Yare-Rust

A library for making bots for yare with Rust.

How it works

You make a Rust library and compile to wasm. Then you use the wasm2yareio script to generate a JavaScript yare bot. The result can be copied into the game.

Setup

You will need Rust, and some additional tools.

rustup toolchain add nightly

rustup target add wasm32-unknown-unknown

rustup component add llvm-tools-preview

rustup update

Create a new Rust library.

cargo new --lib my-yare-bot

Put this in your Cargo.toml.

[lib]

crate-type = ["cdylib"]



[dependencies]

yareio = "0.1.1"



[profile.release]

opt-level = "s"

lto = true

Then copy wasm2yareio.js from the linked submodule into your project and install a dependency. Make sure your Node is up-to-date.

npm i minify

Example

This is an example bot. You need to define an external function called tick that has one parameter. This will be called every tick.

#[no_mangle]
pub extern "C" fn tick(_tick: u32) {
    unsafe {
        let me = player::me();
        let Position {x, y} = base::position(0);
        for index in 0..spirit::count() {
            if spirit::player_id(index) == me && spirit::hp(index) > 0 {
                spirit::goto(index, x, y);
            }
        }
    }
}

You should make safe wrappers for these function so that you don't have to have unsafe blocks in your bot code. For example, you could do something like this:

use std::ffi::CString;
use yareio::spirit;
use yareio::player;

/// Your own Spirit struct with all the information you want.
struct Spirit {
    index: usize,
    alive: bool,
    friendly: bool,
}

impl Spirit {
    /// Safe wrapper for moving a spirit.
    fn goto(&self, x: f32, y: f32) {
        unsafe { spirit::goto(self.index, x, y) }
    }

    /// Safe wrapper for using shout.
    fn shout(&self, string: &str) {
        let c_string = CString::new(string).unwrap();
        unsafe { spirit::shout(self.index, c_string.as_ptr()) }
    }
}

/// Parse all spirits into your own Spirit structs.
fn get_spirits() -> Vec<Spirit> {
    unsafe {
        let me = player::me();
        let count = spirit::count();
        let mut spirits = Vec::with_capacity(count);
        for index in 0..count {
            spirits.push(Spirit {
                index,
                alive: spirit::hp(index) > 0,
                friendly: spirit::player_id(index) == me,
            });
        }
        spirits
    }
}

// No unsafe block needed here!
#[no_mangle]
pub extern "C" fn tick(_tick: u32) {
    let all_spirits = get_spirits();
    for spirit in all_spirits {
        if spirit.friendly && spirit.alive {
            spirit.goto(123., 456.);
            spirit.shout("Hello, world!");
        }
    }
}

Check out this template for an example of how you can structure your code!

Building

To build your yare bot, you first need to compile to wasm. Use this:

cargo rustc --target wasm32-unknown-unknown --release -- -C target-feature=+multivalue

Then you want to pass it through wasm2yareio.

node wasm2yareio target/wasm32-unknown-unknown/release/my-yare-bot.wasm

It is also recommended that you install the tampermonkey script to automatically upload your code to yare.io: Click to install.