Dedupe follower list creation

Author: sparr

src/faction.cpp

@@ -26,7 +26,6 @@
 #include "localized_comparator.h"
 #include "map.h"
 #include "map_scale_constants.h"
-#include "memory_fast.h"
 #include "mission_companion.h"
 #include "mtype.h"
 #include "npc.h"
@@ -1068,16 +1067,7 @@ void faction_manager::display() const
 
     avatar &player_character = get_avatar();
     while( true ) {
-        // create a list of NPCs, visible and the ones on overmapbuffer
-        followers.clear();
-        for( const character_id &elem : g->get_follower_list() ) {
-            shared_ptr_fast<npc> npc_to_get = overmap_buffer.find_npc( elem );
-            if( !npc_to_get ) {
-                continue;
-            }
-            npc *npc_to_add = npc_to_get.get();
-            followers.push_back( npc_to_add );
-        }
+        overmap_buffer.populate_followers_vec( followers );
         valfac.clear();
         for( const auto &elem : g->faction_manager_ptr->all() ) {
             if( elem.second.known_by_u && elem.second.id != faction_your_followers ) {

src/faction_camp.cpp

@@ -2307,15 +2307,7 @@ void basecamp::worker_assignment_ui()
 
     while( true ) {
         // create a list of npcs stationed at this camp
-        followers.clear();
-        for( const character_id &elem : g->get_follower_list() ) {
-            shared_ptr_fast<npc> npc_to_get = overmap_buffer.find_npc( elem );
-            if( !npc_to_get || !npc_to_get->is_following() || npc_to_get->is_hallucination() ) {
-                continue;
-            }
-            npc *npc_to_add = npc_to_get.get();
-            followers.push_back( npc_to_add );
-        }
+        overmap_buffer.populate_followers_vec( followers, true, true );
         cur_npc = nullptr;
         if( !followers.empty() ) {
             cur_npc = followers[selection];

src/npcmove.cpp

@@ -3944,14 +3944,7 @@ bool npc::would_take_that( const item &it, const tripoint_bub_ms &p )
             return false;
         }
         std::vector<npc *> followers;
-        for( const character_id &elem : g->get_follower_list() ) {
-            shared_ptr_fast<npc> npc_to_get = overmap_buffer.find_npc( elem );
-            if( !npc_to_get ) {
-                continue;
-            }
-            npc *npc_to_add = npc_to_get.get();
-            followers.push_back( npc_to_add );
-        }
+        overmap_buffer.populate_followers_vec( followers );
         for( npc *&elem : followers ) {
             if( elem->sees( here, this->pos_bub( here ) ) || elem->sees( here,  p ) ) {
                 return false;

src/overmap_ui.cpp

@@ -23,14 +23,12 @@
 #include "calendar.h"
 #include "cata_assert.h"
 #include "cata_variant.h"
-#include "character_id.h"
 #include "debug.h"
 #include "enum_conversions.h"
 #include "input_enums.h"
 #include "mapdata.h"
 #include "mapgen_parameter.h"
 #include "mapgendata.h"
-#include "memory_fast.h"
 #include "monster.h"
 #include "simple_pathfinding.h"
 #include "translation.h"
@@ -698,15 +696,7 @@ static void draw_ascii( const catacurses::window &w, overmap_draw_data_t &data )
             }
         }
         std::vector<npc *> followers;
-        // get friendly followers
-        for( const character_id &elem : g->get_follower_list() ) {
-            shared_ptr_fast<npc> npc_to_get = overmap_buffer.find_npc( elem );
-            if( !npc_to_get ) {
-                continue;
-            }
-            npc *npc_to_add = npc_to_get.get();
-            followers.push_back( npc_to_add );
-        }
+        overmap_buffer.populate_followers_vec( followers );
         if( !display_path.empty() ) {
             for( const tripoint_abs_omt &elem : display_path ) {
                 npc_path_route.insert( elem );

src/overmapbuffer.cpp

@@ -1420,6 +1420,22 @@ shared_ptr_fast<npc> overmapbuffer::find_npc( character_id id )
     return nullptr;
 }
 
+void overmapbuffer::populate_followers_vec( std::vector<npc *> &followers,
+        bool only_following, bool ignore_hallu ) const
+{
+    followers.clear();
+    for( const character_id &elem : g->get_follower_list() ) {
+        shared_ptr_fast<npc> npc_to_get = overmap_buffer.find_npc( elem );
+        if( !npc_to_get ||
+            ( only_following && !npc_to_get->is_following() ) ||
+            ( ignore_hallu && npc_to_get->is_hallucination() ) ) {
+            continue;
+        }
+        npc *npc_to_add = npc_to_get.get();
+        followers.push_back( npc_to_add );
+    }
+}
+
 void overmapbuffer::foreach_npc( const std::function<void( npc & )> &callback )
 {
     for( auto &it : overmaps ) {
@@ -1485,7 +1501,8 @@ std::vector<overmap *> overmapbuffer::get_overmaps_near( const tripoint_abs_sm &
     return get_overmaps_near( location.xy(), radius );
 }
 
-std::vector<overmap *> overmapbuffer::get_overmaps_near( const point_abs_sm &p, const int radius )
+std::vector<overmap *> overmapbuffer::get_overmaps_near( const point_abs_sm &p,
+        const int radius )
 {
     // Grab the corners of a square around the target location at distance radius.
     // Convert to overmap coordinates and iterate from the minimum to the maximum.

src/overmapbuffer.h

@@ -318,6 +318,12 @@ class overmapbuffer
          * Searches all loaded overmaps.
          */
         shared_ptr_fast<npc> find_npc( character_id id );
+        /**
+         * Clear and fill a vector with NPCs who are your followers.
+         * Optionally only include is_following() or exclude is_hallucination()
+         */
+        void populate_followers_vec( std::vector<npc *> &followers, bool only_following = false,
+                                     bool ignore_hallu = false ) const;
         void foreach_npc( const std::function<void( npc & )> &callback );
         shared_ptr_fast<npc> find_npc_by_unique_id( const std::string &unique_id );
         /**