From 9ee5fffae0b55bbad2c6c87887f78f4a17c96047 Mon Sep 17 00:00:00 2001
From: Joe Vilches <joevilches@meta.com>
Date: Wed, 25 Sep 2024 13:35:56 -0700
Subject: [PATCH] Small perf fix for new iOS view clipping (#46629)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/46629

If we clipped and had no border or corner radius we would end up hitting this path every time. We can optimize this a bit to avoid that.

Changelog: [Internal]

Reviewed By: NickGerleman

Differential Revision: D63299597

fbshipit-source-id: 90031f964b7669049a4a2efe00a553c888d28cd7
---
 .../View/RCTViewComponentView.mm              | 21 +++++++++++--------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm b/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm
index 0f817e2e6e2..04b2ede4f96 100644
--- a/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm
+++ b/packages/react-native/React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm
@@ -1080,15 +1080,10 @@ static RCTBorderStyle RCTBorderStyleFromOutlineStyle(OutlineStyle outlineStyle)
   }
 
   // clipping
+  self.currentContainerView.layer.mask = nil;
   if (self.currentContainerView.clipsToBounds) {
     BOOL clipToPaddingBox = ReactNativeFeatureFlags::enableIOSViewClipToPaddingBox();
-    if (clipToPaddingBox) {
-      CALayer *maskLayer = [self createMaskLayer:RCTCGRectFromRect(_layoutMetrics.getPaddingFrame())
-                                    cornerInsets:RCTGetCornerInsets(
-                                                     RCTCornerRadiiFromBorderRadii(borderMetrics.borderRadii),
-                                                     RCTUIEdgeInsetsFromEdgeInsets(borderMetrics.borderWidths))];
-      self.currentContainerView.layer.mask = maskLayer;
-    } else {
+    if (!clipToPaddingBox) {
       if (borderMetrics.borderRadii.isUniform()) {
         self.currentContainerView.layer.cornerRadius = borderMetrics.borderRadii.topLeft.horizontal;
       } else {
@@ -1110,9 +1105,17 @@ static RCTBorderStyle RCTBorderStyleFromOutlineStyle(OutlineStyle outlineStyle)
           subview.layer.mask = [self createMaskLayer:subview.bounds cornerInsets:cornerInsets];
         }
       }
+    } else if (
+        !borderMetrics.borderWidths.isUniform() || borderMetrics.borderWidths.left != 0 ||
+        !borderMetrics.borderRadii.isUniform()) {
+      CALayer *maskLayer = [self createMaskLayer:RCTCGRectFromRect(_layoutMetrics.getPaddingFrame())
+                                    cornerInsets:RCTGetCornerInsets(
+                                                     RCTCornerRadiiFromBorderRadii(borderMetrics.borderRadii),
+                                                     RCTUIEdgeInsetsFromEdgeInsets(borderMetrics.borderWidths))];
+      self.currentContainerView.layer.mask = maskLayer;
+    } else {
+      self.currentContainerView.layer.cornerRadius = borderMetrics.borderRadii.topLeft.horizontal;
     }
-  } else {
-    self.currentContainerView.layer.mask = nil;
   }
 }