A few changes and improvements (#1153)

A few changes and improvements:
- add some helper members
- improved the SKBitmap.CopyTo and related members
- added Encode(...) to SKBitmap
- added Encode(...) with a .NET Stream to SKBitmap, SKImage and SKPixmap
- start the move from SKEncoding to SKTextEncoding
- added more tests
- generator now has a validator for ensuring all declarations have implementations
- added equality members to all structs

Bugs Fixed
- Bitmaps copied with SKBitmap.Copy sometimes have incorrect colors
- The GC would sometimes collect a stream that was being used by a PDF document

binding/Binding/Definitions.cs

@@ -58,6 +58,58 @@ namespace SkiaSharp
 
 		public static bool IsHorizontal (this SKPixelGeometry pg) =>
 			pg == SKPixelGeometry.BgrHorizontal || pg == SKPixelGeometry.RgbHorizontal;
+
+		public static SKTextEncoding ToTextEncoding (this SKEncoding encoding) =>
+			encoding switch
+			{
+				SKEncoding.Utf8 => SKTextEncoding.Utf8,
+				SKEncoding.Utf16 => SKTextEncoding.Utf16,
+				SKEncoding.Utf32 => SKTextEncoding.Utf32,
+				_ => throw new ArgumentOutOfRangeException (nameof (encoding)),
+			};
+
+		internal static SKEncoding ToEncoding (this SKTextEncoding encoding) =>
+			encoding switch
+			{
+				SKTextEncoding.Utf8 => SKEncoding.Utf8,
+				SKTextEncoding.Utf16 => SKEncoding.Utf16,
+				SKTextEncoding.Utf32 => SKEncoding.Utf32,
+				_ => throw new ArgumentOutOfRangeException (nameof (encoding)),
+			};
+
+		public static int GetBytesPerPixel (this SKColorType colorType) =>
+			colorType switch
+			{
+				SKColorType.Unknown => 0,
+				SKColorType.Alpha8 => 1,
+				SKColorType.Gray8 => 1,
+				SKColorType.Rgb565 => 2,
+				SKColorType.Argb4444 => 2,
+				SKColorType.Bgra8888 => 4,
+				SKColorType.Rgba8888 => 4,
+				SKColorType.Rgb888x => 4,
+				SKColorType.Rgba1010102 => 4,
+				SKColorType.Rgb101010x => 4,
+				SKColorType.RgbaF16 => 8,
+				_ => throw new ArgumentOutOfRangeException (nameof (colorType)),
+			};
+
+		public static SKAlphaType GetAlphaType (this SKColorType colorType, SKAlphaType alphaType = SKAlphaType.Premul) =>
+			colorType switch
+			{
+				SKColorType.Unknown => SKAlphaType.Unknown,
+				SKColorType.Alpha8 => SKAlphaType.Premul,
+				SKColorType.Gray8 => SKAlphaType.Opaque,
+				SKColorType.Rgb565 => SKAlphaType.Opaque,
+				SKColorType.Argb4444 => alphaType,
+				SKColorType.Bgra8888 => alphaType,
+				SKColorType.Rgba8888 => alphaType,
+				SKColorType.Rgb888x => SKAlphaType.Opaque,
+				SKColorType.Rgba1010102 => alphaType,
+				SKColorType.Rgb101010x => SKAlphaType.Opaque,
+				SKColorType.RgbaF16 => alphaType,
+				_ => throw new ArgumentOutOfRangeException (nameof (colorType)),
+			};
 	}
 
 	[EditorBrowsable (EditorBrowsableState.Never)]

binding/Binding/GRBackendTexture.cs

@@ -75,6 +75,7 @@ namespace SkiaSharp
 			}
 		}
 
+		[Obsolete]
 		[StructLayout (LayoutKind.Sequential)]
 		internal struct GRTextureInfoObsolete
 		{

binding/Binding/GRContext.cs

@@ -14,6 +14,8 @@ namespace SkiaSharp
 		protected override void Dispose (bool disposing) =>
 			base.Dispose (disposing);
 
+		// Create
+
 		public static GRContext Create (GRBackend backend) =>
 			backend switch
 			{
@@ -43,12 +45,16 @@ namespace SkiaSharp
 				_ => throw new ArgumentOutOfRangeException (nameof (backend)),
 			};
 
+		// CreateGl
+
 		public static GRContext CreateGl () =>
 			CreateGl (null);
 
 		public static GRContext CreateGl (GRGlInterface backendContext) =>
 			GetObject<GRContext> (SkiaApi.gr_context_make_gl (backendContext == null ? IntPtr.Zero : backendContext.Handle));
 
+		//
+
 		public GRBackend Backend => SkiaApi.gr_context_get_backend (Handle);
 
 		public void AbandonContext (bool releaseResources = false)
@@ -96,7 +102,7 @@ namespace SkiaSharp
 			SkiaApi.gr_context_get_max_surface_sample_count_for_color_type (Handle, colorType);
 
 		[EditorBrowsable (EditorBrowsableState.Never)]
-		[Obsolete ("Use GetMaxSurfaceSampleCount(SKColorType) instead.")]
+		[Obsolete]
 		public int GetRecommendedSampleCount (GRPixelConfig config, float dpi) => 0;
 	}
 }

binding/Binding/Properties/SkiaSharpAssemblyInfo.cs

@@ -22,3 +22,10 @@ using System.Runtime.CompilerServices;
 	"3fbe2ff9c979ce998475e506e8ce82dd5b0f350dc10e93bf2eeecf874b24770c5081dbea7447fd" +
 	"dafa277b22de47d6ffea449674a4f9fccf84d15069089380284dbdd35f46cdff12a1bd78e4ef00" +
 	"65d016df")]
+
+[assembly: InternalsVisibleTo("SkiaSharp.HarfBuzz, PublicKey=" +
+	"002400000480000094000000060200000024000052534131000400000100010079159977d2d03a" +
+	"8e6bea7a2e74e8d1afcc93e8851974952bb480a12c9134474d04062447c37e0e68c080536fcf3c" +
+	"3fbe2ff9c979ce998475e506e8ce82dd5b0f350dc10e93bf2eeecf874b24770c5081dbea7447fd" +
+	"dafa277b22de47d6ffea449674a4f9fccf84d15069089380284dbdd35f46cdff12a1bd78e4ef00" +
+	"65d016df")]

binding/Binding/SKBitmap.cs

@@ -111,6 +111,8 @@ namespace SkiaSharp
 		protected override void DisposeNative () =>
 			SkiaApi.sk_bitmap_destructor (Handle);
 
+		// TryAllocPixels
+
 		public bool TryAllocPixels (SKImageInfo info)
 		{
 			return TryAllocPixels (info, info.RowBytes);
@@ -128,16 +130,22 @@ namespace SkiaSharp
 			return SkiaApi.sk_bitmap_try_alloc_pixels_with_flags (Handle, &cinfo, (uint)flags);
 		}
 
+		// Reset
+
 		public void Reset ()
 		{
 			SkiaApi.sk_bitmap_reset (Handle);
 		}
 
+		// SetImmutable
+
 		public void SetImmutable ()
 		{
 			SkiaApi.sk_bitmap_set_immutable (Handle);
 		}
 
+		// Erase
+
 		public void Erase (SKColor color)
 		{
 			SkiaApi.sk_bitmap_erase (Handle, (uint)color);
@@ -148,11 +156,18 @@ namespace SkiaSharp
 			SkiaApi.sk_bitmap_erase_rect (Handle, (uint)color, &rect);
 		}
 
+		// GetAddr*
+
 		public byte GetAddr8 (int x, int y) => SkiaApi.sk_bitmap_get_addr_8 (Handle, x, y);
+
 		public UInt16 GetAddr16 (int x, int y) => SkiaApi.sk_bitmap_get_addr_16 (Handle, x, y);
+
 		public UInt32 GetAddr32 (int x, int y) => SkiaApi.sk_bitmap_get_addr_32 (Handle, x, y);
+
 		public IntPtr GetAddr (int x, int y) => (IntPtr)SkiaApi.sk_bitmap_get_addr (Handle, x, y);
 
+		// Pixels (color)
+
 		[EditorBrowsable (EditorBrowsableState.Never)]
 		[Obsolete ("The Index8 color type and color table is no longer supported. Use GetPixel(int, int) instead.")]
 		public SKPMColor GetIndex8Color (int x, int y)
@@ -170,41 +185,21 @@ namespace SkiaSharp
 			SkiaApi.sk_bitmap_set_pixel_color (Handle, x, y, (uint)color);
 		}
 
+		// Copy
+
 		public bool CanCopyTo (SKColorType colorType)
 		{
-			var srcCT = ColorType;
+			// TODO: optimize as this does more work that we really want
 
-			if (srcCT == SKColorType.Unknown) {
+			if (colorType == SKColorType.Unknown)
 				return false;
-			}
-			if (srcCT == SKColorType.Alpha8 && colorType != SKColorType.Alpha8) {
-				return false;   // can't convert from alpha to non-alpha
-			}
 
-			bool sameConfigs = (srcCT == colorType);
-			switch (colorType) {
-				case SKColorType.Alpha8:
-				case SKColorType.Rgb565:
-				case SKColorType.Rgba8888:
-				case SKColorType.Bgra8888:
-				case SKColorType.Rgb888x:
-				case SKColorType.Rgba1010102:
-				case SKColorType.Rgb101010x:
-				case SKColorType.RgbaF16:
-					break;
-				case SKColorType.Gray8:
-					if (!sameConfigs) {
-						return false;
-					}
-					break;
-				case SKColorType.Argb4444:
-					return
-						sameConfigs ||
-						srcCT == SKImageInfo.PlatformColorType;
-				default:
-					return false;
-			}
-			return true;
+			using var bmp = new SKBitmap ();
+
+			var info = Info
+				.WithColorType (colorType)
+				.WithSize (1, 1);
+			return bmp.TryAllocPixels (info);
 		}
 
 		public SKBitmap Copy ()
@@ -232,72 +227,37 @@ namespace SkiaSharp
 
 		public bool CopyTo (SKBitmap destination, SKColorType colorType)
 		{
-			if (destination == null) {
+			if (destination == null)
 				throw new ArgumentNullException (nameof (destination));
-			}
 
-			if (!CanCopyTo (colorType)) {
+			if (colorType == SKColorType.Unknown)
 				return false;
-			}
 
-			var srcPM = PeekPixels ();
-			if (srcPM == null) {
+			using var srcPixmap = PeekPixels ();
+			if (srcPixmap == null)
 				return false;
-			}
 
-			var dstInfo = srcPM.Info.WithColorType (colorType);
-			switch (colorType) {
-				case SKColorType.Rgb565:
-					// CopyTo() is not strict on alpha type. Here we set the src to opaque to allow
-					// the call to ReadPixels() to succeed and preserve this lenient behavior.
-					if (srcPM.AlphaType != SKAlphaType.Opaque) {
-						srcPM = srcPM.WithAlphaType (SKAlphaType.Opaque);
-					}
-					dstInfo.AlphaType = SKAlphaType.Opaque;
-					break;
-				case SKColorType.RgbaF16:
-					// The caller does not have an opportunity to pass a dst color space.
-					// Assume that they want linear sRGB.
-					dstInfo.ColorSpace = SKColorSpace.CreateSrgbLinear ();
-					if (srcPM.ColorSpace == null) {
-						// We can't do a sane conversion to F16 without a dst color space.
-						// Guess sRGB in this case.
-						srcPM = srcPM.WithColorSpace (SKColorSpace.CreateSrgb ());
-					}
-					break;
-			}
+			using var temp = new SKBitmap ();
 
-			var tmpDst = new SKBitmap ();
-			if (!tmpDst.TryAllocPixels (dstInfo)) {
+			var dstInfo = srcPixmap.Info.WithColorType (colorType);
+			if (!temp.TryAllocPixels (dstInfo))
 				return false;
-			}
 
-			var dstPM = tmpDst.PeekPixels ();
-			if (dstPM == null) {
-				return false;
-			}
+			using var canvas = new SKCanvas (temp);
 
