18 files changed, 603 insertions, 0 deletions
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..34aa146
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,2 @@
+target/
+pkg/
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
new file mode 100644
index 0000000..a872f80
--- /dev/null
+++ b/.gitlab-ci.yml
@@ -0,0 +1,10 @@
+image: alpine:latest
+pages:
+  stage: deploy
+  script:
+  - echo 'Nothing to do...'
+  artifacts:
+    paths:
+    - public
+  only:
+  - pages
diff --git a/Cargo.lock b/Cargo.lock
new file mode 100644
index 0000000..1c06bd8
--- /dev/null
+++ b/Cargo.lock
@@ -0,0 +1,235 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+[[package]]
+name = "anyhow"
+version = "1.0.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "bumpalo"
+version = "3.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "cfg-if"
+version = "0.1.10"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "console_error_panic_hook"
+version = "0.1.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "game_of_life"
+version = "0.1.0"
+dependencies = [
+ "console_error_panic_hook 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "js-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
+ "web-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "heck"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "unicode-segmentation 1.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "js-sys"
+version = "0.3.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "wasm-bindgen 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "lazy_static"
+version = "1.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "log"
+version = "0.4.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
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+
+[[package]]
+name = "memchr"
+version = "2.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "nom"
+version = "4.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "memchr 2.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
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+
+[[package]]
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+version = "1.0.8"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "unicode-xid 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
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+
+[[package]]
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+version = "1.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.8 (registry+https://github.com/rust-lang/crates.io-index)",
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+
+[[package]]
+name = "sourcefile"
+version = "0.1.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "syn"
+version = "1.0.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "proc-macro2 1.0.8 (registry+https://github.com/rust-lang/crates.io-index)",
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+[[package]]
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+
+[[package]]
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+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "version_check"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.58"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen-macro 0.2.58 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.58"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bumpalo 3.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
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+
+[[package]]
+name = "wasm-bindgen-macro"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
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+
+[[package]]
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+[[package]]
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+ "weedle 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "web-sys"
+version = "0.3.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "anyhow 1.0.26 (registry+https://github.com/rust-lang/crates.io-index)",
+ "js-sys 0.3.35 (registry+https://github.com/rust-lang/crates.io-index)",
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diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..aa18d6f
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,27 @@
+[package]
+name = "game_of_life"
+version = "0.1.0"
+authors = ["Joris"]
+edition = "2018"
+description = ''
+repository = ''
+license = 'LICENSE'
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+wasm-bindgen = "0.2.58"
+js-sys = "0.3.35"
+console_error_panic_hook = "0.1.6"
+
+[dependencies.web-sys]
+version = "0.3.35"
+features = [
+  'CanvasRenderingContext2d',
+  'Document',
+  'Element',
+  'HtmlCanvasElement',
+  'Window',
+  'console',
+]
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/LICENSE
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..e9517c3
--- /dev/null
+++ b/README.md
@@ -0,0 +1,24 @@
+# Game of life
+
+The code is written in Rust and is compiled to WebAssembly.
+[wasm-bindgen](https://github.com/rustwasm/wasm-bindgen) is used to interact
+with JavaScript.
+
+See [the wikipedia page](https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life)
+to get more information about game of life.
+
+## Live
+
+[https://guyonvarch.gitlab.io/game-of-life](https://guyonvarch.gitlab.io/game-of-life)
+
+## Getting started
+
+```bash
+nix-shell --run ./watch
+```
+
+## Deploy
+
+```bash
+nix-shell --run ./deploy
+```
diff --git a/deploy b/deploy
new file mode 100755
index 0000000..b3c6d61
--- /dev/null
+++ b/deploy
@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+set -e
+git branch -D pages
+git checkout -b pages
+rm -f public/game_of_life.js
+rm -f public/game_of_life_bg.wasm
+rm -f public/game_of_life_bg.wasm.gz
+wasm-pack build --release --target web
+mv pkg/game_of_life.js public
+wasm-opt -O -o public/game_of_life_bg.wasm pkg/game_of_life_bg.wasm
+gzip -9 --keep public/game_of_life_bg.wasm
+git add .
