1 files changed, 67 insertions, 0 deletions
diff --git a/graphics/src/timer.rs b/graphics/src/timer.rs
new file mode 100644
index 0000000..8310776
--- /dev/null
+++ b/graphics/src/timer.rs
@@ -0,0 +1,67 @@
+use std::{
+	ops::{Add, Div, Mul},
+	time::{Duration, Instant},
+};
+
+/// How often to update the fps interval on screen
+const FPS_INTERVAL: Duration = Duration::from_millis(250);
+
+/// How much to smooth he `delta_avg` amount (`AVG_RATIO`:1)
+const AVG_RATIO: u32 = 10;
+
+/// Keeps track of frame intervals and FPS
+pub struct Timer {
+	/// Last time updated
+	previous: Instant,
+	/// Current time
+	now: Instant,
+	/// Rolling delta time average
+	delta_avg: Duration,
+	/// Computed fps
+	fps: f64,
+	/// Last time the fps was updated
+	fps_time: Instant,
+	/// Frame count
+	count: u32,
+}
+impl Timer {
+	pub fn new() -> Self {
+		let now = Instant::now();
+		Self {
+			previous: now,
+			now,
+			delta_avg: Duration::ZERO,
+			fps: 0.0,
+			fps_time: now,
+			count: 0,
+		}
+	}
+
+	pub fn update(&mut self) {
+		self.previous = self.now;
+		self.now = Instant::now();
+		self.delta_avg = self
+			.delta_avg
+			.mul(AVG_RATIO)
+			.add(self.delta_time())
+			.div(AVG_RATIO + 1);
+		if (self.now - self.fps_time) > FPS_INTERVAL {
+			self.fps = 1.0 / self.delta_avg.as_secs_f64();
+			self.fps_time = self.now;
+		}
+		self.count += 1;
+	}
+
+	pub fn get_frame(&self) -> u32 {
+		self.count
+	}
+
+	#[expect(clippy::cast_possible_truncation)]
+	pub fn get_fps(&self) -> u32 {
+		self.fps.ceil() as u32
+	}
+
+	pub fn delta_time(&self) -> Duration {
+		self.now - self.previous
+	}
+}