-			// We can't do a sane conversion from F16 without a src color space. Guess sRGB in this case.
-			if (srcPM.ColorType == SKColorType.RgbaF16 && dstPM.ColorSpace == null) {
-				dstPM = dstPM.WithColorSpace (SKColorSpace.CreateSrgb ());
-			}
+			using var paint = new SKPaint {
+				Shader = ToShader (),
+				BlendMode = SKBlendMode.Src
+			};
 
-			// ReadPixels does not yet support color spaces with parametric transfer functions. This
-			// works around that restriction when the color spaces are equal.
-			if (colorType != SKColorType.RgbaF16 && srcPM.ColorType != SKColorType.RgbaF16 && dstPM.ColorSpace == srcPM.ColorSpace) {
-				dstPM = dstPM.WithColorSpace (null);
-				srcPM = srcPM.WithColorSpace (null);
-			}
-
-			if (!srcPM.ReadPixels (dstPM)) {
-				return false;
-			}
-
-			destination.Swap (tmpDst);
+			canvas.DrawPaint (paint);
 
+			destination.Swap (temp);
 			return true;
 		}
 
+		// ExtractSubset
+
 		public bool ExtractSubset (SKBitmap destination, SKRectI subset)
 		{
 			if (destination == null) {
@@ -306,6 +266,8 @@ namespace SkiaSharp
 			return SkiaApi.sk_bitmap_extract_subset (Handle, destination.Handle, &subset);
 		}
 
+		// ExtractAlpha
+
 		public bool ExtractAlpha (SKBitmap destination)
 		{
 			return ExtractAlpha (destination, null, out var offset);
@@ -331,6 +293,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// properties
+
 		public bool ReadyToDraw => SkiaApi.sk_bitmap_ready_to_draw (Handle);
 
 		public SKImageInfo Info {
@@ -373,6 +337,8 @@ namespace SkiaSharp
 			get { return (int)SkiaApi.sk_bitmap_get_byte_count (Handle); }
 		}
 
+		// *Pixels*
+
 		public IntPtr GetPixels () =>
 			GetPixels (out _);
 
@@ -400,6 +366,8 @@ namespace SkiaSharp
 			SetPixels (pixels);
 		}
 
+		// SetColorTable
+
 		[EditorBrowsable (EditorBrowsableState.Never)]
 		[Obsolete ("The Index8 color type and color table is no longer supported.")]
 		public void SetColorTable (SKColorTable ct)
@@ -407,6 +375,8 @@ namespace SkiaSharp
 			// no-op due to unsupperted action
 		}
 
+		// more properties
+
 		public byte[] Bytes {
 			get {
 				var array = GetPixelSpan ().ToArray ();
@@ -456,6 +426,8 @@ namespace SkiaSharp
 		[Obsolete ("The Index8 color type and color table is no longer supported.")]
 		public SKColorTable ColorTable => null;
 
+		// DecodeBounds
+
 		public static SKImageInfo DecodeBounds (Stream stream)
 		{
 			if (stream == null) {
@@ -496,20 +468,20 @@ namespace SkiaSharp
 			}
 		}
 
-		public static SKImageInfo DecodeBounds (byte[] buffer)
-		{
-			if (buffer == null) {
-				throw new ArgumentNullException (nameof (buffer));
-			}
+		public static SKImageInfo DecodeBounds (byte[] buffer) =>
+			DecodeBounds (buffer.AsSpan ());
 
+		public static SKImageInfo DecodeBounds (ReadOnlySpan<byte> buffer)
+		{
 			fixed (byte* b = buffer) {
-				using (var skdata = SKData.Create ((IntPtr)b, buffer.Length))
-				using (var codec = SKCodec.Create (skdata)) {
-					return codec?.Info ?? SKImageInfo.Empty;
-				}
+				using var skdata = SKData.Create ((IntPtr)b, buffer.Length);
+				using var codec = SKCodec.Create (skdata);
+				return codec?.Info ?? SKImageInfo.Empty;
 			}
 		}
 
+		// Decode
+
 		public static SKBitmap Decode (SKCodec codec)
 		{
 			if (codec == null) {
@@ -643,30 +615,32 @@ namespace SkiaSharp
 			}
 		}
 
-		public static SKBitmap Decode (byte[] buffer)
-		{
-			if (buffer == null) {
-				throw new ArgumentNullException (nameof (buffer));
-			}
-			using (var stream = new SKMemoryStream (buffer)) {
-				return Decode (stream);
-			}
-		}
+		public static SKBitmap Decode (byte[] buffer) =>
+			Decode (buffer.AsSpan ());
 
-		public static SKBitmap Decode (byte[] buffer, SKImageInfo bitmapInfo)
-		{
-			if (buffer == null) {
-				throw new ArgumentNullException (nameof (buffer));
-			}
+		public static SKBitmap Decode (byte[] buffer, SKImageInfo bitmapInfo) =>
+			Decode (buffer.AsSpan (), bitmapInfo);
 
+		public static SKBitmap Decode (ReadOnlySpan<byte> buffer)
+		{
 			fixed (byte* b = buffer) {
-				using (var skdata = SKData.Create ((IntPtr)b, buffer.Length))
-				using (var codec = SKCodec.Create (skdata)) {
-					return Decode (codec, bitmapInfo);
-				}
+				using var skdata = SKData.Create ((IntPtr)b, buffer.Length);
+				using var codec = SKCodec.Create (skdata);
+				return Decode (codec);
 			}
 		}
 
+		public static SKBitmap Decode (ReadOnlySpan<byte> buffer, SKImageInfo bitmapInfo)
+		{
+			fixed (byte* b = buffer) {
+				using var skdata = SKData.Create ((IntPtr)b, buffer.Length);
+				using var codec = SKCodec.Create (skdata);
+				return Decode (codec, bitmapInfo);
+			}
+		}
+
+		// InstallPixels
+
 		public bool InstallPixels (SKImageInfo info, IntPtr pixels)
 		{
 			return InstallPixels (info, pixels, info.RowBytes, null, null);
@@ -711,16 +685,22 @@ namespace SkiaSharp
 			return SkiaApi.sk_bitmap_install_pixels_with_pixmap (Handle, pixmap.Handle);
 		}
 
+		// InstallMaskPixels
+
 		public bool InstallMaskPixels (SKMask mask)
 		{
 			return SkiaApi.sk_bitmap_install_mask_pixels (Handle, &mask);
 		}
 
+		// NotifyPixelsChanged
+
 		public void NotifyPixelsChanged ()
 		{
 			SkiaApi.sk_bitmap_notify_pixels_changed (Handle);
 		}
 
+		// PeekPixels
+
 		public SKPixmap PeekPixels ()
 		{
 			SKPixmap pixmap = new SKPixmap ();
@@ -741,6 +721,8 @@ namespace SkiaSharp
 			return SkiaApi.sk_bitmap_peek_pixels (Handle, pixmap.Handle);
 		}
 
+		// Resize
+
 		[EditorBrowsable (EditorBrowsableState.Never)]
 		[Obsolete ("Use Resize(SKImageInfo, SKFilterQuality) instead.")]
 		public SKBitmap Resize (SKImageInfo info, SKBitmapResizeMethod method) =>
@@ -767,6 +749,11 @@ namespace SkiaSharp
 			}
 		}
 
+		public SKBitmap Resize (SKSizeI size, SKFilterQuality quality) =>
+			Resize (Info.WithSize (size), quality);
+
+		// ScalePixels
+
 		public bool ScalePixels (SKBitmap destination, SKFilterQuality quality)
 		{
 			if (destination == null) {
@@ -789,6 +776,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// From/ToImage
+
 		public static SKBitmap FromImage (SKImage image)
 		{
 			if (image == null) {
@@ -804,13 +793,31 @@ namespace SkiaSharp
 			return bmp;
 		}
 
-		[EditorBrowsable (EditorBrowsableState.Never)]
-		[Obsolete ("Use SKPixmap.Encode instead.")]
+		// Encode
+
+		public SKData Encode (SKEncodedImageFormat format, int quality)
+		{
+			using var pixmap = PeekPixels ();
+			return pixmap?.Encode (format, quality);
+		}
+
+		public bool Encode (Stream dst, SKEncodedImageFormat format, int quality)
+		{
+			using var wrapped = new SKManagedWStream (dst);
+			return Encode (wrapped, format, quality);
+		}
+
 		public bool Encode (SKWStream dst, SKEncodedImageFormat format, int quality)
 		{
-			return SKPixmap.Encode (dst, this, format, quality);
+			if (dst == null)
+				throw new ArgumentNullException (nameof (dst));
+
+			using var pixmap = PeekPixels ();
+			return pixmap?.Encode (dst, format, quality) ?? false;
 		}
 
+		// Swap
+
 		private void Swap (SKBitmap other)
 		{
 			SkiaApi.sk_bitmap_swap (Handle, other.Handle);

binding/Binding/SKCanvas.cs

@@ -32,6 +32,8 @@ namespace SkiaSharp
 		public void Discard () =>
 			SkiaApi.sk_canvas_discard (Handle);
 
+		// QuickReject
+
 		public bool QuickReject (SKRect rect)
 		{
 			return SkiaApi.sk_canvas_quick_reject (Handle, &rect);
@@ -44,6 +46,8 @@ namespace SkiaSharp
 			return path.IsEmpty || QuickReject (path.Bounds);
 		}
 
+		// Save*
+
 		public int Save ()
 		{
 			if (Handle == IntPtr.Zero)
@@ -61,11 +65,18 @@ namespace SkiaSharp
 			return SkiaApi.sk_canvas_save_layer (Handle, null, paint == null ? IntPtr.Zero : paint.Handle);
 		}
 
+		public int SaveLayer () =>
+			SaveLayer (null);
+
+		// DrawColor
+
 		public void DrawColor (SKColor color, SKBlendMode mode = SKBlendMode.Src)
 		{
 			SkiaApi.sk_canvas_draw_color (Handle, (uint)color, mode);
 		}
 
+		// DrawLine
+
 		public void DrawLine (SKPoint p0, SKPoint p1, SKPaint paint)
 		{
 			DrawLine (p0.X, p0.Y, p1.X, p1.Y, paint);
@@ -78,6 +89,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_line (Handle, x0, y0, x1, y1, paint.Handle);
 		}
 
+		// Clear
+
 		public void Clear ()
 		{
 			DrawColor (SKColors.Empty, SKBlendMode.Src);
@@ -88,6 +101,8 @@ namespace SkiaSharp
 			DrawColor (color, SKBlendMode.Src);
 		}
 
+		// Restore*
+
 		public void Restore ()
 		{
 			SkiaApi.sk_canvas_restore (Handle);
@@ -98,6 +113,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_restore_to_count (Handle, count);
 		}
 
+		// Translate
+
 		public void Translate (float dx, float dy)
 		{
 			SkiaApi.sk_canvas_translate (Handle, dx, dy);
@@ -107,7 +124,9 @@ namespace SkiaSharp
 		{
 			SkiaApi.sk_canvas_translate (Handle, point.X, point.Y);
 		}
-		
+
+		// Scale
+
 		public void Scale (float s)
 		{
 			SkiaApi.sk_canvas_scale (Handle, s, s);
@@ -130,6 +149,8 @@ namespace SkiaSharp
 			Translate (-px, -py);
 		}
 
+		// Rotate*
+
 		public void RotateDegrees (float degrees)
 		{
 			SkiaApi.sk_canvas_rotate_degrees (Handle, degrees);
@@ -147,13 +168,15 @@ namespace SkiaSharp
 			Translate (-px, -py);
 		}
 
-		public void RotateRadians(float radians, float px, float py)
+		public void RotateRadians (float radians, float px, float py)
 		{
 			Translate (px, py);
 			RotateRadians (radians);
 			Translate (-px, -py);
 		}
 
+		// Skew
+
 		public void Skew (float sx, float sy)
 		{
 			SkiaApi.sk_canvas_skew (Handle, sx, sy);
@@ -164,6 +187,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_skew (Handle, skew.X, skew.Y);
 		}
 
+		// Concat
+
 		public void Concat (ref SKMatrix m)
 		{
 			fixed (SKMatrix* ptr = &m) {
@@ -171,6 +196,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// Clip*
+
 		public void ClipRect (SKRect rect, SKClipOperation operation = SKClipOperation.Intersect, bool antialias = false)
 		{
 			SkiaApi.sk_canvas_clip_rect_with_operation (Handle, &rect, operation, antialias);
@@ -188,7 +215,7 @@ namespace SkiaSharp
 		{
 			if (path == null)
 				throw new ArgumentNullException (nameof (path));
-			
+
 			SkiaApi.sk_canvas_clip_path_with_operation (Handle, path.Handle, operation, antialias);
 		}
 
