[KWo]

The "really" invisible player is invisible for bots as long he (the player) is not pressing the fire button. In that case the bot code presuposes hat the fire from the weapon should be seen - so the player stays "semi-visible" (the bot s trying to aim his body origin - never the head).

bool FBoxVisible (bot_t *pBot, edict_t *pTargetEdict, Vector *pvHit, unsigned char *ucBodyPart) // KWo - 23.03.2012 - rewritten...
{
// KWo - 05.09.2009 - changed variables to static ones
   static int i;
   static int RenderFx;             // KWo - 22.03.2008
   static int RenderMode;           // KWo - 22.03.2008
   static int TargetEntIndex;       // KWo - 17.01.2011
   static int TargetWeapon;         // KWo - 17.01.2011
   static Vector RenderColor;       // KWo - 22.03.2008
   static float RenderAmount;       // KWo - 22.03.2008
   static float LightLevel;         // KWo - 23.03.2008
   static bool SemiTransparent;     // KWo - 22.03.2008
   static bool WeaponIsGun;         // KWo - 17.01.2011
   static TraceResult tr;
   static Vector vecLookerOrigin;
   static Vector vecTarget;
   static Vector vecEnDirection;
   static edict_t *pEdict;

   *ucBodyPart = 0;
   *pvHit = g_vecZero;              // KWo - 04.07.2008
   pEdict = pBot->pEdict;           // KWo - 27.05.2008

   if (FNullEnt(pTargetEdict))      // KWo - 17.01.2011
      return (FALSE);

   TargetEntIndex = ENTINDEX (pTargetEdict) - 1;                                        // 17.01.2011
   if ((TargetEntIndex >= 0) && (TargetEntIndex < gpGlobals->maxClients))
   {
      TargetWeapon = clients[TargetEntIndex].iCurrentWeaponId;                          // 17.01.2011
      WeaponIsGun = (WeaponIsPistol(TargetWeapon) || WeaponIsPrimaryGun(TargetWeapon)); // 17.01.2011
   }
   else
      WeaponIsGun = FALSE;

// Can't see the target entity if blinded or smoked...
   if ((pEdict->v.origin - pTargetEdict->v.origin).Length() > pBot->f_view_distance)   // KWo - 14.09.2008
      return (FALSE);

   // don't look through water
   if (((pEdict->v.waterlevel != 3) && (pTargetEdict->v.waterlevel == 3))
       || ((pEdict->v.waterlevel == 3) && (pTargetEdict->v.waterlevel == 0)))
      return (FALSE);

// KWo - 22.03.2008 - added invisibility check
   RenderFx = pTargetEdict->v.renderfx;
   RenderMode = pTargetEdict->v.rendermode;
   RenderColor = pTargetEdict->v.rendercolor;
   RenderAmount = pTargetEdict->v.renderamt;
   SemiTransparent = false;    // KWo (moved) - 05.09.2009

   if (((RenderFx == kRenderFxExplode) || (pTargetEdict->v.effects & EF_NODRAW))
      && (!(WeaponIsGun) || !(pTargetEdict->v.oldbuttons & IN_ATTACK))) // kRenderFxExplode is always invisible even for mode kRenderNormal
   {
      return (FALSE);
   }
   else if (((RenderFx == kRenderFxExplode) || (pTargetEdict->v.effects & EF_NODRAW))
      && (pTargetEdict->v.oldbuttons & IN_ATTACK) && (WeaponIsGun))  // KWo - 17.01.2011
   {
      SemiTransparent = true;
   }
   else if ((RenderFx != kRenderFxHologram) && (RenderMode != kRenderNormal)) // kRenderFxHologram is always visible no matter what is the mode
   {
      if (RenderFx == kRenderFxGlowShell)
      {
         if ((RenderAmount <= 20.0) && (RenderColor.x <= 20)
            && (RenderColor.y <= 20) && (RenderColor.z <= 20))
         {
            if (!(pTargetEdict->v.oldbuttons & IN_ATTACK) || !(WeaponIsGun))
            {
               return (FALSE);
            }
            else
            {
               SemiTransparent = true;
            }
         }
         else if ((RenderAmount <= 60.0) && (RenderColor.x <= 60)
            && (RenderColor.y <= 60) && (RenderColor.z <= 60))
         {
            SemiTransparent = true;
         }
      }
      else
      {
         if (RenderAmount <= 20)
         {
            if (!(pTargetEdict->v.oldbuttons & IN_ATTACK) || !(WeaponIsGun))
            {
               return (FALSE);
            }
            else
            {
               SemiTransparent = true;
            }
         }
         else if (RenderAmount <= 60)
         {
            SemiTransparent = true;
         }
      }
   }


