UWP: enable ARM64 with new built ANGLE nuget package; enable HiDPI

.appveyor.yml

@@ -9,7 +9,7 @@ environment:
     - solution_name: win32/sdlpal.sln
       APPX_OPTIONS:
     - solution_name: winrt/SDLPal.UWP.sln
-      APPX_OPTIONS:  /p:AppxBundle=Always;AppxBundlePlatforms="x86|x64|ARM";AppxPackageDir="AppPackages"
+      APPX_OPTIONS:  /p:AppxBundle=Always;AppxBundlePlatforms="x86|x64|ARM|ARM64";AppxPackageDir="AppPackages"
 build_script:
   - |-
     msbuild /nologo /m %solution_name% /p:Configuration=Release %APPX_OPTIONS%

winrt/SDLPal.UWP/SDLPal.UWP.vcxproj

@@ -390,12 +390,12 @@
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">
-    <Import Project="..\packages\ANGLE.WindowsStore.2.1.13\build\native\ANGLE.WindowsStore.targets" Condition="Exists('..\packages\ANGLE.WindowsStore.2.1.13\build\native\ANGLE.WindowsStore.targets')" />
+    <Import Project="..\packages\ANGLE.WindowsStore.SDLPal.2.1.14\build\native\ANGLE.WindowsStore.SDLPal.targets" Condition="Exists('..\packages\ANGLE.WindowsStore.SDLPal.2.1.14\build\native\ANGLE.WindowsStore.SDLPal.targets')" />
   </ImportGroup>
   <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
     <PropertyGroup>
       <ErrorText>这台计算机上缺少此项目引用的 NuGet 程序包。使用“NuGet 程序包还原”可下载这些程序包。有关更多信息，请参见 http://go.microsoft.com/fwlink/?LinkID=322105。缺少的文件是 {0}。</ErrorText>
     </PropertyGroup>
-    <Error Condition="!Exists('..\packages\ANGLE.WindowsStore.2.1.13\build\native\ANGLE.WindowsStore.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\ANGLE.WindowsStore.2.1.13\build\native\ANGLE.WindowsStore.targets'))" />
+    <Error Condition="!Exists('..\packages\ANGLE.WindowsStore.SDLPal.2.1.14\build\native\ANGLE.WindowsStore.SDLPal.targets')" Text="$([System.String]::Format('$(ErrorText)', '..\packages\ANGLE.WindowsStore.SDLPal.2.1.14\build\native\ANGLE.WindowsStore.SDLPal.targets'))" />
   </Target>
 </Project>

winrt/SDLPal.UWP/packages.config

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="ANGLE.WindowsStore" version="2.1.13" targetFramework="native" />
+  <package id="ANGLE.WindowsStore.SDLPal" version="2.1.14" targetFramework="native" />
 </packages>

winrt/pal_config.h

@@ -34,7 +34,7 @@
 #define PAL_DEFAULT_WINDOW_HEIGHT  400
 
 #if SDL_VERSION_ATLEAST(2,0,0)
-# define PAL_VIDEO_INIT_FLAGS  (SDL_WINDOW_SHOWN)
+# define PAL_VIDEO_INIT_FLAGS  (SDL_WINDOW_SHOWN | SDL_WINDOW_ALLOW_HIGHDPI)
 #else
 # define PAL_VIDEO_INIT_FLAGS  (SDL_HWSURFACE | SDL_RESIZABLE | (gConfig.fFullScreen ? SDL_FULLSCREEN : 0))
 #endif