@@ -232,6 +259,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// DrawPaint
+
 		public void DrawPaint (SKPaint paint)
 		{
 			if (paint == null)
@@ -239,6 +268,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_paint (Handle, paint.Handle);
 		}
 
+		// DrawRegion
+
 		public void DrawRegion (SKRegion region, SKPaint paint)
 		{
 			if (region == null)
@@ -248,6 +279,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_region (Handle, region.Handle, paint.Handle);
 		}
 
+		// DrawRect
+
 		public void DrawRect (float x, float y, float w, float h, SKPaint paint)
 		{
 			DrawRect (SKRect.Create (x, y, w, h), paint);
@@ -260,6 +293,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_rect (Handle, &rect, paint.Handle);
 		}
 
+		// DrawRoundRect
+
 		public void DrawRoundRect (SKRoundRect rect, SKPaint paint)
 		{
 			if (rect == null)
@@ -286,6 +321,8 @@ namespace SkiaSharp
 			DrawRoundRect (rect, r.Width, r.Height, paint);
 		}
 
+		// DrawOval
+
 		public void DrawOval (float cx, float cy, float rx, float ry, SKPaint paint)
 		{
 			DrawOval (new SKRect (cx - rx, cy - ry, cx + rx, cy + ry), paint);
@@ -303,6 +340,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_oval (Handle, &rect, paint.Handle);
 		}
 
+		// DrawCircle
+
 		public void DrawCircle (float cx, float cy, float radius, SKPaint paint)
 		{
 			if (paint == null)
@@ -314,7 +353,9 @@ namespace SkiaSharp
 		{
 			DrawCircle (c.X, c.Y, radius, paint);
 		}
-		
+
+		// DrawPath
+
 		public void DrawPath (SKPath path, SKPaint paint)
 		{
 			if (paint == null)
@@ -324,7 +365,9 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_path (Handle, path.Handle, paint.Handle);
 		}
 
-		public void DrawPoints (SKPointMode mode, SKPoint [] points, SKPaint paint)
+		// DrawPoints
+
+		public void DrawPoints (SKPointMode mode, SKPoint[] points, SKPaint paint)
 		{
 			if (paint == null)
 				throw new ArgumentNullException (nameof (paint));
@@ -335,6 +378,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// DrawPoint
+
 		public void DrawPoint (SKPoint p, SKPaint paint)
 		{
 			DrawPoint (p.X, p.Y, paint);
@@ -359,6 +404,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// DrawImage
+
 		public void DrawImage (SKImage image, SKPoint p, SKPaint paint = null)
 		{
 			DrawImage (image, p.X, p.Y, paint);
@@ -385,6 +432,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_image_rect (Handle, image.Handle, &source, &dest, paint == null ? IntPtr.Zero : paint.Handle);
 		}
 
+		// DrawPicture
+
 		public void DrawPicture (SKPicture picture, float x, float y, SKPaint paint = null)
 		{
 			var matrix = SKMatrix.MakeTranslation (x, y);
@@ -412,6 +461,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_picture (Handle, picture.Handle, null, paint == null ? IntPtr.Zero : paint.Handle);
 		}
 
+		// DrawDrawable
+
 		public void DrawDrawable (SKDrawable drawable, ref SKMatrix matrix)
 		{
 			if (drawable == null)
@@ -437,6 +488,8 @@ namespace SkiaSharp
 			DrawDrawable (drawable, ref matrix);
 		}
 
+		// DrawBitmap
+
 		public void DrawBitmap (SKBitmap bitmap, SKPoint p, SKPaint paint = null)
 		{
 			DrawBitmap (bitmap, p.X, p.Y, paint);
@@ -463,6 +516,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_bitmap_rect (Handle, bitmap.Handle, &source, &dest, paint == null ? IntPtr.Zero : paint.Handle);
 		}
 
+		// DrawSurface
+
 		public void DrawSurface (SKSurface surface, SKPoint p, SKPaint paint = null)
 		{
 			DrawSurface (surface, p.X, p.Y, paint);
@@ -476,6 +531,8 @@ namespace SkiaSharp
 			surface.Draw (this, x, y, paint);
 		}
 
+		// DrawText (SKTextBlob)
+
 		public void DrawText (SKTextBlob text, float x, float y, SKPaint paint)
 		{
 			if (text == null)
@@ -486,6 +543,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_text_blob (Handle, text.Handle, x, y, paint.Handle);
 		}
 
+		// DrawText
+
 		public void DrawText (string text, SKPoint p, SKPaint paint)
 		{
 			DrawText (text, p.X, p.Y, paint);
@@ -519,7 +578,24 @@ namespace SkiaSharp
 			}
 		}
 
-		public void DrawPositionedText (string text, SKPoint [] points, SKPaint paint)
+		public void DrawText (IntPtr buffer, int length, SKPoint p, SKPaint paint)
+		{
+			DrawText (buffer, length, p.X, p.Y, paint);
+		}
+
+		public void DrawText (IntPtr buffer, int length, float x, float y, SKPaint paint)
+		{
+			if (buffer == IntPtr.Zero && length != 0)
+				throw new ArgumentNullException (nameof (buffer));
+			if (paint == null)
+				throw new ArgumentNullException (nameof (paint));
+
+			SkiaApi.sk_canvas_draw_text (Handle, (void*)buffer, (IntPtr)length, x, y, paint.Handle);
+		}
+
+		// DrawPositionedText
+
+		public void DrawPositionedText (string text, SKPoint[] points, SKPaint paint)
 		{
 			if (text == null)
 				throw new ArgumentNullException (nameof (text));
@@ -532,7 +608,7 @@ namespace SkiaSharp
 			DrawPositionedText (bytes, points, paint);
 		}
 
-		public void DrawPositionedText (byte[] text, SKPoint [] points, SKPaint paint)
+		public void DrawPositionedText (byte[] text, SKPoint[] points, SKPaint paint)
 		{
 			if (text == null)
 				throw new ArgumentNullException (nameof (text));
@@ -547,38 +623,6 @@ namespace SkiaSharp
 			}
 		}
 
-		public void DrawTextOnPath (IntPtr buffer, int length, SKPath path, SKPoint offset, SKPaint paint)
-		{
-			DrawTextOnPath (buffer, length, path, offset.X, offset.Y, paint);
-		}
-
-		public void DrawTextOnPath (IntPtr buffer, int length, SKPath path, float hOffset, float vOffset, SKPaint paint)
-		{
-			if (buffer == IntPtr.Zero && length != 0)
-				throw new ArgumentNullException (nameof (buffer));
-			if (paint == null)
-				throw new ArgumentNullException (nameof (paint));
-			if (paint == null)
-				throw new ArgumentNullException (nameof (paint));
-			
-			SkiaApi.sk_canvas_draw_text_on_path (Handle, (void*)buffer, (IntPtr)length, path.Handle, hOffset, vOffset, paint.Handle);
-		}
-
-		public void DrawText (IntPtr buffer, int length, SKPoint p, SKPaint paint)
-		{
-			DrawText (buffer, length, p.X, p.Y, paint);
-		}
-
-		public void DrawText (IntPtr buffer, int length, float x, float y, SKPaint paint)
-		{
-			if (buffer == IntPtr.Zero && length != 0)
-				throw new ArgumentNullException (nameof (buffer));
-			if (paint == null)
-				throw new ArgumentNullException (nameof (paint));
-			
-			SkiaApi.sk_canvas_draw_text (Handle, (void*)buffer, (IntPtr)length, x, y, paint.Handle);
-		}
-
 		public void DrawPositionedText (IntPtr buffer, int length, SKPoint[] points, SKPaint paint)
 		{
 			if (buffer == IntPtr.Zero && length != 0)
@@ -593,6 +637,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// DrawTextOnPath
+
 		public void DrawTextOnPath (string text, SKPath path, SKPoint offset, SKPaint paint)
 		{
 			DrawTextOnPath (text, path, offset.X, offset.Y, paint);
@@ -602,8 +648,8 @@ namespace SkiaSharp
 		{
 			if (text == null)
 				throw new ArgumentNullException (nameof (text));
-			if (paint == null)
-				throw new ArgumentNullException (nameof (paint));
+			if (path == null)
+				throw new ArgumentNullException (nameof (path));
 			if (paint == null)
 				throw new ArgumentNullException (nameof (paint));
 
@@ -620,8 +666,8 @@ namespace SkiaSharp
 		{
 			if (text == null)
 				throw new ArgumentNullException (nameof (text));
-			if (paint == null)
-				throw new ArgumentNullException (nameof (paint));
+			if (path == null)
+				throw new ArgumentNullException (nameof (path));
 			if (paint == null)
 				throw new ArgumentNullException (nameof (paint));
 
@@ -630,11 +676,32 @@ namespace SkiaSharp
 			}
 		}
 
+		public void DrawTextOnPath (IntPtr buffer, int length, SKPath path, SKPoint offset, SKPaint paint)
+		{
+			DrawTextOnPath (buffer, length, path, offset.X, offset.Y, paint);
+		}
+
+		public void DrawTextOnPath (IntPtr buffer, int length, SKPath path, float hOffset, float vOffset, SKPaint paint)
+		{
+			if (buffer == IntPtr.Zero && length != 0)
+				throw new ArgumentNullException (nameof (buffer));
+			if (path == null)
+				throw new ArgumentNullException (nameof (path));
+			if (paint == null)
+				throw new ArgumentNullException (nameof (paint));
+
+			SkiaApi.sk_canvas_draw_text_on_path (Handle, (void*)buffer, (IntPtr)length, path.Handle, hOffset, vOffset, paint.Handle);
+		}
+
+		// Flush
+
 		public void Flush ()
 		{
 			SkiaApi.sk_canvas_flush (Handle);
 		}
 
+		// Draw*Annotation
+
 		public void DrawAnnotation (SKRect rect, string key, SKData value)
 		{
 			var bytes = StringUtilities.GetEncodedText (key, SKTextEncoding.Utf8);
@@ -679,6 +746,8 @@ namespace SkiaSharp
 			return data;
 		}
 
+		// Draw*NinePatch
+
 		public void DrawBitmapNinePatch (SKBitmap bitmap, SKRectI center, SKRect dst, SKPaint paint = null)
 		{
 			if (bitmap == null)
@@ -701,6 +770,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_image_nine (Handle, image.Handle, &center, &dst, paint == null ? IntPtr.Zero : paint.Handle);
 		}
 
+		// Draw*Lattice
+
 		public void DrawBitmapLattice (SKBitmap bitmap, int[] xDivs, int[] yDivs, SKRect dst, SKPaint paint = null)
 		{
 			var lattice = new SKLattice {
@@ -718,7 +789,7 @@ namespace SkiaSharp
 			};
 			DrawImageLattice (image, lattice, dst, paint);
 		}
-		
+
 		public void DrawBitmapLattice (SKBitmap bitmap, SKLattice lattice, SKRect dst, SKPaint paint = null)
 		{
 			if (bitmap == null)
@@ -757,7 +828,7 @@ namespace SkiaSharp
 				throw new ArgumentNullException (nameof (lattice.XDivs));
 			if (lattice.YDivs == null)
 				throw new ArgumentNullException (nameof (lattice.YDivs));
-			
+
 			fixed (int* x = lattice.XDivs)
 			fixed (int* y = lattice.YDivs)
 			fixed (SKLatticeRectType* r = lattice.RectTypes)
@@ -779,6 +850,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// *Matrix
+
 		public void ResetMatrix ()
 		{
 			SkiaApi.sk_canvas_reset_matrix (Handle);
@@ -791,30 +864,34 @@ namespace SkiaSharp
 
 		public SKMatrix TotalMatrix {
 			get {
-				SKMatrix matrix = new SKMatrix();
+				SKMatrix matrix;
 				SkiaApi.sk_canvas_get_total_matrix (Handle, &matrix);
 				return matrix;
 			}
 		}
 
+		// SaveCount
+
 		public int SaveCount => SkiaApi.sk_canvas_get_save_count (Handle);
 
