refactor: encapsulate funcionalities (#5)

* wip: create plugins

* refactor: separate logic into files

* fix: structure

src/algae.rs

@@ -0,0 +1,56 @@
+use crate::components::*;
+use crate::resources::*;
+use bevy::prelude::*;
+use rand::*;
+
+#[derive(Component)]
+pub struct Algae;
+#[derive(Bundle)]
+pub struct AlgaeBundle {
+    pub(crate) position: Position,
+    pub(crate) sprite: SpriteBundle,
+    pub(crate) algae_component: Algae,
+}
+
+pub struct AlgaePlugin;
+impl Plugin for AlgaePlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Startup, algae_setup)
+            .add_systems(Update, algae_update);
+    }
+}
+
+fn algae_setup(mut commands: Commands, asset_server: Res<AssetServer>) {
+    for _ in 0..10 {
+        let start_pos = Vec2::new(
+            rand::thread_rng().gen_range(-300.0..300.0),
+            rand::thread_rng().gen_range(-300.0..300.0),
+        );
+        commands.spawn(AlgaeBundle {
+            algae_component: Algae,
+            position: Position { v2: start_pos },
+            sprite: SpriteBundle {
+                texture: asset_server.load("embedded://fish-forage/algae.png"),
+                transform: Transform::from_scale(Vec3::splat(1.)),
+                ..default()
+            },
+        });
+    }
+}
+
+fn algae_update(
+    time: Res<Time>,
+    mut timer: ResMut<ChangeObjectiveTimer>,
+    mut algae_query: Query<(&mut Transform, &mut Position), With<Algae>>,
+) {
+    if timer.0.tick(time.delta()).finished() {
+        for (mut transform, mut position) in &mut algae_query {
+            let new_pos = Vec2::new(
+                rand::thread_rng().gen_range(-300.0..300.0),
+                rand::thread_rng().gen_range(-300.0..300.0),
+            );
+            transform.translation = Vec3::new(new_pos.x, new_pos.y, 0.);
+            position.v2 = new_pos;
+        }
+    }
+}

src/components.rs

@@ -0,0 +1,16 @@
+use bevy::prelude::*;
+
+#[derive(Component, Debug, Clone, Copy, PartialEq)]
+pub struct Velocity {
+    pub v2: Vec2,
+}
+
+#[derive(Component, Debug, Clone, Copy, PartialEq)]
+pub struct Position {
+    pub v2: Vec2,
+}
+
+#[derive(Component, Debug, Clone, Copy, PartialEq)]
+pub struct Objective {
+    pub v2: Vec2,
+}

src/fish.rs

@@ -0,0 +1,82 @@
+use bevy::{math::bounding::Aabb2d, prelude::*};
+use rand::*;
+
+use crate::components::*;
+
+#[derive(Component)]
+pub struct Fish;
+#[derive(Bundle)]
+pub struct FishBundle {
+    pub(crate) velocity: Velocity,
+    pub(crate) position: Position,
+    pub(crate) objective: Objective,
+    pub(crate) sprite: SpriteBundle,
+    pub(crate) fish_component: Fish,
+}
+
+pub struct FishPlugin;
+impl Plugin for FishPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(Startup, fish_setup)
+            .add_systems(Update, fish_update);
+    }
+}
+
+fn fish_setup(mut commands: Commands, asset_server: Res<AssetServer>) {
+    for _ in 0..10 {
+        let start_pos = Vec2::new(
+            rand::thread_rng().gen_range(-300.0..300.0),
+            rand::thread_rng().gen_range(-300.0..300.0),
+        );
+        commands.spawn(FishBundle {
+            position: Position { v2: start_pos },
+            velocity: Velocity { v2: Vec2::ZERO },
+            objective: Objective { v2: start_pos },
+            sprite: SpriteBundle {
+                texture: asset_server.load("embedded://fish-forage/fish-sardine.png"),
+                transform: Transform::from_scale(Vec3::splat(2.)),
+                ..default()
+            },
+            fish_component: Fish,
+        });
+    }
+}
+
+fn fish_update(
+    time: Res<Time>,
+    windows: Query<&Window>,
+    algae_query: Query<&Position, Without<Fish>>,
+    mut fish_query: Query<
+        (&mut Velocity, &mut Position, &mut Objective, &mut Transform),
+        With<Fish>,
+    >,
+) {
+    let window = windows.single();
+    let window_size = window.size();
+    let collision_area = Aabb2d::new(Vec2::ZERO, (window_size - 5.0) / 2.);
+
+    let mut algae_iter = algae_query.iter();
+
+    for (mut v, mut p, mut o, mut transform) in &mut fish_query {
+        if let Some(algae_position) = algae_iter.next() {
+            o.v2 = algae_position.v2;
+        } else {
+            // If there are more fish than algae, reset the algae iterator
+            algae_iter = algae_query.iter();
+            if let Some(algae_position) = algae_iter.next() {
+                o.v2 = algae_position.v2;
+            }
+        }
+
+        p.v2 += v.v2 * time.delta_seconds();
+        p.v2.x = p.v2.x.clamp(collision_area.min.x, collision_area.max.x);
+        p.v2.y = p.v2.y.clamp(collision_area.min.y, collision_area.max.y);
+
+        let acc = 100. * (o.v2 - p.v2).normalize_or_zero();
+        v.v2 += acc * time.delta_seconds();
+
+        v.v2 = v.v2.clamp_length_max(80.);
+
+        transform.translation = Vec3::new(p.v2.x, p.v2.y, 0.);
+    }
+}

src/main.rs

@@ -1,124 +1,25 @@
-use std::time::Duration;
+use bevy::prelude::*;
+use bevy_embedded_assets::*;
 
