Retargetting non-executable projects to .NET Standard (#1801)

* Retarget BizHawk.Emulation.* to .NET Standard 2.0

* Retarget BizHawk.Bizware.BizwareGL to .NET Standard 2.0

In practice this mostly involves moving classes to BizHawk.Client.EmuHawk.

BizHawk.Client.Common/Extensions.cs

@@ -1,28 +0,0 @@
-using System;
-using BizHawk.Bizware.BizwareGL;
-
-namespace BizHawk.Client.Common
-{
-	public static class Extensions
-	{
-		public static IGuiRenderer CreateRenderer(this IGL gl)
-		{
-			if (gl is IGL_TK)
-			{
-				return new GuiRenderer(gl);
-			}
-
-			if (gl is IGL_SlimDX9)
-			{
-				return new GuiRenderer(gl);
-			}
-
-			if (gl is IGL_GdiPlus)
-			{
-				return new GDIPlusGuiRenderer((IGL_GdiPlus)gl);
-			}
-
-			throw new NotSupportedException();
-		}
-	}
-}

BizHawk.Client.EmuHawk/BizHawk.Client.EmuHawk.csproj

@@ -96,9 +96,18 @@
 		<Reference Include="Newtonsoft.Json, Version=12.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed"
 			HintPath="$(SolutionDir)packages/Newtonsoft.Json.12.0.3/lib/net45/Newtonsoft.Json.dll"
 			Private="true" />
+		<!--<Reference Include="OpenTK, Version=3.0.1.0, Culture=neutral, PublicKeyToken=bad199fe84eb3df4"
+			HintPath="../packages/OpenTK.3.0.1/lib/net20/OpenTK.dll"
+			Private="true" />-->
+		<Reference Include="OpenTK.GLControl, Version=3.0.1.0, Culture=neutral, PublicKeyToken=bad199fe84eb3df4"
+			HintPath="../packages/OpenTK.GLControl.3.0.1/lib/net20/OpenTK.GLControl.dll"
+			Private="true" />
 		<Reference Include="ICSharpCode.SharpZipLib, Version=1.1.0.145, Culture=neutral, PublicKeyToken=1b03e6acf1164f73"
 			HintPath="$(SolutionDir)packages/SharpZipLib.1.1.0/lib/net45/ICSharpCode.SharpZipLib.dll"
 			Private="true" />
+		<Reference Include="System.Drawing.Common, Version=4.0.0.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51"
+			HintPath="../packages/System.Drawing.Common.4.7.0/lib/net461/System.Drawing.Common.dll"
+			Private="true" />
 	</ItemGroup>
 	<ItemGroup>
 		<Reference Include="GongShell"
@@ -426,6 +435,11 @@
 		<Compile Update="CustomControls/ToolStripEx.cs" SubType="Component" />
 		<Compile Update="CustomControls/TransparentTrackbar.cs" SubType="Component" />
 		<Compile Update="CustomControls/ViewportPanel.cs" SubType="Component" />
+		<Compile Update="GraphicsImplementations/GLControlWrapper_GdiPlus.cs" SubType="Component" />
+		<Compile Update="GraphicsImplementations/GLControlWrapper_SlimDX9.cs" SubType="Component" />
+		<Compile Update="GraphicsImplementations/GraphicsControl.cs" SubType="UserControl" />
+		<Compile Update="GraphicsImplementations/GraphicsControl_TK.cs" SubType="UserControl" />
+		<Compile Update="GraphicsImplementations/RetainedGraphicsControl.cs" SubType="UserControl" />
 		<Compile Update="LogWindow.cs" SubType="Form" />
 		<Compile Update="LogWindow.Designer.cs" DependentUpon="LogWindow.cs" />
 		<EmbeddedResource Update="LogWindow.resx" DependentUpon="LogWindow.cs" />

BizHawk.Client.EmuHawk/GraphicsImplementations/GLControlWrapper_GdiPlus.cs

@@ -9,7 +9,7 @@ using System.Windows.Forms;
 using BizHawk.Bizware.BizwareGL;
 
