Tourists gain experience by seeing new types of creatures up close

Experience equivalent to killing a monster is gained when starting a turn
adjacent to and being able to see the monster.

Breaks saves.

Idea and parts of code via dNetHack

doc/fixes3-7-0.txt

@@ -2730,6 +2730,7 @@ enlightenment/attribute disclosure for saving-grace: include a line for have
 	"X " for explore mode, or "D " for debug mode if any of the games
 	shown in its menu weren't saved during normal play; if they're all
 	normal play, the prefix is suppressed
+tourists gain experience by seeing new types of creatures up close
 
 
 Platform- and/or Interface-Specific New Features

include/hack.h

@@ -673,6 +673,7 @@ struct mvitals {
     uchar born;
     uchar died;
     uchar mvflags;
+    Bitfield(seen_close, 1);
 };
 
 

include/patchlevel.h

@@ -17,7 +17,7 @@
  * Incrementing EDITLEVEL can be used to force invalidation of old bones
  * and save files.
  */
-#define EDITLEVEL 110
+#define EDITLEVEL 111
 
 /*
  * Development status possibilities.

src/allmain.c

@@ -14,6 +14,7 @@
 
 staticfn void moveloop_preamble(boolean);
 staticfn void u_calc_moveamt(int);
+staticfn void see_nearby_monsters(void);
 staticfn void maybe_do_tutorial(void);
 #ifdef POSITIONBAR
 staticfn void do_positionbar(void);
@@ -154,6 +155,28 @@ u_calc_moveamt(int wtcap)
         u.umovement = 0;
 }
 
+/* mark a monster type as seen when we see it next to us */
+staticfn void
+see_nearby_monsters(void)
+{
+    coordxy x, y;
+
+    if (Blind || !Role_if(PM_TOURIST))
+        return;
+
+    for (x = u.ux - 1; x <= u.ux + 1; x++)
+        for (y = u.uy - 1; y <= u.uy + 1; y++)
+            if (isok(x, y) && MON_AT(x, y)) {
+                struct monst *mtmp = m_at(x, y);
+
+                if (canseemon(mtmp) && !svm.mvitals[monsndx(mtmp->data)].seen_close) {
+                    svm.mvitals[monsndx(mtmp->data)].seen_close = TRUE;
+                    more_experienced(experience(mtmp, 0), 0);
+                    newexplevel();
+                }
+            }
+}
+
 #if defined(MICRO) || defined(WIN32)
 static int mvl_abort_lev;
 #endif
@@ -410,6 +433,7 @@ moveloop_core(void)
         else if (u.uburied)
             under_ground(0);
 
+        see_nearby_monsters();
     } /* actual time passed */
 
     /****************************************/