Allow plugging in a software backend for rendering in the shell. (flu…

…tter#3404)

common/settings.h

@@ -25,6 +25,7 @@ struct Settings {
   bool enable_dart_profiling = false;
   bool use_test_fonts = false;
   bool dart_non_checked_mode = false;
+  bool force_software_rendering = false;
   std::string aot_snapshot_path;
   std::string aot_vm_snapshot_data_filename;
   std::string aot_vm_snapshot_instr_filename;

fml/BUILD.gn

@@ -0,0 +1,11 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+source_set("fml") {
+  public_deps = []
+
+  if (is_ios || is_mac) {
+    public_deps += [ "platform/darwin" ]
+  }
+}

fml/platform/darwin/BUILD.gn

@@ -0,0 +1,18 @@
+# Copyright 2017 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+source_set("darwin") {
+  visibility = [ "//flutter/fml" ]
+
+  sources = [
+    "cf_utils.cc",
+    "cf_utils.h",
+  ]
+
+  deps = [
+    "//lib/ftl",
+  ]
+
+  libs = [ "CoreFoundation.framework" ]
+}

fml/platform/darwin/cf_utils.cc

@@ -0,0 +1,11 @@
+// Copyright 2017 The Chromium 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 "flutter/fml/platform/darwin/cf_utils.h"
+
+namespace fml {
+
+//
+
+}  // namespace fml

fml/platform/darwin/cf_utils.h

@@ -0,0 +1,39 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_FML_PLATFORM_DARWIN_CF_UTILS_H_
+#define FLUTTER_FML_PLATFORM_DARWIN_CF_UTILS_H_
+
+#include <CoreFoundation/CoreFoundation.h>
+#include "lib/ftl/macros.h"
+
+namespace fml {
+
+template <class T>
+class CFRef {
+ public:
+  CFRef() : instance_(nullptr) {}
+
+  CFRef(T instance) : instance_(instance) {}
+
+  ~CFRef() {
+    if (instance_ != nullptr) {
+      CFRelease(instance_);
+    }
+    instance_ = nullptr;
+  }
+
+  operator T() const { return instance_; }
+
+  operator bool() const { return instance_ != nullptr; }
+
+ private:
+  T instance_;
+
+  FTL_DISALLOW_COPY_AND_ASSIGN(CFRef);
+};
+
+}  // namespace fml
+
+#endif  // FLUTTER_FML_PLATFORM_DARWIN_CF_UTILS_H_

shell/common/shell.cc

@@ -185,6 +185,9 @@ void Shell::InitStandalone(std::string icu_data_path,
   settings.trace_startup =
       command_line.HasSwitch(FlagForSwitch(Switch::TraceStartup));
 
+  settings.force_software_rendering =
+      command_line.HasSwitch(FlagForSwitch(Switch::ForceSoftwareRendering));
+
   settings.aot_snapshot_path =
       command_line.GetSwitchValueASCII(FlagForSwitch(Switch::AotSnapshotPath));
   settings.aot_vm_snapshot_data_filename = command_line.GetSwitchValueASCII(

shell/common/surface.cc

@@ -17,7 +17,7 @@ SurfaceFrame::SurfaceFrame(sk_sp<SkSurface> surface,
 SurfaceFrame::~SurfaceFrame() {
   if (submit_callback_) {
     // Dropping without a Submit.
-    submit_callback_(nullptr);
+    submit_callback_(*this, nullptr);
   }
 }
 
@@ -35,12 +35,16 @@ SkCanvas* SurfaceFrame::SkiaCanvas() {
   return surface_ != nullptr ? surface_->getCanvas() : nullptr;
 }
 
+sk_sp<SkSurface> SurfaceFrame::SkiaSurface() const {
+  return surface_;
+}
+
 bool SurfaceFrame::PerformSubmit() {
   if (submit_callback_ == nullptr) {
     return false;
   }
 
-  if (submit_callback_(SkiaCanvas())) {
+  if (submit_callback_(*this, SkiaCanvas())) {
     return true;
   }
 

shell/common/surface.h

@@ -17,7 +17,8 @@ namespace shell {
 /// rendering API. A frame may only be sumitted once.
 class SurfaceFrame {
  public:
-  using SubmitCallback = std::function<bool(SkCanvas* canvas)>;
+  using SubmitCallback =
+      std::function<bool(const SurfaceFrame& surface_frame, SkCanvas* canvas)>;
 
   SurfaceFrame(sk_sp<SkSurface> surface, SubmitCallback submit_callback);
 
@@ -27,6 +28,8 @@ class SurfaceFrame {
 
   SkCanvas* SkiaCanvas();
 
