1 files changed, 43 insertions, 0 deletions
diff --git a/engine-ecs/src/time.rs b/engine-ecs/src/time.rs
new file mode 100644
index 0000000..3f888cb
--- /dev/null
+++ b/engine-ecs/src/time.rs
@@ -0,0 +1,43 @@
+use std::ops::Deref;
+use std::time::{Duration, Instant};
+
+use engine_ecs_macros::Sole;
+
+use crate::sole::Single;
+
+#[derive(Debug, Sole)]
+#[non_exhaustive]
+pub struct Time
+{
+    /// Time passed since the beginning of the previous tick.
+    pub delta_time: Duration,
+
+    /// Time at the beginning of the current tick.
+    pub tick_begin: Option<Instant>,
+}
+
+impl Deref for Single<'_, Time>
+{
+    type Target = Time;
+
+    fn deref(&self) -> &Self::Target
+    {
+        let Ok(time) = self.get() else {
+            // Time is always created by World::new
+            unreachable!();
+        };
+
+        time
+    }
+}
+
+pub(crate) fn update(time: &mut Time)
+{
+    let current_time = Instant::now();
+
+    let tick_begin = time.tick_begin.get_or_insert(current_time);
+
+    time.delta_time = current_time.duration_since(*tick_begin);
+
+    time.tick_begin = Some(current_time);
+}