New crouching mechanics for hiding and stealth (#29092)

data/raw/keybindings.json

@@ -2008,7 +2008,7 @@
   },
   {
     "type": "keybinding",
-    "name": "Toggle move mode (run/walk)",
+    "name": "Toggle move mode (run/walk/crouch)",
     "category": "DEFAULTMODE",
     "id": "toggle_move",
     "bindings": [ { "input_method": "keyboard", "key": "\"" } ]

src/action.h

@@ -56,7 +56,7 @@ enum action_id : int {
     ACTION_MOVE_DOWN,
     /** Ascend a staircase */
     ACTION_MOVE_UP,
-    /** Toggle run/walk mode */
+    /** Toggle run/walk/crouch mode */
     ACTION_TOGGLE_MOVE,
     /**@}*/
 

src/creature.cpp

@@ -179,11 +179,40 @@ bool Creature::sees( const Creature &critter ) const
                     abs( posz() - critter.posz() ) <= 1 ) ) ) {
         return false;
     }
-
+    if( const player *p = dynamic_cast<const player *>( &critter ) ) {
+        if( p->move_mode == "crouch" ) {
+            const int coverage = g->m.obstacle_coverage( pos(), critter.pos() );
+            if( coverage < 30 ) {
+                return sees( critter.pos(), critter.is_player() );
+            }
+            float size_modifier = 1.0;
+            switch( p->get_size() ) {
+                case MS_TINY:
+                    size_modifier = 2.0;
+                    break;
+                case MS_SMALL:
+                    size_modifier = 1.4;
+                    break;
+                case MS_MEDIUM:
+                    break;
+                case MS_LARGE:
+                    size_modifier = 0.6;
+                    break;
+                case MS_HUGE:
+                    size_modifier = 0.15;
+                    break;
+            }
+            const int vision_modifier = 30 - 0.5 * coverage * size_modifier;
+            if( vision_modifier > 1 ) {
+                return sees( critter.pos(), critter.is_player(), vision_modifier );
+            }
+            return false;
+        }
+    }
     return sees( critter.pos(), critter.is_player() );
 }
 
-bool Creature::sees( const tripoint &t, bool is_player ) const
+bool Creature::sees( const tripoint &t, bool is_player, int range_mod ) const
 {
     if( !fov_3d && posz() != t.z ) {
         return false;
@@ -207,6 +236,9 @@ bool Creature::sees( const tripoint &t, bool is_player ) const
         if( has_effect( effect_no_sight ) ) {
             range = 1;
         }
+        if( range_mod > 0 ) {
+            range = std::min( range, range_mod );
+        }
         if( is_player ) {
             // Special case monster -> player visibility, forcing it to be symmetric with player vision.
             const float player_visibility_factor = g->u.visibility() / 100.0f;

src/creature.h

@@ -153,7 +153,7 @@ class Creature
          */
         /*@{*/
         virtual bool sees( const Creature &critter ) const;
-        virtual bool sees( const tripoint &t, bool is_player = false ) const;
+        virtual bool sees( const tripoint &t, bool is_player = false, int range_mod = 0 ) const;
         /*@}*/
 
         /**

src/game.cpp

@@ -10513,6 +10513,11 @@ bool game::walk_move( const tripoint &dest_loc )
             } else if( u.has_bionic( bionic_id( "bio_ankles" ) ) ) {
                 volume = 12;
             }
+            if( u.move_mode == "run" ) {
+                volume *= 1.5;
+            } else if( u.move_mode == "crouch" ) {
+                volume /= 2;
+            }
             sounds::sound( dest_loc, volume, sounds::sound_t::movement, _( "footsteps" ), true,
                            "none", "none" );    // Sound of footsteps may awaken nearby monsters
             sfx::do_footstep();

src/map.cpp

@@ -6059,6 +6059,34 @@ bool map::sees( const tripoint &F, const tripoint &T, const int range, int &bres
     return visible;
 }
 
