From b98bc7c3603c19227b58d27429f19b0e989603e0 Mon Sep 17 00:00:00 2001
From: Brandon DeRosier <bdero@google.com>
Date: Fri, 21 Apr 2023 01:45:06 -0700
Subject: [PATCH] [Impeller] Always use BGRA10_XR for wide gamut
 (flutter/engine#41385)

Fixes errors blitting offscreen textures to onscreen textures
when wide gamut is enabled due to the mismatching formats.
---
 .../darwin/ios/framework/Source/FlutterView.mm        |  6 +-----
 .../platform/darwin/ios/ios_surface_metal_impeller.mm | 11 +----------
 2 files changed, 2 insertions(+), 15 deletions(-)

diff --git a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterView.mm b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterView.mm
index c441883999..aa95fb8445 100644
--- a/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterView.mm
+++ b/engine/src/flutter/shell/platform/darwin/ios/framework/Source/FlutterView.mm
@@ -96,11 +96,7 @@ static BOOL IsWideGamutSupported() {
       CGColorSpaceRef srgb = CGColorSpaceCreateWithName(kCGColorSpaceExtendedSRGB);
       layer.colorspace = srgb;
       CFRelease(srgb);
-      if (self.opaque) {
-        layer.pixelFormat = MTLPixelFormatBGR10_XR;
-      } else {
-        layer.pixelFormat = MTLPixelFormatBGRA10_XR;
-      }
+      layer.pixelFormat = MTLPixelFormatBGRA10_XR;
     }
   }
 
diff --git a/engine/src/flutter/shell/platform/darwin/ios/ios_surface_metal_impeller.mm b/engine/src/flutter/shell/platform/darwin/ios/ios_surface_metal_impeller.mm
index b4a7436885..427b91e0fa 100644
--- a/engine/src/flutter/shell/platform/darwin/ios/ios_surface_metal_impeller.mm
+++ b/engine/src/flutter/shell/platform/darwin/ios/ios_surface_metal_impeller.mm
@@ -10,15 +10,6 @@
 
 namespace flutter {
 
-static impeller::PixelFormat InferOffscreenLayerPixelFormat(impeller::PixelFormat pixel_format) {
-  switch (pixel_format) {
-    case impeller::PixelFormat::kB10G10R10XR:
-      return impeller::PixelFormat::kB10G10R10A10XR;
-    default:
-      return pixel_format;
-  }
-}
-
 IOSSurfaceMetalImpeller::IOSSurfaceMetalImpeller(const fml::scoped_nsobject<CAMetalLayer>& layer,
                                                  const std::shared_ptr<IOSContext>& context)
     : IOSSurface(context),
@@ -47,7 +38,7 @@ void IOSSurfaceMetalImpeller::UpdateStorageSizeIfNecessary() {
 // |IOSSurface|
 std::unique_ptr<Surface> IOSSurfaceMetalImpeller::CreateGPUSurface(GrDirectContext*) {
   impeller_context_->UpdateOffscreenLayerPixelFormat(
-      InferOffscreenLayerPixelFormat(impeller::FromMTLPixelFormat(layer_.get().pixelFormat)));
+      impeller::FromMTLPixelFormat(layer_.get().pixelFormat));
   return std::make_unique<GPUSurfaceMetalImpeller>(this,              //
                                                    impeller_context_  //
   );