Add "tutorialmode" var to help the game know when we're in a tutorial or not, add placeholder for tutorial HUD to test it works

src/d_main.c

@@ -714,6 +714,9 @@ void D_StartTitle(void)
 	// reset modeattacking
 	modeattacking = ATTACKING_NONE;
 
+	// The title screen is obviously not a tutorial! (Unless I'm mistaken)
+	tutorialmode = false;
+
 	// empty maptol so mario/etc sounds don't play in sound test when they shouldn't
 	maptol = 0;
 

src/d_netcmd.c

@@ -1815,6 +1815,8 @@ static void Command_Map_f(void)
 	else
 		fromlevelselect = ((netgame || multiplayer) && ((gametype == newgametype) && (newgametype == GT_COOP)));
 
+	tutorialmode = false; // warping takes us out of tutorial mode
+
 	D_MapChange(newmapnum, newgametype, false, newresetplayers, 0, false, fromlevelselect);
 }
 

src/doomstat.h

@@ -133,6 +133,7 @@ extern boolean hidetitlepics;
 extern INT16 bootmap; //bootmap for loading a map on startup
 
 extern INT16 tutorialmap; // map to load for tutorial
+extern boolean tutorialmode; // are we in a tutorial right now?
 
 extern boolean looptitle;
 

src/g_game.c

@@ -128,6 +128,7 @@ boolean hidetitlepics = false;
 INT16 bootmap; //bootmap for loading a map on startup
 
 INT16 tutorialmap = 0; // map to load for tutorial
+boolean tutorialmode = false; // are we in a tutorial right now?
 
 boolean looptitle = false;
 

src/m_menu.c

@@ -6139,6 +6139,8 @@ static void M_StartTutorial(INT32 choice)
 	if (!tutorialmap)
 		return; // no map to go to, don't bother
 
+	tutorialmode = true; // turn on tutorial mode
+
 	emeralds = 0;
 	M_ClearMenus(true);
 	gamecomplete = false;

src/st_stuff.c

@@ -2465,6 +2465,13 @@ static void ST_overlayDrawer(void)
 	ST_drawDebugInfo();
 }
 
+static void ST_drawTutorial(void)
+{
+	// Nothing, ...yet
+	// Except this for now, just to check it works
+	V_DrawCenteredString(BASEVIDWIDTH/2, BASEVIDHEIGHT/2, 0, "Tutorial placeholder");
+}
+
 void ST_Drawer(void)
 {
 #ifdef SEENAMES
@@ -2538,4 +2545,8 @@ void ST_Drawer(void)
 			ST_overlayDrawer();
 		}
 	}
+
+	// Draw tutorial text over everything else
+	if (tutorialmode)
+		ST_drawTutorial();
 }