+int map::obstacle_coverage( const tripoint &loc1, const tripoint &loc2 ) const
+{
+    // Can't hide if you are standing on furniture, or non-flat slowing-down terrain tile.
+    if( furn( loc2 ).obj().id || ( move_cost( loc2 ) > 2 && !has_flag_ter( TFLAG_FLAT, loc2 ) ) ) {
+        return 0;
+    }
+    const int ax = std::abs( loc1.x - loc2.x ) * 2;
+    const int ay = std::abs( loc1.y - loc2.y ) * 2;
+    int offset = std::min( ax, ay ) - ( std::max( ax, ay ) / 2 );
+    tripoint obstaclepos;
+    bresenham( loc2, loc1, offset, 0, [&obstaclepos]( const tripoint & new_point ) {
+        // Only adjacent tile between you and enemy is checked for cover.
+        obstaclepos = new_point;
+        return false;
+    } );
+    if( const auto obstacle_f = furn( obstaclepos ) ) {
+        return obstacle_f->coverage;
+    }
+    if( const auto vp = veh_at( obstaclepos ) ) {
+        if( vp->obstacle_at_part() ) {
+            return 60;
+        } else if( !vp->part_with_feature( VPFLAG_AISLE, true ) ) {
+            return 45;
+        }
+    }
+    return ter( obstaclepos )->coverage;
+}
+
 // This method tries a bunch of initial offsets for the line to try and find a clear one.
 // Basically it does, "Find a line from any point in the source that ends up in the target square".
 std::vector<tripoint> map::find_clear_path( const tripoint &source,

src/map.h

@@ -454,6 +454,12 @@ class map
         **/
         bool sees( const tripoint &F, const tripoint &T, int range, int &bresenham_slope ) const;
     public:
+        /**
+        * Returns coverage of target in relation to the observer. Target is loc2, observer is loc1.
+        * First tile from the target is an obstacle, which has the coverage value.
+        * If there's no obstacle adjacent to the target - no coverage.
+        */
+        int obstacle_coverage( const tripoint &loc1, const tripoint &loc2 ) const;
         /**
          * Check whether there's a direct line of sight between `F` and
          * `T` with the additional movecost restraints.

src/mapdata.cpp

@@ -157,7 +157,8 @@ static const std::unordered_map<std::string, ter_bitflags> ter_bitflags_map = {
         { "NO_FLOOR",                 TFLAG_NO_FLOOR },       // Things should fall when placed on this tile
         { "SEEN_FROM_ABOVE",          TFLAG_SEEN_FROM_ABOVE },// This should be visible if the tile above has no floor
         { "HIDE_PLACE",               TFLAG_HIDE_PLACE },     // Creature on this tile can't be seen by other creature not standing on adjacent tiles
-        { "BLOCK_WIND",               TFLAG_BLOCK_WIND},      // This tile will partially block the wind.
+        { "BLOCK_WIND",               TFLAG_BLOCK_WIND },     // This tile will partially block the wind.
+        { "FLAT",                     TFLAG_FLAT },           // This tile is flat.
         { "RAMP",                     TFLAG_RAMP },           // Can be used to move up a z-level
     }
 };
@@ -1073,6 +1074,7 @@ void ter_t::load( JsonObject &jo, const std::string &src )
     map_data_common_t::load( jo, src );
     mandatory( jo, was_loaded, "name", name_ );
     mandatory( jo, was_loaded, "move_cost", movecost );
+    optional( jo, was_loaded, "coverage", coverage );
     optional( jo, was_loaded, "max_volume", max_volume, legacy_volume_reader,
               DEFAULT_MAX_VOLUME_IN_SQUARE );
     optional( jo, was_loaded, "trap", trap_id_str );
@@ -1173,6 +1175,7 @@ void furn_t::load( JsonObject &jo, const std::string &src )
     map_data_common_t::load( jo, src );
     mandatory( jo, was_loaded, "name", name_ );
     mandatory( jo, was_loaded, "move_cost_mod", movecost );
+    optional( jo, was_loaded, "coverage", coverage );
     optional( jo, was_loaded, "comfort", comfort, 0 );
     optional( jo, was_loaded, "floor_bedding_warmth", floor_bedding_warmth, 0 );
     optional( jo, was_loaded, "bonus_fire_warmth_feet", bonus_fire_warmth_feet, 300 );

src/mapdata.h

@@ -172,6 +172,7 @@ enum ter_bitflags : int {
     TFLAG_RAMP,
     TFLAG_HIDE_PLACE,
     TFLAG_BLOCK_WIND,
+    TFLAG_FLAT,
 
