[WIP]Hot air balloons

data/json/items/vehicle/balloons.json

@@ -0,0 +1,59 @@
+[
+  {
+    "id": "small_hot_air_balloon",
+    "type": "GENERIC",
+    "category": "veh_parts",
+    "name": "small hot air balloon envelope",
+    "description": "A small folded up nylon envelope for use in a hot air balloon.",
+    "price": 600,
+    "weight": "45359 g",
+    "volume": "45359 ml",
+    "looks_like": "tarp",
+    "material": [ "nylon" ],
+    "symbol": "O",
+    "color": "dark_gray"
+  },
+  {
+    "id": "medium_hot_air_balloon",
+    "type": "GENERIC",
+    "category": "veh_parts",
+    "name": "medium hot air balloon envelope",
+    "description": "A folded up nylon envelope for use in a hot air balloon.",
+    "price": 800,
+    "weight": "113398 g",
+    "volume": "113398 ml",
+    "looks_like": "tarp",
+    "material": [ "nylon" ],
+    "symbol": "O",
+    "color": "blue"
+  },
+  {
+    "id": "large_hot_air_balloon",
+    "type": "GENERIC",
+    "category": "veh_parts",
+    "name": "large hot air balloon envelope",
+    "description": "A large folded up nylon envelope for use in a hot air balloon.",
+    "price": 1200,
+    "weight": "544310 g",
+    "volume": "544310 ml",
+    "looks_like": "tarp",
+    "material": [ "nylon" ],
+    "symbol": "O",
+    "color": "blue"
+  },
+  {
+    "id": "balloon_burner",
+    "type": "GENERIC",
+    "category": "veh_parts",
+    "name": "hot air balloon burner",
+    "description": "A hot air balloon burner, operating this outside of its intended use would be a bad idea.",
+    "weight": "12500 g",
+    "to_hit": -4,
+    "color": "red",
+    "symbol": ";",
+    "material": [ "steel" ],
+    "volume": "7500 ml",
+    "bashing": 5,
+    "price": 1200
+  }
+]

data/json/recipes/recipe_vehicle.json

@@ -243,6 +243,26 @@
       [ [ "plastic_chunk", 8 ] ]
     ]
   },
+  {
+    "result": "balloon_burner",
+    "type": "recipe",
+    "category": "CC_OTHER",
+    "subcategory": "CSC_OTHER_PARTS",
+    "skill_used": "fabrication",
+    "skills_required": [ "mechanics", 3 ],
+    "difficulty": 3,
+    "time": "70 m",
+    "autolearn": true,
+    "using": [ [ "welding_standard", 5 ] ],
+    "reversible": true,
+    "qualities": [ { "id": "SCREW", "level": 1 }, { "id": "WRENCH", "level": 1 } ],
+    "components": [
+      [ [ "pilot_light", 1 ] ],
+      [ [ "steel_lump", 3 ], [ "steel_chunk", 12 ], [ "scrap", 36 ] ],
+      [ [ "metal_tank_little", 1 ] ],
+      [ [ "pipe", 3 ] ]
+    ]
+  },
   {
     "result": "mountable_heater",
     "type": "recipe",
@@ -414,6 +434,42 @@
     "using": [ [ "sewing_standard", 100 ] ],
     "components": [ [ [ "sheet", 2 ] ], [ [ "2x4", 4 ], [ "stick", 4 ] ], [ [ "nail", 20 ] ] ]
   },
+  {
+    "type": "recipe",
+    "result": "small_hot_air_balloon",
+    "category": "CC_OTHER",
+    "subcategory": "CSC_OTHER_VEHICLE",
+    "skill_used": "tailor",
+    "difficulty": 6,
+    "time": "1440 m",
+    "autolearn": true,
+    "using": [ [ "sewing_standard", 1000 ] ],
+    "components": [ [ [ "scrap_nylon", 100 ] ], [ [ "cordage", 30, "LIST" ] ] ]
+  },
+  {
+    "type": "recipe",
+    "result": "medium_hot_air_balloon",
+    "category": "CC_OTHER",
+    "subcategory": "CSC_OTHER_VEHICLE",
+    "skill_used": "tailor",
+    "difficulty": 7,
+    "time": "2880 m",
+    "autolearn": true,
+    "using": [ [ "sewing_standard", 2000 ] ],
+    "components": [ [ [ "scrap_nylon", 200 ] ], [ [ "cordage", 60, "LIST" ] ] ]
+  },
+  {
+    "type": "recipe",
+    "result": "small_hot_air_balloon",
+    "category": "CC_OTHER",
+    "subcategory": "CSC_OTHER_VEHICLE",
+    "skill_used": "fabrication",
+    "difficulty": 6,
+    "time": "7000 m",
+    "autolearn": true,
+    "using": [ [ "sewing_standard", 3000 ] ],
+    "components": [ [ [ "scrap_nylon", 300 ] ], [ [ "cordage", 90, "LIST" ] ] ]
+  },
   {
     "type": "recipe",
     "result": "hand_paddles",