+git commit -m "Deploy pages"
+git push --force origin pages
+git checkout master
+git branch -D pages
diff --git a/public/game_of_life.js b/public/game_of_life.js
new file mode 120000
index 0000000..998a5ea
--- /dev/null
+++ b/public/game_of_life.js
@@ -0,0 +1 @@
+../pkg/game_of_life.js
+\ No newline at end of file
diff --git a/public/game_of_life_bg.wasm b/public/game_of_life_bg.wasm
new file mode 120000
index 0000000..fe3f9b8
--- /dev/null
+++ b/public/game_of_life_bg.wasm
@@ -0,0 +1 @@
+../pkg/game_of_life_bg.wasm
+\ No newline at end of file
diff --git a/public/index.html b/public/index.html
new file mode 100644
index 0000000..ed2639f
--- /dev/null
+++ b/public/index.html
@@ -0,0 +1,28 @@
+<html>
+  <head>
+    <meta content="text/html;charset=utf-8" http-equiv="Content-Type"/>
+    <style>
+      body {
+        margin: 0;
+        width: 100%;
+        height: 100%;
+        background-color: #333333;
+        display: flex;
+        align-items: center;
+        justify-content: center;
+      }
+    </style>
+  </head>
+  <body>
+    <canvas id="canvas" height="800" width="800" />
+    <script type="module">
+      import init from './game_of_life.js';
+
+      async function run() {
+        await init();
+      }
+
+      run();
+    </script>
+  </body>
+</html>
diff --git a/shell.nix b/shell.nix
new file mode 100644
index 0000000..45261c8
--- /dev/null
+++ b/shell.nix
@@ -0,0 +1,17 @@
+with import <nixpkgs> {};
+
+let unstable = import (
+      fetchTarball https://github.com/NixOS/nixpkgs-channels/archive/nixos-unstable.tar.gz
+    ) {};
+in
+
+mkShell {
+  buildInputs = [
+    entr
+    gzip
+    python3
+    rustup
+    unstable.binaryen
+    wasm-pack
+  ];
+}
diff --git a/src/canvas.rs b/src/canvas.rs
new file mode 100644
index 0000000..38aef4d
--- /dev/null
+++ b/src/canvas.rs
@@ -0,0 +1,64 @@
+use wasm_bindgen::prelude::JsValue;
+use wasm_bindgen::JsCast;
+use web_sys::CanvasRenderingContext2d;
+
+pub struct Canvas {
+    context: CanvasRenderingContext2d,
+    width: u32,
+    height: u32,
+    scaled_width: u32,
+    scaled_height: u32,
+}
+
+impl Canvas {
+    pub fn new(attr_id: &str, width: u32, height: u32) -> Canvas {
+        let document = web_sys::window().unwrap().document().unwrap();
+        let canvas = document.get_element_by_id(attr_id).unwrap();
+        let canvas: web_sys::HtmlCanvasElement = canvas
+            .dyn_into::<web_sys::HtmlCanvasElement>()
+            .unwrap();
+
+        let context = canvas
+            .get_context("2d")
+            .unwrap()
+            .unwrap()
+            .dyn_into::<web_sys::CanvasRenderingContext2d>()
+            .unwrap();
+
+        let scaled_width = canvas.width() / width;
+        let scaled_height = canvas.height() / height;
+
+        Canvas {
+            context,
+            width,
+            height,
+            scaled_width,
+            scaled_height,
+        }
+    }
+
+    pub fn clear(&self) {
+        self.context.set_fill_style(&JsValue::from_str("white"));
+
+        self.context.fill_rect(
+            f64::from(0),
+            f64::from(0),
+            f64::from(self.width * self.scaled_width),
+            f64::from(self.height * self.scaled_height)
+        );
+    }
+
+    pub fn draw(&self, x: u32, y: u32, color: &str) {
+        assert!(x < self.width);
+        assert!(y < self.height);
+
+        self.context.set_fill_style(&JsValue::from_str(color));
+
+        self.context.fill_rect(
+            f64::from(x * self.scaled_width),
+            f64::from(y * self.scaled_height),
+            f64::from(self.scaled_width),
+            f64::from(self.scaled_height)
+        );
+    }
+}
diff --git a/src/console.rs b/src/console.rs
new file mode 100644
index 0000000..4efbd80
--- /dev/null
+++ b/src/console.rs
@@ -0,0 +1,5 @@
+use wasm_bindgen::prelude::JsValue;
+
+pub fn log(str: &str) {
+    web_sys::console::log_1(&JsValue::from_str(str));
+}
diff --git a/src/game.rs b/src/game.rs
new file mode 100644
index 0000000..4b527d2
--- /dev/null
+++ b/src/game.rs
@@ -0,0 +1,31 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+
+use crate::canvas::Canvas;
+use crate::state::State;
+
+pub struct Game {
+    canvas: Canvas,
+    state: Rc<RefCell<State>>,
+}
+
+impl Game {
+    pub fn new(canvas_id: &str, width: u32, height: u32) -> Game {
+        let canvas = Canvas::new(canvas_id, width, height);
+        let state = Rc::new(RefCell::new(State::new(width, height)));
+
+        Game {
+            canvas,
+            state,