 
-namespace BizHawk.Bizware.BizwareGL
+namespace BizHawk.Client.EmuHawk
 {
 	public class GLControlWrapper_GdiPlus : Control, IGraphicsControl
 	{

BizHawk.Client.EmuHawk/GraphicsImplementations/GLControlWrapper_SlimDX9.cs

@@ -9,7 +9,7 @@ using System.Windows.Forms;
 using BizHawk.Bizware.BizwareGL;
 using SlimDX.Direct3D9;
 
-namespace BizHawk.Bizware.BizwareGL
+namespace BizHawk.Client.EmuHawk
 {
 	public class GLControlWrapper_SlimDX9 : Control, IGraphicsControl
 	{

BizHawk.Client.EmuHawk/GraphicsImplementations/GraphicsControl.cs

@@ -1,7 +1,9 @@
 using System;
 using System.Windows.Forms;
 
-namespace BizHawk.Bizware.BizwareGL
+using BizHawk.Bizware.BizwareGL;
+
+namespace BizHawk.Client.EmuHawk
 {
 	/// <summary>
 	/// a base class for deriving/wrapping from a IGraphicsControl.

BizHawk.Client.EmuHawk/GraphicsImplementations/GraphicsControl_TK.cs

@@ -11,7 +11,7 @@ using OpenTK;
 using OpenTK.Graphics;
 using OpenTK.Graphics.OpenGL;
 
-namespace BizHawk.Bizware.BizwareGL
+namespace BizHawk.Client.EmuHawk
 {
 	class GLControlWrapper : GLControl, IGraphicsControl
 	{

BizHawk.Client.EmuHawk/GraphicsImplementations/IGLExtensions.cs

@@ -0,0 +1,17 @@
+using System;
+
+using BizHawk.Bizware.BizwareGL;
+
+namespace BizHawk.Client.EmuHawk
+{
+	public static class IGLExtensions
+	{
+		public static IGuiRenderer CreateRenderer(this IGL gl) => gl switch
+		{
+			IGL_GdiPlus _ => (IGuiRenderer) new GDIPlusGuiRenderer(gl),
+			IGL_SlimDX9 _ => new GuiRenderer(gl),
+			IGL_TK _ => new GuiRenderer(gl),
+			_ => throw new NotSupportedException()
+		};
+	}
+}

BizHawk.Client.EmuHawk/GraphicsImplementations/IGL_GdiPlus.cs

@@ -16,7 +16,7 @@ using swf = System.Windows.Forms;
 
 //TODO - maybe a layer to cache Graphics parameters (notably, filtering) ?
 
-namespace BizHawk.Bizware.BizwareGL
+namespace BizHawk.Client.EmuHawk
 {
 	public class IGL_GdiPlus : IGL
 	{
@@ -62,7 +62,7 @@ namespace BizHawk.Bizware.BizwareGL
 
 		public void FreeTexture(Texture2d tex)
 		{
-			var tw = tex.Opaque as TextureWrapper;
+			var tw = tex.Opaque as GDIPTextureWrapper;
 			tw.Dispose();
 		}
 		
@@ -151,7 +151,7 @@ namespace BizHawk.Bizware.BizwareGL
 
 		public void TexParameter2d(Texture2d tex, TextureParameterName pname, int param)
 		{
-			var tw = tex.Opaque as TextureWrapper;
+			var tw = tex.Opaque as GDIPTextureWrapper;
 			if (pname == TextureParameterName.TextureMinFilter)
 				tw.MinFilter = (TextureMinFilter)param;
 			if (pname == TextureParameterName.TextureMagFilter)
@@ -161,7 +161,7 @@ namespace BizHawk.Bizware.BizwareGL
 		public Texture2d LoadTexture(sd.Bitmap bitmap)
 		{
 			var sdbmp = (sd.Bitmap)bitmap.Clone();
-			TextureWrapper tw = new TextureWrapper();
+			GDIPTextureWrapper tw = new GDIPTextureWrapper();
 			tw.SDBitmap = sdbmp;
 			return new Texture2d(this, tw, bitmap.Width, bitmap.Height);
 		}
@@ -185,7 +185,7 @@ namespace BizHawk.Bizware.BizwareGL
 
 		public void LoadTextureData(Texture2d tex, BitmapBuffer bmp)
 		{
-			var tw = tex.Opaque as TextureWrapper;
+			var tw = tex.Opaque as GDIPTextureWrapper;
 			bmp.ToSysdrawingBitmap(tw.SDBitmap);
 		}
 
