maxcell / rust-wasm-game-of-life

Rust + WASM Conway's Game of Life

Here is my implementation following the Rust + WASM book. This goes through the first half of the section for creating the life game, so still using the pre before putting as a canvas.

How to Read this Repository

Primarily the pieces of work that are being done are happening in src/lib.rs and www/index.js. Before continuing, you must also have wasm-pack installed.

Then in the directory, you can run wasm-pack build which should create a pkg/, this is how we are able to connect our own package to be consumed by the browser. From there you can move into the www directory (cd www/), install the packages npm installand run npm run start and it should be running http://localhost:8080.

Notes about errors caught on stream

During the stream, we got through all the steps and we encountered a HUGE output. Turns out the output was composed of two things:

1. The .wat output
2. An error with wasm-opt

This is the error output I saw:

[wasm-validator error in module] unexpected true: Exported global cannot be mutable, on 
global$0
Fatal: error in validating input
Error: failed to execute `wasm-opt`: exited with exit code: 1
  full command: "/Users/<current_user>/Library/Caches/.wasm-pack/wasm-opt-a528729925722b63/wasm-opt" "/<path_to_project>/wasm-game-of-life/pkg/wasm_game_of_life_bg.wasm" "-o" "/<path_to_project>/wasm-game-of-life/pkg/wasm_game_of_life_bg.wasm-opt.wasm" "-O"
To disable `wasm-opt`, add `wasm-opt = false` to your package metadata in your `Cargo.toml`.

There was a comment on a related issue that solved it for me.

Adding this to Cargo.toml:

[package.metadata.wasm-pack.profile.release]
wasm-opt = ["-Oz", "--enable-mutable-globals"]