+		// DrawVertices
+
 		public void DrawVertices (SKVertexMode vmode, SKPoint[] vertices, SKColor[] colors, SKPaint paint)
 		{
-			var vert = SKVertices.CreateCopy(vmode, vertices, colors);
-			DrawVertices(vert, SKBlendMode.Modulate, paint);
+			var vert = SKVertices.CreateCopy (vmode, vertices, colors);
+			DrawVertices (vert, SKBlendMode.Modulate, paint);
 		}
 
 		public void DrawVertices (SKVertexMode vmode, SKPoint[] vertices, SKPoint[] texs, SKColor[] colors, SKPaint paint)
 		{
-			var vert = SKVertices.CreateCopy(vmode, vertices, texs, colors);
-			DrawVertices(vert, SKBlendMode.Modulate, paint);
+			var vert = SKVertices.CreateCopy (vmode, vertices, texs, colors);
+			DrawVertices (vert, SKBlendMode.Modulate, paint);
 		}
 
 		public void DrawVertices (SKVertexMode vmode, SKPoint[] vertices, SKPoint[] texs, SKColor[] colors, UInt16[] indices, SKPaint paint)
 		{
-			var vert = SKVertices.CreateCopy(vmode, vertices, texs, colors, indices);
-			DrawVertices(vert, SKBlendMode.Modulate, paint);
+			var vert = SKVertices.CreateCopy (vmode, vertices, texs, colors, indices);
+			DrawVertices (vert, SKBlendMode.Modulate, paint);
 		}
 
 		public void DrawVertices (SKVertexMode vmode, SKPoint[] vertices, SKPoint[] texs, SKColor[] colors, SKBlendMode mode, UInt16[] indices, SKPaint paint)
@@ -832,6 +909,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_vertices (Handle, vertices.Handle, mode, paint.Handle);
 		}
 
+		// DrawArc
+
 		public void DrawArc (SKRect oval, float startAngle, float sweepAngle, bool useCenter, SKPaint paint)
 		{
 			if (paint == null)
@@ -839,6 +918,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_arc (Handle, &oval, startAngle, sweepAngle, useCenter, paint.Handle);
 		}
 
+		// DrawRoundRectDifference
+
 		public void DrawRoundRectDifference (SKRoundRect outer, SKRoundRect inner, SKPaint paint)
 		{
 			if (outer == null)
@@ -851,6 +932,8 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_drrect (Handle, outer.Handle, inner.Handle, paint.Handle);
 		}
 
+		// DrawAtlas
+
 		public void DrawAtlas (SKImage atlas, SKRect[] sprites, SKRotationScaleMatrix[] transforms, SKPaint paint) =>
 			DrawAtlas (atlas, sprites, transforms, null, SKBlendMode.Dst, null, paint);
 
@@ -881,6 +964,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// DrawPatch
+
 		public void DrawPatch (SKPoint[] cubics, SKColor[] colors, SKPoint[] texCoords, SKPaint paint) =>
 			DrawPatch (cubics, colors, texCoords, SKBlendMode.Modulate, paint);
 
@@ -949,4 +1034,3 @@ namespace SkiaSharp
 		}
 	}
 }
-

binding/Binding/SKColor.cs

@@ -100,8 +100,8 @@ namespace SkiaSharp
 		public readonly bool Equals (SKColor obj) =>
 			obj.color == color;
 
-		public readonly override bool Equals (object obj) =>
-			obj is SKColor f && Equals (f);
+		public readonly override bool Equals (object other) =>
+			other is SKColor f && Equals (f);
 
 		public static bool operator == (SKColor left, SKColor right) =>
 			left.Equals (right);

binding/Binding/SKColorSpace.cs

@@ -29,6 +29,8 @@ namespace SkiaSharp
 		protected override void Dispose (bool disposing) =>
 			base.Dispose (disposing);
 
+		// properties
+
 		public bool GammaIsCloseToSrgb =>
 			SkiaApi.sk_colorspace_gamma_close_to_srgb (Handle);
 
@@ -57,10 +59,16 @@ namespace SkiaSharp
 			return SkiaApi.sk_colorspace_equals (left.Handle, right.Handle);
 		}
 
+		// CreateSrgb
+
 		public static SKColorSpace CreateSrgb () => srgb;
 
+		// CreateSrgbLinear
+
 		public static SKColorSpace CreateSrgbLinear () => srgbLinear;
 
+		// CreateIcc
+
 		public static SKColorSpace CreateIcc (IntPtr input, long length)
 		{
 			if (input == IntPtr.Zero)
@@ -89,6 +97,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// CreateRgb
+
 		[EditorBrowsable (EditorBrowsableState.Never)]
 		[Obsolete ("Use CreateRgb(SKColorSpaceRenderTargetGamma, SKMatrix44) instead.")]
 		public static SKColorSpace CreateRgb (SKColorSpaceRenderTargetGamma gamma, SKMatrix44 toXyzD50, SKColorSpaceFlags flags) =>
@@ -142,13 +152,7 @@ namespace SkiaSharp
 		public static SKColorSpace CreateRgb (SKNamedGamma gamma, SKColorSpaceGamut gamut) =>
 			GetObject<SKColorSpace> (SkiaApi.sk_colorspace_new_rgb_with_gamma_named_and_gamut (gamma, gamut));
 
-		public bool ToXyzD50 (SKMatrix44 toXyzD50)
-		{
-			if (toXyzD50 == null)
-				throw new ArgumentNullException (nameof (toXyzD50));
-
-			return SkiaApi.sk_colorspace_to_xyzd50 (Handle, toXyzD50.Handle);
-		}
+		// GetNumericalTransferFunction
 
 		public bool GetNumericalTransferFunction (out SKColorSpaceTransferFn fn)
 		{
@@ -157,12 +161,24 @@ namespace SkiaSharp
 			}
 		}
 
+		// *XyzD50
+
 		public SKMatrix44 ToXyzD50 () =>
 			GetObject<SKMatrix44> (SkiaApi.sk_colorspace_as_to_xyzd50 (Handle), false);
 
+		public bool ToXyzD50 (SKMatrix44 toXyzD50)
+		{
+			if (toXyzD50 == null)
+				throw new ArgumentNullException (nameof (toXyzD50));
+
+			return SkiaApi.sk_colorspace_to_xyzd50 (Handle, toXyzD50.Handle);
+		}
+
 		public SKMatrix44 FromXyzD50 () =>
 			GetObject<SKMatrix44> (SkiaApi.sk_colorspace_as_from_xyzd50 (Handle), false);
 
+		//
+
 		private sealed class SKColorSpaceStatic : SKColorSpace
 		{
 			internal SKColorSpaceStatic (IntPtr x)

binding/Binding/SKData.cs

@@ -3,6 +3,7 @@ using System.Runtime.InteropServices;
 using System.IO;
 using System.Text;
 using System.ComponentModel;
+using System.Buffers;
 
 namespace SkiaSharp
 {
@@ -41,6 +42,8 @@ namespace SkiaSharp
 
 		public static SKData Empty => empty.Value;
 
+		// CreateCopy
+
 		public static SKData CreateCopy (IntPtr bytes, ulong length)
 		{
 			if (SizeOf <IntPtr> () == 4 && length > UInt32.MaxValue)
@@ -65,6 +68,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// Create
+
 		public static SKData Create (int size)
 		{
 			return GetObject<SKData> (SkiaApi.sk_data_new_uninitialized ((IntPtr) size));
@@ -83,7 +88,7 @@ namespace SkiaSharp
 			if (string.IsNullOrEmpty (filename))
 				throw new ArgumentException ("The filename cannot be empty.", nameof (filename));
 
-			var utf8path = StringUtilities.GetEncodedText (filename, SKEncoding.Utf8);
+			var utf8path = StringUtilities.GetEncodedText (filename, SKTextEncoding.Utf8);
 			fixed (byte* u = utf8path) {
 				return GetObject<SKData> (SkiaApi.sk_data_new_from_file (u));
 			}
@@ -180,6 +185,8 @@ namespace SkiaSharp
 			return SKData.CreateCopy (bytes, (ulong)(bytes.Length + 1)); // + 1 for the terminating char
 		}
 
+		// Subset
+
 		public SKData Subset (ulong offset, ulong length)
 		{
 			if (SizeOf <IntPtr> () == 4) {
@@ -191,6 +198,8 @@ namespace SkiaSharp
 			return GetObject<SKData> (SkiaApi.sk_data_new_subset (Handle, (IntPtr) offset, (IntPtr) length));
 		}
 
+		// ToArray
+
 		public byte[] ToArray ()
 		{
 			var array = AsSpan ().ToArray ();
@@ -198,41 +207,54 @@ namespace SkiaSharp
 			return array;
 		}
 
+		// properties
+
 		public bool IsEmpty => Size == 0;
 
 		public long Size => (long)SkiaApi.sk_data_get_size (Handle);
 
 		public IntPtr Data => (IntPtr)SkiaApi.sk_data_get_data (Handle);
 
+		// AsStream
+
 		public Stream AsStream () =>
 			new SKDataStream (this, false);
 
 		public Stream AsStream (bool streamDisposesData) =>
 			new SKDataStream (this, streamDisposesData);
 
+		// AsSpan
+
 		public ReadOnlySpan<byte> AsSpan ()
 		{
 			return new ReadOnlySpan<byte> ((void*)Data, (int)Size);
 		}
 
+		// SaveTo
+
 		public void SaveTo (Stream target)
 		{
 			if (target == null)
 				throw new ArgumentNullException (nameof (target));
 
-			var buffer = new byte [CopyBufferSize];
 			var ptr = Data;
 			var total = Size;
-
-			for (var left = total; left > 0; ) {
-				var copyCount = (int) Math.Min (CopyBufferSize, left);
-				Marshal.Copy (ptr, buffer, 0, copyCount);
-				left -= copyCount;
-				ptr += copyCount;
-				target.Write (buffer, 0, copyCount);
+			var buffer = ArrayPool<byte>.Shared.Rent (CopyBufferSize);
+			try {
+				for (var left = total; left > 0;) {
+					var copyCount = (int)Math.Min (CopyBufferSize, left);
+					Marshal.Copy (ptr, buffer, 0, copyCount);
+					left -= copyCount;
+					ptr += copyCount;
+					target.Write (buffer, 0, copyCount);
+				}
+			} finally {
+				ArrayPool<byte>.Shared.Return (buffer);
 			}
 		}
 
+		//
+
 		private class SKDataStream : UnmanagedMemoryStream
 		{
 			private SKData host;

binding/Binding/SKDocument.cs

@@ -8,9 +8,6 @@ namespace SkiaSharp
 	{
 		public const float DefaultRasterDpi = 72.0f;
 
-		// keep the stream alive for as long as the document exists
-		private SKWStream underlyingStream;
-
 		[Preserve]
 		internal SKDocument (IntPtr handle, bool owns)
 			: base (handle, owns)
@@ -111,7 +108,7 @@ namespace SkiaSharp
 				throw new ArgumentNullException (nameof (stream));
 			}
 
-			return GetObject<SKDocument> (SkiaApi.sk_document_create_pdf_from_stream (stream.Handle));
+			return Referenced (GetObject<SKDocument> (SkiaApi.sk_document_create_pdf_from_stream (stream.Handle)), stream);
 		}
 
 		public static SKDocument CreatePdf (string path, float dpi) =>
@@ -167,37 +164,19 @@ namespace SkiaSharp
 					fEncodingQuality = metadata.EncodingQuality,
 				};
 
+				SKTimeDateTimeInternal creation;
 				if (metadata.Creation != null) {
-					var creation = SKTimeDateTimeInternal.Create (metadata.Creation.Value);
+					creation = SKTimeDateTimeInternal.Create (metadata.Creation.Value);
 					cmetadata.fCreation = &creation;
 				}
+				SKTimeDateTimeInternal modified;
 				if (metadata.Modified != null) {
-					var modified = SKTimeDateTimeInternal.Create (metadata.Modified.Value);
+					modified = SKTimeDateTimeInternal.Create (metadata.Modified.Value);
 					cmetadata.fModified = &modified;
 				}
 
 				return Referenced (GetObject<SKDocument> (SkiaApi.sk_document_create_pdf_from_stream_with_metadata (stream.Handle, &cmetadata)), stream);
 			}
 		}
-
-		private static SKDocument Owned (SKDocument doc, SKWStream stream)
-		{
-			if (stream != null) {
-				if (doc != null)
-					doc.SetDisposeChild (stream);
-				else
-					stream.Dispose ();
-			}
-
-			return doc;
-		}
-
-		private static SKDocument Referenced (SKDocument doc, SKWStream stream)
-		{
-			if (stream != null && doc != null)
-				doc.underlyingStream = stream;
-
-			return doc;
-		}
 	}
 }

binding/Binding/SKFontManager.cs

@@ -85,7 +85,7 @@ namespace SkiaSharp
 			if (path == null)
 				throw new ArgumentNullException (nameof (path));
 