+        }
+    }
+
+    pub fn update(&self) {
+        let next_state = self.state.borrow().next();
+        *self.state.borrow_mut() = next_state;
+    }
+
+    pub fn render(&self) {
+        self.state.borrow().draw(&self.canvas);
+    }
+}
diff --git a/src/game_loop.rs b/src/game_loop.rs
new file mode 100644
index 0000000..34dd477
--- /dev/null
+++ b/src/game_loop.rs
@@ -0,0 +1,31 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+
+use wasm_bindgen::prelude::Closure;
+use wasm_bindgen::JsCast;
+
+use crate::game::Game;
+
+pub fn run(game: Game, update_period: i32) {
+    game.render();
+
+    let f = Rc::new(RefCell::new(None));
+    let g = f.clone();
+
+    *g.borrow_mut() = Some(Closure::wrap(Box::new(move |_| {
+
+        game.update();
+        game.render();
+
+        set_timeout(f.borrow().as_ref().unwrap(), update_period);
+
+    }) as Box<dyn FnMut(i32)>));
+
+    set_timeout(g.borrow().as_ref().unwrap(), update_period);
+}
+
+fn set_timeout(f: &Closure<dyn FnMut(i32)>, timeout: i32) {
+    web_sys::window().unwrap()
+        .set_timeout_with_callback_and_timeout_and_arguments_0(f.as_ref().unchecked_ref(), timeout)
+        .unwrap();
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..f7fa24c
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,26 @@
+use wasm_bindgen::prelude::{wasm_bindgen, JsValue};
+
+mod canvas;
+mod state;
+mod game;
+mod game_loop;
+
+use game::Game;
+
+#[wasm_bindgen(start)]
+pub fn main() -> Result<(), JsValue> {
+    set_panic_hook();
+    game_loop::run(Game::new("canvas", 100, 100), 100);
+    Ok(())
+}
+
+pub fn set_panic_hook() {
+    // When the `console_error_panic_hook` feature is enabled, we can call the
+    // `set_panic_hook` function at least once during initialization, and then
+    // we will get better error messages if our code ever panics.
+    //
+    // For more details see
+    // https://github.com/rustwasm/console_error_panic_hook#readme
+    #[cfg(feature = "console_error_panic_hook")]
+    console_error_panic_hook::set_once();
+}
diff --git a/src/state.rs b/src/state.rs
new file mode 100644
index 0000000..5d13902
--- /dev/null
+++ b/src/state.rs
@@ -0,0 +1,72 @@
+use crate::canvas::Canvas;
+
+#[derive(Debug, Clone)]
+pub struct State {
+    width: u32,
+    height: u32,
+    cells: Vec::<bool>,
+}
+
+impl State {
+    pub fn new(width: u32, height: u32) -> State {
+        let cells = (0..width * height)
+            .map(|_| js_sys::Math::random() < 0.5)
+            .collect();
+
+        State {
+            width,
+            height,
+            cells,
+        }
+    }
+
+    pub fn neighbor_count(&self, x: u32, y: u32) -> u32 {
+        let mut count = 0;
+        for delta_x in [self.height - 1, 0, 1].iter().clone() {
+            for delta_y in [self.width - 1, 0, 1].iter().clone() {
+                let neighbor_x = (x + delta_x) % self.width;
+                let neighbor_y = (y + delta_y) % self.height;
+
+                if (*delta_x, *delta_y) != (0, 0) && self.is_on(neighbor_x, neighbor_y) {
+                    count += 1;
+                }
+            }
+        }
+        count
+    }
+
+    pub fn next(&self) -> State {
+        let cells = (0..self.width * self.height)
+            .map(|i| {
+                let x = i % self.width;
+                let y = i / self.width;
+                let neighbor_count = self.neighbor_count(x, y);
+                neighbor_count == 3 || self.is_on(x, y) && neighbor_count == 2
+            })
+            .collect();
+
+        State {
+            width: self.width,
+            height: self.height,
+            cells,
+        }
+    }
+
+    fn is_on(&self, x: u32, y: u32) -> bool {
+        let inside_x = (x + self.width) % self.width;
+        let inside_y = (y + self.height) % self.height;
+        self.cells[(inside_x + inside_y * self.width) as usize]
+    }
+
+    pub fn draw(&self, canvas: &Canvas) {
+        canvas.clear();
+
+        for y in 0..self.height {
+            for x in 0..self.width {
+                if self.is_on(x, y) {
+                    canvas.draw(x, y, "green");
+                }
+            }
+        }
+    }
+}
diff --git a/watch b/watch
new file mode 100755
index 0000000..802c503
--- /dev/null
+++ b/watch
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+python -m http.server --directory public 8000 &
+
+trap "fuser -k 8000/tcp" EXIT
+
+CMD="clear && wasm-pack build --target web"
+
+while true; do
+
+  find src | entr -d -s "$CMD"
+
+done