[WIP] Skylights and other fragile terrain break when creatures step on them

data/json/furniture_and_terrain/terrain-roofs.json

@@ -182,7 +182,7 @@
     "color": "cyan",
     "move_cost": 2,
     "//": "TODO: Should break when you step on it if there's no supporting terrain below, might want some warning akin to examine_action ledge",
-    "flags": [ "TRANSPARENT", "TRANSPARENT_FLOOR" ],
+    "flags": [ "TRANSPARENT", "TRANSPARENT_FLOOR", "FRAGILE" ],
     "bash": {
       "str_min": 3,
       "str_max": 6,

data/json/furniture_and_terrain/terrain-windows.json

@@ -4457,15 +4457,18 @@
     "move_cost": 2,
     "coverage": 0,
     "examine_action": "ledge",
-    "deconstruct": { "ter_set": "t_null", "items": [ { "item": "2x4", "count": [ 3, 4 ] }, { "item": "nail", "charges": [ 12, 16 ] } ] },
+    "deconstruct": {
+      "ter_set": "t_open_air",
+      "items": [ { "item": "2x4", "count": [ 3, 4 ] }, { "item": "nail", "charges": [ 12, 16 ] } ]
+    },
     "bash": {
       "str_min": 1,
       "str_max": 1,
       "sound": "whump!",
       "sound_fail": "whack!",
       "sound_vol": 12,
       "sound_fail_vol": 8,
-      "ter_set": "t_null",
+      "ter_set": "t_open_air",
       "items": [ { "item": "2x4", "count": [ 2, 4 ] } ]
     },
     "flags": [ "TRANSPARENT", "NO_FLOOR", "FLAMMABLE" ]

data/json/move_modes.json

@@ -12,7 +12,8 @@
     "change_good_animal": "You nudge your steed into a steady trot.",
     "change_good_mech": "You set your mech's leg power to a loping fast walk.",
     "move_type": "walking",
-    "move_speed_multiplier": 1.0
+    "move_speed_multiplier": 1.0,
+    "bash_weight_modifier": 2
   },
   {
     "type": "movement_mode",
@@ -34,7 +35,8 @@
     "sound_multiplier": 1.5,
     "move_speed_multiplier": 2.0,
     "stamina_multiplier": 7.0,
-    "swim_speed_mod": -80
+    "swim_speed_mod": -80,
+    "bash_weight_modifier": 1
   },
   {
     "type": "movement_mode",
@@ -51,7 +53,8 @@
     "move_type": "crouching",
     "sound_multiplier": 0.5,
     "move_speed_multiplier": 0.5,
-    "swim_speed_mod": 50
+    "swim_speed_mod": 50,
+    "bash_weight_modifier": 2
   },
   {
     "type": "movement_mode",
@@ -68,6 +71,7 @@
     "move_type": "prone",
     "sound_multiplier": 0.2,
     "move_speed_multiplier": 0.2,
-    "swim_speed_mod": 50
+    "swim_speed_mod": 50,
+    "bash_weight_modifier": 8
   }
 ]

src/character.cpp

@@ -1976,6 +1976,14 @@ move_mode_id Character::current_movement_mode() const
     return move_mode;
 }
 
+int Character::fragile_terrain_weight_modifier() const
+{
+    if( !move_mode.is_valid() ) {
+        return 2; // defaut if move_mode is invalid
+    }
+    return move_mode->get_bash_weight_modifier();
+}
+
 bool Character::movement_mode_is( const move_mode_id &mode ) const
 {
     return move_mode == mode;
@@ -7708,6 +7716,27 @@ bool Character::can_fly()
     return false;
 }
 
