[Impeller] Ensure that overlay surfaces are constructed with wide gamut settings.

ci/licenses_golden/excluded_files

@@ -176,6 +176,7 @@
 ../../../flutter/impeller/renderer/backend/vulkan/pass_bindings_cache_unittests.cc
 ../../../flutter/impeller/renderer/backend/vulkan/resource_manager_vk_unittests.cc
 ../../../flutter/impeller/renderer/backend/vulkan/test
+../../../flutter/impeller/renderer/blit_pass_unittests.cc
 ../../../flutter/impeller/renderer/capabilities_unittests.cc
 ../../../flutter/impeller/renderer/compute_subgroup_unittests.cc
 ../../../flutter/impeller/renderer/compute_unittests.cc

impeller/renderer/BUILD.gn

@@ -122,6 +122,7 @@ impeller_component("renderer_unittests") {
   testonly = true
 
   sources = [
+    "blit_pass_unittests.cc",
     "capabilities_unittests.cc",
     "device_buffer_unittests.cc",
     "host_buffer_unittests.cc",

impeller/renderer/backend/metal/context_mtl.mm

@@ -12,6 +12,7 @@
 #include "flutter/fml/logging.h"
 #include "flutter/fml/paths.h"
 #include "flutter/fml/synchronization/sync_switch.h"
+#include "impeller/core/formats.h"
 #include "impeller/core/sampler_descriptor.h"
 #include "impeller/renderer/backend/metal/gpu_tracer_mtl.h"
 #include "impeller/renderer/backend/metal/sampler_library_mtl.h"

impeller/renderer/blit_pass.cc

@@ -8,6 +8,7 @@
 
 #include "impeller/base/strings.h"
 #include "impeller/base/validation.h"
+#include "impeller/core/formats.h"
 #include "impeller/core/host_buffer.h"
 #include "impeller/renderer/blit_command.h"
 
@@ -52,6 +53,16 @@ bool BlitPass::AddCopy(std::shared_ptr<Texture> source,
         static_cast<int>(destination->GetTextureDescriptor().sample_count));
     return false;
   }
+  if (source->GetTextureDescriptor().format !=
+      destination->GetTextureDescriptor().format) {
+    VALIDATION_LOG << SPrintF(
+        "The source pixel format (%s) must match the destination pixel format "
+        "(%s) "
+        "for blits.",
+        PixelFormatToString(source->GetTextureDescriptor().format),
+        PixelFormatToString(destination->GetTextureDescriptor().format));
+    return false;
+  }
 
   if (!source_region.has_value()) {
     source_region = IRect::MakeSize(source->GetSize());