-			var utf8path = StringUtilities.GetEncodedText (path, SKEncoding.Utf8);
+			var utf8path = StringUtilities.GetEncodedText (path, SKTextEncoding.Utf8);
 			fixed (byte* u = utf8path) {
 				return GetObject<SKTypeface> (SkiaApi.sk_fontmgr_create_from_file (Handle, u, index));
 			}

binding/Binding/SKImage.cs

@@ -43,7 +43,7 @@ namespace SkiaSharp
 			if (pixels == null)
 				throw new ArgumentNullException (nameof (pixels));
 			using (var data = SKData.Create (pixels)) {
-				return FromPixelData (info, data, rowBytes);
+				return FromPixels (info, data, rowBytes);
 			}
 		}
 
@@ -55,7 +55,7 @@ namespace SkiaSharp
 			if (pixels == null)
 				throw new ArgumentNullException (nameof (pixels));
 			using (var data = SKData.Create (pixels)) {
-				return FromPixelData (info, data, rowBytes);
+				return FromPixels (info, data, rowBytes);
 			}
 		}
 
@@ -67,7 +67,7 @@ namespace SkiaSharp
 			if (pixels == null)
 				throw new ArgumentNullException (nameof (pixels));
 			using (var data = SKData.CreateCopy (pixels)) {
-				return FromPixelData (info, data, rowBytes);
+				return FromPixels (info, data, rowBytes);
 			}
 		}
 
@@ -103,12 +103,14 @@ namespace SkiaSharp
 			if (pixels == null)
 				throw new ArgumentNullException (nameof (pixels));
 			using (var data = SKData.CreateCopy (pixels)) {
-				return FromPixelData (info, data, rowBytes);
+				return FromPixels (info, data, rowBytes);
 			}
 		}
 
 		// create a new image around existing pixel data
 
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use FromPixels (SKImageInfo, SKData, int) instead.")]
 		public static SKImage FromPixelData (SKImageInfo info, SKData data, int rowBytes)
 		{
 			if (data == null)
@@ -117,6 +119,9 @@ namespace SkiaSharp
 			return GetObject<SKImage> (SkiaApi.sk_image_new_raster_data (&cinfo, data.Handle, (IntPtr)rowBytes));
 		}
 
+		public static SKImage FromPixels (SKImageInfo info, SKData data) =>
+			FromPixels (info, data, info.RowBytes);
+
 		public static SKImage FromPixels (SKImageInfo info, SKData data, int rowBytes)
 		{
 			if (data == null)

binding/Binding/SKImageFilter.cs

@@ -19,11 +19,15 @@ namespace SkiaSharp
 		protected override void Dispose (bool disposing) =>
 			base.Dispose (disposing);
 
+		// CreateMatrix
+
 		public static SKImageFilter CreateMatrix(SKMatrix matrix, SKFilterQuality quality, SKImageFilter input = null)
 		{
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_matrix(&matrix, quality, input == null ? IntPtr.Zero : input.Handle));
 		}
 
+		// CreateAlphaThreshold
+
 		public static SKImageFilter CreateAlphaThreshold(SKRectI region, float innerThreshold, float outerThreshold, SKImageFilter input = null)
 		{
 			var reg = new SKRegion ();
@@ -39,11 +43,15 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_alpha_threshold(region.Handle, innerThreshold, outerThreshold, input == null ? IntPtr.Zero : input.Handle));
 		}
 
+		// CreateBlur
+
 		public static SKImageFilter CreateBlur(float sigmaX, float sigmaY, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_blur(sigmaX, sigmaY, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// CreateColorFilter
+
 		public static SKImageFilter CreateColorFilter(SKColorFilter cf, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			if (cf == null)
@@ -51,6 +59,8 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_color_filter(cf.Handle, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// CreateCompose
+
 		public static SKImageFilter CreateCompose(SKImageFilter outer, SKImageFilter inner)
 		{
 			if (outer == null)
@@ -60,6 +70,8 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_compose(outer.Handle, inner.Handle));
 		}
 
+		// CreateDisplacementMapEffect
+
 		public static SKImageFilter CreateDisplacementMapEffect(SKDisplacementMapEffectChannelSelectorType xChannelSelector, SKDisplacementMapEffectChannelSelectorType yChannelSelector, float scale, SKImageFilter displacement, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			if (displacement == null)
@@ -67,11 +79,15 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_displacement_map_effect(xChannelSelector, yChannelSelector, scale, displacement.Handle, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// CreateDropShadow
+
 		public static SKImageFilter CreateDropShadow(float dx, float dy, float sigmaX, float sigmaY, SKColor color, SKDropShadowImageFilterShadowMode shadowMode, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_drop_shadow(dx, dy, sigmaX, sigmaY, (uint)color, shadowMode, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// Create*LitDiffuse
+
 		public static SKImageFilter CreateDistantLitDiffuse(SKPoint3 direction, SKColor lightColor, float surfaceScale, float kd, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_distant_lit_diffuse(&direction, (uint)lightColor, surfaceScale, kd, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
@@ -87,6 +103,8 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_spot_lit_diffuse(&location, &target, specularExponent, cutoffAngle, (uint)lightColor, surfaceScale, kd, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// Create*LitSpecular
+
 		public static SKImageFilter CreateDistantLitSpecular(SKPoint3 direction, SKColor lightColor, float surfaceScale, float ks, float shininess, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_distant_lit_specular(&direction, (uint)lightColor, surfaceScale, ks, shininess, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
@@ -102,11 +120,15 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_spot_lit_specular(&location, &target, specularExponent, cutoffAngle, (uint)lightColor, surfaceScale, ks, shininess, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// CreateMagnifier
+
 		public static SKImageFilter CreateMagnifier(SKRect src, float inset, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_magnifier(&src, inset, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// CreateMatrixConvolution
+
 		public static SKImageFilter CreateMatrixConvolution(SKSizeI kernelSize, float[] kernel, float gain, float bias, SKPointI kernelOffset, SKMatrixConvolutionTileMode tileMode, bool convolveAlpha, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			if (kernel == null)
@@ -118,11 +140,13 @@ namespace SkiaSharp
 			}
 		}
 
+		// CreateMerge
+
 		[EditorBrowsable (EditorBrowsableState.Never)]
 		[Obsolete("Use CreateMerge(SKImageFilter, SKImageFilter, SKImageFilter.CropRect) instead.")]
 		public static SKImageFilter CreateMerge(SKImageFilter first, SKImageFilter second, SKBlendMode mode, SKImageFilter.CropRect cropRect = null)
 		{
-			return CreateMerge(new [] { first, second }, new [] { mode, mode }, cropRect);
+			return CreateMerge(new [] { first, second }, cropRect);
 		}
 
 		public static SKImageFilter CreateMerge(SKImageFilter first, SKImageFilter second, SKImageFilter.CropRect cropRect = null)
@@ -151,21 +175,29 @@ namespace SkiaSharp
 			}
 		}
 
+		// CreateDilate
+
 		public static SKImageFilter CreateDilate(int radiusX, int radiusY, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_dilate(radiusX, radiusY, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// CreateErode
+
 		public static SKImageFilter CreateErode(int radiusX, int radiusY, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_erode(radiusX, radiusY, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// CreateOffset
+
 		public static SKImageFilter CreateOffset(float dx, float dy, SKImageFilter input = null, SKImageFilter.CropRect cropRect = null)
 		{
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_offset(dx, dy, input == null ? IntPtr.Zero : input.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// CreatePicture
+
 		public static SKImageFilter CreatePicture(SKPicture picture)
 		{
 			if (picture == null)
@@ -180,6 +212,8 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_picture_with_croprect(picture.Handle, &cropRect));
 		}
 
+		// CreateTile
+
 		public static SKImageFilter CreateTile(SKRect src, SKRect dst, SKImageFilter input)
 		{
 			if (input == null)
@@ -187,6 +221,8 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_tile(&src, &dst, input.Handle));
 		}
 
+		// CreateBlendMode
+
 		public static SKImageFilter CreateBlendMode(SKBlendMode mode, SKImageFilter background, SKImageFilter foreground = null, SKImageFilter.CropRect cropRect = null)
 		{
 			if (background == null)
@@ -194,6 +230,8 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_xfermode(mode, background.Handle, foreground == null ? IntPtr.Zero : foreground.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// CreateArithmetic
+
 		public static SKImageFilter CreateArithmetic(float k1, float k2, float k3, float k4, bool enforcePMColor, SKImageFilter background, SKImageFilter foreground = null, SKImageFilter.CropRect cropRect = null)
 		{
 			if (background == null)
@@ -201,6 +239,8 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_arithmetic(k1, k2, k3, k4, enforcePMColor, background.Handle, foreground == null ? IntPtr.Zero : foreground.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		// CreateImage
+
 		public static SKImageFilter CreateImage(SKImage image)
 		{
 			if (image == null)
@@ -215,6 +255,8 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_image_source(image.Handle, &src, &dst, filterQuality));
 		}
 
+		// CreatePaint
+
 		public static SKImageFilter CreatePaint(SKPaint paint, SKImageFilter.CropRect cropRect = null)
 		{
 			if (paint == null)
@@ -222,6 +264,8 @@ namespace SkiaSharp
 			return GetObject<SKImageFilter>(SkiaApi.sk_imagefilter_new_paint(paint.Handle, cropRect == null ? IntPtr.Zero : cropRect.Handle));
 		}
 
+		//
+
 		public class CropRect : SKObject
 		{
 			internal CropRect(IntPtr handle, bool owns)

binding/Binding/SKImageInfo.cs

@@ -100,21 +100,7 @@ namespace SkiaSharp
 		}
 
 		public readonly int BytesPerPixel =>
-			ColorType switch
-			{
-				SKColorType.Unknown => 0,
-				SKColorType.Alpha8 => 1,
-				SKColorType.Gray8 => 1,
-				SKColorType.Rgb565 => 2,
-				SKColorType.Argb4444 => 2,
-				SKColorType.Bgra8888 => 4,
-				SKColorType.Rgba8888 => 4,
-				SKColorType.Rgb888x => 4,
-				SKColorType.Rgba1010102 => 4,
-				SKColorType.Rgb101010x => 4,
-				SKColorType.RgbaF16 => 8,
-				_ => throw new ArgumentOutOfRangeException (nameof (ColorType)),
-			};
+			ColorType.GetBytesPerPixel ();
 
 		public readonly int BitsPerPixel => BytesPerPixel * 8;
 
@@ -134,6 +120,9 @@ namespace SkiaSharp
 
 		public readonly SKRectI Rect => SKRectI.Create (Width, Height);
 
+		public readonly SKImageInfo WithSize (SKSizeI size) =>
+			WithSize (size.Width, size.Height);
+
 		public readonly SKImageInfo WithSize (int width, int height)
 		{
 			var copy = this;

binding/Binding/SKManagedStream.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Buffers;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Text;
@@ -33,12 +34,16 @@ namespace SkiaSharp
 			if (destination == null)
 				throw new ArgumentNullException (nameof (destination));
 