-use bevy::{math::bounding::Aabb2d, prelude::*};
-use bevy_embedded_assets::EmbeddedAssetPlugin;
-use rand::Rng;
+mod algae;
+mod components;
+mod fish;
+mod resources;
+use algae::*;
+use fish::*;
+use resources::*;
 
 fn main() {
     App::new()
         .add_plugins(DefaultPlugins)
         .add_plugins(EmbeddedAssetPlugin::default())
-        .add_systems(Startup, setup)
-        .add_systems(Update, (swim, move_algae))
-        .insert_resource(ChangeObjectiveTimer(Timer::from_seconds(
-            5.0,
-            TimerMode::Repeating,
-        )))
+        .add_systems(Startup, camera_setup)
+        .add_plugins(FishPlugin)
+        .add_plugins(AlgaePlugin)
+        .add_plugins(TimerPlugin)
         .run();
 }
 
-#[derive(Component)]
-struct Swimmer {
-    position: Vec2,
-    velocity: Vec2,
-    objective: Vec2,
-}
-
-#[derive(Resource)]
-struct ChangeObjectiveTimer(Timer);
-
-#[derive(Component)]
-struct Algae;
-
-fn setup(
-    mut commands: Commands,
-    asset_server: Res<AssetServer>,
-    mut timer: ResMut<ChangeObjectiveTimer>,
-) {
-    timer.0.tick(Duration::from_secs_f32(4.9));
-
+fn camera_setup(mut commands: Commands) {
     commands.spawn(Camera2dBundle::default());
-    for _ in 0..10 {
-        let start_pos = Vec2::new(
-            rand::thread_rng().gen_range(-300.0..300.0),
-            rand::thread_rng().gen_range(-300.0..300.0),
-        );
-        commands.spawn((
-            SpriteBundle {
-                texture: asset_server.load("embedded://fish-forage/fish-sardine.png"),
-                transform: Transform::from_scale(Vec3::splat(2.)),
-                ..default()
-            },
-            Swimmer {
-                position: start_pos,
-                velocity: Vec2::ZERO,
-                objective: start_pos,
-            },
-        ));
-    }
-
-    commands.spawn((
-        SpriteBundle {
-            texture: asset_server.load("embedded://fish-forage/algae.png"),
-            transform: Transform::from_scale(Vec3::splat(2.)),
-            ..default()
-        },
-        Algae,
-    ));
-}
-
-fn swim(
-    time: Res<Time>,
-    windows: Query<&Window>,
-    mut fish_query: Query<(&mut Swimmer, &mut Transform)>,
-) {
-    let window = windows.single();
-    let window_size = window.size();
-    let collision_area = Aabb2d::new(Vec2::ZERO, (window_size - 5.0) / 2.);
-
-    for (mut swimmer, mut transform) in &mut fish_query {
-        let v = swimmer.velocity;
-        swimmer.position += v * time.delta_seconds();
-
-        swimmer.position.x = swimmer
-            .position
-            .x
-            .clamp(collision_area.min.x, collision_area.max.x);
-        swimmer.position.y = swimmer
-            .position
-            .y
-            .clamp(collision_area.min.y, collision_area.max.y);
-
-        let acc = 100. * (swimmer.objective - swimmer.position).normalize_or_zero();
-        swimmer.velocity += acc * time.delta_seconds();
-
-        swimmer.velocity = swimmer.velocity.clamp_length_max(80.);
-
-        transform.translation = Vec3::new(swimmer.position.x, swimmer.position.y, 0.);
-
-        // println!(
-        //     "position: {:?}, velocity: {:?}",
-        //     swimmer.position, swimmer.velocity
-        // );
-    }
-}
-
-fn move_algae(
-    time: Res<Time>,
-    mut timer: ResMut<ChangeObjectiveTimer>,
-    mut swimmer_query: Query<&mut Swimmer>,
-    mut algae_query: Query<&mut Transform, With<Algae>>,
-) {
-    if timer.0.tick(time.delta()).just_finished() {
-        for mut algae in &mut algae_query {
-            let new_pos = Vec2::new(
-                rand::thread_rng().gen_range(-300.0..300.0),
-                rand::thread_rng().gen_range(-300.0..300.0),
-            );
-            algae.translation = Vec3::new(new_pos.x, new_pos.y, 0.);
-            for mut swimmer in &mut swimmer_query {
-                swimmer.objective = new_pos;
-            }
-        }
-    }
 }

src/resources.rs

@@ -0,0 +1,21 @@
+use bevy::prelude::*;
+use std::time::Duration;
+
+#[derive(Resource)]
+pub struct ChangeObjectiveTimer(pub Timer);
+
+pub struct TimerPlugin;
+
+impl Plugin for TimerPlugin {
+    fn build(&self, app: &mut App) {
+        app.insert_resource(ChangeObjectiveTimer(Timer::from_seconds(
+            5.0,
+            TimerMode::Repeating,
+        )))
+        .add_systems(Update, update_timer);
+    }
+}
+
+fn update_timer(mut timer: ResMut<ChangeObjectiveTimer>) {
+    timer.0.tick(Duration::from_secs_f32(5.0));
+}