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#[macro_export]
macro_rules! fixedstep_loop {
{
Step($ticks:expr, $skip:expr),
Update => $Update:block,
Render($delta:pat) => $Render:block,
} => {
{
use std::time::{Duration, Instant};
let ticks = 1.0 / $ticks as f64;
let ticks_s = ticks as u64;
let ticks_ns = (ticks.fract() * 1000_000_000.0) as u32;
let update_interval = Duration::new(ticks_s, ticks_ns);
let skip_threshold: i32 = 3;
let mut last = Instant::now();
let mut accumulator = Duration::new(0, 0);
let mut should_close = false;
while !should_close
{
let now = Instant::now();
accumulator += now - last;
last = now;
let mut update_count = 0;
while accumulator > update_interval && update_count < skip_threshold
{
should_close = $Update;
update_count += 1;
accumulator -= update_interval;
}
if $skip && accumulator > update_interval
{
accumulator = Duration::new(0, 0);
}
let elapsed = last.elapsed();
let $delta = ((elapsed.as_secs() as f64 + elapsed.subsec_nanos() as f64 / 1000_000_000.0) / ticks).min(1.0);
$Render
}
}
};
{
Step($ticks:expr),
Update => $Update:block,
Render($delta:pat) => $Render:block,
} => {
fixedstep_loop!(
Step($ticks, true),
Update => $Update,
Render($delta) => $Render,
)
};
{
Update => $Update:block,
Render($delta:pat) => $Render:block,
} => {
fixedstep_loop!(
Step(60),
Update => $Update,
Render($delta) => $Render,
)
};
}