use std::time::{Duration, Instant}; #[derive(Debug)] pub struct Timer { pub t: f32, frame: u32, last_report_time: Instant, last_report_frame: u32, accum_draw_time: Duration, accum_idle_time: Duration, pub pause: bool, } impl Timer { pub fn new() -> Self { let now = Instant::now(); Timer { t: 0.0, frame: 0, last_report_time: now, last_report_frame: 0, accum_draw_time: Duration::default(), accum_idle_time: Duration::default(), pause: false, } } pub fn update(&mut self) { let now = Instant::now(); if !self.pause { // Increment time self.t += 0.01; self.frame += 1; } self.maybe_report(now); } #[cfg(not(feature = "logging"))] fn maybe_report(&mut self, _: Instant) {} #[cfg(feature = "logging")] fn maybe_report(&mut self, now: Instant) { if now - self.last_report_time > Duration::from_secs(5) { self.report(now); self.last_report_time = now; self.last_report_frame = self.frame; self.accum_draw_time = Duration::new(0, 0); self.accum_idle_time = Duration::new(0, 0); } } #[cfg(feature = "logging")] fn report(&self, now: Instant) { fn millis(d : Duration) -> f32 { d.as_secs() as f32 * 1e3 + d.subsec_nanos() as f32 / 1e6 } let frames_done = self.frame - self.last_report_frame; let fps = frames_done as f32 / (now - self.last_report_time).as_secs() as f32; let avg_draw_time = millis(self.accum_draw_time / frames_done); let avg_idle_time = millis(self.accum_idle_time / frames_done); println!("fps={:.1} draw={:.1}ms idle={:.1}ms", fps, avg_draw_time, avg_idle_time); } }