Crate framepace 

Rolling frame-time statistics for game loops and real-time applications.

framepace tracks per-frame wall-time durations in a fixed-size ring buffer and exposes mean, min, max, and percentile (p50, p95, p99) statistics over the window. There is no rendering, no rate-limiting, and no loop control — just measurement.

Quick start

use framepace::FrameTimer;

let mut timer: FrameTimer = FrameTimer::new();

// At the top of every tick:
timer.begin_frame();

// Query at any point:
if let Some(stats) = timer.stats() {
    println!("fps={:.1}  avg={:.2}ms  p95={:.2}ms", stats.fps, stats.avg_ms, stats.p95_ms);
}

Named phases

Break down where time goes within a frame using RAII phase guards:

use framepace::FrameTimer;

let mut timer: FrameTimer = FrameTimer::new();
timer.begin_frame();

{
    let _update = timer.phase("update");
    // ... update logic ...
} // guard drops here, recording the elapsed time

{
    let _render = timer.phase("render");
    // ... render logic ...
}

if let Some(stats) = timer.phase_stats("render") {
    println!("render p95={:.2}ms", stats.p95_ms);
}

Custom time sources

The default DefaultTime uses std::time::Instant. Implement TimeSource to use a higher-precision clock (e.g. TSC via the quanta crate) or to adapt to platforms where Instant is unavailable:

use framepace::{FrameTimer, TimeSource};

struct QuantaTime;

impl TimeSource for QuantaTime {
    fn now_us() -> u64 {
        // e.g. quanta::Instant::now().as_u64() / 1_000
        0 // placeholder
    }
}

let mut timer: FrameTimer<64, QuantaTime> = FrameTimer::new();
timer.begin_frame();

Re-exports

pub use time::DefaultTime;

pub use time::TimeSource;

Modules

time

Time source abstraction and the built-in StdTime implementation.

Structs

FrameStats

Frame-timing statistics computed over the current sample window.

FrameTimer

Rolling frame-time tracker with optional named sub-phase timers.

PhaseGuard

RAII guard that times a named sub-phase of a frame.

Constants

MAX_PHASES

Maximum number of named phases a FrameTimer can track simultaneously.