I'm new to Rust, and Web assembly.
I am trying to do a run through of the game of life tutorial before going through it again to get a better understanding.
I think this tutorial needs updating, so if you help me get through it, I might make a YouTube video that helps others.
I'm stuck on this section.
https://rustwasm.github.io/docs/book/game-of-life/debugging.html
My .toml is unhappy with and addressing this is probably the best place to start.
[dependencies.web-sys]
version = "0.3"
features = [
"console",
]
This instruction on where to insert this isn't the clearest, so I have inserted utils::set_panic_hook(); at the TOP of the my pub fn new() -> Universe{} that I had already placed much earlier in the tutorial. It is instructed at the very beginning of this Debugging page.
And then I have no clue where to place:
extern crate web_sys;
// A macro to provide `println!(..)`-style syntax for `console.log` logging.
macro_rules! log {
( $( $t:tt )* ) => {
web_sys::console::log_1(&format!( $( $t )* ).into());
}
}
}
Here is my lib.rs, utils.rs and .toml file in their entirety,
[package]
name = "wasm-game-of-life"
version = "0.1.0"
authors = ["arschrader <arschrader@gmail.com>"]
edition = "2018"
[lib]
crate-type = ["cdylib", "rlib"]
[features]
default = ["console_error_panic_hook"]
[dependencies]
wasm-bindgen = "0.2.63"
[dependencies.web-sys]
version = "0.3"
features = [
"console",
]
# The `console_error_panic_hook` crate provides better debugging of panics by
# logging them with `console.error`. This is great for development, but requires
# all the `std::fmt` and `std::panicking` infrastructure, so isn't great for
# code size when deploying.
console_error_panic_hook = { version = "0.1.6", optional = true }
# `wee_alloc` is a tiny allocator for wasm that is only ~1K in code size
# compared to the default allocator's ~10K. It is slower than the default
# allocator, however.
#
# Unfortunately, `wee_alloc` requires nightly Rust when targeting wasm for now.
wee_alloc = { version = "0.4.5", optional = true }
[dev-dependencies]
wasm-bindgen-test = "0.3.13"
[profile.release]
# Tell `rustc` to optimize for small code size.
opt-level = "s"
lib.rs
mod utils;
use std::fmt;
use wasm_bindgen::prelude::*;
// When the `wee_alloc` feature is enabled, use `wee_alloc` as the global
// allocator.
#[cfg(feature = "wee_alloc")]
#[global_allocator]
static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
#[wasm_bindgen]
#[repr(u8)]
#[derive(Clone, Copy, Debug, PartialEq, Eq)]
pub enum Cell {
Dead = 0,
Alive = 1,
}
#[wasm_bindgen]
pub struct Universe {
width: u32,
height: u32,
cells: Vec<Cell>,
}
#[wasm_bindgen]
impl Universe {
pub fn tick(&mut self) {
let mut next = self.cells.clone();
for row in 0..self.height {
for col in 0..self.width {
let idx = self.get_index(row, col);
let cell = self.cells[idx];
let live_neighbors = self.live_neighbor_count(row, col);
let next_cell = match (cell, live_neighbors) {
// Rule 1: Any live cell with fewer than two live neighbours
// dies, as if caused by underpopulation.
(Cell::Alive, x) if x < 2 => Cell::Dead,
// Rule 2: Any live cell with two or three live neighbours
// lives on to the next generation.
(Cell::Alive, 2) | (Cell::Alive, 3) => Cell::Alive,
// Rule 3: Any live cell with more than three live
// neighbours dies, as if by overpopulation.
(Cell::Alive, x) if x > 3 => Cell::Dead,
// Rule 4: Any dead cell with exactly three live neighbours
// becomes a live cell, as if by reproduction.
(Cell::Dead, 3) => Cell::Alive,
// All other cells remain in the same state.
(otherwise, _) => otherwise,
};
next[idx] = next_cell;
}
}
self.cells = next;
}
fn get_index(&self, row: u32, column: u32) -> usize {
(row * self.width + column) as usize
}
fn live_neighbor_count(&self, row: u32, column: u32) -> u8 {
let mut count = 0;
for delta_row in [self.height - 1, 0, 1].iter().cloned() {
for delta_col in [self.width - 1, 0, 1].iter().cloned() {
if delta_row == 0 && delta_col == 0 {
continue;
}
let neighbor_row = (row + delta_row) % self.height;
let neighbor_col = (column + delta_col) % self.width;
let idx = self.get_index(neighbor_row, neighbor_col);
count += self.cells[idx] as u8;
}
}
count
}
pub fn new() -> Universe {
let width = 64;
let height = 64;
utils::set_panic_hook();
let cells = (0..width * height)
.map(|i| {
if i % 2 == 0 || i % 7 == 0 {
Cell::Alive
} else {
Cell::Dead
}
})
.collect();
Universe {
width,
height,
cells,
}
}
pub fn render(&self) -> String {
self.to_string()
}
pub fn width(&self) -> u32 {
self.width
}
pub fn height(&self) -> u32 {
self.height
}
pub fn cells(&self) -> *const Cell {
self.cells.as_ptr()
}
/// Set the width of the universe.
///
/// Resets all cells to the dead state.
pub fn set_width(&mut self, width: u32) {
self.width = width;
self.cells = (0..width * self.height).map(|_i| Cell::Dead).collect();
}
/// Set the height of the universe.
///
/// Resets all cells to the dead state.
pub fn set_height(&mut self, height: u32) {
self.height = height;
self.cells = (0..self.width * height).map(|_i| Cell::Dead).collect();
}
}
impl Universe {
/// Get the dead and alive values of the entire universe.
pub fn get_cells(&self) -> &[Cell] {
&self.cells
}
/// Set cells to be alive in a universe by passing the row and column
/// of each cell as an array.
pub fn set_cells(&mut self, cells: &[(u32, u32)]) {
for (row, col) in cells.iter().cloned() {
let idx = self.get_index(row, col);
self.cells[idx] = Cell::Alive;
}
}}
impl fmt::Display for Universe {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for line in self.cells.as_slice().chunks(self.width as usize) {
for &cell in line {
let symbol = if cell == Cell::Dead { '◻' } else { '◼' };
write!(f, "{}", symbol)?;
}
write!(f, "\n")?;
}
Ok(())
}
}
utils.rs
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();
}
Thank you.