@@ -194,14 +194,14 @@ namespace BizHawk.Bizware.BizwareGL
 		{
 			//definitely needed (by TextureFrugalizer at least)
 			var sdbmp = bmp.ToSysdrawingBitmap();
-			var tw = new TextureWrapper();
+			var tw = new GDIPTextureWrapper();
 			tw.SDBitmap = sdbmp;
 			return new Texture2d(this, tw, bmp.Width, bmp.Height);
 		}
 
 		public unsafe BitmapBuffer ResolveTexture2d(Texture2d tex)
 		{
-			var tw = tex.Opaque as TextureWrapper;
+			var tw = tex.Opaque as GDIPTextureWrapper;
 			var blow = new BitmapLoadOptions()
 			{
 				AllowWrap = false //must be an independent resource
@@ -320,7 +320,7 @@ namespace BizHawk.Bizware.BizwareGL
 				}
 				else
 				{
-					var tw = Target.Texture2d.Opaque as TextureWrapper;
+					var tw = Target.Texture2d.Opaque as GDIPTextureWrapper;
 					r = Target.Texture2d.Rectangle;
 					refGraphics = Graphics.FromImage(tw.SDBitmap);
 				}
@@ -368,7 +368,7 @@ namespace BizHawk.Bizware.BizwareGL
 
 		public unsafe RenderTarget CreateRenderTarget(int w, int h)
 		{
-			TextureWrapper tw = new TextureWrapper();
+			GDIPTextureWrapper tw = new GDIPTextureWrapper();
 			tw.SDBitmap = new Bitmap(w,h, sdi.PixelFormat.Format32bppArgb);
 			var tex = new Texture2d(this, tw, w, h);
 
@@ -406,7 +406,7 @@ namespace BizHawk.Bizware.BizwareGL
 			}
 			else
 			{
-				var tw = rt.Texture2d.Opaque as TextureWrapper;
+				var tw = rt.Texture2d.Opaque as GDIPTextureWrapper;
 				CurrentRenderTargetWrapper = rt.Opaque as RenderTargetWrapper;
 				_CurrentOffscreenGraphics = Graphics.FromImage(tw.SDBitmap);
 				//if (CurrentRenderTargetWrapper.MyBufferedGraphics == null)
@@ -429,21 +429,6 @@ namespace BizHawk.Bizware.BizwareGL
 
 		public BufferedGraphicsContext MyBufferedGraphicsContext;
 
-		public class TextureWrapper : IDisposable
-		{
-			public sd.Bitmap SDBitmap;
-			public TextureMinFilter MinFilter = TextureMinFilter.Nearest;
-			public TextureMagFilter MagFilter = TextureMagFilter.Nearest;
-			public void Dispose()
-			{
-				if (SDBitmap != null)
-				{
-					SDBitmap.Dispose();
-					SDBitmap = null;
-				}
-			}
-		}
-
 
 	} //class IGL_GdiPlus
 

BizHawk.Client.EmuHawk/GraphicsImplementations/IGL_SlimDX9.cs

@@ -21,7 +21,7 @@ using swf = System.Windows.Forms;
 
 //todo - do a better job selecting shader model? base on caps somehow? try several and catch compilation exceptions (yuck, exceptions)
 
-namespace BizHawk.Bizware.BizwareGL
+namespace BizHawk.Client.EmuHawk
 {
 
 	public class IGL_SlimDX9 : IGL

BizHawk.Client.EmuHawk/GraphicsImplementations/IGL_TK.cs

@@ -25,7 +25,7 @@ using sd = System.Drawing;
 using sdi = System.Drawing.Imaging;
 using swf = System.Windows.Forms;
 
-namespace BizHawk.Bizware.BizwareGL
+namespace BizHawk.Client.EmuHawk
 {
 	/// <summary>
 	/// OpenTK implementation of the BizwareGL.IGL interface. 

