Movement code

Cargo.lock

@@ -103,7 +103,6 @@ version = "0.1.0"
 dependencies = [
  "float-ord",
  "grid",
- "lazy_static",
  "pancurses",
  "pathfinding",
  "rand",

Cargo.toml

@@ -8,7 +8,6 @@ edition = "2021"
 [dependencies]
 specs = "0.17.0"
 specs-derive = "0.4.1"
-lazy_static = "1"
 pancurses = "0.17.0"
 rand = "0.8.4"
 grid = "0.6.0"

src/components.rs

@@ -30,10 +30,28 @@ pub struct TurnTaker {
     pub maximum: u32,
 }
 
+/// Entities that can move, attack other mobile entities, use items,
+/// etc.
+#[derive(Component)]
+pub struct Mobile {
+    pub next_action: MobAction,
+}
+
 /// Registers every existing component with the given ECS world.
 pub fn register_all(world: &mut World) {
     world.register::<Position>();
     world.register::<CharRender>();
     world.register::<Player>();
     world.register::<TurnTaker>();
+    world.register::<Mobile>();
+}
+
+/// An action that a mob can perform that takes up a turn.
+#[derive(Clone, Copy)]
+pub enum MobAction {
+    /// Do nothing.
+    Nop,
+
+    /// Physically move by the given vector.
+    Move(i32, i32),
 }

src/main.rs

@@ -1,11 +1,16 @@
-use components::{register_all, CharRender, Player, Position, TurnTaker};
+use std::process::exit;
+
+use components::{register_all, CharRender, MobAction, Mobile, Player, Position, TurnTaker};
 use game::{BranchConfig, DungeonLevel};
 
+use pancurses::{endwin, initscr, noecho, Window};
+use player::player_turn;
 use specs::prelude::*;
-use systems::{IOSystem, TurnTickSystem};
+use systems::{MobSystem, TimeSystem};
 
 mod components;
 mod game;
+mod player;
 mod rooms;
 mod systems;
 mod util;
@@ -25,6 +30,9 @@ fn main() {
         .with(Position { x: 5, y: 6 })
         .with(CharRender { glyph: '@' })
         .with(Player)
+        .with(Mobile {
+            next_action: MobAction::Nop,
+        })
         .with(TurnTaker {
             next: 0,
             maximum: 10,
@@ -32,11 +40,49 @@ fn main() {
         .build();
 
     let mut dispatcher = DispatcherBuilder::new()
-        .with(TurnTickSystem, "turn_tick", &[])
+        .with(TimeSystem, "time", &[])
-        .with(IOSystem::new(), "render", &["turn_tick"])
+        .with(MobSystem, "mobs", &[])
         .build();
 
+    let mut window = init_window();
+
     loop {
         dispatcher.dispatch(&world);
+
+        let players = world.read_storage::<Player>();
+        let turns = world.read_storage::<TurnTaker>();
+
+        if (&players, &turns).join().any(|(_plr, turn)| turn.next == 0) {
+            drop(players);
+            drop(turns);
+            player_turn(&mut world, &mut window);
+        } else {
+            drop(players);
+            drop(turns);
+        }
     }
 }
+
+/// Initializes the terminal to accept user input, and creates a new
+/// Window.
+fn init_window() -> Window {
+    // Create a new window over the terminal.
+    let window = initscr();
+
+    // Enable keypad mode (off by default for historical reasons), so
+    // we can read special keycodes other than just characters.
+    window.keypad(true);
+
+    // Disable echoing so the user doesn't see flickering in the
+    // upper-left corner of the screen when they type a character.
+    noecho();
+
+    window
+}
+
+/// Cleans everything up and exits the game.
+fn quit() -> ! {
+    endwin();
+
+    exit(0)
+}

src/player.rs

@@ -0,0 +1,86 @@
+//! Code for controlling the player, and for I/O.
+
+use pancurses::Window;
+use specs::prelude::*;
+
+use crate::{
+    components::{CharRender, MobAction, Mobile, Player, Position},
+    game::DungeonLevel,
+    quit,
+};
+
+/// Runs a player turn on the ECS, using the given `screen` for input
+/// and output.
+///
+/// At some point this should maybe become a system rather than a
+/// standalone function.
+pub fn player_turn(ecs: &mut World, screen: &mut Window) {
+    render_screen(ecs, screen);
+
+    let action = loop {
+        let key = screen.getch();
+
+        use pancurses::Input;
+        let action = match key {
+            Some(key) => match key {
+                Input::Character(ch) => match ch {
+                    '.' => Some(MobAction::Nop),
+
+                    'h' => Some(MobAction::Move(-1, 0)),
+                    'j' => Some(MobAction::Move(0, 1)),
+                    'k' => Some(MobAction::Move(0, -1)),
+                    'l' => Some(MobAction::Move(1, 0)),
+
+                    'y' => Some(MobAction::Move(-1, -1)),
+                    'u' => Some(MobAction::Move(1, -1)),
+                    'b' => Some(MobAction::Move(-1, 1)),
+                    'n' => Some(MobAction::Move(1, 1)),
+
+                    'q' => quit(),
+
+                    _ => None,
+                },
+
+                Input::KeyUp => Some(MobAction::Move(0, -1)),
+                Input::KeyLeft => Some(MobAction::Move(-1, 0)),
+                Input::KeyDown => Some(MobAction::Move(0, 1)),
+                Input::KeyRight => Some(MobAction::Move(1, 0)),
+                _ => None,
+            },
+
+            // User closed stdin.
+            None => quit(),
+        };
+
+        if let Some(action) = action {
+            break action;
+        }
+    };
+
+    let plrs = ecs.read_storage::<Player>();
+    let mut mobs = ecs.write_storage::<Mobile>();
+    for (_plr, mob) in (&plrs, &mut mobs).join() {
+        mob.next_action = action;
+    }
+}
+
+/// Renders the state of the world onto the screen.
+fn render_screen(ecs: &mut World, screen: &mut Window) {
+    // screen.clear();
+
+    // Draw the base level.
+    let level = ecs.fetch::<DungeonLevel>();
+    level.draw(screen);
+
+    // Draw all renderable entities.
+    let renderables = ecs.read_storage::<CharRender>();
+    let positions = ecs.read_storage::<Position>();
+    for (render, pos) in (&renderables, &positions).join() {
+        screen.mvaddch(pos.y as _, pos.x as _, render.glyph);
+    }
+
+    // Leave the cursor at the lower-left.
+    screen.mv(0, 0);
+
+    screen.refresh();
+}