+bool Character::flies() const
+{
+    if( has_effect( effect_stunned ) ) {
+        return false;
+    }
+    // GLIDE is for artifacts or things like jetpacks that don't care if you're tired or hurt.
+    if( has_flag( json_flag_GLIDE ) ) {
+        return true;
+    }
+    // TODO: Remove grandfathering traits in after Limb Stuff
+    if( has_flag( json_flag_WINGS_2 ) ||
+        has_flag( json_flag_WING_GLIDE ) || count_flag( json_flag_WING_ARMS ) >= 2 ) {
+
+        if( 100 * weight_carried() / weight_capacity() > 50 || !has_two_arms_lifting() ) {
+            return false;
+        }
+        return true;
+    }
+    return false;
+}
+
 // FIXME: Relies on hardcoded bash damage type
 void Character::knock_back_to( const tripoint_bub_ms &to )
 {

src/character.h

@@ -43,6 +43,7 @@
 #include "item_location.h"
 #include "memory_fast.h"
 #include "monster.h"
+#include "move_mode.h"
 #include "pimpl.h"
 #include "player_activity.h"
 #include "pocket_type.h"
@@ -99,7 +100,7 @@
 enum action_id : int;
 enum class proficiency_bonus_type : int;
 enum class recipe_filter_flags : int;
 enum class steed_type : int;
 enum npc_attitude : int;
 struct bionic;
 struct construction;
@@ -1061,6 +1062,8 @@
         bool movement_mode_is( const move_mode_id &mode ) const;
         move_mode_id current_movement_mode() const;
 
+        int fragile_terrain_weight_modifier() const override;
+
         bool is_running() const;
         bool is_walking() const;
         bool is_crouching() const;
@@ -2700,6 +2703,7 @@
         int impact( int force, const tripoint_bub_ms &pos ) override;
         /** Checks to see if the character is able to use their wings properly */
         bool can_fly();
+        bool flies() const override;
         /** Knocks the player to a specified tile */
         void knock_back_to( const tripoint_bub_ms &to ) override;
 

src/creature.cpp

@@ -211,12 +211,68 @@ tripoint_bub_ms Creature::pos_bub( const map &here ) const
     return here.get_bub( location );
 }
 
+void Creature::maybe_break_fragile_underfoot( Creature &cr, const tripoint_bub_ms &p )
+{
+    map &here = get_map();
+    if( here.has_flag( ter_furn_flag::TFLAG_FRAGILE, p ) ) {
+
+
+        /*
+        bool can_fly = false;
+        if (const monster* mon = dynamic_cast<const monster*>(&cr)) {
+            can_fly = mon->flies();
+        }
+        */
+
+        if( !cr.is_hallucination() && !cr.flies() && cr.get_weight() >= 5_kilogram ) {
+            std::string who_name = cr.disp_name();
+            /*
+            int bash_strength = cr.get_weight() / 5_kilogram;
+            //check if monster
+            if (const monster* mon = dynamic_cast<const monster*>(&cr)) {
+                who_name = mon->disp_name();
+                bash_strength = bash_strength / 2;
+
+            } //check for character
+            else if (const Character* ch = dynamic_cast<const Character*>(&cr)) {
+                who_name = ch->disp_name();
+                //if char is prone, less likely to break glass
+                if (ch->is_prone()) {
+                    bash_strength = bash_strength / 8;
+                }
+                else {
+                    bash_strength = bash_strength / 2;
+                }
+            } //default case
+            else {
+                who_name = _("something");
+                bash_strength = bash_strength / 2;
+            } */
+
+            int bash_strength = ( cr.get_weight() / 5_kilogram ) / cr.fragile_terrain_weight_modifier();
+            //store terrain name for message
+            const std::string old_name = here.tername( p );
+            //damage fragile terrain
+            const auto res = here.bash( p, bash_strength, true, false, false, nullptr, false );
+            //if broken output message
+            if( res.success ) {
+                add_msg( m_warning,
+                         string_format( _( "The %s breaks under the weight of %s!" ),
+                                        old_name, who_name ) );
+            }
+        }
+    }
+    return;
+}
+
 void Creature::setpos( map &here, const tripoint_bub_ms &p, bool check_gravity/* = true*/ )
 {
     const tripoint_abs_ms old_loc = pos_abs();
     set_pos_abs_only( here.get_abs( p ) );
     on_move( old_loc );
+
     if( check_gravity ) {
+        maybe_break_fragile_underfoot( *this, p );
         gravity_check( &here );
     }
 }
@@ -227,6 +283,10 @@ void Creature::setpos( const tripoint_abs_ms &p, bool check_gravity/* = true*/ )
     set_pos_abs_only( p );
     on_move( old_loc );
     if( check_gravity ) {
+        map &here = get_map();
+        if( here.inbounds( p ) ) {
+            maybe_break_fragile_underfoot( *this, here.get_bub( p ) );
+        }
         gravity_check();
     }
 }

src/creature.h

@@ -323,6 +323,7 @@ class Creature : public viewer
         }
         virtual void gravity_check();
         virtual void gravity_check( map *here );
+        void maybe_break_fragile_underfoot( Creature &cr, const tripoint_bub_ms &p );
         void setpos( map &here, const tripoint_bub_ms &p, bool check_gravity = true );
         void setpos( const tripoint_abs_ms &p, bool check_gravity = true );
 
