Make sure to save/restore the canvas matrix

source/SkiaSharp.Views/SkiaSharp.Views.Gtk/SKWidget.cs

@@ -29,7 +29,10 @@ namespace SkiaSharp.Views.Gtk
 			CreateDrawingObjects();
 
 			// start drawing
+			using (new SKAutoCanvasRestore(surface.Canvas, true))
+			{
 				OnPaintSurface(new SKPaintSurfaceEventArgs(surface, imgInfo));
+			}
 
 			surface.Canvas.Flush();