Add support for building in Flutter Windows UWP configuration

BUILD.gn

@@ -245,6 +245,12 @@ config("includes_config") {
   include_dirs = [ "include" ]
 }
 
+config("angle_uwp_env") {
+  if (angle_is_winuwp) {
+    defines = [ "WINAPI_FAMILY=WINAPI_FAMILY_PC_APP" ]
+  }
+}
+
 angle_source_set("includes") {
   sources = libangle_includes
   public_configs = [ ":includes_config" ]
@@ -630,6 +636,10 @@ config("angle_backend_config") {
   if (angle_enable_vulkan) {
     configs += [ "src/libANGLE/renderer/vulkan:angle_vulkan_backend_config" ]
   }
+
+  if (angle_is_winuwp) {
+    configs += [ "src/libANGLE/renderer/d3d:angle_enable_winuwp_config" ]
+  }
 }
 
 config("libANGLE_config") {
@@ -736,7 +746,7 @@ angle_source_set("libANGLE_base") {
     ":includes",
   ]
 
-  if (is_win) {
+  if (is_win && !angle_is_winuwp) {
     libs += [
       "gdi32.lib",
       "user32.lib",
@@ -763,6 +773,14 @@ angle_source_set("libANGLE_base") {
     public_deps += [ "src/libANGLE/renderer/vulkan:angle_vulkan_backend" ]
   }
 
+  if (angle_is_winuwp) {
+    public_deps += [ "src/libANGLE/renderer/d3d:angle_enable_winuwp" ]
+  }
+
+  if (angle_enable_d3d11) {
+    libs += [ "dxguid.lib" ]
+  }
+
   if (angle_enable_metal) {
     public_deps += [ "src/libANGLE/renderer/metal:angle_metal_backend" ]
   }
@@ -1004,6 +1022,7 @@ if (is_win && !angle_is_winuwp) {
 angle_static_library("libGLESv2_static") {
   sources = libglesv2_sources
   configs += [ ":debug_annotations_config" ]
+
   public_configs += [ ":angle_static" ]
   deps = [ ":includes" ]
   public_deps = [ ":libANGLE" ]

gni/angle.gni

@@ -82,7 +82,7 @@ declare_args() {
   angle_shared_libvulkan = !is_mac
 
   # There's no "is_winuwp" helper in BUILDCONFIG.gn, so we define one ourselves
-  angle_is_winuwp = is_win && current_os == "winuwp"
+  angle_is_winuwp = is_win && target_os == "winuwp"
 
   # Default to using "_angle" suffix on Android
   if (is_android) {
@@ -185,6 +185,7 @@ angle_common_configs = [
   angle_root + ":constructor_and_destructor_warnings",
   angle_root + ":extra_warnings",
   angle_root + ":internal_config",
+  angle_root + ":angle_uwp_env",
 ]
 
 angle_remove_configs = []

src/libANGLE/renderer/d3d/BUILD.gn

@@ -254,6 +254,8 @@ if (angle_enable_d3d11) {
 
   if (angle_is_winuwp) {
     _d3d11_backend_sources += [
+      "d3d11/converged/CompositorNativeWindow11.cpp",
+      "d3d11/converged/CompositorNativeWindow11.h",
       "d3d11/winrt/CoreWindowNativeWindow.cpp",
       "d3d11/winrt/CoreWindowNativeWindow.h",
       "d3d11/winrt/InspectableNativeWindow.cpp",
@@ -321,4 +323,12 @@ if (angle_enable_d3d11) {
     public_deps = [ ":angle_d3d_shared" ]
     public_configs = [ ":angle_d3d11_backend_config" ]
   }
+
+  config("angle_enable_winuwp_config") {
+    defines = [ "ANGLE_ENABLE_WINDOWS_UWP 1" ]
+  }
+
+  angle_source_set("angle_enable_winuwp") {
+    public_configs = [ ":angle_enable_winuwp_config" ]
+  }
 }

src/libANGLE/renderer/d3d/d3d11/Renderer11.cpp

@@ -63,6 +63,7 @@
 #include "libANGLE/trace.h"
 
 #ifdef ANGLE_ENABLE_WINDOWS_UWP
+#    include "libANGLE/renderer/d3d/d3d11/converged/CompositorNativeWindow11.h"
 #    include "libANGLE/renderer/d3d/d3d11/winrt/NativeWindow11WinRT.h"
 #else
 #    include "libANGLE/renderer/d3d/d3d11/converged/CompositorNativeWindow11.h"
@@ -1314,13 +1315,11 @@ void Renderer11::generateDisplayExtensions(egl::DisplayExtensions *outExtensions
     // All D3D feature levels support robust resource init
     outExtensions->robustResourceInitialization = true;
 
-#if !defined(ANGLE_ENABLE_WINDOWS_UWP)
     // Compositor Native Window capabilies require WinVer >= 1803
     if (CompositorNativeWindow11::IsSupportedWinRelease())
     {
         outExtensions->windowsUIComposition = true;
     }
-#endif
 }
 
 angle::Result Renderer11::flush(Context11 *context11)
@@ -1379,7 +1378,12 @@ bool Renderer11::isValidNativeWindow(EGLNativeWindowType window) const
                   "Pointer size must match Window Handle size");
 
