From 1155a70f99f8ac30fdb41311191db7566f714dfb Mon Sep 17 00:00:00 2001
From: Tobie Langel <tobie@codespeaks.com>
Date: Tue, 21 Feb 2017 09:07:04 +0100
Subject: [PATCH] Meta: Fix scroll jank

Debounce scroll events.
Only update the DOM during requestAnimationFrame.
Closes #314.
---
 index.bs | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/index.bs b/index.bs
index 5040a8d1..c83849d1 100644
--- a/index.bs
+++ b/index.bs
@@ -13108,6 +13108,7 @@ The following conformance classes are defined by this specification:
             options = options || {};
 
             var OFFSET = 80,
+                needsUpdate = false,
                 previous = null,
                 current = null,
                 currentNav = null,
@@ -13124,7 +13125,15 @@ The following conformance classes are defined by this specification:
                 return sections;
             }, []);
 
-            function onscroll(event) {
+            function onscroll() {
+                if (!needsUpdate) {
+                    needsUpdate = true;
+                    requestAnimationFrame(updatePosition);
+                }
+            }
+
+            function updatePosition() {
+                needsUpdate = false;
                 var scrollTop = (options.offset || 0) + getScrollTop();
                 current = sections.filter(function(section){
                     return section.offsetTop < scrollTop;