-			var buffer = new byte[SKData.CopyBufferSize];
 			var total = 0;
 			int len;
-			while ((len = stream.Read (buffer, 0, buffer.Length)) > 0) {
-				destination.Write (buffer, len);
-				total += len;
+			var buffer = ArrayPool<byte>.Shared.Rent (SKData.CopyBufferSize);
+			try {
+				while ((len = stream.Read (buffer, 0, buffer.Length)) > 0) {
+					destination.Write (buffer, len);
+					total += len;
+				}
+			} finally {
+				ArrayPool<byte>.Shared.Return (buffer);
 			}
 			destination.Flush ();
 			return total;

binding/Binding/SKManagedWStream.cs

@@ -1,6 +1,7 @@
 using System;
-using System.Runtime.InteropServices;
+using System.Buffers;
 using System.IO;
+using System.Runtime.InteropServices;
 
 namespace SkiaSharp
 {
@@ -42,11 +43,15 @@ namespace SkiaSharp
 		protected override bool OnWrite (IntPtr buffer, IntPtr size)
 		{
 			var count = (int)size;
-			var managedBuffer = new byte[count];
-			if (buffer != IntPtr.Zero) { 
-				Marshal.Copy (buffer, managedBuffer, 0, count);
+			var managedBuffer = ArrayPool<byte>.Shared.Rent (count);
+			try {
+				if (buffer != IntPtr.Zero) {
+					Marshal.Copy (buffer, managedBuffer, 0, count);
+				}
+				stream.Write (managedBuffer, 0, count);
+			} finally {
+				ArrayPool<byte>.Shared.Return (managedBuffer);
 			}
-			stream.Write (managedBuffer, 0, count);
 			return true;
 		}
 
@@ -55,7 +60,7 @@ namespace SkiaSharp
 			stream.Flush ();
 		}
 
-		protected override IntPtr OnBytesWritten()
+		protected override IntPtr OnBytesWritten ()
 		{
 			return (IntPtr)stream.Position;
 		}

binding/Binding/SKMask.cs

@@ -28,6 +28,9 @@ namespace SkiaSharp
 			set => fImage = (byte*)value;
 		}
 
+		public Span<byte> GetImageSpan () =>
+			new Span<byte> ((void*)Image, (int)ComputeTotalImageSize ());
+
 		public SKRectI Bounds {
 			readonly get => fBounds;
 			set => fBounds = value;
@@ -131,22 +134,28 @@ namespace SkiaSharp
 		public static void FreeImage (IntPtr image) =>
 			SkiaApi.sk_mask_free_image ((byte*)image);
 
-		public static SKMask Create (byte[] image, SKRectI bounds, UInt32 rowBytes, SKMaskFormat format)
+		public static SKMask Create (byte[] image, SKRectI bounds, UInt32 rowBytes, SKMaskFormat format) =>
+			Create (image.AsSpan (), bounds, rowBytes, format);
+
+		public static SKMask Create (ReadOnlySpan<byte> image, SKRectI bounds, UInt32 rowBytes, SKMaskFormat format)
 		{
 			// create the mask
 			var mask = new SKMask (bounds, rowBytes, format);
 
+			// calculate the size
+			var imageSize = (int)mask.ComputeTotalImageSize ();
+
 			// is there the right amount of space in the mask
-			if (image.Length != mask.ComputeTotalImageSize ()) {
+			if (image.Length != imageSize) {
 				// Note: buffer.Length must match bounds.Height * rowBytes
-				var expectedHeight = bounds.Height * rowBytes;
-				var message = $"Length of image ({image.Length}) does not match the computed size of the mask ({expectedHeight}). Check the {nameof (bounds)} and {nameof (rowBytes)}.";
+				var expectedSize = bounds.Height * rowBytes;
+				var message = $"Length of image ({image.Length}) does not match the computed size of the mask ({expectedSize}). Check the {nameof (bounds)} and {nameof (rowBytes)}.";
 				throw new ArgumentException (message);
 			}
 
-			// copy the image data
+			// allocate and copy the image data
 			mask.AllocateImage ();
-			Marshal.Copy (image, 0, (IntPtr)mask.fImage, image.Length);
+			image.CopyTo (new Span<byte> ((void*)mask.Image, imageSize));
 
 			// return the mask
 			return mask;

binding/Binding/SKMatrix.cs

@@ -26,6 +26,26 @@ namespace SkiaSharp
 			public const int Count = 9;
 		}
 
+		public SKMatrix (float[] values)
+		{
+			if (values == null)
+				throw new ArgumentNullException (nameof (values));
+			if (values.Length != Indices.Count)
+				throw new ArgumentException ($"The matrix array must have a length of {Indices.Count}.", nameof (values));
+
+			scaleX = values[Indices.ScaleX];
+			skewX = values[Indices.SkewX];
+			transX = values[Indices.TransX];
+
+			skewY = values[Indices.SkewY];
+			scaleY = values[Indices.ScaleY];
+			transY = values[Indices.TransY];
+
+			persp0 = values[Indices.Persp0];
+			persp1 = values[Indices.Persp1];
+			persp2 = values[Indices.Persp2];
+		}
+
 		public SKMatrix (
 			float scaleX, float skewX, float transX,
 			float skewY, float scaleY, float transY,
@@ -42,6 +62,8 @@ namespace SkiaSharp
 			this.persp2 = persp2;
 		}
 
+		public readonly bool IsIdentity => Equals (Identity);
+
 		// Values
 
 		public float[] Values {
@@ -457,6 +479,9 @@ namespace SkiaSharp
 
 		// MapVectors
 
+		public readonly SKPoint MapVector (SKPoint vector) =>
+			MapVector (vector.X, vector.Y);
+
 		public readonly SKPoint MapVector (float x, float y)
 		{
 			SKPoint result;

binding/Binding/SKMatrix44.cs

@@ -51,19 +51,12 @@ namespace SkiaSharp
 		}
 
 		public SKMatrix44 (SKMatrix src)
-			: this (CreateNew (ref src), true)
+			: this (SkiaApi.sk_matrix44_new_matrix (&src), true)
 		{
 			if (Handle == IntPtr.Zero)
 				throw new InvalidOperationException ("Unable to create a new SKMatrix44 instance.");
 		}
 
-		private static IntPtr CreateNew (ref SKMatrix src)
-		{
-			fixed (SKMatrix* s = &src) {
-				return SkiaApi.sk_matrix44_new_matrix (s);
-			}
-		}
-
 		// properties
 
 		public SKMatrix Matrix {
@@ -220,6 +213,25 @@ namespace SkiaSharp
 			}
 		}
 
+		public void Set3x3ColumnMajor (float[] src)
+		{
+			if (src.Length != 9)
+				throw new ArgumentException ("The source array must be 9 entries.", nameof (src));
+
+			var row = stackalloc float[9] { src[0], src[3], src[6], src[1], src[4], src[7], src[2], src[5], src[8] };
+			SkiaApi.sk_matrix44_set_3x3_row_major (Handle, row);
+		}
+
+		public void Set3x3RowMajor (float[] src)
+		{
+			if (src.Length != 9)
+				throw new ArgumentException ("The source array must be 9 entries.", nameof (src));
+
+			fixed (float* s = src) {
+				SkiaApi.sk_matrix44_set_3x3_row_major (Handle, s);
+			}
+		}
+
 		public void SetTranslate (float dx, float dy, float dz) =>
 			SkiaApi.sk_matrix44_set_translate (Handle, dx, dy, dz);
 

binding/Binding/SKObject.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Concurrent;
-using System.Collections.Generic;
 using System.Linq;
 using System.Reflection;
 using System.Runtime.InteropServices;
@@ -18,6 +17,7 @@ namespace SkiaSharp
 		internal static readonly ConcurrentDictionary<IntPtr, WeakReference> instances;
 
 		internal readonly ConcurrentDictionary<IntPtr, SKObject> ownedObjects = new ConcurrentDictionary<IntPtr, SKObject> ();
+		internal readonly ConcurrentDictionary<IntPtr, SKObject> keepAliveObjects = new ConcurrentDictionary<IntPtr, SKObject> ();
 
 		static SKObject ()
 		{
@@ -58,6 +58,7 @@ namespace SkiaSharp
 				child.Value.DisposeInternal ();
 			}
 			ownedObjects.Clear ();
+			keepAliveObjects.Clear ();
 		}
 
 		protected override void DisposeNative ()
@@ -199,15 +200,6 @@ namespace SkiaSharp
 			return false;
 		}
 
-		// indicate that when this object is disposed on the managed side,
-		// dispose the child as well
-		internal void SetDisposeChild (SKObject child)
-		{
-			if (child == null)
-				return;
-			ownedObjects[child.Handle] = child;
-		}
-
 		// indicate that the ownership of this object is now in the hands of
 		// the native object
 		internal void RevokeOwnership (SKObject newOwner)
@@ -218,19 +210,45 @@ namespace SkiaSharp
 			if (newOwner == null)
 				DisposeInternal ();
 			else
-				newOwner.SetDisposeChild (this);
+				newOwner.ownedObjects[Handle] = this;
+		}
+
+		// indicate that the child was created by the managed code and
+		// should be disposed when the owner is
+		internal static T Owned<T> (T owner, SKObject child)
+			where T : SKObject
+		{
+			if (child != null) {
+				if (owner != null)
+					owner.ownedObjects[child.Handle] = child;
+				else
+					child.Dispose ();
+			}
+
+			return owner;
+		}
+
+		// indicate that the chile should not be garbage collected while
+		// the owner still lives
+		internal static T Referenced<T> (T owner, SKObject child)
+			where T : SKObject
+		{
+			if (child != null && owner != null)
+				owner.keepAliveObjects[child.Handle] = child;
+
+			return owner;
 		}
 
 		internal static int SizeOf<T> () =>
 #if WINDOWS_UWP || NET_STANDARD
-			Marshal.SizeOf <T> ();
+			Marshal.SizeOf<T> ();
 #else
 			Marshal.SizeOf (typeof (T));
 #endif
 
 		internal static T PtrToStructure<T> (IntPtr intPtr) =>
 #if WINDOWS_UWP || NET_STANDARD
-			Marshal.PtrToStructure <T> (intPtr);
+			Marshal.PtrToStructure<T> (intPtr);
 #else
 			(T)Marshal.PtrToStructure (intPtr, typeof (T));
 #endif

binding/Binding/SKPMColor.cs

@@ -58,8 +58,8 @@ namespace SkiaSharp
 		public readonly bool Equals (SKPMColor obj) =>
 			obj.color == color;
 
-		public readonly override bool Equals (object obj) =>
-			obj is SKPMColor f && Equals (f);
+		public readonly override bool Equals (object other) =>
+			other is SKPMColor f && Equals (f);
 
 		public static bool operator == (SKPMColor left, SKPMColor right) =>
 			left.Equals (right);

binding/Binding/SKPaint.cs

@@ -24,11 +24,15 @@ namespace SkiaSharp
 		protected override void DisposeNative () =>
 			SkiaApi.sk_paint_delete (Handle);
 
+		// Reset
+
 		public void Reset ()
 		{
 			SkiaApi.sk_paint_reset (Handle);
 		}
 
+		// properties
+
 		public bool IsAntialias {
 			get => SkiaApi.sk_paint_is_antialias (Handle);
 			set => SkiaApi.sk_paint_set_antialias (Handle, value);
@@ -184,9 +188,13 @@ namespace SkiaSharp
 			set => SkiaApi.sk_paint_set_path_effect (Handle, value == null ? IntPtr.Zero : value.Handle);
 		}
 
+		// FontSpacing
+
 		public float FontSpacing =>
 			SkiaApi.sk_paint_get_fontmetrics (Handle, null, 0);
 
+		// FontMetrics
+
 		public SKFontMetrics FontMetrics {
 			get {
 				GetFontMetrics (out var metrics);
@@ -201,6 +209,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// Clone
+
 		public SKPaint Clone () =>
 			GetObject<SKPaint> (SkiaApi.sk_paint_clone (Handle));
 

binding/Binding/SKPath.cs

@@ -323,6 +323,14 @@ namespace SkiaSharp
 		public void Transform (SKMatrix matrix) =>
 			SkiaApi.sk_path_transform (Handle, &matrix);
 
+		public void Transform (SKMatrix matrix, SKPath destination)
+		{
+			if (destination == null)
+				throw new ArgumentNullException (nameof (destination));
+
+			SkiaApi.sk_path_transform_to_dest (Handle, &matrix, destination.Handle);
+		}
+
 		public void AddPath (SKPath other, float dx, float dy, SKPathAddMode mode = SKPathAddMode.Append)
 		{
 			if (other == null)
@@ -566,4 +574,3 @@ namespace SkiaSharp
 		}
 	}
 }
-

binding/Binding/SKPathMeasure.cs

@@ -32,6 +32,8 @@ namespace SkiaSharp
 		protected override void DisposeNative () =>
 			SkiaApi.sk_pathmeasure_destroy (Handle);
 