BizHawk.Client.EmuHawk/GraphicsImplementations/RetainedGraphicsControl.cs

@@ -8,7 +8,7 @@ using System.Text;
 using BizHawk.Bizware.BizwareGL;
 using OpenTK.Graphics.OpenGL;
 
-namespace BizHawk.Bizware.BizwareGL
+namespace BizHawk.Client.EmuHawk
 {
 	/// <summary>
 	/// Adapts a GraphicsControl to gain the power of remembering what was drawn to it, and keeping it presented in response to Paint events

BizHawk.Client.EmuHawk/Program.cs

@@ -130,7 +130,7 @@ namespace BizHawk.Client.EmuHawk
 			}
 
 			// create IGL context. we do this whether or not the user has selected OpenGL, so that we can run opengl-based emulator cores
-			GlobalWin.IGL_GL = new Bizware.BizwareGL.IGL_TK(2, 0, false);
+			GlobalWin.IGL_GL = new IGL_TK(2, 0, false);
 
 			// setup the GL context manager, needed for coping with multiple opengl cores vs opengl display method
 			GLManager.CreateInstance();
@@ -140,13 +140,13 @@ namespace BizHawk.Client.EmuHawk
 		REDO_DISPMETHOD:
 			if (Global.Config.DispMethod == EDispMethod.GdiPlus)
 			{
-				GlobalWin.GL = new Bizware.BizwareGL.IGL_GdiPlus();
+				GlobalWin.GL = new IGL_GdiPlus();
 			}
 			else if (Global.Config.DispMethod == EDispMethod.SlimDX9)
 			{
 				try
 				{
-					GlobalWin.GL = new Bizware.BizwareGL.IGL_SlimDX9();
+					GlobalWin.GL = new IGL_SlimDX9();
 				}
 				catch(Exception ex)
 				{
@@ -248,7 +248,7 @@ namespace BizHawk.Client.EmuHawk
 			//cleanup:
 			//cleanup IGL stuff so we can get better refcounts when exiting process, for debugging
 			//DOESNT WORK FOR SOME REASON
-			//GlobalWin.IGL_GL = new Bizware.BizwareGL.Drivers.OpenTK.IGL_TK();
+			//GlobalWin.IGL_GL = new IGL_TK();
 			//GLManager.Instance.Dispose();
 			//if (GlobalWin.IGL_GL != GlobalWin.GL)
 			//  GlobalWin.GL.Dispose();

BizHawk.Client.EmuHawk/ProjectPkgRefs.props

@@ -6,11 +6,29 @@
 			Name="Newtonsoft.Json"
 			Private="true"
 			SpecificVersion="true" />
+		<!--<PackageReference Include="OpenTK" Version="3.0.1" PrivateAssets="All" />
+		<Reference Include="$(MachineNuGetPackageDir)/opentk/3.0.1/lib/net20/OpenTK.dll"
+			FusionName="OpenTK, Version=3.0.1.0, Culture=neutral, PublicKeyToken=bad199fe84eb3df4"
+			Name="OpenTK"
+			Private="true"
+			SpecificVersion="true" />-->
+		<PackageReference Include="OpenTK.GLControl" Version="3.0.1" PrivateAssets="All" />
+		<Reference Include="$(MachineNuGetPackageDir)/opentk.glcontrol/3.0.1/lib/net20/OpenTK.GLControl.dll"
+			FusionName="OpenTK.GLControl, Version=3.0.1.0, Culture=neutral, PublicKeyToken=bad199fe84eb3df4"
+			Name="OpenTK.GLControl"
+			Private="true"
+			SpecificVersion="true" />
 		<PackageReference Include="SharpZipLib" Version="1.1.0" PrivateAssets="All" />
 		<Reference Include="$(MachineNuGetPackageDir)/sharpziplib/1.1.0/lib/net45/ICSharpCode.SharpZipLib.dll"
 			FusionName="ICSharpCode.SharpZipLib, Version=1.1.0.145, Culture=neutral, PublicKeyToken=1b03e6acf1164f73"
 			Name="ICSharpCode.SharpZipLib"
 			Private="true"
 			SpecificVersion="true" />
+		<PackageReference Include="System.Drawing.Common" Version="4.7.0" PrivateAssets="All" />
+		<Reference Include="$(MachineNuGetPackageDir)/system.drawing.common/4.7.0/lib/net461/System.Drawing.Common.dll"
+			FusionName="System.Drawing.Common, Version=4.0.0.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51"
+			Name="System.Drawing.Common"
+			Private="true"
+			SpecificVersion="true" />
 	</ItemGroup>
 </Project>

