Changeset 286805 in webkit

Timestamp:

Dec 9, 2021, 3:01:05 PM (5 years ago)

Author:

timothy_horton@apple.com

Message:

Momentum Generator: Scroll tail hiccup only when scrolling up on 60Hz displays
​https://bugs.webkit.org/show_bug.cgi?id=234104
<rdar://problem/86291413>

Reviewed by Simon Fraser.

• WebProcess/WebPage/MomentumEventDispatcher.cpp:

(WebKit::MomentumEventDispatcher::equalizeTailGaps):
Sort in the correct direction based on the sign of the first delta...

Location:

trunk/Source/WebKit

Files:

• ChangeLog (modified) (1 diff)
• WebProcess/WebPage/MomentumEventDispatcher.cpp (modified) (2 diffs)

trunk/Source/WebKit/ChangeLog

@@ +1 @@
+2021-12-09  Tim Horton  <timothy_horton@apple.com>
+
+        Momentum Generator: Scroll tail hiccup only when scrolling up on 60Hz displays
+        https://bugs.webkit.org/show_bug.cgi?id=234104
+        <rdar://problem/86291413>
+
+        Reviewed by Simon Fraser.
+
+        * WebProcess/WebPage/MomentumEventDispatcher.cpp:
+        (WebKit::MomentumEventDispatcher::equalizeTailGaps):
+        Sort in the correct direction based on the sign of the first delta...
+
 2021-12-09  Chris Dumez  <cdumez@apple.com>
 

trunk/Source/WebKit/WebProcess/WebPage/MomentumEventDispatcher.cpp

@@ -415 +415 @@
     auto& table = m_currentGesture.tailDeltaTable;
     size_t initialTableSize = table.size();
+    if (!initialTableSize)
+        return;
 
     enum Axis { Horizontal, Vertical };
@@ -430 +432 @@
             firstZeroIndex[Vertical] = i;
     }
-    
-    if (auto index = firstZeroIndex[Horizontal])
-        std::sort(deltas[Horizontal].begin(), std::next(deltas[Horizontal].begin(), index));
-    if (auto index = firstZeroIndex[Vertical])
-        std::sort(deltas[Vertical].begin(), std::next(deltas[Vertical].begin(), index));
+
+    auto sortDeltas = [&] (Axis axis) {
+        if (!firstZeroIndex[axis])
+            return;
+
+        if (deltas[axis][0] > 0)
+            std::sort(deltas[axis].begin(), std::next(deltas[axis].begin(), firstZeroIndex[axis]), std::greater<float>());
+        else
+            std::sort(deltas[axis].begin(), std::next(deltas[axis].begin(), firstZeroIndex[axis]), std::less<float>());
+    };
+
+    sortDeltas(Horizontal);
+    sortDeltas(Vertical);
 
     // GapSize is a count of contiguous frames with zero deltas.