Randomize cell initialization

Cargo.toml

@@ -16,6 +16,7 @@ default = ["console_error_panic_hook"]
 
 [dependencies]
 wasm-bindgen = "0.2.63"
+js-sys = "0.3"
 
 # The `console_error_panic_hook` crate provides better debugging of panics by
 # logging them with `console.error`. This is great for development, but requires

src/lib.rs

@@ -1,5 +1,7 @@
 mod utils;
 
+extern crate js_sys;
+
 use wasm_bindgen::prelude::*;
 
 // When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
@@ -129,10 +131,9 @@ impl Universe {
     let width = w;
     let height = h;
 
-
     let cells = (0..width * height)
-      .map(|i| {
-        if i % 2 == 0 || i % 7 == 0 {
+      .map(|_| {
+        if js_sys::Math::random() < 0.5 {
           Cell::Alive
         } else {
           Cell::Dead