scissor attempt

uidev/src/rate_limiter.rs

@@ -0,0 +1,37 @@
+use crate::timestep::get_micros;
+
+#[derive(Default)]
+pub struct RateLimiter {
+	rate: u16,
+	start_us: u64,
+	end_us: u64,
+}
+
+impl RateLimiter {
+	pub fn new() -> Self {
+		Self {
+			rate: 0,
+			end_us: 0,
+			start_us: 0,
+		}
+	}
+
+	pub fn start(&mut self, rate: u16) {
+		self.rate = rate;
+		self.start_us = get_micros();
+	}
+
+	pub fn end(&mut self) {
+		if self.rate == 0 {
+			return;
+		}
+
+		self.end_us = get_micros();
+		let microseconds = self.end_us - self.start_us;
+		let frametime_microseconds = ((1000.0 / self.rate as f32) * 1000.0) as u64;
+		let delay = frametime_microseconds as i64 - microseconds as i64;
+		if delay > 0 {
+			std::thread::sleep(std::time::Duration::from_micros(delay as u64));
+		}
+	}
+}