@@ -608,7 +609,14 @@ class Creature : public viewer
         virtual float fall_damage_mod() const = 0;
         /** Deals falling/collision damage with terrain/creature at pos */
         virtual int impact( int force, const tripoint_bub_ms &pos ) = 0;
-
+        // After dividing mass by 5kg, how much to further divide mass for use in breaking skylights/ice. 2 is default.
+        virtual int fragile_terrain_weight_modifier() const {
+            return 2;
+        }
+        //virtual check for if creature flies
+        virtual bool flies() const {
+            return false;
+        }
         /**
          * This function checks the creatures @ref is_dead_state and (if true) calls @ref die.
          * You can either call this function after hitting this creature, or let the game

src/mapdata.cpp

@@ -325,6 +325,7 @@ std::string enum_to_string<ter_furn_flag>( ter_furn_flag data )
         case ter_furn_flag::TFLAG_WIRED_WALL: return "WIRED_WALL";
         case ter_furn_flag::TFLAG_MON_AVOID_STRICT: return "MON_AVOID_STRICT";
         case ter_furn_flag::TFLAG_REGION_PSEUDO: return "REGION_PSEUDO";
+        case ter_furn_flag::TFLAG_FRAGILE: return "FRAGILE";
 
         // *INDENT-ON*
         case ter_furn_flag::NUM_TFLAG_FLAGS:

src/mapdata.h

@@ -375,6 +375,7 @@ enum class ter_furn_flag : int {
     TFLAG_WIRED_WALL,
     TFLAG_MON_AVOID_STRICT,
     TFLAG_REGION_PSEUDO,
+    TFLAG_FRAGILE,
 
     NUM_TFLAG_FLAGS
 };

src/monster.h

@@ -173,7 +173,7 @@ class monster : public Creature
         bool digging() const override;  // digs() or can_dig() and diggable terrain
         bool can_dig() const;
         bool digs() const;
-        bool flies() const;
+        bool flies() const override;
         bool climbs() const;
         bool swims() const;
 

src/move_mode.cpp

@@ -75,6 +75,7 @@ void move_mode::load( const JsonObject &jo, std::string_view/*src*/ )
     optional( jo, was_loaded, "move_speed_multiplier", _move_speed_mult, 1.0 );
     optional( jo, was_loaded, "mech_power_use", _mech_power_use, 2 );
     optional( jo, was_loaded, "swim_speed_mod", _swim_speed_mod, 0 );
+    optional( jo, was_loaded, "bash_weight_modifier", _bash_weight_modifier, 2 );
 
     optional( jo, was_loaded, "stop_hauling", _stop_hauling );
 }
@@ -87,6 +88,8 @@ void move_mode::reset()
 
 void move_mode::finalize()
 {
+    //Make sure no json modders make 0 or negative bwm, this avoids divbyzeros
+    _bash_weight_modifier = std::max( 1, _bash_weight_modifier );
 }
 
 void move_mode::finalize_all()
@@ -191,6 +194,11 @@ int move_mode::swim_speed_mod() const
     return _swim_speed_mod;
 }
 
+int move_mode::get_bash_weight_modifier() const
+{
+    return _bash_weight_modifier;
+}
+
 nc_color move_mode::panel_color() const
 {
     return _panel_color;

src/move_mode.h

@@ -61,6 +61,7 @@ class move_mode
 
         int _mech_power_use = 0;
         int _swim_speed_mod = 0;
+        int _bash_weight_modifier = 2;
 
         nc_color _panel_color;
         nc_color _symbol_color;
@@ -92,6 +93,7 @@ class move_mode
 
         units::energy mech_power_use() const;
         int swim_speed_mod() const;
+        int get_bash_weight_modifier() const;
 
         nc_color panel_color() const;
         nc_color symbol_color() const;