BizHawk.Client.EmuHawk/packages.config

@@ -1,5 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Newtonsoft.Json" version="12.0.3" targetFramework="net45" />
+  <!--<package id="OpenTK" version="3.0.1" targetFramework="net20" />-->
+  <package id="OpenTK.GLControl" version="3.0.1" targetFramework="net20" />
   <package id="SharpZipLib" version="1.1.0" targetFramework="net45" />
+  <package id="System.Drawing.Common" version="4.7.0" targetFramework="net461" />
 </packages>

BizHawk.Emulation.Common/BizHawk.Emulation.Common.csproj

@@ -2,25 +2,11 @@
 	<Import Project="$(SolutionDir)Common.props" />
 	<PropertyGroup>
 		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-		<TargetFramework>net48</TargetFramework>
+		<TargetFrameworks>netstandard2.0;netcoreapp3.1</TargetFrameworks>
 	</PropertyGroup>
-	<ItemGroup>
-		<PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" />
-		<!--<Reference Include="Microsoft.CSharp" />-->
-		<!--<Reference Include="System" />-->
-		<!--<Reference Include="System.Core" />-->
-		<!--<Reference Include="System.Data" />-->
-		<!--<Reference Include="System.Data.DataSetExtensions" />-->
-		<!--<Reference Include="System.Xml" />-->
-		<!--<Reference Include="System.Xml.Linq" />-->
-	</ItemGroup>
 	<ItemGroup>
 		<PackageReference Include="Newtonsoft.Json" Version="12.0.3" PrivateAssets="All" />
-	</ItemGroup>
-	<ItemGroup>
 		<ProjectReference Include="$(SolutionDir)BizHawk.Emulation.DiscSystem/BizHawk.Emulation.DiscSystem.csproj" />
-	</ItemGroup>
-	<ItemGroup>
 		<Compile Include="$(SolutionDir)Version/svnrev.cs" />
 		<Compile Include="$(SolutionDir)Version/VersionInfo.cs" />
 	</ItemGroup>