impeller/renderer/blit_pass_unittests.cc

@@ -0,0 +1,77 @@
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "gtest/gtest.h"
+#include "impeller/base/validation.h"
+#include "impeller/core/formats.h"
+#include "impeller/core/texture_descriptor.h"
+#include "impeller/playground/playground_test.h"
+#include "impeller/renderer/command_buffer.h"
+
+namespace impeller {
+namespace testing {
+
+using BlitPassTest = PlaygroundTest;
+INSTANTIATE_PLAYGROUND_SUITE(BlitPassTest);
+
+TEST_P(BlitPassTest, BlitAcrossDifferentPixelFormatsFails) {
+  ScopedValidationDisable scope;  // avoid noise in output.
+  auto context = GetContext();
+  auto cmd_buffer = context->CreateCommandBuffer();
+  auto blit_pass = cmd_buffer->CreateBlitPass();
+
+  TextureDescriptor src_desc;
+  src_desc.format = PixelFormat::kA8UNormInt;
+  src_desc.size = {100, 100};
+  auto src = context->GetResourceAllocator()->CreateTexture(src_desc);
+
+  TextureDescriptor dst_format;
+  dst_format.format = PixelFormat::kR8G8B8A8UNormInt;
+  dst_format.size = {100, 100};
+  auto dst = context->GetResourceAllocator()->CreateTexture(dst_format);
+
+  EXPECT_FALSE(blit_pass->AddCopy(src, dst));
+}
+
+TEST_P(BlitPassTest, BlitAcrossDifferentSampleCountsFails) {
+  ScopedValidationDisable scope;  // avoid noise in output.
+  auto context = GetContext();
+  auto cmd_buffer = context->CreateCommandBuffer();
+  auto blit_pass = cmd_buffer->CreateBlitPass();
+
+  TextureDescriptor src_desc;
+  src_desc.format = PixelFormat::kR8G8B8A8UNormInt;
+  src_desc.sample_count = SampleCount::kCount4;
+  src_desc.size = {100, 100};
+  auto src = context->GetResourceAllocator()->CreateTexture(src_desc);
+
+  TextureDescriptor dst_format;
+  dst_format.format = PixelFormat::kR8G8B8A8UNormInt;
+  dst_format.size = {100, 100};
+  auto dst = context->GetResourceAllocator()->CreateTexture(dst_format);
+
+  EXPECT_FALSE(blit_pass->AddCopy(src, dst));
+}
+
+TEST_P(BlitPassTest, BlitPassesForMatchingFormats) {
+  ScopedValidationDisable scope;  // avoid noise in output.
+  auto context = GetContext();
+  auto cmd_buffer = context->CreateCommandBuffer();
+  auto blit_pass = cmd_buffer->CreateBlitPass();
+
+  TextureDescriptor src_desc;
+  src_desc.format = PixelFormat::kR8G8B8A8UNormInt;
+  src_desc.size = {100, 100};
+  auto src = context->GetResourceAllocator()->CreateTexture(src_desc);
+
+  TextureDescriptor dst_format;
+  dst_format.format = PixelFormat::kR8G8B8A8UNormInt;
+  dst_format.size = {100, 100};
+  auto dst = context->GetResourceAllocator()->CreateTexture(dst_format);
+
+  EXPECT_TRUE(blit_pass->AddCopy(src, dst));
+}
+
+}  // namespace testing
+}  // namespace impeller

shell/platform/darwin/ios/framework/Source/FlutterOverlayView.h

@@ -5,13 +5,15 @@
 #ifndef SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTER_OVERLAY_VIEW_H_
 #define SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTER_OVERLAY_VIEW_H_
 
+#include <Metal/Metal.h>
 #include <UIKit/UIKit.h>
 
 #include <memory>
 
 #include "flutter/fml/memory/weak_ptr.h"
 #include "flutter/shell/common/shell.h"
 #import "flutter/shell/platform/darwin/ios/ios_surface.h"
+#include "fml/platform/darwin/cf_utils.h"
 
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.h"
 
@@ -27,12 +29,12 @@
 /// views also handle touch propagation and the like for touches that occurs
 /// either on overlays or otherwise may be intercepted by the platform views.
 @interface FlutterOverlayView : UIView
-
 - (instancetype)initWithFrame:(CGRect)frame NS_UNAVAILABLE;
 - (instancetype)initWithCoder:(NSCoder*)aDecoder NS_UNAVAILABLE;
 
 - (instancetype)init NS_DESIGNATED_INITIALIZER;
-- (instancetype)initWithContentsScale:(CGFloat)contentsScale;
+- (instancetype)initWithContentsScale:(CGFloat)contentsScale
+                          pixelFormat:(MTLPixelFormat)pixelFormat;
 
 @end
 

shell/platform/darwin/ios/framework/Source/FlutterOverlayView.mm

@@ -3,6 +3,8 @@
 // found in the LICENSE file.
 
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterOverlayView.h"
+#include <CoreGraphics/CGColorSpace.h>
+#include <Metal/Metal.h>
 
 #include "flutter/common/settings.h"
 #include "flutter/common/task_runners.h"
@@ -18,7 +20,9 @@
 
 // This is mostly a duplication of FlutterView.
 // TODO(amirh): once GL support is in evaluate if we can merge this with FlutterView.
-@implementation FlutterOverlayView
+@implementation FlutterOverlayView {
+  fml::CFRef<CGColorSpaceRef> _colorSpaceRef;
+}
 
 - (instancetype)initWithFrame:(CGRect)frame {
   NSAssert(NO, @"FlutterOverlayView must init or initWithContentsScale");
@@ -42,15 +46,24 @@ - (instancetype)init {
   return self;
 }
 
