crawl-ref/source/mon-stealth.cc

   1 /*
   2  *  File:       mon-stealth.cc
   3  *  Summary:    Monsters stealth methods.
   4  */
   5
   6 #include "AppHdr.h"
   7
   8 #include "monster.h"
   9 #include "mon-util.h"
  10
  11 static int _clamp_stealth (int stealth)
  12 {
  13     if (stealth > 3)
  14     {
  15         return (3);
  16     }
  17     else if (stealth < -3)
  18     {
  19         return (-3);
  20     }
  21     else
  22     {
  23         return (stealth);
  24     }
  25 }
  26
  27 // Monster stealth is a value between:
  28 //
  29 // -3 - Extremely unstealthy
  30 // -2 - Very unstealthy
  31 // -1 - Unstealthy
  32 //  0 - Normal
  33 //  1 - Stealthy
  34 //  2 - Very stealthy
  35 //  3 - Extremely stealthy
  36 //
  37 int monster::stealth() const
  38 {
  39     int base_stealth = -(std::min((int) body_size(), 6) - 3);
  40
  41     int actual_stealth = base_stealth;
  42
  43     // Undead are inherently more stealthy.
  44     if (holiness() == MH_UNDEAD)
  45     {
  46         // Zombies are less stealthy.
  47         if (type == MONS_ZOMBIE_SMALL)
  48             actual_stealth--;
  49
  50         // Larger zombies even more so.
  51         else if (type == MONS_ZOMBIE_LARGE)
  52             actual_stealth -= 2;
  53
  54         // Other undead are otherwise stealthy.
  55         else
  56             actual_stealth++;
  57     }
  58
  59     // If you're floundering in water, you're unstealthy.
  60     if (floundering())
  61         actual_stealth -= 2;
  62
  63     // Orcs are a noisy bunch and get a penalty here to affect orc wizard
  64     // invisibility.
  65     if (mons_genus(this->type) == MONS_ORC)
  66         actual_stealth--;
  67
  68     // Not an issue with invisibility, but glowing or haloes make you
  69     // unstealthy.
  70     if (glows_naturally() || halo_radius2() != -1)
  71         actual_stealth -= 3;
  72
  73     // Some specific overrides
  74     if (type == MONS_UNSEEN_HORROR)
  75         actual_stealth = 3;
  76
  77     return _clamp_stealth(actual_stealth);
  78 }