+		// properties
+
 		public float Length {
 			get {
 				return SkiaApi.sk_pathmeasure_get_length (Handle);
@@ -44,11 +46,18 @@ namespace SkiaSharp
 			}
 		}
 
+		// SetPath
+
+		public void SetPath (SKPath path) =>
+			SetPath (path, false);
+
 		public void SetPath (SKPath path, bool forceClosed)
 		{
 			SkiaApi.sk_pathmeasure_set_path (Handle, path == null ? IntPtr.Zero : path.Handle, forceClosed);
 		}
 
+		// GetPositionAndTangent
+
 		public bool GetPositionAndTangent (float distance, out SKPoint position, out SKPoint tangent)
 		{
 			fixed (SKPoint* p = &position)
@@ -57,6 +66,15 @@ namespace SkiaSharp
 			}
 		}
 
+		// GetPosition
+
+		public SKPoint GetPosition (float distance)
+		{
+			if (!GetPosition (distance, out var position))
+				position = SKPoint.Empty;
+			return position;
+		}
+
 		public bool GetPosition (float distance, out SKPoint position)
 		{
 			fixed (SKPoint* p = &position) {
@@ -64,6 +82,15 @@ namespace SkiaSharp
 			}
 		}
 
+		// GetTangent
+
+		public SKPoint GetTangent (float distance)
+		{
+			if (!GetTangent (distance, out var tangent))
+				tangent = SKPoint.Empty;
+			return tangent;
+		}
+
 		public bool GetTangent (float distance, out SKPoint tangent)
 		{
 			fixed (SKPoint* t = &tangent) {
@@ -71,6 +98,15 @@ namespace SkiaSharp
 			}
 		}
 
+		// GetMatrix
+
+		public SKMatrix GetMatrix (float distance, SKPathMeasureMatrixFlags flags)
+		{
+			if (!GetMatrix (distance, out var matrix, flags))
+				matrix = SKMatrix.Empty;
+			return matrix;
+		}
+
 		public bool GetMatrix (float distance, out SKMatrix matrix, SKPathMeasureMatrixFlags flags)
 		{
 			fixed (SKMatrix* m = &matrix) {
@@ -78,6 +114,8 @@ namespace SkiaSharp
 			}
 		}
 
+		// GetSegment
+
 		public bool GetSegment (float start, float stop, SKPath dst, bool startWithMoveTo)
 		{
 			if (dst == null)
@@ -85,10 +123,21 @@ namespace SkiaSharp
 			return SkiaApi.sk_pathmeasure_get_segment (Handle, start, stop, dst.Handle, startWithMoveTo);
 		}
 
+		public SKPath GetSegment (float start, float stop, bool startWithMoveTo)
+		{
+			var dst = new SKPath ();
+			if (!GetSegment (start, stop, dst, startWithMoveTo)) {
+				dst.Dispose ();
+				dst = null;
+			}
+			return dst;
+		}
+
+		// NextContour
+
 		public bool NextContour ()
 		{
 			return SkiaApi.sk_pathmeasure_next_contour (Handle);
 		}
 	}
 }
-

binding/Binding/SKPixmap.cs

@@ -1,5 +1,6 @@
 using System;
 using System.ComponentModel;
+using System.IO;
 
 namespace SkiaSharp
 {
@@ -49,6 +50,8 @@ namespace SkiaSharp
 		protected override void DisposeNative () =>
 			SkiaApi.sk_pixmap_destructor (Handle);
 
+		// Reset
+
 		public void Reset ()
 		{
 			SkiaApi.sk_pixmap_reset (Handle);
@@ -67,6 +70,8 @@ namespace SkiaSharp
 			SkiaApi.sk_pixmap_reset_with_params (Handle, &cinfo, (void*)addr, (IntPtr)rowBytes);
 		}
 
+		// properties
+
 		public SKImageInfo Info {
 			get {
 				SKImageInfoNative cinfo;
@@ -95,6 +100,8 @@ namespace SkiaSharp
 
 		public int BytesSize => Info.BytesSize;
 
+		// pixels
+
 		public IntPtr GetPixels () =>
 			(IntPtr)SkiaApi.sk_pixmap_get_pixels (Handle);
 
@@ -111,10 +118,14 @@ namespace SkiaSharp
 			return SkiaApi.sk_pixmap_get_pixel_color (Handle, x, y);
 		}
 
+		// ColorTable
+
 		[EditorBrowsable (EditorBrowsableState.Never)]
 		[Obsolete ("The Index8 color type and color table is no longer supported.")]
 		public SKColorTable ColorTable => null;
 
+		// Resize
+
 		[EditorBrowsable (EditorBrowsableState.Never)]
 		[Obsolete ("Use ScalePixels(SKPixmap, SKFilterQuality) instead.")]
 		public static bool Resize (SKPixmap dst, SKPixmap src, SKBitmapResizeMethod method)
@@ -127,6 +138,8 @@ namespace SkiaSharp
 			return src.ScalePixels (dst, method.ToFilterQuality ());
 		}
 
+		// ScalePixels
+
 		public bool ScalePixels (SKPixmap destination, SKFilterQuality quality)
 		{
 			if (destination == null)
@@ -135,6 +148,8 @@ namespace SkiaSharp
 			return SkiaApi.sk_pixmap_scale_pixels (Handle, destination.Handle, quality);
 		}
 
+		// ReadPixels
+
 		public bool ReadPixels (SKImageInfo dstInfo, IntPtr dstPixels, int dstRowBytes, int srcX, int srcY, SKTransferFunctionBehavior behavior)
 		{
 			var cinfo = SKImageInfoNative.FromManaged (ref dstInfo);
@@ -161,19 +176,34 @@ namespace SkiaSharp
 			return ReadPixels (pixmap.Info, pixmap.GetPixels (), pixmap.RowBytes, 0, 0, SKTransferFunctionBehavior.Respect);
 		}
 
+		// Encode
+
 		public SKData Encode (SKEncodedImageFormat encoder, int quality)
 		{
-			using (var stream = new SKDynamicMemoryWStream ()) {
-				var result = Encode (stream, this, encoder, quality);
-				return result ? stream.DetachAsData () : null;
-			}
+			using var stream = new SKDynamicMemoryWStream ();
+			var result = Encode (stream, encoder, quality);
+			return result ? stream.DetachAsData () : null;
+		}
+
+		public bool Encode (Stream dst, SKEncodedImageFormat encoder, int quality)
+		{
+			if (dst == null)
+				throw new ArgumentNullException (nameof (dst));
+
+			using var wrapped = new SKManagedWStream (dst);
+			return Encode (wrapped, encoder, quality);
 		}
 
 		public bool Encode (SKWStream dst, SKEncodedImageFormat encoder, int quality)
 		{
-			return Encode (dst, this, encoder, quality);
+			if (dst == null)
+				throw new ArgumentNullException (nameof (dst));
+
+			return SkiaApi.sk_pixmap_encode_image (dst.Handle, Handle, encoder, quality);
 		}
 
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use Encode(SKWStream, SKEncodedImageFormat, int) instead.")]
 		public static bool Encode (SKWStream dst, SKBitmap src, SKEncodedImageFormat format, int quality)
 		{
 			if (dst == null)
@@ -181,11 +211,11 @@ namespace SkiaSharp
 			if (src == null)
 				throw new ArgumentNullException (nameof (src));
 
-			using (var pixmap = new SKPixmap ()) {
-				return src.PeekPixels (pixmap) && Encode (dst, pixmap, format, quality);
-			}
+			return src.Encode (dst, format, quality);
 		}
 
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use Encode(SKWStream, SKEncodedImageFormat, int) instead.")]
 		public static bool Encode (SKWStream dst, SKPixmap src, SKEncodedImageFormat encoder, int quality)
 		{
 			if (dst == null)
@@ -193,22 +223,37 @@ namespace SkiaSharp
 			if (src == null)
 				throw new ArgumentNullException (nameof (src));
 
-			return SkiaApi.sk_pixmap_encode_image (dst.Handle, src.Handle, encoder, quality);
+			return src.Encode (dst, encoder, quality);
 		}
 
+		// Encode (webp)
+
 		public SKData Encode (SKWebpEncoderOptions options)
 		{
-			using (var stream = new SKDynamicMemoryWStream ()) {
-				var result = Encode (stream, this, options);
-				return result ? stream.DetachAsData () : null;
-			}
+			using var stream = new SKDynamicMemoryWStream ();
+			var result = Encode (stream, options);
+			return result ? stream.DetachAsData () : null;
+		}
+
+		public bool Encode (Stream dst, SKWebpEncoderOptions options)
+		{
+			if (dst == null)
+				throw new ArgumentNullException (nameof (dst));
+
+			using var wrapped = new SKManagedWStream (dst);
+			return Encode (wrapped, options);
 		}
 
 		public bool Encode (SKWStream dst, SKWebpEncoderOptions options)
 		{
-			return Encode (dst, this, options);
+			if (dst == null)
+				throw new ArgumentNullException (nameof (dst));
+
+			return SkiaApi.sk_webpencoder_encode (dst.Handle, Handle, &options);
 		}
 
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use Encode(SKWStream, SKWebpEncoderOptions) instead.")]
 		public static bool Encode (SKWStream dst, SKPixmap src, SKWebpEncoderOptions options)
 		{
 			if (dst == null)
@@ -216,22 +261,37 @@ namespace SkiaSharp
 			if (src == null)
 				throw new ArgumentNullException (nameof (src));
 
-			return SkiaApi.sk_webpencoder_encode (dst.Handle, src.Handle, options);
+			return src.Encode (dst, options);
 		}
 
+		// Encode (jpeg)
+
 		public SKData Encode (SKJpegEncoderOptions options)
 		{
-			using (var stream = new SKDynamicMemoryWStream ()) {
-				var result = Encode (stream, this, options);
-				return result ? stream.DetachAsData () : null;
-			}
+			using var stream = new SKDynamicMemoryWStream ();
+			var result = Encode (stream, options);
+			return result ? stream.DetachAsData () : null;
+		}
+
+		public bool Encode (Stream dst, SKJpegEncoderOptions options)
+		{
+			if (dst == null)
+				throw new ArgumentNullException (nameof (dst));
+
+			using var wrapped = new SKManagedWStream (dst);
+			return Encode (wrapped, options);
 		}
 
 		public bool Encode (SKWStream dst, SKJpegEncoderOptions options)
 		{
-			return Encode (dst, this, options);
+			if (dst == null)
+				throw new ArgumentNullException (nameof (dst));
+
+			return SkiaApi.sk_jpegencoder_encode (dst.Handle, Handle, &options);
 		}
 
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use Encode(SKWStream, SKJpegEncoderOptions) instead.")]
 		public static bool Encode (SKWStream dst, SKPixmap src, SKJpegEncoderOptions options)
 		{
 			if (dst == null)
@@ -239,22 +299,37 @@ namespace SkiaSharp
 			if (src == null)
 				throw new ArgumentNullException (nameof (src));
 
-			return SkiaApi.sk_jpegencoder_encode (dst.Handle, src.Handle, options);
+			return src.Encode (dst, options);
 		}
 
+		// Encode (png)
+
 		public SKData Encode (SKPngEncoderOptions options)
 		{
-			using (var stream = new SKDynamicMemoryWStream ()) {
-				var result = Encode (stream, this, options);
-				return result ? stream.DetachAsData () : null;
-			}
+			using var stream = new SKDynamicMemoryWStream ();
+			var result = Encode (stream, options);
+			return result ? stream.DetachAsData () : null;
+		}
+
+		public bool Encode (Stream dst, SKPngEncoderOptions options)
+		{
+			if (dst == null)
+				throw new ArgumentNullException (nameof (dst));
+
+			using var wrapped = new SKManagedWStream (dst);
+			return Encode (wrapped, options);
 		}
 
 		public bool Encode (SKWStream dst, SKPngEncoderOptions options)
 		{
-			return Encode (dst, this, options);
+			if (dst == null)
+				throw new ArgumentNullException (nameof (dst));
+
+			return SkiaApi.sk_pngencoder_encode (dst.Handle, Handle, &options);
 		}
 