src/systems.rs

@@ -1,90 +1,15 @@
 //! ECS systems.
 
-use std::sync::atomic::{AtomicBool, Ordering};
-
-use lazy_static::lazy_static;
-use pancurses::{endwin, initscr, Window};
 use specs::prelude::*;
 
-use crate::{
+use crate::components::{MobAction, Mobile, Position, TurnTaker};
-    components::{CharRender, Player, Position, TurnTaker},
-    game::DungeonLevel,
-};
-
-/// System for drawing the state of the game, and potentially waiting
-/// (blocking) for user input.
-pub struct IOSystem {
-    window: Window,
-}
-
-lazy_static! {
-    static ref WINDOW_INITIALIZED: AtomicBool = AtomicBool::new(false);
-}
-
-impl IOSystem {
-    pub fn new() -> Self {
-        // See the note on `impl Send for IOSystem`.
-        if WINDOW_INITIALIZED.swap(true, Ordering::Relaxed) {
-            panic!("Refusing to initialize the renderer twice");
-        }
-
-        Self { window: initscr() }
-    }
-}
-
-impl Drop for IOSystem {
-    fn drop(&mut self) {
-        endwin();
-        WINDOW_INITIALIZED.store(false, Ordering::Relaxed);
-    }
-}
-
-// The `Window` type from pancurses contains a raw pointer, and as a
-// result Rust isn't convinced that it's safe to send between threads.
-// Since we guarantee that only one `Window` object is ever created at
-// a time, it is in fact safe to send the render system's data between
-// threads.
-unsafe impl Send for IOSystem {}
-
-impl<'a> System<'a> for IOSystem {
-    type SystemData = (
-        ReadExpect<'a, DungeonLevel>,
-        ReadStorage<'a, CharRender>,
-        ReadStorage<'a, Position>,
-        ReadStorage<'a, Player>,
-        ReadStorage<'a, TurnTaker>,
-    );
-
-    fn run(&mut self, (level, renderables, positions, players, turns): Self::SystemData) {
-        self.window.clear();
-
-        // Draw the base level.
-        level.draw(&self.window);
-
-        // Draw all renderable entities in the ECS.
-        for (render, pos) in (&renderables, &positions).join() {
-            self.window.mvaddch(pos.y as _, pos.x as _, render.glyph);
-        }
-
-        // Leave the cursor at the lower-left.
-        self.window.mv(0, 0);
-
-        // On the player's turn, read input.
-        for (_player, turn) in (&players, &turns).join() {
-            if turn.next == 0 {
-                self.window.refresh();
-                self.window.getch();
-            }
-        }
-    }
-}
 
 /// System for ticking the turn counter on every entity; this system
 /// implements the relationship between real-world time and in-game
 /// time.
-pub struct TurnTickSystem;
+pub struct TimeSystem;
 
-impl<'a> System<'a> for TurnTickSystem {
+impl<'a> System<'a> for TimeSystem {
     type SystemData = WriteStorage<'a, TurnTaker>;
 
     fn run(&mut self, mut turn_takers: Self::SystemData) {
@@ -93,3 +18,31 @@ impl<'a> System<'a> for TurnTickSystem {
         }
     }
 }
+
+/// System for executing actions that mobs have chosen.
+pub struct MobSystem;
+
+impl<'a> System<'a> for MobSystem {
+    type SystemData = (
+        WriteStorage<'a, Position>,
+        ReadStorage<'a, TurnTaker>,
+        WriteStorage<'a, Mobile>,
+    );
+
+    fn run(&mut self, (mut pos, turn, mut mob): Self::SystemData) {
+        for (pos, _turn, mob) in (&mut pos, &turn, &mut mob)
+            .join()
+            .filter(|(_pos, turn, _mob)| turn.next == 0)
+        {
+            match mob.next_action {
+                MobAction::Nop => {}
+                MobAction::Move(dx, dy) => {
+                    pos.x = (pos.x as i32 + dx) as _;
+                    pos.y = (pos.y as i32 + dy) as _;
+                }
+            }
+
+            mob.next_action = MobAction::Nop;
+        }
+    }
+}