Removed some bugs

binding/Binding/SKAbstractDrawable.cs

@@ -14,9 +14,9 @@ namespace SkiaSharp
 		[UnmanagedFunctionPointer (CallingConvention.Cdecl)]
 		internal delegate IntPtr draw_delegate (IntPtr managedDrawablePtr, IntPtr canvasPtr);
 		[UnmanagedFunctionPointer (CallingConvention.Cdecl)]
-		internal delegate IntPtr getBounds_delegate (IntPtr managedDrawablePtr, ref SKRect bounds);
+		internal delegate SKRect getBounds_delegate (IntPtr managedDrawablePtr);
 		[UnmanagedFunctionPointer (CallingConvention.Cdecl)]
-		internal delegate IntPtr newPictureSnapshot_delegate (IntPtr managedDrawablePtr);
+		internal delegate SKPicture newPictureSnapshot_delegate (IntPtr managedDrawablePtr);
 
 		// delegate fields
 		private static readonly draw_delegate fDraw;
@@ -94,16 +94,15 @@ namespace SkiaSharp
 		}
 
 		[MonoPInvokeCallback(typeof(getBounds_delegate))]
-		private static IntPtr GetBoundsInternal (IntPtr managedDrawablePtr, ref SKRect bounds)
+		private static SKRect GetBoundsInternal (IntPtr managedDrawablePtr)
 		{
-			bounds = AsManagedDrawable (managedDrawablePtr).OnGetBounds ();
-			return IntPtr.Zero;
+			return AsManagedDrawable (managedDrawablePtr).OnGetBounds ();
 		}
 
 		[MonoPInvokeCallback(typeof(newPictureSnapshot_delegate))]
-		private static IntPtr NewPictureSnapshotInternal (IntPtr managedDrawablePtr)
+		private static SKPicture NewPictureSnapshotInternal (IntPtr managedDrawablePtr)
 		{
-			return AsManagedDrawable (managedDrawablePtr).OnNewPictureSnapshot ().Handle;
+			return GetObject<SKPicture> (AsManagedDrawable (managedDrawablePtr).OnNewPictureSnapshot ().Handle);
 		}
 
 		private static SKAbstractDrawable AsManagedDrawable (IntPtr ptr)

binding/Binding/SKCanvas.cs

@@ -404,6 +404,20 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_picture (Handle, picture.Handle, IntPtr.Zero, paint == null ? IntPtr.Zero : paint.Handle);
 		}
 
+		public void DrawDrawable (SKDrawable drawable, ref SKMatrix matrix)
+		{
+			if (drawable == null)
+				throw new ArgumentNullException (nameof (drawable));
+			SkiaApi.sk_canvas_draw_drawable (Handle, drawable.Handle, ref matrix);
+		}
+
+		public void DrawDrawable (SKDrawable drawable, float x, float y)
+		{
+			if (drawable == null)
+				throw new ArgumentNullException (nameof (drawable));
+			SkiaApi.sk_canvas_draw_drawable (Handle, drawable.Handle, x, y);
+		}
+
 		public void DrawBitmap (SKBitmap bitmap, SKPoint p, SKPaint paint = null)
 		{
 			DrawBitmap (bitmap, p.X, p.Y, paint);

binding/Binding/SKDrawable.cs

@@ -11,6 +11,10 @@ namespace SkiaSharp
 		{
 		}
 
+		public SKDrawable() : base ()
+		{
+		}
+
 		protected override void Dispose (bool disposing)
 		{
 			if (Handle != IntPtr.Zero && OwnsHandle) {
@@ -24,29 +28,37 @@ namespace SkiaSharp
 
 		public SKRect Bounds {
 			get {
-				SkiaApi.sk_manageddrawable_get_bounds (Handle, out var rect);
-				return rect;
+				return SkiaApi.sk_manageddrawable_get_bounds (Handle);
 			}
 		}
 
 		public void Draw (SKCanvas canvas, ref SKMatrix matrix)
 		{
-			SkiaApi.sk_manageddrawable_draw (canvas.Handle, ref matrix);
+			SkiaApi.sk_manageddrawable_draw (Handle, canvas.Handle, ref matrix);
 		}
 
