move boundary code to module

src/boid_mesh.rs

@@ -19,7 +19,7 @@ pub fn build_boid_mesh(mut meshes: ResMut<Assets<Mesh>>, mut boid_mesh: ResMut<B
 pub fn make_boid_mesh() -> Mesh {
     const TRIANGLE_HEIGHT: f32 = 10.;
     const TRIANGLE_WIDTH: f32 = 5.;
-    const STROKE_WIDTH: f32 = 0.25;
+    const STROKE_WIDTH: f32 = 0.5;
 
     const HALF_HEIGHT: f32 = TRIANGLE_HEIGHT / 2.0;
     const HALF_WIDTH: f32 = TRIANGLE_WIDTH / 2.0;

src/boundary.rs

@@ -0,0 +1,39 @@
+use super::Boid;
+use bevy::prelude::*;
+
+pub(crate) fn boid_border_teleport(
+    mut boids: Query<&mut Transform, With<Boid>>,
+    windows: Query<&Window>,
+) {
+    let window = windows.get_single().unwrap();
+    let width = window.resolution.width();
+    let height = window.resolution.height();
+
+    let half_width = width / 2.;
+    let half_height = height / 2.;
+
+    let left_bound = -half_width;
+    let right_bound = half_width;
+    let top_bound = half_height;
+    let bottom_bound = -half_height;
+
+    for mut boid_transform in &mut boids {
+        let translation = &mut boid_transform.translation;
+
+        if translation.y > top_bound {
+            translation.y = bottom_bound;
+        }
+
+        if translation.y < bottom_bound {
+            translation.y = top_bound;
+        }
+
+        if translation.x < left_bound {
+            translation.x = right_bound;
+        }
+
+        if translation.x > right_bound {
+            translation.x = left_bound;
+        }
+    }
+}

src/main.rs

@@ -1,4 +1,5 @@
 mod boid_mesh;
+mod boundary;
 
 use bevy::{color::palettes::tailwind, prelude::*, sprite::MaterialMesh2dBundle};
 use boid_mesh::BoidMesh;
@@ -8,7 +9,7 @@ fn main() {
         .init_resource::<BoidMesh>()
         .add_plugins(DefaultPlugins)
         .add_systems(Startup, (boid_mesh::build_boid_mesh, setup).chain())
-        .add_systems(Update, move_boids)
+        .add_systems(Update, (move_boids, boundary::boid_border_teleport).chain())
         .run();
 }
 
@@ -16,7 +17,7 @@ fn main() {
 struct Boid;
 
 #[derive(Component, Default)]
-struct Velocity(Vec3);
+struct Velocity(Vec2);
 
 #[derive(Bundle, Default)]
 struct BoidBundle {
@@ -27,7 +28,7 @@ struct BoidBundle {
 
 fn move_boids(mut boids: Query<(&mut Transform, &Velocity), With<Boid>>, time: Res<Time>) {
     for (mut transform, velocity) in &mut boids {
-        transform.translation += velocity.0 * time.delta_seconds();
+        transform.translation += velocity.0.extend(0.) * time.delta_seconds();
     }
 }
 
@@ -47,7 +48,7 @@ fn setup(
             transform: Transform::from_scale(Vec3::splat(2.5)),
             ..default()
         },
-        velocity: Velocity(Vec3::Y * 25.),
+        velocity: Velocity(Vec2::Y * 100.),
         ..default()
     });
 }