data/json/vehicleparts/balloons.json

@@ -0,0 +1,72 @@
+[
+  {
+    "abstract": "hot_air_balloon",
+    "type": "vehicle_part",
+    "location": "on_roof",
+    "symbol": "O",
+    "color": "light_blue",
+    "broken_symbol": "s",
+    "broken_color": "light_gray",
+    "flags": [ "BALLOON" ],
+    "description": "A synthetic fabric balloon, designed to be filled with hot air, to make it rise, hopefully taking people with it."
+  },
+  {
+    "id": "small_hot_air_balloon",
+    "copy-from": "hot_air_balloon",
+    "type": "vehicle_part",
+    "name": "small hot air balloon",
+    "item": "small_hot_air_balloon",
+    "//": "balloon volume is in meters cubed",
+    "balloon_volume": 1000,
+    "difficulty": 4,
+    "durability": 30,
+    "description": "A small synthetic fabric balloon, designed to be filled with hot air, to make it rise, hopefully taking people with it.",
+    "damage_modifier": 50,
+    "breaks_into": [ { "item": "scrap_nylon", "count": [ 20, 80 ] } ]
+  },
+  {
+    "id": "medium_hot_air_balloon",
+    "copy-from": "hot_air_balloon",
+    "type": "vehicle_part",
+    "name": "medium hot air balloon",
+    "item": "medium_hot_air_balloon",
+    "//": "balloon volume is in meters cubed",
+    "balloon_volume": 2800,
+    "difficulty": 5,
+    "durability": 30,
+    "damage_modifier": 50,
+    "breaks_into": [ { "item": "scrap_nylon", "count": [ 60, 240 ] } ]
+  },
+  {
+    "id": "large_hot_air_balloon",
+    "copy-from": "hot_air_balloon",
+    "type": "vehicle_part",
+    "name": "large hot air balloon",
+    "item": "large_hot_air_balloon",
+    "//": "balloon volume is in meters cubed",
+    "description": "A large synthetic fabric balloon, designed to be filled with hot air, to make it rise, hopefully taking people with it.",
+    "balloon_volume": 12000,
+    "difficulty": 6,
+    "durability": 30,
+    "damage_modifier": 50,
+    "breaks_into": [ { "item": "scrap_nylon", "count": [ 240, 500 ] } ]
+  },
+  {
+    "id": "balloon_burner",
+    "type": "vehicle_part",
+    "name": "balloon burner",
+    "item": "balloon_burner",
+    "location": "center",
+    "symbol": "Y",
+    "broken_symbol": "y",
+    "color": "red",
+    "durability": 400,
+    "requirements": {
+      "install": { "skills": [ [ "mechanics", 1 ] ], "time": "2 m", "using": [ [ "vehicle_screw", 1 ] ] },
+      "removal": { "skills": [ [ "mechanics", 1 ] ], "time": "1 m", "using": [ [ "vehicle_screw", 1 ] ] },
+      "repair": { "skills": [ [ "mechanics", 1 ] ], "time": "30 s", "using": [ [ "adhesive", 1 ] ] }
+    },
+    "breaks_into": [ { "item": "steel_lump" }, { "item": "steel_chunk", "count": [ 1, 3 ] }, { "item": "scrap", "count": [ 1, 3 ] } ],
+    "flags": [ "BURNER" ]
+  }
+]