// KWo - 26.03.2008 - added darkness check
   LightLevel = UTIL_IlluminationOf(pTargetEdict);
//   ALERT(at_logged,"[DEBUG] Bot %s checks the illumination of %s. It's = %f.\n",
//      STRING(pEdict->v.netname), STRING(pTargetEdict->v.netname), LightLevel);

   if ((!pBot->bUsesNVG) && (((LightLevel < 3.0) && (g_f_cv_skycolor > 50.0)) || ((LightLevel < 25.0) && (g_f_cv_skycolor <= 50.0)))
      && (!(pTargetEdict->v.effects & EF_DIMLIGHT)) && (!(pTargetEdict->v.oldbuttons & IN_ATTACK) || !(WeaponIsGun))) // KWo - 17.01.2011
   {
      return (FALSE);
   }
   else if (((((LightLevel < 10.0) && (g_f_cv_skycolor > 50.0)) || ((LightLevel < 30.0) && (g_f_cv_skycolor <= 50.0)))
      && (pTargetEdict->v.oldbuttons & IN_ATTACK) && (WeaponIsGun)) && (!(pTargetEdict->v.effects & EF_DIMLIGHT)) && (!pBot->bUsesNVG)) // KWo - 17.01.2011
   {
      SemiTransparent = true; // in this case we can notice the enemy, but not so good...
   }

//   if (SemiTransparent)
//      ALERT(at_logged, "[DEBUG] FBoxVisible - Bot's %s target SemiTransparent = true, LightLevel = %.2f \n", pBot->name, LightLevel);

   vecLookerOrigin = GetGunPosition (pEdict);
   vecTarget = pTargetEdict->v.origin;

   // Check direct Line to waist
   UTIL_TraceLine (vecLookerOrigin, vecTarget, ignore_monsters, ignore_glass, pEdict, &tr);

   if ((tr.flFraction >= 1.0) || (tr.pHit == pTargetEdict))
   {
      *pvHit = tr.vecEndPos  + Vector (0.0, 0.0, 3.0); // KWo - 13.07.2008
      *ucBodyPart |= WAIST_VISIBLE;
   }

   vecEnDirection = pTargetEdict->v.angles; // KWo - 05.09.2009 (moved)
   MAKE_VECTORS (vecEnDirection);

   // Check direct Line to head
   vecTarget = vecTarget + pTargetEdict->v.view_ofs + Vector(0.0, 0.0, 2.0); // KWo - 02.04.2010
   if (!(pTargetEdict->v.oldbuttons & IN_DUCK))       // KWo - 13.07.2008
   {
      vecTarget = vecTarget + Vector(0.0, 0.0, 1.0);  // KWo - 02.04.2010
   }

   UTIL_TraceLine (vecLookerOrigin, vecTarget, ignore_monsters, ignore_glass, pEdict, &tr);

   // if the player is rendered, his head cannot be good seen...
   if (((tr.flFraction >= 1.0) || (tr.pHit == pTargetEdict)) && (!SemiTransparent))
   {
      *pvHit = tr.vecEndPos;
      *ucBodyPart |= HEAD_VISIBLE;
   }

   if (*ucBodyPart != 0)
      return (TRUE);

   // Nothing visible - check randomly other Parts of Body
   for (i = 0; i < 6; i++)
   {
      vecTarget = pTargetEdict->v.origin;
      switch(i)
      {
         case 0: // left arm
         {
            vecTarget.x -= 10.0 * gpGlobals->v_right.x;
            vecTarget.y -= 10.0 * gpGlobals->v_right.y;
            vecTarget.z += 8.0;
            break;
         }
         case 1: // right arm
         {
            vecTarget.x += 10.0 * gpGlobals->v_right.x;
            vecTarget.y += 10.0 * gpGlobals->v_right.y;
            vecTarget.z += 8.0;
            break;
         }
         case 2: // left leg
         {
            vecTarget.x -= 10.0 * gpGlobals->v_right.x;
            vecTarget.y -= 10.0 * gpGlobals->v_right.y;
            vecTarget.z -= 12.0;
            break;
         }
         case 3: // right leg
         {
            vecTarget.x += 10.0 * gpGlobals->v_right.x;
            vecTarget.y += 10.0 * gpGlobals->v_right.y;
            vecTarget.z -= 12.0;
            break;
         }
         case 4: // left foot
         {
            vecTarget.x -= 10.0 * gpGlobals->v_right.x;
            vecTarget.y -= 10.0 * gpGlobals->v_right.y;
            vecTarget.z -= 24.0;
            break;
         }
         case 5: // right foot
         {
            vecTarget.x += 10.0 * gpGlobals->v_right.x;
            vecTarget.y += 10.0 * gpGlobals->v_right.y;
            vecTarget.z -= 24.0;
            break;
         }
      }
/*
      vecTarget.x += RANDOM_FLOAT (pTargetEdict->v.mins.x, pTargetEdict->v.maxs.x);
      vecTarget.y += RANDOM_FLOAT (pTargetEdict->v.mins.y, pTargetEdict->v.maxs.y);
      vecTarget.z += RANDOM_FLOAT (pTargetEdict->v.mins.z, pTargetEdict->v.maxs.z);
*/

      UTIL_TraceLine (vecLookerOrigin, vecTarget, dont_ignore_monsters, ignore_glass, pEdict, &tr);

      if ((tr.flFraction >= 1.0) && (tr.pHit == pTargetEdict))
      {
         // Return seen position
         *pvHit = tr.vecEndPos;
         *ucBodyPart |= CUSTOM_VISIBLE;
         return (TRUE);
      }
   }

   return (FALSE);
}