xrGame/ai/monsters/monster_enemy_memory.cpp: monsters now calculating distance to enemy that created sound they hear

Calculating distance to actor is wrong

Also, I moved actor presence check to be earlier, so we don't do
unneeded calculations

Author: Xottab-DUTY

src/xrGame/ai/monsters/monster_enemy_memory.cpp

@@ -55,7 +55,8 @@ void CMonsterEnemyMemory::update()
         }
     }
 
-    if (monster->SoundMemory.IsRememberSound())
+    if (monster->SoundMemory.IsRememberSound() && g_actor
+        && g_actor->memory().visual().visible_now(monster))
     {
         SoundElem sound;
         bool dangerous;
@@ -64,12 +65,11 @@ void CMonsterEnemyMemory::update()
         {
             if (CEntityAlive const* enemy = smart_cast<CEntityAlive const*>(sound.who))
             {
-                float const xz_dist = monster->Position().distance_to_xz(g_actor->Position());
-                float const y_dist = _abs(monster->Position().y - g_actor->Position().y);
+                float const xz_dist = monster->Position().distance_to_xz(enemy->Position());
+                float const y_dist = _abs(monster->Position().y - enemy->Position().y);
 
                 if (monster->CCustomMonster::useful(&monster->memory().enemy(), enemy) && y_dist < 10 &&
-                    xz_dist < monster->get_feel_enemy_who_made_sound_max_distance() &&
-                    g_actor->memory().visual().visible_now(monster))
+                    xz_dist < monster->get_feel_enemy_who_made_sound_max_distance())
                 {
                     add_enemy(enemy);