src/handle_action.cpp

@@ -468,12 +468,17 @@ static void pldrive( int x, int y, int z = 0 )
             return;
         }
     }
-    if( !remote && z != 0 && !u.has_trait( trait_PROF_HELI_PILOT ) ) {
+    if( !remote && z != 0 && ( veh->is_rotorcraft() && !u.has_trait( trait_PROF_HELI_PILOT ) ) ) {
         u.add_msg_if_player( m_info, _( "You have no idea how to make the vehicle fly." ) );
         return;
     }
-    if( z != 0 && !g->m.has_zlevels() ) {
-        u.add_msg_if_player( m_info, _( "This vehicle doesn't look very airworthy." ) );
+    if( z != 0 && ( !g->m.has_zlevels() || !veh->is_rotorcraft() ) ) {
+        if( veh->is_hot_air_balloon() ) {
+            u.add_msg_if_player( m_info,
+                                 _( "To fly in a hot air balloon, operate the burner from the controls." ) );
+        } else {
+            u.add_msg_if_player( m_info, _( "This vehicle doesn't look very airworthy." ) );
+        }
         return;
     }
     if( z == -1 ) {

src/item_factory.cpp

@@ -1848,7 +1848,7 @@ void Item_factory::load( islot_comestible &slot, const JsonObject &jo, const std
     assign( jo, "spoils_in", slot.spoils, strict, 1_hours );
     assign( jo, "cooks_like", slot.cooks_like, strict );
     assign( jo, "smoking_result", slot.smoking_result, strict );
-  
+
     for( const JsonObject &jsobj : jo.get_array( "contamination" ) ) {
         slot.contamination.emplace( diseasetype_id( jsobj.get_string( "disease" ) ),
                                     jsobj.get_int( "probability" ) );

src/map.cpp

@@ -410,7 +410,7 @@ bool map::vehproceed( VehicleList &vehicle_list )
     // Then vertical-only movement
     if( cur_veh == nullptr ) {
         for( wrapped_vehicle &vehs_v : vehicle_list ) {
-            if( vehs_v.v->is_falling || ( vehs_v.v->is_rotorcraft() && vehs_v.v->get_z_change() != 0 ) ) {
+            if( vehs_v.v->is_falling || ( vehs_v.v->get_z_change() != 0 && vehs_v.v->is_airworthy() ) ) {
                 cur_veh = &vehs_v;
                 break;
             }
@@ -483,7 +483,7 @@ vehicle *map::move_vehicle( vehicle &veh, const tripoint &dp, const tileray &fac
     // Split into vertical and horizontal movement
     const int &coll_velocity = vertical ? veh.vertical_velocity : veh.velocity;
     const int velocity_before = coll_velocity;
-    if( velocity_before == 0 && !veh.is_rotorcraft() && !veh.is_flying_in_air() ) {
+    if( velocity_before == 0 && !veh.is_flying_in_air() && !veh.is_airworthy() ) {
         debugmsg( "%s tried to move %s with no velocity",
                   veh.name, vertical ? "vertically" : "horizontally" );
         return &veh;
@@ -539,7 +539,7 @@ vehicle *map::move_vehicle( vehicle &veh, const tripoint &dp, const tileray &fac
 
     const int velocity_after = coll_velocity;
     bool can_move = velocity_after != 0 && sgn( velocity_after ) == sgn( velocity_before );
-    if( dp.z != 0 && veh.is_rotorcraft() ) {
+    if( dp.z != 0 && veh.is_airworthy() ) {
         can_move = true;
     }
     int coll_turn = 0;
@@ -1030,7 +1030,6 @@ bool map::displace_vehicle( vehicle &veh, const tripoint &dp )
                  src.x, src.y, src.z, dst.x, dst.y, dst.z );
         return false;
     }
-
     point src_offset;
     point dst_offset;
     submap *src_submap = get_submap_at( src, src_offset );
@@ -1072,7 +1071,7 @@ bool map::displace_vehicle( vehicle &veh, const tripoint &dp )
     const bool remote = veh.remote_controlled( g->u );
 
     // record every passenger and pet inside
-    std::vector<rider_data> riders = veh.get_riders();
+    std::vector<rider_data> riders = veh.get_riders( dp.z != 0 );
 
     bool need_update = false;
     int z_change = 0;

src/savegame_json.cpp

@@ -2738,6 +2738,7 @@ void vehicle::deserialize( JsonIn &jsin )
     data.read( "is_following", is_following );
     data.read( "is_patrolling", is_patrolling );
     data.read( "autodrive_local_target", autodrive_local_target );
+    data.read( "desired_altitude", desired_altitude );
     // Need to manually backfill the active item cache since the part loader can't call its vehicle.
     for( const vpart_reference &vp : get_any_parts( VPFLAG_CARGO ) ) {
         auto it = vp.part().items.begin();
@@ -2898,6 +2899,7 @@ void vehicle::serialize( JsonOut &json ) const
     json.member( "is_following", is_following );
     json.member( "is_patrolling", is_patrolling );
     json.member( "autodrive_local_target", autodrive_local_target );
+    json.member( "desired_altitude", desired_altitude );
     json.end_object();
 }
 