BizHawk.Emulation.Cores/BizHawk.Emulation.Cores.csproj

@@ -2,66 +2,23 @@
 	<Import Project="$(SolutionDir)Common.props" />
 	<PropertyGroup>
 		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-		<TargetFramework>net48</TargetFramework>
+		<TargetFrameworks>netstandard2.0;netcoreapp3.1</TargetFrameworks>
-	</PropertyGroup>
-	<!-- This stuff was unique to this project and also not mentioned in the tutorial, so I've left them commented here. -->
-	<!--
-	<PropertyGroup>
-		<FileUpgradeFlags />
-		<OldToolsVersion>3.5</OldToolsVersion>
-		<UpgradeBackupLocation />
-		<PublishUrl>publish/</PublishUrl>
-		<Install>true</Install>
-		<InstallFrom>Disk</InstallFrom>
-		<UpdateEnabled>false</UpdateEnabled>
-		<UpdateMode>Foreground</UpdateMode>
-		<UpdateInterval>7</UpdateInterval>
-		<UpdateIntervalUnits>Days</UpdateIntervalUnits>
-		<UpdatePeriodically>false</UpdatePeriodically>
-		<UpdateRequired>false</UpdateRequired>
-		<MapFileExtensions>true</MapFileExtensions>
-		<ApplicationRevision>0</ApplicationRevision>
-		<ApplicationVersion>1.0.0.%2a</ApplicationVersion>
-		<IsWebBootstrapper>false</IsWebBootstrapper>
-		<UseApplicationTrust>false</UseApplicationTrust>
-		<BootstrapperEnabled>true</BootstrapperEnabled>
-		<UseVSHostingProcess>false</UseVSHostingProcess>
 	</PropertyGroup>
 	<ItemGroup>
-		<BootstrapperPackage Include="Microsoft.Net.Client.3.5" Install="false" ProductName=".NET Framework 3.5 SP1 Client Profile" Visible="False" />
+		<PackageReference Include="System.ComponentModel.Annotations" Version="4.7.0" PrivateAssets="All" />
-		<BootstrapperPackage Include="Microsoft.Net.Framework.3.5.SP1" Install="true" ProductName=".NET Framework 3.5 SP1" Visible="False" />
-		<BootstrapperPackage Include="Microsoft.Windows.Installer.3.1" Install="true" ProductName="Windows Installer 3.1" Visible="False" />
-	</ItemGroup>
-	-->
-	<ItemGroup>
-		<PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" />
-		<!--<Reference Include="System" />-->
-		<!--<Reference Include="System.ComponentModel.DataAnnotations" />-->
-		<!--<Reference Include="System.Core" RequiredTargetFramework="3.5" />-->
-		<!--<Reference Include="System.Data" />-->
-		<!--<Reference Include="System.Data.DataSetExtensions" RequiredTargetFramework="3.5" />-->
-		<!--<Reference Include="System.Drawing" />-->
-		<!--<Reference Include="System.Numerics" />-->
-		<Reference Include="System.Windows.Forms" />
-		<!--<Reference Include="System.Xml" />-->
-		<!--<Reference Include="System.Xml.Linq" RequiredTargetFramework="3.5" />-->
-	</ItemGroup>
-	<ItemGroup>
 		<PackageReference Include="ELFSharp" Version="0.1.0" PrivateAssets="All" />
 		<PackageReference Include="Newtonsoft.Json" Version="12.0.3" PrivateAssets="All" />
 		<PackageReference Include="OpenTK" Version="3.0.1" PrivateAssets="All" />
-		<Reference Include="PeNet" HintPath="$(SolutionDir)References/PeNet.dll" Private="true" />
+		<Reference Include="PeNet"
-		<Reference Include="Virtu" HintPath="$(SolutionDir)References/Virtu.dll" Private="true" />
+			HintPath="$(SolutionDir)References/PeNet.dll"
-	</ItemGroup>
+			Private="true" />
-	<ItemGroup>
+		<Reference Include="Virtu"
+			HintPath="$(SolutionDir)References/Virtu.dll"
+			Private="true" />
 		<ProjectReference Include="$(SolutionDir)BizHawk.BizInvoke/BizHawk.BizInvoke.csproj" />
 		<ProjectReference Include="$(SolutionDir)BizHawk.Emulation.Common/BizHawk.Emulation.Common.csproj" />
-	</ItemGroup>
-	<ItemGroup>
 		<Compile Include="$(SolutionDir)Version/svnrev.cs" />
 		<Compile Include="$(SolutionDir)Version/VersionInfo.cs" />
-	</ItemGroup>
-	<ItemGroup>
 		<None Include="Resources/*" />
 	</ItemGroup>
 	<ItemGroup>

BizHawk.Emulation.DiscSystem/BizHawk.Emulation.DiscSystem.csproj

@@ -2,24 +2,11 @@
 	<Import Project="$(SolutionDir)Common.props" />
 	<PropertyGroup>
 		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-		<TargetFramework>net48</TargetFramework>
+		<TargetFrameworks>netstandard2.0;netcoreapp3.1</TargetFrameworks>
 	</PropertyGroup>
-	<ItemGroup>
-		<PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" />
-		<!--<Reference Include="Microsoft.CSharp" />-->
-		<!--<Reference Include="System" />-->
-		<!--<Reference Include="System.Core" />-->
-		<!--<Reference Include="System.Data" />-->
-		<!--<Reference Include="System.Data.DataSetExtensions" />-->
-		<!--<Reference Include="System.Xml" />-->
-		<!--<Reference Include="System.Xml.Linq" />-->
-	</ItemGroup>
 	<ItemGroup>
 		<ProjectReference Include="$(SolutionDir)BizHawk.Common/BizHawk.Common.csproj" />
-	</ItemGroup>
-	<ItemGroup>
 		<Compile Include="$(SolutionDir)Version/svnrev.cs" />
 		<Compile Include="$(SolutionDir)Version/VersionInfo.cs" />
 	</ItemGroup>
 </Project>
-

