boids-rs/src/boundary.rs

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.;

    const PADDING: f32 = 50.;

    let left_bound = -half_width - PADDING;
    let right_bound = half_width + PADDING;
    let top_bound = half_height + PADDING;
    let bottom_bound = -half_height - PADDING;

    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;
        }
    }
}