From d11f336bb0d80125ffec3efc9eb5435bf54dd69f Mon Sep 17 00:00:00 2001
From: Alexander Zinchuk <alx.zinchuk@gmail.com>
Date: Sun, 9 May 2021 03:11:45 +0300
Subject: [PATCH] [Perf] Disable mask image even on iOS

---
 src/components/middle/MiddleColumn.tsx | 4 ++--
 src/util/environment.ts                | 3 +--
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/src/components/middle/MiddleColumn.tsx b/src/components/middle/MiddleColumn.tsx
index 524119f9..1595610f 100644
--- a/src/components/middle/MiddleColumn.tsx
+++ b/src/components/middle/MiddleColumn.tsx
@@ -16,7 +16,7 @@ import {
   ANIMATION_LEVEL_MAX,
   ANIMATION_END_DELAY,
 } from '../../config';
-import { IS_MOBILE_SCREEN, IS_TOUCH_ENV, MASK_IMAGE_ENABLED } from '../../util/environment';
+import { IS_MOBILE_SCREEN, IS_TOUCH_ENV, MASK_IMAGE_DISABLED } from '../../util/environment';
 import { DropAreaState } from './composer/DropArea';
 import {
   selectChat,
@@ -173,7 +173,7 @@ const MiddleColumn: FC<StateProps & DispatchProps> = ({
     customBackground && !isCustomBackgroundColor && 'custom-bg-image',
     customBackground && isCustomBackgroundColor && 'custom-bg-color',
     customBackground && isBackgroundBlurred && 'blurred',
-    MASK_IMAGE_ENABLED ? 'mask-image-enabled' : 'mask-image-disabled',
+    MASK_IMAGE_DISABLED ? 'mask-image-disabled' : 'mask-image-enabled',
   );
 
   const messagingDisabledClassName = buildClassName(
diff --git a/src/util/environment.ts b/src/util/environment.ts
index 71e48697..5f20f2d6 100644
--- a/src/util/environment.ts
+++ b/src/util/environment.ts
@@ -50,8 +50,7 @@ export const IS_OPUS_SUPPORTED = Boolean((new Audio()).canPlayType('audio/ogg; c
 
 export const DPR = window.devicePixelRatio || 1;
 
-// `mask-image` CSS property for custom background slows down the scroll performance significantly
-export const MASK_IMAGE_ENABLED = IS_IOS;
+export const MASK_IMAGE_DISABLED = true;
 
 let isWebpSupportedCache: boolean | undefined;