race strategy

src/main.rs

@@ -375,6 +375,23 @@ impl eframe::App for AppUi {
                         .unwrap_or(Duration::from_secs(0))
                         .as_secs_f32()
                 ));
+
+                if let Some(race) = &state.current_race {
+                    ui.separator();
+                    ui.heading("Strategy");
+                    if let Some(tyre_wear) = race.tyre_wear() {
+                        ui.heading(&format!("p50 Tyre Wear: {}", tyre_wear));
+                        if let Some(tyres) = frame.tyres {
+                            ui.label(&format!("Out of tires in {:.1} lap(s)", (tyres as f64) / (tyre_wear as f64)));
+                        }
+                    }
+                    if let Some(gas_wear) = race.gas_per_lap() {
+                        ui.heading(&format!("p50 Gas Wear: {}", gas_wear));
+                        if let Some(gas) = frame.gas {
+                            ui.label(&format!("Out of gas in {:.1} lap(s)", (gas as f64) / (gas_wear as f64)));
+                        }
+                    }
+                }
             }
 
             ui.separator();

src/state.rs

@@ -63,6 +63,21 @@ impl LapState {
     }
 }
 
+fn median_wear(values: Vec<Option<usize>>) -> Option<usize> {
+    let mut wear_values = Vec::new();
+    let mut last_value = 100;
+    for val in values {
+        if let Some(val) = val {
+            if val < last_value {
+                wear_values.push(last_value - val);
+            }
+            last_value = val;
+        }
+    }
+    wear_values.sort();
+    wear_values.get(wear_values.len() / 2).cloned()
+}
+
 #[derive(Default)]
 pub struct RaceState {
     pub race_time: Option<SystemTime>,
@@ -94,6 +109,14 @@ impl RaceState {
     pub fn fastest_lap(&self) -> Option<Duration> {
         self.laps.iter().filter_map(|lap| lap.lap_time).min()
     }
+
+    pub fn tyre_wear(&self) -> Option<usize> {
+        median_wear(self.laps.iter().map(|lap| lap.tyres).collect())
+    }
+
+    pub fn gas_per_lap(&self) -> Option<usize> {
+        median_wear(self.laps.iter().map(|lap| lap.gas).collect())
+    }
 }
 
 pub struct DebugOcrFrame {