = FALSE;
 		currlevel = 0;
 		plr[myplr].plrlevel = 0;
 		leveltype = DTYPE_TOWN;
 	} else {
 		if (portal[portalindex].setlvl) {
-			setlevel = 1;
+			setlevel = TRUE;
 			setlvlnum = portal[portalindex].level;
 			currlevel = portal[portalindex].level;
 			plr[myplr].plrlevel = setlvlnum;
 			leveltype = portal[portalindex].ltype;
 		} else {
-			setlevel = 0;
+			setlevel = FALSE;
 			currlevel = portal[portalindex].level;
 			plr[myplr].plrlevel = currlevel;
 			leveltype = portal[portalindex].ltype;

Source/trigs.cpp

@@ -695,7 +695,6 @@ void CheckTrigForce()
 		ClearPanel();
 	}
 }
-// 5CF31D: using guessed type char setlevel;
 
 void CheckTriggers()
 {