+  sk_sp<SkSurface> SkiaSurface() const;
+
  private:
   bool submitted_;
   sk_sp<SkSurface> surface_;

shell/common/switches.h

@@ -93,6 +93,10 @@ DEF_SWITCH(DartNonCheckedMode,
            "precompiled and checked mode is unsupported. However, this flag "
            "may be specified if the user wishes to run in the debug product "
            "mode (i.e. with JIT or DBC) with checked mode off.")
+DEF_SWITCH(ForceSoftwareRendering,
+           "force-software-rendering",
+           "On platforms where it is supported (only iOS simulator currently), "
+           "the shell will attempt to use the software backend for rendering.")
 DEF_SWITCHES_END
 
 void PrintUsage(const std::string& executable_name);

shell/gpu/BUILD.gn

@@ -10,6 +10,8 @@ source_set("gpu") {
     "gpu_rasterizer.h",
     "gpu_surface_gl.cc",
     "gpu_surface_gl.h",
+    "gpu_surface_software.cc",
+    "gpu_surface_software.h",
   ]
 
   if (shell_enable_vulkan) {
@@ -31,8 +33,6 @@ source_set("gpu") {
   ]
 
   if (shell_enable_vulkan) {
-    deps += [
-      "//flutter/vulkan",
-    ]
+    deps += [ "//flutter/vulkan" ]
   }
 }

shell/gpu/gpu_surface_gl.cc

@@ -84,7 +84,8 @@ std::unique_ptr<SurfaceFrame> GPUSurfaceGL::AcquireFrame(const SkISize& size) {
 
   auto weak_this = weak_factory_.GetWeakPtr();
 
-  SurfaceFrame::SubmitCallback submit_callback = [weak_this](SkCanvas* canvas) {
+  SurfaceFrame::SubmitCallback submit_callback = [weak_this](
+      const SurfaceFrame& surface_frame, SkCanvas* canvas) {
     return weak_this ? weak_this->PresentSurface(canvas) : false;
   };
 

shell/gpu/gpu_surface_software.cc

@@ -0,0 +1,63 @@
+// Copyright 2017 The Chromium 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 "flutter/shell/gpu/gpu_surface_software.h"
+
+#include <memory>
+#include "lib/ftl/logging.h"
+
+namespace shell {
+
+GPUSurfaceSoftware::GPUSurfaceSoftware(GPUSurfaceSoftwareDelegate* delegate)
+    : delegate_(delegate), weak_factory_(this) {}
+
+GPUSurfaceSoftware::~GPUSurfaceSoftware() = default;
+
+bool GPUSurfaceSoftware::Setup() {
+  return IsValid();
+}
+
+bool GPUSurfaceSoftware::IsValid() {
+  return delegate_ != nullptr;
+}
+
+std::unique_ptr<SurfaceFrame> GPUSurfaceSoftware::AcquireFrame(
+    const SkISize& size) {
+  if (!IsValid()) {
+    return nullptr;
+  }
+
+  auto backing_store = delegate_->AcquireBackingStore(size);
+
+  if (backing_store == nullptr) {
+    return nullptr;
+  }
+
+  if (size != SkISize::Make(backing_store->width(), backing_store->height())) {
+    return nullptr;
+  }
+
+  SurfaceFrame::SubmitCallback
+      on_submit = [self = weak_factory_.GetWeakPtr()](
+                      const SurfaceFrame& surface_frame, SkCanvas* canvas)
+                      ->bool {
+    // If the surface itself went away, there is nothing more to do.
+    if (!self || !self->IsValid() || canvas == nullptr) {
+      return false;
+    }
+
+    canvas->flush();
+
+    return self->delegate_->PresentBackingStore(surface_frame.SkiaSurface());
+  };
+
+  return std::make_unique<SurfaceFrame>(backing_store, on_submit);
+}
+
+GrContext* GPUSurfaceSoftware::GetContext() {
+  // The is no GrContext associated with a software surface.
+  return nullptr;
+}
+
+}  // namespace shell

shell/gpu/gpu_surface_software.h

@@ -0,0 +1,45 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_SHELL_GPU_GPU_SURFACE_SOFTWARE_H_
+#define FLUTTER_SHELL_GPU_GPU_SURFACE_SOFTWARE_H_
+
+#include "flutter/shell/common/surface.h"
+#include "lib/ftl/macros.h"
+#include "lib/ftl/memory/weak_ptr.h"
+#include "third_party/skia/include/core/SkSurface.h"
+
+namespace shell {
+
+class GPUSurfaceSoftwareDelegate {
+ public:
+  virtual sk_sp<SkSurface> AcquireBackingStore(const SkISize& size) = 0;
+  virtual bool PresentBackingStore(sk_sp<SkSurface> backing_store) = 0;
+};
+
+class GPUSurfaceSoftware : public Surface {
+ public:
+  GPUSurfaceSoftware(GPUSurfaceSoftwareDelegate* delegate);
+
+  ~GPUSurfaceSoftware() override;
+
+  bool Setup() override;
+
+  bool IsValid() override;
+
+  std::unique_ptr<SurfaceFrame> AcquireFrame(const SkISize& size) override;
+
+  GrContext* GetContext() override;
+
+ private:
+  GPUSurfaceSoftwareDelegate* delegate_;
+
+  ftl::WeakPtrFactory<GPUSurfaceSoftware> weak_factory_;
+
+  FTL_DISALLOW_COPY_AND_ASSIGN(GPUSurfaceSoftware);
+};
+
+}  // namespace shell
+
+#endif  // FLUTTER_SHELL_GPU_GPU_SURFACE_SOFTWARE_H_