-- (instancetype)initWithContentsScale:(CGFloat)contentsScale {
+- (instancetype)initWithContentsScale:(CGFloat)contentsScale
+                          pixelFormat:(MTLPixelFormat)pixelFormat {
   self = [self init];
 
   if ([self.layer isKindOfClass:NSClassFromString(@"CAMetalLayer")]) {
     self.layer.allowsGroupOpacity = NO;
     self.layer.contentsScale = contentsScale;
     self.layer.rasterizationScale = contentsScale;
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability-new"
+    CAMetalLayer* layer = (CAMetalLayer*)self.layer;
+#pragma clang diagnostic pop
+    layer.pixelFormat = pixelFormat;
+    if (pixelFormat == MTLPixelFormatRGBA16Float) {
+      self->_colorSpaceRef = fml::CFRef(CGColorSpaceCreateWithName(kCGColorSpaceExtendedSRGB));
+      layer.colorspace = self->_colorSpaceRef;
+    }
   }
-
   return self;
 }
 

shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include <Metal/Metal.h>
 #import <UIKit/UIGestureRecognizerSubclass.h>
 
 #include <list>
@@ -14,6 +15,7 @@
 #import "flutter/shell/platform/darwin/common/framework/Headers/FlutterChannels.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterOverlayView.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.h"
+#import "flutter/shell/platform/darwin/ios/framework/Source/FlutterView.h"
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterViewController_Internal.h"
 #import "flutter/shell/platform/darwin/ios/ios_surface.h"
 
@@ -85,13 +87,15 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
 
 std::shared_ptr<FlutterPlatformViewLayer> FlutterPlatformViewLayerPool::GetLayer(
     GrDirectContext* gr_context,
-    const std::shared_ptr<IOSContext>& ios_context) {
+    const std::shared_ptr<IOSContext>& ios_context,
+    MTLPixelFormat pixel_format) {
   if (available_layer_index_ >= layers_.size()) {
     std::shared_ptr<FlutterPlatformViewLayer> layer;
     fml::scoped_nsobject<UIView> overlay_view;
     fml::scoped_nsobject<UIView> overlay_view_wrapper;
 
-    if (!gr_context) {
+    bool impeller_enabled = !!ios_context->GetImpellerContext();
+    if (!gr_context && !impeller_enabled) {
       overlay_view.reset([[FlutterOverlayView alloc] init]);
       overlay_view_wrapper.reset([[FlutterOverlayView alloc] init]);
 
@@ -104,8 +108,10 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
           std::move(surface));
     } else {
       CGFloat screenScale = [UIScreen mainScreen].scale;
-      overlay_view.reset([[FlutterOverlayView alloc] initWithContentsScale:screenScale]);
-      overlay_view_wrapper.reset([[FlutterOverlayView alloc] initWithContentsScale:screenScale]);
+      overlay_view.reset([[FlutterOverlayView alloc] initWithContentsScale:screenScale
+                                                               pixelFormat:pixel_format]);
+      overlay_view_wrapper.reset([[FlutterOverlayView alloc] initWithContentsScale:screenScale
+                                                                       pixelFormat:pixel_format]);
 
       auto ca_layer = fml::scoped_nsobject<CALayer>{[[overlay_view.get() layer] retain]};
       std::unique_ptr<IOSSurface> ios_surface = IOSSurface::Create(ios_context, ca_layer);
@@ -735,13 +741,15 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
         // on the overlay layer.
         background_canvas->ClipRect(joined_rect, DlCanvas::ClipOp::kDifference);
         // Get a new host layer.
-        std::shared_ptr<FlutterPlatformViewLayer> layer = GetLayer(gr_context,                //
-                                                                   ios_context,               //
-                                                                   slice,                     //
-                                                                   joined_rect,               //
-                                                                   current_platform_view_id,  //
-                                                                   overlay_id                 //
-        );
+        std::shared_ptr<FlutterPlatformViewLayer> layer =
+            GetLayer(gr_context,                                      //
+                     ios_context,                                     //
+                     slice,                                           //
+                     joined_rect,                                     //
+                     current_platform_view_id,                        //
+                     overlay_id,                                      //
+                     ((FlutterView*)flutter_view_.get()).pixelFormat  //
+            );
         did_submit &= layer->did_submit_last_frame;
         platform_view_layers[current_platform_view_id].push_back(layer);
         overlay_id++;
@@ -811,9 +819,11 @@ static bool ClipRRectContainsPlatformViewBoundingRect(const SkRRect& clip_rrect,
     EmbedderViewSlice* slice,
     SkRect rect,
     int64_t view_id,
-    int64_t overlay_id) {
+    int64_t overlay_id,
+    MTLPixelFormat pixel_format) {
   FML_DCHECK(flutter_view_);
-  std::shared_ptr<FlutterPlatformViewLayer> layer = layer_pool_->GetLayer(gr_context, ios_context);
+  std::shared_ptr<FlutterPlatformViewLayer> layer =
+      layer_pool_->GetLayer(gr_context, ios_context, pixel_format);
 
