Complete chapter 2.11

.gitignore

@@ -111,3 +111,6 @@ Cargo.lock
 *.pdb
 
 # End of https://www.toptal.com/developers/gitignore/api/rust,jetbrains+all
+
+# Ignore save game file
+savegame.json

src/gui.rs

@@ -51,6 +51,16 @@ pub fn draw_ui(ecs: &World, ctx: &mut Rltk) {
         );
     }
 
+    let map = ecs.fetch::<Map>();
+    let depth = format!("Depth: {}", map.depth);
+    ctx.print_color(
+        2,
+        43,
+        RGB::named(rltk::YELLOW),
+        RGB::named(rltk::BLACK),
+        &depth,
+    );
+
     // Display logs
     let log = ecs.fetch::<GameLog>();
     let mut y = 44;

src/main.rs

@@ -59,6 +59,7 @@ pub enum RunState {
         menu_selection: gui::MainMenuSelection,
     },
     SaveGame,
+    NextLevel,
 }
 
 pub struct State {
@@ -252,6 +253,10 @@ impl GameState for State {
                     menu_selection: gui::MainMenuSelection::LoadGame,
                 }
             }
+            RunState::NextLevel => {
+                self.goto_next_level();
+                newrunstate = RunState::PreRun;
+            }
         }
 
         {
@@ -263,6 +268,95 @@ impl GameState for State {
     }
 }
 
+impl State {
+    fn entities_to_remove_on_level_change(&mut self) -> Vec<Entity> {
+        let entities = self.ecs.entities();
+        let player = self.ecs.read_storage::<Player>();
+        let backpack = self.ecs.read_storage::<InBackpack>();
+        let player_entity = self.ecs.fetch::<Entity>();
+
+        let mut to_delete: Vec<Entity> = Vec::new();
+        for entity in entities.join() {
+            let mut should_delete = true;
+
+            // Don't delete the player
+            let p = player.get(entity);
+            if let Some(_p) = p {
+                should_delete = false;
+            }
+
+            // Don't delete the player's equipment
+            let bp = backpack.get(entity);
+            if let Some(bp) = bp {
+                if bp.owner == *player_entity {
+                    should_delete = false;
+                }
+            }
+
+            if should_delete {
+                to_delete.push(entity);
+            }
+        }
+
+        to_delete
+    }
+
+    fn goto_next_level(&mut self) {
+        // Delete entities that aren't the palyer or their equipment
+        let to_delete = self.entities_to_remove_on_level_change();
+        for target in to_delete {
+            self.ecs
+                .delete_entity(target)
+                .expect("failed to delete entity");
+        }
+
+        // Build a new map and place the player
+        let worldmap;
+        {
+            let mut worldmap_resource = self.ecs.write_resource::<Map>();
+            let current_depth = worldmap_resource.depth;
+
+            *worldmap_resource = Map::new_map_rooms_and_corridors(current_depth + 1);
+            worldmap = worldmap_resource.clone();
+        }
+
+        // Spawn bad guys
+        for room in worldmap.rooms.iter().skip(1) {
+            spawner::spawn_room(&mut self.ecs, room);
+        }
+
+        // Place the player and update resources
+        let (player_x, player_y) = worldmap.rooms[0].center();
+        let mut player_position = self.ecs.write_resource::<Point>();
+        *player_position = Point::new(player_x, player_y);
+        let mut position_components = self.ecs.write_storage::<Position>();
+        let player_entity = self.ecs.fetch::<Entity>();
+        let player_pos_comp = position_components.get_mut(*player_entity);
+        if let Some(player_pos_comp) = player_pos_comp {
+            player_pos_comp.x = player_x;
+            player_pos_comp.y = player_y;
+        }
+
+        // Mark the player's visibility as dirty
+        let mut viewshed_components = self.ecs.write_storage::<Viewshed>();
+        let vs = viewshed_components.get_mut(*player_entity);
+        if let Some(vs) = vs {
+            vs.dirty = true;
+        }
+
+        // Notify the player and give them some health
+        let mut gamelog = self.ecs.fetch_mut::<GameLog>();
+        gamelog
+            .entries
+            .push("You descend to the next level, and take a moment to heal.".to_string());
+        let mut player_health_store = self.ecs.write_storage::<CombatStats>();
+        let player_health = player_health_store.get_mut(*player_entity);
+        if let Some(player_health) = player_health {
+            player_health.hp = i32::max(player_health.hp, player_health.max_hp / 2);
+        }
+    }
+}
+
 fn main() -> rltk::BError {
     use rltk::RltkBuilder;
 