shell/platform/android/android_surface.h

@@ -6,6 +6,7 @@
 #define FLUTTER_SHELL_PLATFORM_ANDROID_ANDROID_SURFACE_H_
 
 #include <memory>
+
 #include "flutter/shell/common/platform_view.h"
 #include "flutter/shell/common/surface.h"
 #include "flutter/shell/platform/android/android_native_window.h"

shell/platform/darwin/common/BUILD.gn

@@ -22,6 +22,7 @@ source_set("common") {
     "//dart/runtime:libdart",
     "//flutter/common",
     "//flutter/flow",
+    "//flutter/fml",
     "//flutter/runtime",
     "//flutter/shell/common",
     "//flutter/shell/gpu",

shell/platform/darwin/ios/BUILD.gn

@@ -47,6 +47,14 @@ shared_library("flutter_framework_dylib") {
     "framework/Source/platform_message_router.mm",
     "framework/Source/vsync_waiter_ios.h",
     "framework/Source/vsync_waiter_ios.mm",
+    "ios_gl_context.h",
+    "ios_gl_context.mm",
+    "ios_surface.h",
+    "ios_surface.mm",
+    "ios_surface_gl.h",
+    "ios_surface_gl.mm",
+    "ios_surface_software.h",
+    "ios_surface_software.mm",
     "platform_view_ios.h",
     "platform_view_ios.mm",
   ]
@@ -55,6 +63,7 @@ shared_library("flutter_framework_dylib") {
     "//base:base",
     "//dart/runtime:libdart",
     "//flutter/flow",
+    "//flutter/fml",
     "//flutter/glue",
     "//flutter/lib/ui",
     "//flutter/shell/common",

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

@@ -3,6 +3,8 @@
 // found in the LICENSE file.
 
 #include "flutter/shell/platform/darwin/ios/framework/Source/FlutterView.h"
+
+#include "flutter/common/settings.h"
 #include "flutter/common/threads.h"
 #include "flutter/flow/layers/layer_tree.h"
 #include "flutter/shell/common/rasterizer.h"
@@ -17,19 +19,25 @@ @interface FlutterView ()<UIInputViewAudioFeedback>
 @implementation FlutterView
 
 - (void)layoutSubviews {
-  CGFloat screenScale = [UIScreen mainScreen].scale;
-  CAEAGLLayer* layer = reinterpret_cast<CAEAGLLayer*>(self.layer);
-
-  layer.allowsGroupOpacity = YES;
-  layer.opaque = YES;
-  layer.contentsScale = screenScale;
-  layer.rasterizationScale = screenScale;
+  if ([self.layer isKindOfClass:[CAEAGLLayer class]]) {
+    CAEAGLLayer* layer = reinterpret_cast<CAEAGLLayer*>(self.layer);
+    layer.allowsGroupOpacity = YES;
+    layer.opaque = YES;
+    CGFloat screenScale = [UIScreen mainScreen].scale;
+    layer.contentsScale = screenScale;
+    layer.rasterizationScale = screenScale;
+  }
 
   [super layoutSubviews];
 }
 
 + (Class)layerClass {
+#if TARGET_IPHONE_SIMULATOR
+  return blink::Settings::Get().force_software_rendering ? [CALayer class]
+                                                         : [CAEAGLLayer class];
+#else   // TARGET_IPHONE_SIMULATOR
   return [CAEAGLLayer class];
+#endif  // TARGET_IPHONE_SIMULATOR
 }
 
 - (BOOL)enableInputClicksWhenVisible {

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

@@ -10,8 +10,6 @@
 #include "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "flutter/common/threads.h"
-#include "flutter/shell/gpu/gpu_rasterizer.h"
-#include "flutter/shell/gpu/gpu_surface_gl.h"
 #include "flutter/shell/platform/darwin/common/platform_mac.h"
 #include "flutter/shell/platform/darwin/common/string_conversions.h"
 #include "flutter/shell/platform/darwin/ios/framework/Source/FlutterDartProject_Internal.h"
@@ -473,8 +471,7 @@ - (void)surfaceUpdated:(BOOL)appeared {
   CHECK(_platformView != nullptr);
 
   if (appeared) {
-    _platformView->NotifyCreated(
-        std::make_unique<shell::GPUSurfaceGL>(_platformView.get()));
+    _platformView->NotifyCreated();
   } else {
     _platformView->NotifyDestroyed();
   }