Bizware/BizHawk.Bizware.BizwareGL/BizHawk.Bizware.BizwareGL.csproj

@@ -2,24 +2,15 @@
 	<Import Project="$(SolutionDir)Common.props" />
 	<PropertyGroup>
 		<AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-		<TargetFramework>net48</TargetFramework>
+		<TargetFramework>netstandard2.0</TargetFramework>
 	</PropertyGroup>
 	<ItemGroup>
-		<PackageReference Include="Microsoft.NETFramework.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" />
+		<PackageReference Include="Microsoft.CSharp" Version="4.7.0" PrivateAssets="All" />
-		<Reference Include="System.Windows.Forms" />
+		<PackageReference Include="System.Drawing.Common" Version="4.7.0" PrivateAssets="All" />
 		<PackageReference Include="OpenTK" Version="3.0.1" PrivateAssets="All" />
-		<PackageReference Include="OpenTK.GLControl" Version="3.0.1" PrivateAssets="All" />
-		<Reference Include="SlimDX"
-			HintPath="$(SolutionDir)References/x64/SlimDX.dll"
-			Private="true" />
 		<ProjectReference Include="$(SolutionDir)BizHawk.Common/BizHawk.Common.csproj" />
 	</ItemGroup>
 	<ItemGroup>
-		<Compile Update="GLControlWrapper_GdiPlus.cs" SubType="Component" />
-		<Compile Update="GLControlWrapper_SlimDX9.cs" SubType="Component" />
-		<Compile Update="GraphicsControl.cs" SubType="UserControl" />
-		<Compile Update="GraphicsControl_TK.cs" SubType="UserControl" />
 		<Compile Update="IGuiRenderer.cs" SubType="Code" />
-		<Compile Update="RetainedGraphicsControl.cs" SubType="UserControl" />
 	</ItemGroup>
 </Project>

Bizware/BizHawk.Bizware.BizwareGL/GDIPTextureWrapper.cs

@@ -0,0 +1,21 @@
+using System;
+
+using OpenTK.Graphics.OpenGL;
+
+namespace BizHawk.Bizware.BizwareGL
+{
+	public class GDIPTextureWrapper : IDisposable
+	{
+		public System.Drawing.Bitmap SDBitmap;
+		public TextureMinFilter MinFilter = TextureMinFilter.Nearest;
+		public TextureMagFilter MagFilter = TextureMagFilter.Nearest;
+		public void Dispose()
+		{
+			if (SDBitmap != null)
+			{
+				SDBitmap.Dispose();
+				SDBitmap = null;
+			}
+		}
+	}
+}

Bizware/BizHawk.Bizware.BizwareGL/GdiPlusGuiRenderer.cs

@@ -15,10 +15,9 @@ namespace BizHawk.Bizware.BizwareGL
 {
 	public class GDIPlusGuiRenderer : IGuiRenderer
 	{
-		public GDIPlusGuiRenderer(IGL_GdiPlus gl)
+		public GDIPlusGuiRenderer(IGL gl)
 		{
 			Owner = gl;
-			Gdi = gl as IGL_GdiPlus;
 		}
 
 		OpenTK.Graphics.Color4[] CornerColors = new OpenTK.Graphics.Color4[4] {
@@ -164,8 +163,8 @@ namespace BizHawk.Bizware.BizwareGL
 
 		public void DrawSubrect(Texture2d tex, float x, float y, float w, float h, float u0, float v0, float u1, float v1)
 		{
-			var tw = tex.Opaque as IGL_GdiPlus.TextureWrapper;
+			var tw = tex.Opaque as GDIPTextureWrapper;
-			var g = Gdi.GetCurrentGraphics();
+			var g = ((dynamic) Gdi).GetCurrentGraphics() as sd.Graphics;
 			PrepDraw(g, tex);
 			SetupMatrix(g);
 
