Implementing merfolk monsters. There are two types, merfolk fighters,

and mermaids. The latter are more interesting. ;)

Whenever a mermaid sings there's a chance you get beheld, meaning you
cannot move away from the mermaid, that is cannot increase the 
distance between you and her. (Because of the distance pecularities
this means at dist 1 you can only be NSW or E of the mermaid but not
the diagonal directions.) 
If you manage to be beheld by several mermaids at the same time, your 
movements have to respect the distance to all of them.

I've added a vector beheld_by that keeps track of beholding monsters
and makes checking distance and updating beholding status easier.

Merfolk are immune to the mermaid song.


git-svn-id: https://crawl-ref.svn.sourceforge.net/svnroot/crawl-ref/trunk@2453 c06c8d41-db1a-0410-9941-cceddc491573

1 files changed, 67 insertions, 1 deletions

diff --git a/crawl-ref/source/player.cc b/crawl-ref/source/player.cc
index 674e2df54c..02266afb2a 100644
--- a/crawl-ref/source/player.cc
+++ b/crawl-ref/source/player.cc
@@ -2324,7 +2324,7 @@ int player_see_invis(bool calc_unid)
 
 // This does NOT do line of sight!  It checks the monster's visibility 
 // with repect to the players perception, but doesn't do walls or range...
-// to find if the square the monster is in is visible see mons_near().
+// to find if the square the monster is in los see mons_near().
 bool player_monster_visible( const monsters *mon )
 {
     if (mon->has_ench(ENCH_SUBMERGED)
@@ -2336,6 +2336,69 @@ bool player_monster_visible( const monsters *mon )
     return (true);
 }
 
+// returns true if player is beheld by a given monster
+bool player_beheld_by( const monsters *mon )
+{
+    if (!you.duration[DUR_BEHELD])
+        return false;
+        
+    // can this monster even behold you?
+    if (mon->type != MONS_MERMAID)
+        return false;
+
+#ifdef DEBUG_DIAGNOSTICS
+    mprf(MSGCH_DIAGNOSTICS, "beheld_by.size: %d, DUR_BEHELD: %d, current mon: %d",
+                            you.beheld_by.size(), you.duration[DUR_BEHELD],
+                            monster_index(mon));
+#endif
+
+    if (you.beheld_by.empty()) // shouldn't happen
+    {
+        you.duration[DUR_BEHELD] = 0;
+        return false;
+    }
+    
+    for (unsigned int i = 0; i < you.beheld_by.size(); i++)
+    {
+         unsigned int which_mon = you.beheld_by[i];
+         if (monster_index(mon) == which_mon)
+             return true;
+    }
+    
+    return false;
+}
+
+// removes a monster from the list of beholders
+// if force == true (e.g. monster dead) or one of
+// several cases is met
+void update_beholders(const monsters *mon, bool force)
+{
+    if (!player_beheld_by(mon)) // not in list?
+        return;
+        
+    // is an update even necessary?
+    if (force || !mons_near(mon) || mons_friendly(mon) || mon->submerged()
+        || mon->has_ench(ENCH_CONFUSION) || mons_is_paralysed(mon) || mon->asleep()
+        || silenced(you.x_pos, you.y_pos) || silenced(mon->x, mon->y))
+    {
+        const std::vector<int> help = you.beheld_by;
+        you.beheld_by.clear();
+
+        for (unsigned int i = 0; i < help.size(); i++)
+        {
+             unsigned int which_mon = help[i];
+             if (monster_index(mon) != which_mon)
+                 you.beheld_by.push_back(i);
+        }
+
+        if (you.beheld_by.empty())
+        {
+            mpr("You are no longer entranced.", MSGCH_RECOVERY);
+            you.duration[DUR_BEHELD] = 0;
+        }
+    }
+}
+
 int player_sust_abil(bool calc_unid)
 {
     int sa = 0;
@@ -3362,6 +3425,9 @@ void display_char_status()
     if (you.duration[DUR_CONF])
         mpr( "You are confused." );
 
+    if (you.duration[DUR_BEHELD])
+        mpr( "You are beheld." );
+
     if (you.duration[DUR_PARALYSIS])
         mpr( "You are paralysed." );