src/veh_interact.cpp

@@ -707,7 +707,10 @@ bool veh_interact::can_install_part()
             }
         }
     }
-
+    bool already_balloon = false;
+    if( sel_vpart_info->has_flag( "BALLOON" ) && veh->has_part( "BALLOON" ) ) {
+        already_balloon = true;
+    }
     int dif_steering = 0;
     if( sel_vpart_info->has_flag( "STEERABLE" ) ) {
         std::set<int> axles;
@@ -730,9 +733,11 @@ bool veh_interact::can_install_part()
     std::string msg;
     bool ok = format_reqs( msg, reqs, sel_vpart_info->install_skills,
                            sel_vpart_info->install_time( g->u ) );
-
     msg += _( "<color_white>Additional requirements:</color>\n" );
-
+    if( already_balloon ) {
+        msg += _( "<color_red>Cannot install more than one balloon envelope." );
+        ok = false;
+    }
     if( dif_eng > 0 ) {
         if( g->u.get_skill_level( skill_mechanics ) < dif_eng ) {
             ok = false;

src/veh_type.cpp

@@ -244,6 +244,17 @@ void vpart_info::load_rotor( cata::optional<vpslot_rotor> &roptr, const JsonObje
     assert( roptr );
 }
 
+void vpart_info::load_balloon( cata::optional<vpslot_balloon> &balptr, const JsonObject &jo )
+{
+    vpslot_balloon balloon_info{};
+    if( balptr ) {
+        balloon_info = *balptr;
+    }
+    assign( jo, "balloon_volume", balloon_info.balloon_volume );
+    balptr = balloon_info;
+    assert( balptr );
+}
+
 void vpart_info::load_wheel( cata::optional<vpslot_wheel> &whptr, const JsonObject &jo )
 {
     vpslot_wheel wh_info{};
@@ -425,6 +436,9 @@ void vpart_info::load( const JsonObject &jo, const std::string &src )
     if( def.has_flag( "ROTOR" ) ) {
         load_rotor( def.rotor_info, jo );
     }
+    if( def.has_flag( "BALLOON" ) ) {
+        load_balloon( def.balloon_info, jo );
+    }
 
     if( def.has_flag( "WORKBENCH" ) ) {
         load_workbench( def.workbench_info, jo );
@@ -888,6 +902,11 @@ int vpart_info::rotor_diameter() const
     return has_flag( VPFLAG_ROTOR ) ? rotor_info->rotor_diameter : 0;
 }
 
+int vpart_info::balloon_volume() const
+{
+    return has_flag( "BALLOON" ) ? balloon_info->balloon_volume : 0;
+}
+
 const cata::optional<vpslot_workbench> &vpart_info::get_workbench_info() const
 {
     return workbench_info;

src/veh_type.h

@@ -121,6 +121,10 @@ struct vpslot_rotor {
     int rotor_diameter = 1;
 };
 
+struct vpslot_balloon {
+    int balloon_volume = 1;
+};
+
 struct vpslot_workbench {
     // Base multiplier applied for crafting here
     float multiplier = 1.0f;
@@ -147,6 +151,7 @@ class vpart_info
         cata::optional<vpslot_engine> engine_info;
         cata::optional<vpslot_wheel> wheel_info;
         cata::optional<vpslot_rotor> rotor_info;
+        cata::optional<vpslot_balloon> balloon_info;
         cata::optional<vpslot_workbench> workbench_info;
 
     public:
@@ -314,6 +319,9 @@ class vpart_info
         /** @name rotor specific functions
         */
         int rotor_diameter() const;
+        /** @name balloon specific functions
+        */
+        int balloon_volume() const;
         /**
          * Getter for optional workbench info
          */
@@ -355,6 +363,7 @@ class vpart_info
         static void load_wheel( cata::optional<vpslot_wheel> &whptr, const JsonObject &jo );
         static void load_workbench( cata::optional<vpslot_workbench> &wbptr, const JsonObject &jo );
         static void load_rotor( cata::optional<vpslot_rotor> &whptr, const JsonObject &jo );
+        static void load_balloon( cata::optional<vpslot_balloon> &balptr, const JsonObject &jo );
         static void load( const JsonObject &jo, const std::string &src );
         static void finalize();
         static void check();