   UIView* overlay_view_wrapper = layer->overlay_view_wrapper.get();
   auto screenScale = [UIScreen mainScreen].scale;

shell/platform/darwin/ios/framework/Source/FlutterPlatformViews_Internal.h

@@ -5,6 +5,7 @@
 #ifndef FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_FLUTTERPLATFORMVIEWS_INTERNAL_H_
 #define FLUTTER_SHELL_PLATFORM_DARWIN_IOS_FRAMEWORK_SOURCE_FLUTTERPLATFORMVIEWS_INTERNAL_H_
 
+#include <Metal/Metal.h>
 #include "flutter/flow/embedded_views.h"
 #include "flutter/fml/platform/darwin/scoped_nsobject.h"
 #include "flutter/shell/common/shell.h"
@@ -167,9 +168,9 @@ class FlutterPlatformViewLayerPool {
 
   // Gets a layer from the pool if available, or allocates a new one.
   // Finally, it marks the layer as used. That is, it increments `available_layer_index_`.
-  std::shared_ptr<FlutterPlatformViewLayer> GetLayer(
-      GrDirectContext* gr_context,
-      const std::shared_ptr<IOSContext>& ios_context);
+  std::shared_ptr<FlutterPlatformViewLayer> GetLayer(GrDirectContext* gr_context,
+                                                     const std::shared_ptr<IOSContext>& ios_context,
+                                                     MTLPixelFormat pixel_format);
 
   // Gets the layers in the pool that aren't currently used.
   // This method doesn't mark the layers as unused.
@@ -320,7 +321,8 @@ class FlutterPlatformViewsController {
                                                      EmbedderViewSlice* slice,
                                                      SkRect rect,
                                                      int64_t view_id,
-                                                     int64_t overlay_id);
+                                                     int64_t overlay_id,
+                                                     MTLPixelFormat pixel_format);
   // Removes overlay views and platform views that aren't needed in the current frame.
   // Must run on the platform thread.
   void RemoveUnusedLayers();

shell/platform/darwin/ios/framework/Source/FlutterView.h

@@ -5,6 +5,7 @@
 #ifndef SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTER_VIEW_H_
 #define SHELL_PLATFORM_IOS_FRAMEWORK_SOURCE_FLUTTER_VIEW_H_
 
+#include <Metal/Metal.h>
 #import <UIKit/UIKit.h>
 
 #include <memory>
@@ -47,6 +48,7 @@
                  enableWideGamut:(BOOL)isWideGamutEnabled NS_DESIGNATED_INITIALIZER;
 
 - (UIScreen*)screen;
+- (MTLPixelFormat)pixelFormat;
 
 // Set by FlutterEngine or FlutterViewController to override software rendering.
 @property(class, nonatomic) BOOL forceSoftwareRendering;

shell/platform/darwin/ios/framework/Source/FlutterView.mm

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #import "flutter/shell/platform/darwin/ios/framework/Source/FlutterView.h"
+#include <Metal/Metal.h>
 
 #include "flutter/common/settings.h"
 #include "flutter/common/task_runners.h"
@@ -43,6 +44,17 @@ - (UIScreen*)screen {
   return UIScreen.mainScreen;
 }
 
+- (MTLPixelFormat)pixelFormat {
+  if ([self.layer isKindOfClass:NSClassFromString(@"CAMetalLayer")]) {
+// It is a known Apple bug that CAMetalLayer incorrectly reports its supported
+// SDKs. It is, in fact, available since iOS 8.
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wunguarded-availability-new"
+    CAMetalLayer* layer = (CAMetalLayer*)self.layer;
+    return layer.pixelFormat;
+  }
+  return MTLPixelFormatBGRA8Unorm;
+}
 - (BOOL)isWideGamutSupported {
   if (![_delegate isUsingImpeller]) {
     return NO;