     NUM_TERFLAGS
 };
@@ -220,6 +221,7 @@ struct map_data_common_t {
         std::array<long, SEASONS_PER_YEAR> symbol_;
 
         int movecost;   // The amount of movement points required to pass this terrain by default.
+        int coverage; // The coverage percentage of a furniture piece of terrain. <30 won't cover from sight.
         units::volume max_volume; // Maximal volume of items that can be stored in/on this furniture
 
         std::string description;

src/panels.cpp

@@ -1041,7 +1041,8 @@ void draw_stealth( player &u, const catacurses::window &w )
     mvwprintz( w, 0, 0, c_light_gray, _( "Speed" ) );
     mvwprintz( w, 0, 7, value_color( u.get_speed() ), "%s", u.get_speed() );
     mvwprintz( w, 0, 15 - to_string( u.movecounter ).length(), c_light_gray,
-               to_string( u.movecounter ) + ( u.move_mode == "walk" ? "W" : "R" ) );
+               to_string( u.movecounter ) + ( u.move_mode == "walk" ? "W" : ( u.move_mode == "crouch" ? "C" :
+                       "R" ) ) );
 
     if( u.is_deaf() ) {
         mvwprintz( w, 0, 22, c_red, _( "DEAF" ) );
@@ -1205,7 +1206,9 @@ void draw_char( player &u, const catacurses::window &w )
 
     const auto str_walk = pgettext( "movement-type", "W" );
     const auto str_run = pgettext( "movement-type", "R" );
-    const char *move = u.move_mode == "walk" ? str_walk : str_run;
+    const auto str_crouch = pgettext( "movement-type", "C" );
+    const char *move = u.move_mode == "walk" ? str_walk : ( u.move_mode == "crouch" ? str_crouch :
+                       str_run );
     std::string movecost = std::to_string( u.movecounter ) + "(" + move + ")";
     bool m_style = get_option<std::string>( "MORALE_STYLE" ) == "horizontal";
     std::string smiley = morale_emotion( morale_pair.second, get_face_type( u ), m_style );
@@ -1435,7 +1438,8 @@ void draw_health_classic( player &u, const catacurses::window &w )
         mvwprintz( w, 5, 21, u.get_speed() < 100 ? c_red : c_white,
                    _( "Spd " ) + to_string( u.get_speed() ) );
         mvwprintz( w, 5, 26 + to_string( u.get_speed() ).length(), c_white,
-                   to_string( u.movecounter ) + " " + ( u.move_mode == "walk" ? "W" : "R" ) );
+                   to_string( u.movecounter ) + " " + ( u.move_mode == "walk" ? "W" : ( u.move_mode == "crouch" ? "C" :
+                           "R" ) ) );
     }
 
     // temperature

src/player.cpp

@@ -1827,6 +1827,9 @@ int player::run_cost( int base_cost, bool diag ) const
         // Rationale: Average running speed is 2x walking speed. (NOT sprinting)
         stamina_modifier *= 2.0;
     }
+    if( move_mode == "crouch" ) {
+        stamina_modifier *= 0.5;
+    }
     movecost /= stamina_modifier;
 
     if( diag ) {
@@ -2977,10 +2980,15 @@ void player::toggle_move_mode()
             add_msg( _( "You start running." ) );
         } else {
             add_msg( m_bad, _( "You're too tired to run." ) );
+            move_mode = "crouch";
+            add_msg( _( "You start crouching." ) );
         }
     } else if( move_mode == "run" ) {
+        move_mode = "crouch";
+        add_msg( _( "You slow down and start crouching." ) );
+    } else if( move_mode == "crouch" ) {
         move_mode = "walk";
-        add_msg( _( "You slow to a walk." ) );
+        add_msg( _( "You stop crouching." ) );
     }
 }
 
@@ -12032,7 +12040,7 @@ void player::clear_memorized_tile( const tripoint &pos )
     player_map_memory.clear_memorized_tile( pos );
 }
 
-bool player::sees( const tripoint &t, bool ) const
+bool player::sees( const tripoint &t, bool, int ) const
 {
     static const bionic_id str_bio_night( "bio_night" );
     const int wanted_range = rl_dist( pos(), t );

src/player.h

@@ -417,7 +417,7 @@ class player : public Character
         void clear_memorized_tile( const tripoint &pos );
 
         // see Creature::sees
-        bool sees( const tripoint &c, bool is_player = false ) const override;
+        bool sees( const tripoint &c, bool is_player = false, int range_mod = 0 ) const override;
         // see Creature::sees
         bool sees( const Creature &critter ) const override;
         /**