Handle NaNs in diagnostics

crates/bevy_diagnostic/src/diagnostic.rs

@@ -107,7 +107,7 @@ impl std::fmt::Display for DiagnosticPath {
 }
 
 /// A single measurement of a [`Diagnostic`].
-#[derive(Debug)]
+#[derive(Debug, Copy, Clone)]
 pub struct DiagnosticMeasurement {
  pub time: Instant,
  pub value: f64,
@@ -130,7 +130,9 @@ pub struct Diagnostic {
 impl Diagnostic {
  /// Add a new value as a [`DiagnosticMeasurement`].
  pub fn add_measurement(&mut self, measurement: DiagnosticMeasurement) {
- if let Some(previous) = self.measurement() {
+ if measurement.value.is_nan() {
+ // Do nothing about the ema.
+ } else if let Some(previous) = self.measurement() {
  let delta = (measurement.time - previous.time).as_secs_f64();
  let alpha = (delta / self.ema_smoothing_factor).clamp(0.0, 1.0);
  self.ema += alpha * (measurement.value - self.ema);
@@ -139,16 +141,24 @@ impl Diagnostic {
  }
 
  if self.max_history_length > 1 {
- if self.history.len() == self.max_history_length {
+ if self.history.len() >= self.max_history_length {
  if let Some(removed_diagnostic) = self.history.pop_front() {
- self.sum -= removed_diagnostic.value;
+ if !removed_diagnostic.value.is_nan() {
+ self.sum -= removed_diagnostic.value;
+ }
  }
  }
 
- self.sum += measurement.value;
+ if measurement.value.is_nan() {
+ self.sum += measurement.value;
+ }
  } else {
  self.history.clear();
- self.sum = measurement.value;
+ if measurement.value.is_nan() {
+ self.sum = 0.0;
+ } else {
+ self.sum = measurement.value;
+ }
  }
 
  self.history.push_back(measurement);
@@ -172,8 +182,13 @@ impl Diagnostic {
  #[must_use]
  pub fn with_max_history_length(mut self, max_history_length: usize) -> Self {
  self.max_history_length = max_history_length;
- self.history.reserve(self.max_history_length);
- self.history.shrink_to(self.max_history_length);
+
+ // reserve/reserve_exact reserve space for n *additional* elements.
+ let expected_capacity = self
+ .max_history_length
+ .saturating_sub(self.history.capacity());
+ self.history.reserve_exact(expected_capacity);
+ self.history.shrink_to(expected_capacity);
  self
  }