Add ECS stuff

Cargo.lock

@@ -2,6 +2,29 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "ahash"
+version = "0.7.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fcb51a0695d8f838b1ee009b3fbf66bda078cd64590202a864a8f3e8c4315c47"
+dependencies = [
+ "getrandom",
+ "once_cell",
+ "version_check",
+]
+
+[[package]]
+name = "arrayvec"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "23b62fc65de8e4e7f52534fb52b0f3ed04746ae267519eef2a83941e8085068b"
+
+[[package]]
+name = "atom"
+version = "0.3.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c9ff149ed9780025acfdb36862d35b28856bb693ceb451259a7164442f22fdc3"
+
 [[package]]
 name = "autocfg"
 version = "1.0.1"
@@ -20,15 +43,72 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "crossbeam-channel"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06ed27e177f16d65f0f0c22a213e17c696ace5dd64b14258b52f9417ccb52db4"
+dependencies = [
+ "cfg-if",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-deque"
+version = "0.8.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6455c0ca19f0d2fbf751b908d5c55c1f5cbc65e03c4225427254b46890bdde1e"
+dependencies = [
+ "cfg-if",
+ "crossbeam-epoch",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.9.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ec02e091aa634e2c3ada4a392989e7c3116673ef0ac5b72232439094d73b7fd"
+dependencies = [
+ "cfg-if",
+ "crossbeam-utils",
+ "lazy_static",
+ "memoffset",
+ "scopeguard",
+]
+
+[[package]]
+name = "crossbeam-queue"
+version = "0.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9b10ddc024425c88c2ad148c1b0fd53f4c6d38db9697c9f1588381212fa657c9"
+dependencies = [
+ "cfg-if",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d82cfc11ce7f2c3faef78d8a684447b40d503d9681acebed6cb728d45940c4db"
+dependencies = [
+ "cfg-if",
+ "lazy_static",
+]
+
 [[package]]
 name = "dungeon_game"
 version = "0.1.0"
 dependencies = [
  "float-ord",
  "grid",
+ "lazy_static",
  "pancurses",
  "pathfinding",
  "rand",
+ "specs",
+ "specs-derive",
 ]
 
 [[package]]
@@ -74,6 +154,28 @@ name = "hashbrown"
 version = "0.11.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ab5ef0d4909ef3724cc8cce6ccc8572c5c817592e9285f5464f8e86f8bd3726e"
+dependencies = [
+ "ahash",
+]
+
+[[package]]
+name = "hermit-abi"
+version = "0.1.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "62b467343b94ba476dcb2500d242dadbb39557df889310ac77c5d99100aaac33"
+dependencies = [
+ "libc",
+]
+
+[[package]]
+name = "hibitset"
+version = "0.6.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "93a1bb8316a44459a7d14253c4d28dd7395cbd23cc04a68c46e851b8e46d64b1"
+dependencies = [
+ "atom",
+ "rayon",
+]
 
 [[package]]
 name = "indexmap"
@@ -103,6 +205,12 @@ dependencies = [
  "either",
 ]
 
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
+
 [[package]]
 name = "libc"
 version = "0.2.112"
@@ -118,6 +226,27 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "memchr"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "308cc39be01b73d0d18f82a0e7b2a3df85245f84af96fdddc5d202d27e47b86a"
+
+[[package]]
+name = "memoffset"
+version = "0.6.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5aa361d4faea93603064a027415f07bd8e1d5c88c9fbf68bf56a285428fd79ce"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "mopa"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a785740271256c230f57462d3b83e52f998433a7062fc18f96d5999474a9f915"
+
 [[package]]
 name = "ncurses"
 version = "5.101.0"
@@ -135,6 +264,16 @@ version = "0.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b93853da6d84c2e3c7d730d6473e8817692dd89be387eb01b94d7f108ecb5b8c"
 
