Improve Our Rust Skills

by making an ECS library

But First...Who Am I?

Technical Team Lead at Health Scholars

Worked in the IT industry for over 15 years

Including contracting at NASA as a systems administrator

Live-coding Rust based projects fun visualizations, and tutorials on Twitch.tv

How building an ECS Library will improve our skills?

Game Dev is a different domain

Game Dev is fun*

*your fun amount may vary

What is ECS?

	Player	Enemy	Tree	Another Enemy
Location	{x: 100.0, y: 200.0}	{x: 150.0, y: 200.0	{x: 200.0, y: 750.0}	{x: 450.0, y: 200.0}
Size	100.0	50.0	800.0	50.0
Health	100	10		10
Velocity	{x: 10.0, y: 0.0}	{x: -5.0, y: 0.0}		{x: -5.0, y: 0.0}

Features

	Player	Enemy	Tree	Another Enemy
Location	{x: 100.0, y: 200.0}	{x: 150.0, y: 200.0	{x: 200.0, y: 750.0}	{x: 450.0, y: 200.0}
Size	100.0	50.0	800.0	50.0
Health	100	10		10
Velocity	{x: 10.0, y: 0.0}	{x: -5.0, y: 0.0}		{x: -5.0, y: 0.0}

What does a system look like?

https://github.com/brooks-builds/zombie_simulator/blob/f01d1f81730c3bb427034dcebe80bb8c834e8df6/src/systems/update_location.rs#L8

We Need a Map

	Player	Enemy	Tree	Another Enemy
Location	{x: 100.0, y: 200.0}	{x: 150.0, y: 200.0	{x: 200.0, y: 750.0}	{x: 450.0, y: 200.0}
Size	100.0	50.0	800.0	50.0
Health	100	10		10
Velocity	{x: 10.0, y: 0.0}	{x: -5.0, y: 0.0}		{x: -5.0, y: 0.0}

	00001111	00001111	00000011	00001111

Location	00000001
Size	00000010
Health	00000100
Velocity	00001000

A Use for BitWise Operations

https://play.rust-lang.org/?version=stable&mode=debug&edition=2018&gist=9b446d704a611c05d94702f8bc136067

fn main() {
    let location_mask = 0b00000001;
    let size_mask =     0b00000010;
    let mut map = 0;
    
    // We insert a location for the entity
    map |= location_mask;
    dbg!(map);
    
    // Next we insert a size for the entity
    map |= size_mask;
    dbg!(map);
}