move uidev to workspace root

uidev/src/timestep.rs

@@ -0,0 +1,70 @@
+use std::{sync::LazyLock, time::Instant};
+static TIME_START: LazyLock<Instant> = LazyLock::new(Instant::now);
+
+pub fn get_micros() -> u64 {
+	TIME_START.elapsed().as_micros() as u64
+}
+
+#[derive(Default)]
+pub struct Timestep {
+	current_time_us: u64,
+	accumulator: f32,
+	time_micros: u64,
+	ticks: u32,
+	speed: f32,
+	pub alpha: f32,
+	delta: f32,
+	loopnum: u8,
+}
+
+impl Timestep {
+	pub fn new() -> Timestep {
+		let mut timestep = Timestep {
+			speed: 1.0,
+			..Default::default()
+		};
+
+		timestep.reset();
+		timestep
+	}
+
+	fn calculate_alpha(&mut self) {
+		self.alpha = (self.accumulator / self.delta).clamp(0.0, 1.0);
+	}
+
+	pub fn set_tps(&mut self, tps: f32) {
+		self.delta = 1000.0 / tps;
+	}
+
+	pub fn reset(&mut self) {
+		self.current_time_us = get_micros();
+		self.accumulator = 0.0;
+	}
+
+	pub fn on_tick(&mut self) -> bool {
+		let newtime = get_micros();
+		let frametime = newtime - self.current_time_us;
+		self.time_micros += frametime;
+		self.current_time_us = newtime;
+		self.accumulator += frametime as f32 * self.speed / 1000.0;
+		self.calculate_alpha();
+
+		if self.accumulator >= self.delta {
+			self.accumulator -= self.delta;
+			self.loopnum += 1;
+			self.ticks += 1;
+
+			if self.loopnum > 5 {
+				// cannot keep up!
+				self.loopnum = 0;
+				self.accumulator = 0.0;
+				return false;
+			}
+
+			true
+		} else {
+			self.loopnum = 0;
+			false
+		}
+	}
+}