1 files changed, 23 insertions, 0 deletions
diff --git a/src/Godosa.Core/Runs/FrameClock.cs b/src/Godosa.Core/Runs/FrameClock.cs
new file mode 100644
index 0000000..eedb78d
--- /dev/null
+++ b/src/Godosa.Core/Runs/FrameClock.cs
@@ -0,0 +1,23 @@
+namespace Godosa.Core.Runs;
+
+/// <summary>Game time per frame: deterministic → a fixed <see cref="Step"/> whatever the wall clock; otherwise the wall dt
+/// clamped to [0, maxDt]. <see cref="Held"/> (e.g. a map still loading) → no game time and no frame counted.</summary>
+public sealed class FrameClock(bool deterministic, double step = 1.0 / 60, double maxDt = 0.1)
+{
+    public bool Deterministic { get; } = deterministic;
+    public double Step { get; } = step;
+    public long Frame { get; private set; }
+    public double Seconds { get; private set; }
+    public bool Held { get; set; }
+
+    /// <summary>The game dt of this frame (0 when held); counts the frame unless held.</summary>
+    public double Next(double wallDt)
+    {
+        if (Held)
+            return 0;
+        var dt = Deterministic ? Step : Math.Clamp(wallDt, 0, maxDt);
+        Frame++;
+        Seconds += dt;
+        return dt;
+    }
+}