+[[package]]
+name = "nom"
+version = "5.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ffb4262d26ed83a1c0a33a38fe2bb15797329c85770da05e6b828ddb782627af"
+dependencies = [
+ "memchr",
+ "version_check",
+]
+
 [[package]]
 name = "num-traits"
 version = "0.2.14"
@@ -144,6 +283,22 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "num_cpus"
+version = "1.13.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19e64526ebdee182341572e50e9ad03965aa510cd94427a4549448f285e957a1"
+dependencies = [
+ "hermit-abi",
+ "libc",
+]
+
+[[package]]
+name = "once_cell"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "da32515d9f6e6e489d7bc9d84c71b060db7247dc035bbe44eac88cf87486d8d5"
+
 [[package]]
 name = "pancurses"
 version = "0.17.0"
@@ -193,6 +348,24 @@ version = "0.2.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ed0cfbc8191465bed66e1718596ee0b0b35d5ee1f41c5df2189d0fe8bde535ba"
 
+[[package]]
+name = "proc-macro2"
+version = "1.0.36"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c7342d5883fbccae1cc37a2353b09c87c9b0f3afd73f5fb9bba687a1f733b029"
+dependencies = [
+ "unicode-xid",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "47aa80447ce4daf1717500037052af176af5d38cc3e571d9ec1c7353fc10c87d"
+dependencies = [
+ "proc-macro2",
+]
+
 [[package]]
 name = "rand"
 version = "0.8.4"
@@ -233,12 +406,134 @@ dependencies = [
  "rand_core",
 ]
 
+[[package]]
+name = "rayon"
+version = "1.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c06aca804d41dbc8ba42dfd964f0d01334eceb64314b9ecf7c5fad5188a06d90"
+dependencies = [
+ "autocfg",
+ "crossbeam-deque",
+ "either",
+ "rayon-core",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.9.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d78120e2c850279833f1dd3582f730c4ab53ed95aeaaaa862a2a5c71b1656d8e"
+dependencies = [
+ "crossbeam-channel",
+ "crossbeam-deque",
+ "crossbeam-utils",
+ "lazy_static",
+ "num_cpus",
+]
+
 [[package]]
 name = "rustc-hash"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
+[[package]]
+name = "scopeguard"
+version = "1.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d29ab0c6d3fc0ee92fe66e2d99f700eab17a8d57d1c1d3b748380fb20baa78cd"
+
+[[package]]
+name = "shred"
+version = "0.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "eb0210289d693217926314867c807e0b7b42f7e23c136adb31f8697f5bf242d3"
+dependencies = [
+ "arrayvec",
+ "hashbrown",
+ "mopa",
+ "rayon",
+ "smallvec",
+ "tynm",
+]
+
+[[package]]
+name = "shrev"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b5752e017e03af9d735b4b069f53b7a7fd90fefafa04d8bd0c25581b0bff437f"
+
+[[package]]
+name = "smallvec"
+version = "1.7.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1ecab6c735a6bb4139c0caafd0cc3635748bbb3acf4550e8138122099251f309"
+
+[[package]]
+name = "specs"
+version = "0.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5dcc1e4ba7ab1f08ecb3d7e2f693defc3907e2c03bb0924f9978be45b364f83f"
+dependencies = [
+ "crossbeam-queue",
+ "hashbrown",
+ "hibitset",
+ "log",
+ "rayon",
+ "shred",
+ "shrev",
+ "tuple_utils",
+]
+
+[[package]]
+name = "specs-derive"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3e23e09360f3d2190fec4222cd9e19d3158d5da948c0d1ea362df617dd103511"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
+[[package]]
+name = "syn"
+version = "1.0.84"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ecb2e6da8ee5eb9a61068762a32fa9619cc591ceb055b3687f4cd4051ec2e06b"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
+
+[[package]]
+name = "tuple_utils"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "44834418e2c5b16f47bedf35c28e148db099187dd5feee6367fb2525863af4f1"
+
+[[package]]
+name = "tynm"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4df2caa2dc9c3d1f7641ba981f4cd40ab229775aa7aeb834c9ab2850d50623d"
+dependencies = [
+ "nom",
+]
+
+[[package]]
+name = "unicode-xid"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8ccb82d61f80a663efe1f787a51b16b5a51e3314d6ac365b08639f52387b33f3"
+
+[[package]]
+name = "version_check"
+version = "0.9.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
+
 [[package]]
 name = "wasi"
 version = "0.10.2+wasi-snapshot-preview1"

