hello-rust-sdl2-wasm

A minimal working "game" written in Rust with SDL2, compiled to WASM.

Note: these instructions are written for macOS and Ubuntu. If you'd like to submit instructions for any other OS, please open a PR.

Prerequisites

• rustup must be installed
• git must be installed

install the SDL2 development libraries

On macOS, this is as easy as

brew install sdl2

Make sure these libraries are on your LIBRARY_PATH, as well. If you installed with brew, run

export LIBRARY_PATH="$LIBRARY_PATH:$(brew --prefix)/lib"

So you don't have to do this in each new shell you open, maybe also add this to your ~/.bashrc or ~/.zshrc (or other shell startup script).

On Ubuntu:

sudo apt install libsdl2-dev

(setting LIBRARY_PATH is not needed on Ubuntu)

clone this repo and cd into it

git clone https://github.com/awwsmm/hello-rust-sdl2-wasm.git && cd hello-rust-sdl2-wasm

Building locally

To build a desktop (standalone binary executable) app, run

cargo run

Building for WASM

To build the WASM app instead, there are a few more setup steps.

install the target architecture toolchain

rustup target add asmjs-unknown-emscripten

We use emscripten to convert Rust LLVM bytecode to WASM.

install the emscripten compiler

On MacOS:

brew install emscripten

(This will take a few minutes.)

On Ubuntu, follow emscripten's recommended installation instructions:

git clone https://github.com/emscripten-core/emsdk.git && cd emsdk
./emsdk install latest
./emsdk activate latest
source ./emsdk_env.sh

set this one environment variable

export EMCC_CFLAGS="-s USE_SDL=2"

build

cargo build --target asmjs-unknown-emscripten

Open the browser app with

open index.html

Resources

This work is largely based on Michał Kalbarczyk's blog post here, with some help from Greg Buchholz's message board post here, which is itself based on Tobias Widlund's work here. Thanks, all!

See Mozilla's Rust to WASM guide if you want a simpler Rust-to-WASM example (which doesn't use SDL2).