 #if defined(ANGLE_ENABLE_WINDOWS_UWP)
-    return NativeWindow11WinRT::IsValidNativeWindow(window);
+    bool winrt = NativeWindow11WinRT::IsValidNativeWindow(window);
+    if (!winrt)
+    {
+        return CompositorNativeWindow11::IsValidNativeWindow(window);
+    }
+    return true;
 #else
     if (NativeWindow11Win32::IsValidNativeWindow(window))
     {
@@ -1395,9 +1399,19 @@ NativeWindowD3D *Renderer11::createNativeWindow(EGLNativeWindowType window,
                                                 const egl::AttributeMap &attribs) const
 {
 #if defined(ANGLE_ENABLE_WINDOWS_UWP)
-    return new NativeWindow11WinRT(window, config->alphaSize > 0);
+    auto useWinUiComp = window != nullptr && CompositorNativeWindow11::IsValidNativeWindow(window);
+    if (useWinUiComp)
+    {
+        return new CompositorNativeWindow11(window, config->alphaSize > 0);
+    }
+    else
+    {
+        return new NativeWindow11WinRT(window, config->alphaSize > 0);
+    }
+    return nullptr;
 #else
-    auto useWinUiComp = window != nullptr && !NativeWindow11Win32::IsValidNativeWindow(window);
+    auto useWinUiComp = window != nullptr && !NativeWindow11Win32::IsValidNativeWindow(window) &&
+                        CompositorNativeWindow11::IsValidNativeWindow(window);
 
     if (useWinUiComp)
     {

src/libANGLE/renderer/d3d/d3d11/converged/CompositorNativeWindow11.cpp

@@ -118,7 +118,9 @@ HRESULT CompositorNativeWindow11::createSwapChain(ID3D11Device *device,
     swapChainDesc.Scaling     = DXGI_SCALING_STRETCH;
     swapChainDesc.SwapEffect  = DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL;
     swapChainDesc.AlphaMode   = mHasAlpha ? DXGI_ALPHA_MODE_PREMULTIPLIED : DXGI_ALPHA_MODE_IGNORE;
+#ifndef ANGLE_ENABLE_WINDOWS_UWP
     swapChainDesc.Flags = DXGI_SWAP_CHAIN_FLAG::DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT;
+#endif
     Microsoft::WRL::ComPtr<IDXGISwapChain1> swapChain1;
     hr = factory2->CreateSwapChainForComposition(device, &swapChainDesc, nullptr, &swapChain1);
     if (SUCCEEDED(hr))
@@ -237,10 +239,17 @@ RoHelper::RoHelper()
       mComBaseModule(nullptr),
       mCoreMessagingModule(nullptr)
 {
-    if (!IsWindows10OrGreater())
-    {
-        return;
-    }
+
+#ifdef ANGLE_ENABLE_WINDOWS_UWP
+    mFpWindowsCreateStringReference    = &::WindowsCreateStringReference;
+    mFpRoInitialize                    = &::RoInitialize;
+    mFpRoUninitialize                  = &::RoUninitialize;
+    mFpWindowsDeleteString             = &::WindowsDeleteString;
+    mFpGetActivationFactory            = &::RoGetActivationFactory;
+    mFpWindowsCompareStringOrdinal     = &::WindowsCompareStringOrdinal;
+    mFpCreateDispatcherQueueController = &::CreateDispatcherQueueController;
+    mWinRtAvailable                    = true;
+#else
 
     mComBaseModule = LoadLibraryA("ComBase.dll");
 
@@ -294,14 +303,18 @@ RoHelper::RoHelper()
         return;
     }
 
-    if (SUCCEEDED(RoInitialize(RO_INIT_MULTITHREADED)))
+    auto result = RoInitialize(RO_INIT_SINGLETHREADED);
+
+    if (SUCCEEDED(result) || result == S_FALSE || result == RPC_E_CHANGED_MODE)
     {
         mWinRtAvailable = true;
     }
+#endif
 }
 
 RoHelper::~RoHelper()
 {
+#ifndef ANGLE_ENABLE_WINDOWS_UWP
     if (mWinRtAvailable)
     {
         RoUninitialize();
@@ -318,6 +331,7 @@ RoHelper::~RoHelper()
         FreeLibrary(mComBaseModule);
         mComBaseModule = nullptr;
     }
+#endif
 }
 
 bool RoHelper::WinRtAvailable() const
@@ -327,7 +341,7 @@ bool RoHelper::WinRtAvailable() const
 
 bool RoHelper::SupportedWindowsRelease()
 {
-    if (!IsWindows10OrGreater() || !mWinRtAvailable)
+    if (!mWinRtAvailable)
     {
         return false;
     }

src/libANGLE/renderer/d3d/d3d11/winrt/InspectableNativeWindow.h

@@ -18,6 +18,7 @@
 #include <EGL/eglplatform.h>
 
 #include <windows.applicationmodel.core.h>
+#undef GetCurrentTime
 #include <windows.ui.xaml.h>
 #include <windows.ui.xaml.media.dxinterop.h>
 #include <wrl.h>

src/libGLESv2.gni

@@ -95,7 +95,7 @@ if (is_apple) {
 
 if (is_win) {
   libangle_common_sources += [ "src/common/system_utils_win.cpp" ]
-  if (current_os == "winuwp") {
+  if (target_os == "winuwp") {
     libangle_common_sources += [ "src/common/system_utils_winuwp.cpp" ]
   } else {
     libangle_common_sources += [ "src/common/system_utils_win32.cpp" ]