@@ -200,7 +199,7 @@ namespace BizHawk.Bizware.BizwareGL
 
 		void PrepDraw(sd.Graphics g, Texture2d tex)
 		{
-			var tw = tex.Opaque as IGL_GdiPlus.TextureWrapper;
+			var tw = tex.Opaque as GDIPTextureWrapper;
 			//TODO - we can support bicubic for the final presentation..
 			if ((int)tw.MagFilter != (int)tw.MinFilter)
 				throw new InvalidOperationException($"{nameof(tw)}.{nameof(tw.MagFilter)} != {nameof(tw)}.{nameof(tw.MinFilter)}");
@@ -253,7 +252,7 @@ namespace BizHawk.Bizware.BizwareGL
 
 		unsafe void DrawInternal(Texture2d tex, float x, float y, float w, float h, float u0, float v0, float u1, float v1)
 		{
-			var g = Gdi.GetCurrentGraphics();
+			var g = ((dynamic) Gdi).GetCurrentGraphics() as sd.Graphics;
 			PrepDraw(g, tex);
 
 			SetupMatrix(g);
@@ -271,7 +270,7 @@ namespace BizHawk.Bizware.BizwareGL
 			float sw = sx2 - sx;
 			float sh = sy2 - sy;
 
-			var tw = tex.Opaque as IGL_GdiPlus.TextureWrapper;
+			var tw = tex.Opaque as GDIPTextureWrapper;
 			g.PixelOffsetMode = sd.Drawing2D.PixelOffsetMode.Half;
 			g.DrawImage(tw.SDBitmap, destPoints, new sd.RectangleF(sx, sy, sw, sh), sd.GraphicsUnit.Pixel, CurrentImageAttributes);
 			g.Transform = new sd.Drawing2D.Matrix(); //.Reset() doesnt work ? ?
@@ -285,7 +284,7 @@ namespace BizHawk.Bizware.BizwareGL
 		
 		public bool IsActive { get; private set; }
 		public IGL Owner { get; private set; }
-		public IGL_GdiPlus Gdi;
+		public IGL Gdi => Owner;
 
 	}
 }

Bizware/BizHawk.Bizware.BizwareGL/IGL.cs

@@ -5,8 +5,6 @@ using System.Drawing;
 using OpenTK;
 using OpenTK.Graphics.OpenGL;
 
-using swf = System.Windows.Forms;
-
 namespace BizHawk.Bizware.BizwareGL
 {
 
@@ -208,10 +206,12 @@ namespace BizHawk.Bizware.BizwareGL
 		/// </summary>
 		void SetViewport(int width, int height);
 
+#if false // Unused and WinForms unavailable on .NET Standard
 		/// <summary>
 		/// sets the viewport (and scissor) according to the client area of the provided control
 		/// </summary>
-		void SetViewport(swf.Control control);
+		void SetViewport(System.Windows.Forms.Control control);
+#endif
 
 		/// <summary>
 		/// sets the viewport (and scissor) according to the provided specifications

Bizware/BizHawk.Bizware.BizwareGL/RetroShader.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Drawing;
-using System.Windows.Forms;
 
 using OpenTK;
 using OpenTK.Graphics.OpenGL;

Common.props

@@ -4,6 +4,7 @@
 		<ErrorReport>prompt</ErrorReport>
 		<GenerateAssemblyInfo>false</GenerateAssemblyInfo>
 		<LangVersion>8.0</LangVersion>
+		<NoWarn>NU1701</NoWarn><!-- can't use .ruleset, and NU1702 can't be silenced at all (see https://github.com/NuGet/Home/issues/8797) -->
 		<OutputPath>$(SolutionDir)output/dll</OutputPath>
 		<PlatformTarget>AnyCPU</PlatformTarget>
 		<RunAnalyzersDuringBuild Condition=" '$(MachineRunAnalyzersDuringBuild)' == '' ">false</RunAnalyzersDuringBuild>