feat(balance): allow reading at penalty with full night vision, other visual/detection improvements

data/json/mutations/mutations.json

@@ -1269,7 +1269,7 @@
     "id": "NIGHTVISION3",
     "name": { "str": "Full Night Vision" },
     "points": 6,
-    "description": "You can see in pitch blackness as if you were wearing night-vision goggles.  Activate to toggle NV-visible areas on or off.",
+    "description": "You can see in pitch blackness as if you were wearing night-vision goggles, and read in darkness as one can in dim lighting.  Activate to toggle NV-visible areas on or off.",
     "prereqs": [ "NIGHTVISION2" ],
     "leads_to": [ "INFRARED" ],
     "cancels": [ "ELFA_NV", "ELFA_FNV", "FEL_NV", "URSINE_EYE" ],

doc/src/content/docs/en/mod/json/reference/json_info.md

@@ -1245,7 +1245,7 @@ wake up for the first time after 24 hours into the game.
     ]
 ],
 "stealth_modifier" : 0, // Percentage to be subtracted from player's visibility range, capped to 60. Negative values work, but are not very effective due to the way vision ranges are capped
-"night_vision_range" : 0.0, // Night range vision. Only the best and the worst value out of all mutations are added. (default: 0.0)
+"night_vision_range" : 0.0, // Night range vision. Only the best and the worst value out of all mutations are added. A value of 8 or higher will allow reading in complete darkness as though the player were in dim lighting. (default: 0.0)
 "active" : true, //When set the mutation is an active mutation that the player needs to activate (default: false)
 "starts_active" : true, //When true, this 'active' mutation starts active (default: false, requires 'active')
 "cost" : 8, // Cost to activate this mutation. Needs one of the hunger, thirst, or fatigue values set to true. (default: 0)

src/avatar_action.cpp

@@ -449,7 +449,8 @@ bool avatar_action::move( avatar &you, map &m, const tripoint &d )
     }
 
     // Invalid move
-    const bool waste_moves = you.is_blind() || you.has_effect( effect_stunned );
+    const bool waste_moves = ( you.is_blind() && you.clairvoyance() < 1 ) ||
+                             you.has_effect( effect_stunned );
     if( waste_moves || dest_loc.z != you.posz() ) {
         add_msg( _( "You bump into the %s!" ), m.obstacle_name( dest_loc ) );
         // Only lose movement if we're blind

src/character.cpp

@@ -6869,7 +6869,9 @@ bool Character::sees_with_specials( const Creature &critter ) const
         return true;
     }
 
-    return false;
+    const int dist = rl_dist( pos(), critter.pos() );
+    return ( dist <= 5 && ( has_active_mutation( trait_ANTENNAE ) ||
+                            ( has_active_bionic( bio_ground_sonar ) && !critter.has_flag( MF_FLIES ) ) ) );
 }
 
 detached_ptr<item> Character::pour_into( item &container, detached_ptr<item> &&liquid, int limit )
@@ -11015,7 +11017,8 @@ bool Character::sees( const Creature &critter ) const
 {
     // This handles only the player/npc specific stuff (monsters don't have traits or bionics).
     const int dist = rl_dist( pos(), critter.pos() );
-    if( dist <= 3 && has_active_mutation( trait_ANTENNAE ) ) {
+    if( dist <= 5 && ( has_active_mutation( trait_ANTENNAE ) ||
+                       ( has_active_bionic( bio_ground_sonar ) && !critter.has_flag( MF_FLIES ) ) ) ) {
         return true;
     }
 

src/character_functions.cpp

@@ -178,13 +178,16 @@ float fine_detail_vision_mod( const Character &who, const tripoint &p )
           !who.has_trait( trait_PER_SLIME_OK ) ) ) {
         return 11.0;
     }
+    // Regular NV trait isn't enough to help at all, while Full Night Vision allows reading at a penalty
+    float nvbonus = who.mutation_value( "night_vision_range" ) >= 8 ? 4 : 0;
     // Scale linearly as light level approaches LIGHT_AMBIENT_LIT.
     // If we're actually a source of light, assume we can direct it where we need it.
     // Therefore give a hefty bonus relative to ambient light.
     float own_light = std::max( 1.0f, LIGHT_AMBIENT_LIT - who.active_light() - 2.0f );
 
-    // Same calculation as above, but with a result 3 lower.
-    float ambient_light = std::max( 1.0f, LIGHT_AMBIENT_LIT - get_map().ambient_light_at( p ) + 1.0f );
+    // Same calculation as above, but with a result 3 lower, and night vision is allowed to affect it.
+    float ambient_light = std::max( 1.0f,
+                                    LIGHT_AMBIENT_LIT - get_map().ambient_light_at( p ) - nvbonus + 1.0f );
 
     return std::min( own_light, ambient_light );
 }

src/game.cpp

@@ -6005,7 +6005,8 @@ void game::print_items_info( const tripoint &lp, const catacurses::window &w_loo
         return;
     } else if( m.has_flag( "CONTAINER", lp ) && !m.could_see_items( lp, u ) ) {
         mvwprintw( w_look, point( column, ++line ), _( "You cannot see what is inside of it." ) );
-    } else if( u.has_effect( effect_blind ) || u.worn_with_flag( flag_BLIND ) ) {
+    } else if( ( u.has_effect( effect_blind ) || u.worn_with_flag( flag_BLIND ) ) &&
+               u.clairvoyance() < 1 ) {
         mvwprintz( w_look, point( column, ++line ), c_yellow,
                    _( "There's something there, but you can't see what it is." ) );
         return;
@@ -9369,7 +9370,7 @@ point game::place_player( const tripoint &dest_loc )
     if( !m.has_flag( "SEALED", u.pos() ) ) {
         if( get_option<bool>( "NO_AUTO_PICKUP_ZONES_LIST_ITEMS" ) ||
             !check_zone( zone_type_id( "NO_AUTO_PICKUP" ), u.pos() ) ) {
-            if( u.is_blind() && !m.i_at( u.pos() ).empty() ) {
+            if( u.is_blind() && !m.i_at( u.pos() ).empty() && u.clairvoyance() < 1 ) {
                 add_msg( _( "There's something here, but you can't see what it is." ) );
             } else if( m.has_items( u.pos() ) ) {
                 std::vector<std::string> names;