notedeck

One damus client to rule them all
git clone git://jb55.com/notedeck
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frame_history.rs (1362B)

      1 use egui::util::History;
      2 
      3 pub struct FrameHistory {
      4     frame_times: History<f32>,
      5 }
      6 
      7 impl Default for FrameHistory {
      8     fn default() -> Self {
      9         let max_age: f32 = 1.0;
     10         let max_len = (max_age * 300.0).round() as usize;
     11         Self {
     12             frame_times: History::new(0..max_len, max_age),
     13         }
     14     }
     15 }
     16 
     17 impl FrameHistory {
     18     // Called first
     19     pub fn on_new_frame(&mut self, now: f64, previous_frame_time: Option<f32>) {
     20         let previous_frame_time = previous_frame_time.unwrap_or_default();
     21         if let Some(latest) = self.frame_times.latest_mut() {
     22             *latest = previous_frame_time; // rewrite history now that we know
     23         }
     24         self.frame_times.add(now, previous_frame_time); // projected
     25     }
     26 
     27     pub fn mean_frame_time(&self) -> f32 {
     28         self.frame_times.average().unwrap_or_default()
     29     }
     30 
     31     pub fn fps(&self) -> f32 {
     32         1.0 / self.frame_times.mean_time_interval().unwrap_or_default()
     33     }
     34 
     35     pub fn _ui(&mut self, ui: &mut egui::Ui) {
     36         ui.label(format!(
     37             "Mean CPU usage: {:.2} ms / frame",
     38             1e3 * self.mean_frame_time()
     39         ))
     40         .on_hover_text(
     41             "Includes egui layout and tessellation time.\n\
     42             Does not include GPU usage, nor overhead for sending data to GPU.",
     43         );
     44         egui::warn_if_debug_build(ui);
     45     }
     46 }