create an interface for GDIRenderer

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

@@ -566,6 +566,7 @@
     <Compile Include="CoreFeatureAnalysis.Designer.cs">
       <DependentUpon>CoreFeatureAnalysis.cs</DependentUpon>
     </Compile>
+    <Compile Include="CustomControls\ControlRenderer\IControlRenderer.cs" />
     <Compile Include="CustomControls\ExceptionBox.cs">
       <SubType>Form</SubType>
     </Compile>
@@ -575,7 +576,7 @@
     <Compile Include="CustomControls\FolderBrowserDialogEx.cs">
       <SubType>Component</SubType>
     </Compile>
-    <Compile Include="CustomControls\GDIRenderer.cs" />
+    <Compile Include="CustomControls\ControlRenderer\GDIRenderer.cs" />
     <Compile Include="CustomControls\HexTextBox.cs">
       <SubType>Component</SubType>
     </Compile>

BizHawk.Client.EmuHawk/CustomControls/ControlRenderer/IControlRenderer.cs

@@ -0,0 +1,28 @@
+using System;
+using System.Drawing;
+
+namespace BizHawk.Client.EmuHawk.CustomControls
+{
+	public interface IControlRenderer : IDisposable
+	{
+		IDisposable LockGraphics(Graphics g);
+
+		void StartOffScreenBitmap(int width, int height);
+		void EndOffScreenBitmap();
+		void CopyToScreen();
+
+		Size MeasureString(string str, Font font);
+
+		void SetBrush(Color color);
+		void SetSolidPen(Color color);
+
+		// TODO: use the Font version
+		void PrepDrawString(IntPtr hFont, Color color);
+		void DrawString(string str, Point point);
+
+		void DrawRectangle(int nLeftRect, int nTopRect, int nRightRect, int nBottomRect);
+		void FillRectangle(int x, int y, int w, int h);
+		void DrawBitmap(Bitmap bitmap, Point point, bool blend = false);
+		void Line(int x1, int y1, int x2, int y2);
+	}
+}

BizHawk.Client.EmuHawk/CustomControls/InputRoll.cs

@@ -15,7 +15,7 @@ namespace BizHawk.Client.EmuHawk
 	// Row width is specified for horizontal orientation
 	public partial class InputRoll : Control
 	{
-		private readonly GDIRenderer _gdi;
+		private readonly IControlRenderer _gdi;
 		private readonly SortedSet<Cell> _selectedItems = new SortedSet<Cell>(new SortCell());
 
 		private readonly VScrollBar _vBar;