Merge pull request #38263 from kevingranade/cap-aim-at-unseen-targets

Cap aim level when there is no target or when the target is not visible

src/ranged.cpp

@@ -838,13 +838,13 @@ static int find_target( const std::vector<Creature *> &t, const tripoint &tpos )
     return -1;
 }
 
-static void do_aim( player &p, const item &relevant )
+static void do_aim( player &p, const item &relevant, const double min_recoil )
 {
     const double aim_amount = p.aim_per_move( relevant, p.recoil );
-    if( aim_amount > 0 ) {
+    if( aim_amount > 0 && p.recoil > min_recoil ) {
         // Increase aim at the cost of moves
         p.mod_moves( -1 );
-        p.recoil = std::max( 0.0, p.recoil - aim_amount );
+        p.recoil = std::max( min_recoil, p.recoil - aim_amount );
     } else {
         // If aim is already maxed, we're just waiting, so pass the turn.
         p.set_moves( 0 );
@@ -1022,6 +1022,21 @@ static int print_ranged_chance( const player &p, const catacurses::window &w, in
     return line_number;
 }
 
+// Handle capping aim level when the player cannot see the target tile or there is nothing to aim at.
+static double calculate_aim_cap( const player &p, const tripoint &target )
+{
+    double min_recoil = 0.0;
+    const Creature *victim = g->critter_at( target, true );
+    if( victim == nullptr || !p.sees( *victim ) ) {
+        const int range = rl_dist( p.pos(), target );
+        // Get angle of triangle that spans the target square.
+        const double angle = atan2( 1, range );
+        // Convert from radians to arcmin.
+        min_recoil = 60 * 180 * angle / M_PI;
+    }
+    return min_recoil;
+}
+
 static int print_aim( const player &p, const catacurses::window &w, int line_number,
                       input_context &ctxt, item *weapon,
                       const double target_size, const tripoint &pos, double predicted_recoil )
@@ -1034,7 +1049,9 @@ static int print_aim( const player &p, const catacurses::window &w, int line_num
     dispersion_sources dispersion = p.get_weapon_dispersion( *weapon );
     dispersion.add_range( p.recoil_vehicle() );
 
-    const double min_dispersion = p.effective_dispersion( p.weapon.sight_dispersion() );
+    const double min_recoil = calculate_aim_cap( p, pos );
+    const double effective_recoil = p.effective_dispersion( p.weapon.sight_dispersion() );
+    const double min_dispersion = std::max( min_recoil, effective_recoil );
     const double steadiness_range = MAX_RECOIL - min_dispersion;
     // This is a relative measure of how steady the player's aim is,
     // 0 is the best the player can do.
@@ -1597,8 +1614,9 @@ std::vector<tripoint> target_handler::target_ui( player &pc, target_mode mode,
             recoil_pos = dst;
 
             set_last_target( dst );
+            const double min_recoil = calculate_aim_cap( pc, dst );
             for( int i = 0; i < 10; ++i ) {
-                do_aim( pc, *relevant );
+                do_aim( pc, *relevant, min_recoil );
             }
             if( pc.moves <= 0 ) {
                 // We've run out of moves, clear target vector, but leave target selected.
@@ -1659,12 +1677,13 @@ std::vector<tripoint> target_handler::target_ui( player &pc, target_mode mode,
             }
             int aim_threshold = it->threshold;
             set_last_target( dst );
+            const double min_recoil = calculate_aim_cap( pc, dst );
             do {
-                do_aim( pc, relevant ? *relevant : null_item_reference() );
-            } while( pc.moves > 0 && pc.recoil > aim_threshold && pc.recoil - sight_dispersion > 0 );
+                do_aim( pc, relevant ? *relevant : null_item_reference(), min_recoil );
+            } while( pc.moves > 0 && pc.recoil > aim_threshold && pc.recoil - sight_dispersion > min_recoil );
 
             if( pc.recoil <= aim_threshold ||
-                pc.recoil - sight_dispersion == 0 ) {
+                pc.recoil - sight_dispersion == min_recoil ) {
                 // If we made it under the aim threshold, go ahead and fire.
                 // Also fire if we're at our best aim level already.
                 pc.view_offset = old_offset;