Cargo.toml

@@ -6,8 +6,11 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [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"
 float-ord = "0.3.2"
-pathfinding = "3.0.5"
+pathfinding = "3"

src/components.rs

@@ -0,0 +1,23 @@
+//! ECS components.
+
+use specs::prelude::*;
+use specs_derive::Component;
+
+/// Entities that have a physical position in the world.
+#[derive(Component)]
+pub struct Position {
+    pub x: usize,
+    pub y: usize,
+}
+
+/// Entities that need to be drawn as a single character.
+#[derive(Component)]
+pub struct CharRender {
+    pub glyph: char,
+}
+
+/// Registers every existing component with the given ECS world.
+pub fn register_all(world: &mut World) {
+    world.register::<Position>();
+    world.register::<CharRender>();
+}

src/game.rs

@@ -57,9 +57,6 @@ impl DungeonLevel {
                 win.addch(self.render_tile(x, y));
             }
         }
-
-        // Leave the cursor at the lower-left.
-        win.mv(0, 0);
     }
 
     /// Renders the tile at the given coordinates.

src/main.rs

@@ -1,19 +1,36 @@
+use components::{register_all, Position, CharRender};
 use game::{BranchConfig, DungeonLevel};
-use pancurses::{endwin, initscr};
 
+use specs::prelude::*;
+use systems::IOSystem;
+
+mod components;
 mod game;
 mod rooms;
+mod systems;
 mod util;
 
 fn main() {
-    let window = initscr();
+    let mut world = World::new();
+
+    register_all(&mut world);
 
     let cfg = BranchConfig;
     let level = DungeonLevel::new(&cfg);
 
-    level.draw(&window);
-    window.refresh();
-    window.getch();
+    world.insert(level);
 
-    endwin();
+    world
+        .create_entity()
+        .with(Position { x: 5, y: 6 })
+        .with(CharRender { glyph: '@' })
+        .build();
+
+    let mut dispatcher = DispatcherBuilder::new()
+        .with(IOSystem::new(), "render_system", &[])
+        .build();
+
+    loop {
+        dispatcher.dispatch(&mut world);
+    }
 }

src/systems.rs

@@ -0,0 +1,73 @@
+//! ECS systems.
+
+use std::sync::Mutex;
+
+use lazy_static::lazy_static;
+use pancurses::{Window, endwin, initscr};
+use specs::prelude::*;
+
+use crate::{components::{Position, CharRender}, 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: Mutex<bool> = Mutex::new(false);
+}
+
+impl IOSystem {
+    pub fn new() -> Self {
+        let mut init = WINDOW_INITIALIZED.lock().unwrap();
+        if *init {
+            // See the note on `impl Send for IOSystem`.
+            panic!("Refusing to initialize the renderer twice");
+        }
+
+        *init = true;
+        Self { window: initscr() }
+    }
+}
+
+impl Drop for IOSystem {
+    fn drop(&mut self) {
+        endwin();
+        *WINDOW_INITIALIZED.lock().unwrap() = false;
+    }
+}
+
+// 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>,
+    );
+
+    fn run(&mut self, (level, renderables, positions): Self::SystemData) {
+        // 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);
+        self.window.refresh();
+
+        // For now, just get a character to avoid redrawing over and
+        // over.
+        self.window.getch();
+    }
+}
+