 		public void Draw (SKCanvas canvas, float x, float y)
 		{
-			SkiaApi.sk_manageddrawable_draw (canvas.Handle, x, y);
+			var matrix = SKMatrix.MakeTranslation (x, y);
+			SkiaApi.sk_manageddrawable_draw (Handle, canvas.Handle, ref matrix);
 		}
 
 		public SKPicture NewPictureSnapshot ()
 		{
-			return GetObject<SKPicture> (SkiaApi.sk_manageddrawable_new_picture_snapshot ());
+			return GetObject<SKPicture> (SkiaApi.sk_manageddrawable_new_picture_snapshot (Handle));
 		}
 
 		public void NotifyDrawingChanged ()
 		{
-			SkiaApi.sk_manageddrawable_notify_drawing_changed ();
+			SkiaApi.sk_manageddrawable_notify_drawing_changed (Handle);
+		}
+
+		protected override SKPicture OnNewPictureSnapshot ()
+		{
+			var recorder = new SKPictureRecorder ();
+			var canvas = recorder.BeginRecording (Bounds);
+			Draw (canvas, 0, 0);
+			return recorder.EndRecording ();
 		}
 	}
 }

binding/Binding/SkiaApi.cs

@@ -962,15 +962,13 @@ namespace SkiaSharp
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static uint sk_manageddrawable_get_generation_id (sk_manageddrawable_t d);
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
-		public extern static void sk_manageddrawable_get_bounds (sk_manageddrawable_t d, out SKRect rect);
+		public extern static SKRect sk_manageddrawable_get_bounds (sk_manageddrawable_t d);
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
-		public extern static void sk_manageddrawable_draw (sk_canvas_t c, ref SKMatrix matrix);
+		public extern static void sk_manageddrawable_draw (sk_manageddrawable_t d, sk_canvas_t c, ref SKMatrix matrix);
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
-		public extern static void sk_manageddrawable_draw (sk_canvas_t c, float x, float y);
+		public extern static sk_picture_t sk_manageddrawable_new_picture_snapshot (sk_manageddrawable_t d);
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
-		public extern static sk_picture_t sk_manageddrawable_new_picture_snapshot ();
-		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
-		public extern static void sk_manageddrawable_notify_drawing_changed ();
+		public extern static void sk_manageddrawable_notify_drawing_changed (sk_manageddrawable_t d);
 
 		// shader
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]

samples/Basic/Desktop/SkiaSharpSample/Class1.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using SkiaSharp;
+
+namespace SkiaSharpSample
+{
+	public class Class1 : SKDrawable
+	{
+		public Class1()
+		{ }
+
+		protected override void OnDraw(SKCanvas canvas)
+		{
+			var path = new SKPath();
+			var paint = new SKPaint();
+			path.MoveTo(20, 20);
+			path.LineTo(100, 100);
+			path.Close();
+			paint.Color = SKColors.Red;
+			paint.StrokeWidth = 2;
+			paint.Style = SKPaintStyle.Stroke;
+			canvas.DrawPath(path, paint);
+		}
+
+		protected override SKRect OnGetBounds()
+		{
+			return new SKRect(20, 20, 100, 100);
+		}
+	}
+}

samples/Basic/Desktop/SkiaSharpSample/Form1.cs

@@ -38,6 +38,12 @@ namespace SkiaSharpSample
 			};
 			var coord = new SKPoint(scaledSize.Width / 2, (scaledSize.Height + paint.TextSize) / 2);
 			canvas.DrawText("SkiaSharp", coord, paint);
+			var drawable = new Class1();
+			var bounds = drawable.Bounds;
+			canvas.DrawDrawable(drawable, 0, 0);
+			drawable.NewPictureSnapshot();
+			var id = drawable.GenerationID;
+			drawable.NotifyDrawingChanged();
 		}
 	}
 }

samples/Basic/Desktop/SkiaSharpSample/SkiaSharpSample.csproj

@@ -64,6 +64,7 @@
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Class1.cs" />
     <Compile Include="Form1.cs">
       <SubType>Form</SubType>
     </Compile>