add update_gauges system (dummy data for now)

src/hud.rs

@@ -42,6 +42,7 @@ impl Plugin for HudPlugin {
             update_hud,
             update_dashboard,
             update_speedometer,
+            update_gauges,
             handle_input,
             handle_target_event,
         ));
@@ -84,6 +85,7 @@ impl Plugin for HudPlugin {
 #[derive(Component)] struct Speedometer2;
 #[derive(Component)] struct Dashboard;
 #[derive(Component)] struct DashboardFlashlight;
+#[derive(Component)] struct GaugeLength(f32);
 #[derive(Component)] pub struct ToggleableHudElement;
 #[derive(Component)] pub struct ToggleableHudMapElement;
 #[derive(Component)] struct Selectagon;
@@ -386,6 +388,7 @@ fn setup(
                     ..Default::default()
                 },
                 gauge.clone(),
+                GaugeLength(bar_length),
             ));
         });
 
@@ -662,6 +665,27 @@ fn update_speedometer(
     }
 }
 
+fn update_gauges(
+    mut q_gauges: Query<(&mut Style, &mut BackgroundColor, &Gauge, &GaugeLength)>,
+    settings: Res<var::Settings>,
+) {
+    for (mut style, mut bg, gauge, len) in &mut q_gauges {
+        let value = match gauge {
+            Gauge::Health => 0.9,
+            Gauge::Oxygen => 0.1,
+            Gauge::Fuel => 0.3,
+            Gauge::Power => 1.0,
+        };
+        if value < 0.5 {
+            *bg = settings.hud_color_alert.into();
+        }
+        else {
+            *bg = settings.hud_color.into();
+        }
+        style.width = Val::Px(len.0 * value);
+    }
+}
+
 fn update_hud(
     diagnostics: Res<DiagnosticsStore>,
     time: Res<Time>,