====== Saturday, 30th April, 2022 ====== 

<wrap lo> This is the first dev log </wrap>
\\ Today I started this log I guess... The plan is two fold. I want to learn the [[https://bevyengine.org/ | bevy]] framework and also break down super letter linker to try and make an exact copy of it. I am a lazy, so lets see how well this goes!! 🤞🤞🤞

Bevy is a strange engine to me. I do not have any experience with entity component systems but this seems like a cool paradigm.I am mostly using it to use rust to compile down to web assembly. Rust makes me feel like a 90s hacker kid. ((also dokuwiki is pretty cool))

{{:devlogs:ecs_example.png?direct&400|}}

Everything I learn is basically a brain copy pasta of what is on [[https://bevyengine.org/learn/book/getting-started/ | this site]], so your better of reading that but if you so inclined for some god for-saken reason then yea keep reading..... bro. ((AGAIN EVERYTHING YOU READ HERE IS WRONG...jk.......)) ((or am i?))

==== ECS ====
== Basically I think ==

**Component** : Blocks of data that make sense. eg in bevy:
<code rust>
#[derive(Component)]
struct Person;
</code>



**Entity** : the objects them selves. They are made up of components. eg in bevy:
<code rust>
commands.spawn().insert(Person).insert(Name("Elaina Protractor".to_string()));
</code>
<wrap lo>The above code basically spawns an entity with a person and name component. \\ the name component takes a string as a parameter</wrap>



**Systems**: Systems transform the data in components. 
<code rust>
fn greet_people(query: Query<&Name, With<Person>>){
    for name in query.iter() {
        println!("hello {}!", name.0);
    }
}
</code>

<wrap lo>The above code is a system that loops through any entity with the components Name and Person and prints "Hello name"</wrap>

==== Plugins ====
Plugins are the life of bevy. Everything is a plugin the renderers, UI ect... We can add "DefaultPlugins" to include the basic shtuff and it will also make a window and make the game loop I think...

**To make our own plugin** 
<code rust> 
pub struct HelloPlugin;

impl Plugin for HelloPlugin {
    fn build(&self, app: &mut App) {
        app.add_startup_system(add_people)
            .add_system(hello_world)
            .add_system(greet_people);
    }
}
</code>

==== Resources ====
Resources are globally unique data of some kind.

<wrap lo> taken directly from book </wrap> \\
Here are some examples of data that could be encoded as Resources:

  * Elapsed Time
  * Asset Collections (sounds, textures, meshes)
  * Renderers

This example takes the above greet_people function and makes it repeat every 2 seconds by using the timer resource that the DefaultPlugins provide
<code rust>
fn greet_people(
    time: Res<Time>, mut timer: ResMut<GreetTimer>, query: Query<&Name, With<Person>>) {
    // update our timer with the time elapsed since the last update
    // if that caused the timer to finish, we say hello to everyone
    if timer.0.tick(time.delta()).just_finished() {
        for name in query.iter() {
            println!("hello {}!", name.0);
        }
    }
}
</code> 
\\

==== TUTORIAL - Snake ====
[[https://mbuffett.com/posts/bevy-snake-tutorial/ | following this link]]

I am following this tutorial to make a snake game to get an idea of how games are made in bevy while also seeing wtf rust is about.

== Some interesting snippits ==
**code for sizing sprites in our tile system**
<code rust>
fn size_scaling(windows: Res<Windows>, mut q: Query<(&Size, &mut Transform)>) {
    let window = windows.get_primary().unwrap();
    for (sprite_size, mut transform) in q.iter_mut() {
        transform.scale = Vec3::new(
            sprite_size.width / ARENA_WIDTH as f32 * window.width() as f32,
            sprite_size.height / ARENA_HEIGHT as f32 * window.height() as f32,
            1.0,
        );
    }
}
</code>

The sizing logic goes like so: if something has a width of 1 in a grid of 40, and the window is 400px across, then it should have a width of 10.
\\
\\

Im gonna leave this at here for now and pick it up later

==== External links ====
[[https://bevyengine.org/examples | examples]] \\
[[https://docs.rs/bevy/latest/bevy/ | docs]] \\
[[https://github.com/bevyengine/bevy/blob/latest/examples/games/breakout.rs | breakout source example]] \\
[[https://bevyengine.org/assets/ | Plugins and Assets]] \\
[[https://bevy-cheatbook.github.io/ | Cheatbook]] \\ 

~~DISCUSSION | wagsonwasoff~~