@@ -301,7 +395,7 @@ fn main() -> rltk::BError {
 
     gs.ecs.insert(SimpleMarkerAllocator::<SerializeMe>::new());
 
-    let map = Map::new_map_rooms_and_corridors();
+    let map = Map::new_map_rooms_and_corridors(1);
     let (player_x, player_y) = map.rooms[0].center();
 
     let player_entity = spawner::player(&mut gs.ecs, player_x, player_y);

src/map.rs

@@ -12,6 +12,7 @@ pub const MAP_COUNT: usize = MAP_HEIGHT * MAP_WIDTH;
 pub enum TileType {
     Wall,
     Floor,
+    DownStairs,
 }
 
 #[derive(Default, Serialize, Deserialize, Clone)]
@@ -23,6 +24,7 @@ pub struct Map {
     pub revealed_tiles: Vec<bool>,
     pub visible_tiles: Vec<bool>,
     pub blocked: Vec<bool>,
+    pub depth: i32,
 
     #[serde(skip_serializing)]
     #[serde(skip_deserializing)]
@@ -65,7 +67,7 @@ impl Map {
 
     /// Makes a new map using the algorithm from http://rogueliketutorials.com/tutorials/tcod/part-3/
     /// This gives a handful of random rooms and corridors joining them together
-    pub fn new_map_rooms_and_corridors() -> Map {
+    pub fn new_map_rooms_and_corridors(new_depth: i32) -> Map {
         let mut map = Map {
             tiles: vec![TileType::Wall; MAP_COUNT],
             rooms: Vec::new(),
@@ -75,6 +77,7 @@ impl Map {
             visible_tiles: vec![false; MAP_COUNT],
             blocked: vec![false; MAP_COUNT],
             tile_content: vec![Vec::new(); MAP_COUNT],
+            depth: new_depth,
         };
 
         const MAX_ROOMS: i32 = 30;
@@ -118,6 +121,10 @@ impl Map {
             }
         }
 
+        let stairs_position = map.rooms[map.rooms.len() - 1].center();
+        let stairs_idx = map.xy_idx(stairs_position.0, stairs_position.1);
+        map.tiles[stairs_idx] = TileType::DownStairs;
+
         map
     }
 
@@ -222,6 +229,10 @@ pub fn draw_map(ecs: &World, ctx: &mut Rltk) {
                     glyph = rltk::to_cp437('#');
                     fg = RGB::from_f32(0., 1.0, 0.);
                 }
+                TileType::DownStairs => {
+                    glyph = rltk::to_cp437('>');
+                    fg = RGB::from_f32(0., 1.0, 1.0);
+                }
             }
 
             if !map.visible_tiles[idx] {

src/player.rs

@@ -1,7 +1,7 @@
-use crate::{
-    game_log::GameLog, CombatStats, Item, Map, Player, Position, RunState, State, Viewshed,
-    WantsToMelee, WantsToPickupItem,
+use crate::components::{
+    CombatStats, Item, Player, Position, Viewshed, WantsToMelee, WantsToPickupItem,
 };
+use crate::{game_log::GameLog, Map, RunState, State, TileType};
 use rltk::{Point, Rltk, VirtualKeyCode};
 use specs::prelude::*;
 use std::cmp::{max, min};
@@ -107,6 +107,13 @@ pub fn player_input(gs: &mut State, ctx: &mut Rltk) -> RunState {
             // Save and Quit
             VirtualKeyCode::Escape => return RunState::SaveGame,
 
+            // Level changes
+            VirtualKeyCode::Period => {
+                if try_next_level(&mut gs.ecs) {
+                    return RunState::NextLevel;
+                }
+            }
+
             _ => return RunState::AwaitingInput,
         },
     }
@@ -147,3 +154,19 @@ fn get_item(ecs: &mut World) {
         }
     }
 }
+
+pub fn try_next_level(ecs: &mut World) -> bool {
+    let player_pos = ecs.fetch::<Point>();
+    let map = ecs.fetch::<Map>();
+    let player_idx = map.xy_idx(player_pos.x, player_pos.y);
+
+    if map.tiles[player_idx] == TileType::DownStairs {
+        true
+    } else {
+        let mut gamelog = ecs.fetch_mut::<GameLog>();
+        gamelog
+            .entries
+            .push("There is no way down from here.".to_string());
+        false
+    }
+}