Add support using libgdiplus on macOS

Author: AlexNDRmac

src/ImageSharp/ImageSharp.csproj

@@ -28,6 +28,14 @@
     <PackageReference Include="System.Runtime.CompilerServices.Unsafe" />
   </ItemGroup>
 
+  <!-- Enable support for using libgdiplus on macOS -->
+  <ItemGroup Condition="$(TargetFramework.StartsWith('netcoreapp')) AND $([MSBuild]::IsOSPlatform('OSX'))">
+    <PackageReference Include="runtime.osx.10.10-x64.CoreCompat.System.Drawing" Version="5.8.64" />
+  </ItemGroup>
+  <ItemGroup Condition="$(TargetFramework.StartsWith('netstandard')) AND $([MSBuild]::IsOSPlatform('OSX'))">
+    <PackageReference Include="runtime.osx.10.10-x64.CoreCompat.System.Drawing" Version="5.8.64" />
+  </ItemGroup>
+
   <ItemGroup Condition=" $(TargetFramework.StartsWith('netstandard')) OR '$(TargetFramework)' == 'net472'">
     <PackageReference Include="System.Numerics.Vectors" />
     <PackageReference Include="System.Buffers" />

tests/ImageSharp.Benchmarks/ImageSharp.Benchmarks.csproj

@@ -26,7 +26,9 @@
     <PackageReference Include="BenchmarkDotNet.Diagnostics.Windows" Condition="'$(OS)' == 'Windows_NT'" />
     <PackageReference Include="Colourful" />
     <PackageReference Include="Pfim" />
-    <PackageReference Include="SharpZipLib"  />
+    <!-- Enable support for using libgdiplus on macOS -->
+    <PackageReference Include="runtime.osx.10.10-x64.CoreCompat.System.Drawing" Version="5.8.64" Condition="$([MSBuild]::IsOSPlatform('OSX'))" />
+    <PackageReference Include="SharpZipLib" />
     <PackageReference Include="System.Drawing.Common" />
   </ItemGroup>
 

tests/ImageSharp.Tests/ImageSharp.Tests.csproj

@@ -22,6 +22,8 @@
     <PackageReference Include="Microsoft.DotNet.RemoteExecutor" />
     <PackageReference Include="Microsoft.DotNet.XUnitExtensions" />
     <PackageReference Include="Moq" />
+    <!-- Enable support for using libgdiplus on macOS -->
+    <PackageReference Include="runtime.osx.10.10-x64.CoreCompat.System.Drawing" Version="5.8.64" Condition="$([MSBuild]::IsOSPlatform('OSX'))" />
     <PackageReference Include="SharpZipLib" />
     <PackageReference Include="System.Drawing.Common" />
   </ItemGroup>