From c8c2a10c89b068ad6f1037ce51dadfa2bc165607 Mon Sep 17 00:00:00 2001
From: Muffin <muffin@muffin.ink>
Date: Sat, 2 Nov 2024 11:49:09 -0500
Subject: [PATCH] XeroName/Deltatime: don't report delta time of 0 (#1741)

If projects do things like "5 / delta time", they'll break horribly when
delta time is 0, so let's not return that.
---
 extensions/XeroName/Deltatime.js | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/extensions/XeroName/Deltatime.js b/extensions/XeroName/Deltatime.js
index bb99cc01dc..07c6b3eb3d 100644
--- a/extensions/XeroName/Deltatime.js
+++ b/extensions/XeroName/Deltatime.js
@@ -21,7 +21,15 @@
 
   vm.runtime.on("BEFORE_EXECUTE", () => {
     const now = performance.now();
-    deltaTime = previousTime === 0 ? 0 : (now - previousTime) / 1000;
+
+    if (previousTime === 0) {
+      // First frame. We used to always return 0 here, but that can break projects that
+      // expect delta time to always be non-zero. Instead we'll make our best guess.
+      deltaTime = 1 / vm.runtime.frameLoop.framerate;
+    } else {
+      deltaTime = (now - previousTime) / 1000;
+    }
+
     previousTime = now;
   });