Initial work on menus

src/menus/scaling.rs

@@ -0,0 +1,29 @@
+use bevy::camera::CameraProjection;
+use bevy::camera::Projection::Orthographic;
+use bevy::prelude::*;
+use bevy::window::WindowResized;
+
+fn compute_ui_scale(window_size: Vec2) -> f32 {
+    const BASE_SIZE: Vec2 = Vec2::new(1920.0, 1080.0);
+    const BASE_ASPECT_RATIO: f32 = BASE_SIZE.x / BASE_SIZE.y;
+    let new_aspect_ratio = window_size.x / window_size.y;
+    if new_aspect_ratio > BASE_ASPECT_RATIO {
+        window_size.y / BASE_SIZE.y
+    } else {
+        window_size.x / BASE_SIZE.x
+    }
+}
+
+pub fn ui_update_scale_on_startup(window: Single<&Window>, mut ui_scale: ResMut<UiScale>) {
+    ui_scale.0 = compute_ui_scale(window.size()); 
+}
+
+pub fn ui_scaling_system(mut resize_reader: MessageReader<WindowResized>, mut ui_scale: ResMut<UiScale>) {
+
+    for event in resize_reader.read() {
+        let dimensions = Vec2::new(event.width, event.height);
+        *ui_scale = UiScale(compute_ui_scale(dimensions));
+        
+        break
+    }
+}