tor-browser

commit 310a2828942440d9ee3456966230b2da1a8d1d10
parent a08fe7ba212e959f5056c0eb13c510a3a8ebf60c
Author: Ting-Yu Lin <tlin@mozilla.com>
Date:   Wed, 19 Nov 2025 05:08:18 +0000

Bug 2000488 - Remove AxisPolarityFlipped() in ReflowInput.cpp. r=layout-reviewers,jfkthame

`AxisPolarityFlipped()` returns the negation of
`WritingMode::ParallelAxisStartsOnSameSide()`. It is sufficient to keep one
implementation in `WritingMode` and port the shortcut in
`ParallelAxisStartsOnSameSide()`.

Differential Revision: https://phabricator.services.mozilla.com/D272826

Diffstat:
M
layout/generic/ReflowInput.cpp
 | 
33
++++-----------------------------
M
layout/generic/WritingModes.h
 | 
5
+++++

2 files changed, 9 insertions(+), 29 deletions(-)
diff --git a/layout/generic/ReflowInput.cpp b/layout/generic/ReflowInput.cpp
@@ -1327,33 +1327,6 @@ static bool AreAllEarlierInFlowFramesEmpty(nsIFrame* aFrame,
   return true;
 }
 
-static bool AxisPolarityFlipped(LogicalAxis aThisAxis, WritingMode aThisWm,
-                                WritingMode aOtherWm) {
-  if (MOZ_LIKELY(aThisWm == aOtherWm)) {
-    // Dedicated short circuit for the common case.
-    return false;
-  }
-  LogicalAxis otherAxis = aThisWm.IsOrthogonalTo(aOtherWm)
-                              ? GetOrthogonalAxis(aThisAxis)
-                              : aThisAxis;
-  NS_ASSERTION(
-      aThisWm.PhysicalAxis(aThisAxis) == aOtherWm.PhysicalAxis(otherAxis),
-      "Physical axes must match!");
-  Side thisStartSide =
-      aThisWm.PhysicalSide(MakeLogicalSide(aThisAxis, LogicalEdge::Start));
-  Side otherStartSide =
-      aOtherWm.PhysicalSide(MakeLogicalSide(otherAxis, LogicalEdge::Start));
-  return thisStartSide != otherStartSide;
-}
-
-static bool InlinePolarityFlipped(WritingMode aThisWm, WritingMode aOtherWm) {
-  return AxisPolarityFlipped(LogicalAxis::Inline, aThisWm, aOtherWm);
-}
-
-static bool BlockPolarityFlipped(WritingMode aThisWm, WritingMode aOtherWm) {
-  return AxisPolarityFlipped(LogicalAxis::Block, aThisWm, aOtherWm);
-}
-
 // In the code below, |aCBReflowInput->mFrame| is the absolute containing block,
 // while |blockContainer| is the nearest block container of the placeholder
 // frame, which may be different from the absolute containing block.
@@ -1592,13 +1565,15 @@ void ReflowInput::CalculateHypotheticalPosition(
   // padding edge and our current values are relative to the border edge, so
   // translate.
   const LogicalMargin border = aCBReflowInput->ComputedLogicalBorder(wm);
-  if (hypotheticalPosWillUseCbwm && InlinePolarityFlipped(wm, cbwm)) {
+  if (hypotheticalPosWillUseCbwm &&
+      !wm.ParallelAxisStartsOnSameSide(LogicalAxis::Inline, cbwm)) {
     aHypotheticalPos.mIStart += border.IEnd(wm);
   } else {
     aHypotheticalPos.mIStart -= border.IStart(wm);
   }
 
-  if (hypotheticalPosWillUseCbwm && BlockPolarityFlipped(wm, cbwm)) {
+  if (hypotheticalPosWillUseCbwm &&
+      !wm.ParallelAxisStartsOnSameSide(LogicalAxis::Block, cbwm)) {
     aHypotheticalPos.mBStart += border.BEnd(wm);
   } else {
     aHypotheticalPos.mBStart -= border.BStart(wm);
diff --git a/layout/generic/WritingModes.h b/layout/generic/WritingModes.h
@@ -532,6 +532,11 @@ class WritingMode {
    */
   bool ParallelAxisStartsOnSameSide(LogicalAxis aLogicalAxis,
                                     const WritingMode& aOther) const {
+    if (MOZ_LIKELY(*this == aOther)) {
+      // Dedicated short circuit for the common case.
+      return true;
+    }
+
     mozilla::Side myStartSide =
         this->PhysicalSide(MakeLogicalSide(aLogicalAxis, LogicalEdge::Start));