Fix issue with auto_aim (#40662)

src/avatar_action.cpp

@@ -609,7 +609,7 @@ static float rate_critter( const Creature &c )
 void avatar_action::autoattack( avatar &you, map &m )
 {
     int reach = you.weapon.reach_range( you );
-    std::vector<Creature *> critters = you.get_targetable_creatures( reach );
+    std::vector<Creature *> critters = you.get_targetable_creatures( reach, true );
     critters.erase( std::remove_if( critters.begin(), critters.end(), []( const Creature * c ) {
         if( !c->is_npc() ) {
             return false;

src/character.cpp

@@ -10498,15 +10498,19 @@ std::vector<Creature *> Character::get_visible_creatures( const int range ) cons
     } );
 }
 
-std::vector<Creature *> Character::get_targetable_creatures( const int range ) const
+std::vector<Creature *> Character::get_targetable_creatures( const int range, bool melee ) const
 {
-    return g->get_creatures_if( [this, range]( const Creature & critter ) -> bool {
-        bool can_see = sees( critter ) || sees_with_infrared( critter );
-        if( can_see )   //handles the case where we can see something with glass in the way or a mutation lets us see through walls
+    return g->get_creatures_if( [this, range, melee]( const Creature & critter ) -> bool {
+        //the call to map.sees is to make sure that even if we can see it through walls
+        //via a mutation or cbm we only attack targets with a line of sight
+        bool can_see = ( ( sees( critter ) || sees_with_infrared( critter ) ) && g->m.sees( pos(), critter.pos(), 100 ) );
+        if( can_see && melee )  //handles the case where we can see something with glass in the way for melee attacks
         {
             std::vector<tripoint> path = g->m.find_clear_path( pos(), critter.pos() );
             for( const tripoint &point : path ) {
-                if( g->m.impassable( point ) ) {
+                if( g->m.impassable( point ) &&
+                    !( weapon.has_flag( "SPEAR" ) && // Fences etc. Spears can stab through those
+                       g->m.has_flag( "THIN_OBSTACLE", point ) ) ) { //this mirrors melee.cpp function reach_attack
                     can_see = false;
                     break;
                 }

src/character.h

@@ -1895,7 +1895,7 @@ class Character : public Creature, public visitable<Character>
          * As above, but includes all creatures the player can detect well enough to target
          * with ranged weapons, e.g. with infrared vision.
          */
-        std::vector<Creature *> get_targetable_creatures( int range ) const;
+        std::vector<Creature *> get_targetable_creatures( int range, bool melee ) const;
         /** Returns an enumeration of visible mutations with colors */
         std::string visible_mutations( int visibility_cap ) const;
         player_activity get_destination_activity() const;

src/ranged.cpp

@@ -2332,9 +2332,7 @@ void target_ui::update_target_list( player &pc )
     }
 
     // Get targets in range and sort them by distance (targets[0] is the closest)
-    // FIXME: get_targetable_creatures does not consider some of the visible creatures
-    //        as targets (e.g. those behind fences), but you can still see and shoot them
-    targets = pc.get_targetable_creatures( range );
+    targets = pc.get_targetable_creatures( range, mode == TargetMode::Reach );
     std::sort( targets.begin(), targets.end(), [&]( const Creature * lhs, const Creature * rhs ) {
         return rl_dist_exact( lhs->pos(), pc.pos() ) < rl_dist_exact( rhs->pos(), pc.pos() );
     } );