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use Encode(SKWStream, SKPngEncoderOptions) instead.")]
 		public static bool Encode (SKWStream dst, SKPixmap src, SKPngEncoderOptions options)
 		{
 			if (dst == null)
@@ -262,9 +337,11 @@ namespace SkiaSharp
 			if (src == null)
 				throw new ArgumentNullException (nameof (src));
 
-			return SkiaApi.sk_pngencoder_encode (dst.Handle, src.Handle, options);
+			return src.Encode (dst, options);
 		}
 
+		// ExtractSubset
+
 		public SKPixmap ExtractSubset (SKRectI subset)
 		{
 			var result = new SKPixmap ();
@@ -283,6 +360,8 @@ namespace SkiaSharp
 			return SkiaApi.sk_pixmap_extract_subset (Handle, result.Handle, &subset);
 		}
 
+		// Erase
+
 		public bool Erase (SKColor color)
 		{
 			return Erase (color, Rect);
@@ -299,6 +378,8 @@ namespace SkiaSharp
 		public bool Erase (SKColorF color, SKRectI subset) =>
 			SkiaApi.sk_pixmap_erase_color4f (Handle, &color, &subset);
 
+		// With*
+
 		public SKPixmap WithColorType (SKColorType newColorType)
 		{
 			return new SKPixmap (Info.WithColorType (newColorType), GetPixels (), RowBytes);

binding/Binding/SKSVG.cs

@@ -1,4 +1,6 @@
 using System;
+using System.ComponentModel;
+using System.IO;
 
 namespace SkiaSharp
 {
@@ -7,14 +9,38 @@ namespace SkiaSharp
 		private SKSvgCanvas ()
 		{
 		}
-		
+
+		// Create
+
+		public static SKCanvas Create (SKRect bounds, Stream stream)
+		{
+			if (stream == null)
+				throw new ArgumentNullException (nameof (stream));
+
+			var managed = new SKManagedWStream (stream);
+			return SKObject.Owned (Create (bounds, managed), managed);
+		}
+
+		public static SKCanvas Create (SKRect bounds, SKWStream stream)
+		{
+			if (stream == null)
+				throw new ArgumentNullException (nameof (stream));
+
+			// TODO: there seems to be a memory issue with things getting destroyed in the incorrect order
+			//return SKObject.Referenced (SKObject.GetObject<SKCanvas> (SkiaApi.sk_svgcanvas_create_with_stream (&bounds, stream.Handle)), stream);
+
+			var writer = new SKXmlStreamWriter (stream);
+			return SKObject.Owned (SKObject.GetObject<SKCanvas> (SkiaApi.sk_svgcanvas_create_with_writer (&bounds, writer.Handle)), writer);
+		}
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use Create(SKRect, Stream) instead.")]
 		public static SKCanvas Create (SKRect bounds, SKXmlWriter writer)
 		{
-			if (writer == null) {
+			if (writer == null)
 				throw new ArgumentNullException (nameof (writer));
-			}
 
-			return SKObject.GetObject<SKCanvas> (SkiaApi.sk_svgcanvas_create (&bounds, writer.Handle));
+			return SKObject.Referenced (SKObject.GetObject<SKCanvas> (SkiaApi.sk_svgcanvas_create_with_writer (&bounds, writer.Handle)), writer);
 		}
 	}
 }

binding/Binding/SKStream.cs

@@ -273,7 +273,7 @@ namespace SkiaSharp
 
 		private static IntPtr CreateNew (string path)
 		{
-			var bytes = StringUtilities.GetEncodedText (path, SKEncoding.Utf8);
+			var bytes = StringUtilities.GetEncodedText (path, SKTextEncoding.Utf8);
 			fixed (byte* p = bytes) {
 				return SkiaApi.sk_filestream_new (p);
 			}
@@ -488,7 +488,7 @@ namespace SkiaSharp
 
 		private static IntPtr CreateNew (string path)
 		{
-			var bytes = StringUtilities.GetEncodedText (path, SKEncoding.Utf8);
+			var bytes = StringUtilities.GetEncodedText (path, SKTextEncoding.Utf8);
 			fixed (byte* p = bytes) {
 				return SkiaApi.sk_filewstream_new (p);
 			}
@@ -553,6 +553,17 @@ namespace SkiaSharp
 			SkiaApi.sk_dynamicmemorywstream_copy_to (Handle, (void*)data);
 		}
 
+		public void CopyTo (Span<byte> data)
+		{
+			var size = BytesWritten;
+			if (data.Length < size)
+				throw new Exception ($"Not enough space to copy. Expected at least {size}, but received {data.Length}.");
+
+			fixed (void* d = data) {
+				SkiaApi.sk_dynamicmemorywstream_copy_to (Handle, d);
+			}
+		}
+
 		public bool CopyTo (SKWStream dst)
 		{
 			if (dst == null)
@@ -560,6 +571,15 @@ namespace SkiaSharp
 			return SkiaApi.sk_dynamicmemorywstream_write_to_stream (Handle, dst.Handle);
 		}
 
+		public bool CopyTo (Stream dst)
+		{
+			if (dst == null)
+				throw new ArgumentNullException (nameof (dst));
+
+			using var wrapped = new SKManagedWStream (dst);
+			return CopyTo (wrapped);
+		}
+
 		protected override void Dispose (bool disposing) =>
 			base.Dispose (disposing);
 

binding/Binding/SKString.cs

@@ -48,7 +48,7 @@ namespace SkiaSharp
 		{
 			var cstr = SkiaApi.sk_string_get_c_str (Handle);
 			var clen = SkiaApi.sk_string_get_size (Handle);
-			return StringUtilities.GetString (cstr, (int)clen, SKTextEncoding.Utf8); 
+			return StringUtilities.GetString ((IntPtr)cstr, (int)clen, SKTextEncoding.Utf8);
 		}
 
 		public static explicit operator string (SKString skString)

binding/Binding/SKSwizzle.cs

@@ -19,6 +19,9 @@ namespace SkiaSharp
 			SkiaApi.sk_swizzle_swap_rb ((uint*)dest, (uint*)src, count);
 		}
 
+		public static void SwapRedBlue (Span<byte> pixels) =>
+			SwapRedBlue (pixels, pixels, pixels.Length);
+
 		public static void SwapRedBlue (ReadOnlySpan<byte> pixels, int count) =>
 			SwapRedBlue (pixels, pixels, count);
 

binding/Binding/SKTextBlob.cs

@@ -56,13 +56,13 @@ namespace SkiaSharp
 
 		public void AddRun (SKPaint font, float x, float y, ushort[] glyphs, string text, uint[] clusters)
 		{
-			var utf8Text = StringUtilities.GetEncodedText (text, SKEncoding.Utf8);
+			var utf8Text = StringUtilities.GetEncodedText (text, SKTextEncoding.Utf8);
 			AddRun (font, x, y, glyphs, utf8Text, clusters, null);
 		}
 
 		public void AddRun (SKPaint font, float x, float y, ushort[] glyphs, string text, uint[] clusters, SKRect bounds)
 		{
-			var utf8Text = StringUtilities.GetEncodedText (text, SKEncoding.Utf8);
+			var utf8Text = StringUtilities.GetEncodedText (text, SKTextEncoding.Utf8);
 			AddRun (font, x, y, glyphs, utf8Text, clusters, (SKRect?)bounds);
 		}
 
@@ -116,13 +116,13 @@ namespace SkiaSharp
 
 		public void AddHorizontalRun (SKPaint font, float y, ushort[] glyphs, float[] positions, string text, uint[] clusters)
 		{
-			var utf8Text = StringUtilities.GetEncodedText (text, SKEncoding.Utf8);
+			var utf8Text = StringUtilities.GetEncodedText (text, SKTextEncoding.Utf8);
 			AddHorizontalRun (font, y, glyphs, positions, utf8Text, clusters, null);
 		}
 
 		public void AddHorizontalRun (SKPaint font, float y, ushort[] glyphs, float[] positions, string text, uint[] clusters, SKRect bounds)
 		{
-			var utf8Text = StringUtilities.GetEncodedText (text, SKEncoding.Utf8);
+			var utf8Text = StringUtilities.GetEncodedText (text, SKTextEncoding.Utf8);
 			AddHorizontalRun (font, y, glyphs, positions, utf8Text, clusters, (SKRect?)bounds);
 		}
 
@@ -181,13 +181,13 @@ namespace SkiaSharp
 
 		public void AddPositionedRun (SKPaint font, ushort[] glyphs, SKPoint[] positions, string text, uint[] clusters)
 		{
-			var utf8Text = StringUtilities.GetEncodedText (text, SKEncoding.Utf8);
+			var utf8Text = StringUtilities.GetEncodedText (text, SKTextEncoding.Utf8);
 			AddPositionedRun (font, glyphs, positions, utf8Text, clusters, null);
 		}
 
 		public void AddPositionedRun (SKPaint font, ushort[] glyphs, SKPoint[] positions, string text, uint[] clusters, SKRect bounds)
 		{
-			var utf8Text = StringUtilities.GetEncodedText (text, SKEncoding.Utf8);
+			var utf8Text = StringUtilities.GetEncodedText (text, SKTextEncoding.Utf8);
 			AddPositionedRun (font, glyphs, positions, utf8Text, clusters, (SKRect?)bounds);
 		}
 

binding/Binding/SKTypeface.cs

@@ -36,6 +36,8 @@ namespace SkiaSharp
 		{
 		}
 
+		// Default
+
 		protected override void Dispose (bool disposing) =>
 			base.Dispose (disposing);
 
@@ -46,6 +48,8 @@ namespace SkiaSharp
 			return GetObject<SKTypeface> (SkiaApi.sk_typeface_create_default ());
 		}
 
+		// FromFamilyName
+
 		[EditorBrowsable (EditorBrowsableState.Never)]
 		[Obsolete ("Use FromFamilyName(string, SKFontStyleWeight, SKFontStyleWidth, SKFontStyleSlant) instead.")]
 		public static SKTypeface FromFamilyName (string familyName, SKTypefaceStyle style)
@@ -79,6 +83,8 @@ namespace SkiaSharp
 			return FromFamilyName (familyName, (int)weight, (int)width, slant);
 		}
 
+		// From*
+
 		[EditorBrowsable (EditorBrowsableState.Never)]
 		[Obsolete]
 		public static SKTypeface FromTypeface (SKTypeface typeface, SKTypefaceStyle style)
@@ -98,7 +104,7 @@ namespace SkiaSharp
 			if (path == null)
 				throw new ArgumentNullException (nameof (path));
 
-			var utf8path = StringUtilities.GetEncodedText (path, SKEncoding.Utf8);
+			var utf8path = StringUtilities.GetEncodedText (path, SKTextEncoding.Utf8);
 			fixed (byte* u = utf8path) {
 				return GetObject<SKTypeface> (SkiaApi.sk_typeface_create_from_file (u, index));
 			}
@@ -129,18 +135,25 @@ namespace SkiaSharp
 
 		public static SKTypeface FromData (SKData data, int index = 0)
 		{
-			return SKTypeface.FromStream (new SKMemoryStream (data), index);
+			if (data == null)
+				throw new ArgumentNullException (nameof (data));
+
+			return FromStream (new SKMemoryStream (data), index);
 		}
 
+		// CharsToGlyphs
+
 		[EditorBrowsable (EditorBrowsableState.Never)]
 		[Obsolete ("Use GetGlyphs(string, out ushort[]) instead.")]
-		public int CharsToGlyphs (string chars, out ushort[] glyphs)
-			=> GetGlyphs (chars, out glyphs);
+		public int CharsToGlyphs (string chars, out ushort[] glyphs) =>
+			GetGlyphs (chars, out glyphs);
 
 		[EditorBrowsable (EditorBrowsableState.Never)]
-		[Obsolete ("Use GetGlyphs(IntPtr, int, SKEncoding, out ushort[]) instead.")]
-		public int CharsToGlyphs (IntPtr str, int strlen, SKEncoding encoding, out ushort[] glyphs)
-			=> GetGlyphs (str, strlen, encoding, out glyphs);
+		[Obsolete ("Use GetGlyphs(IntPtr, int, SKTextEncoding, out ushort[]) instead.")]
+		public int CharsToGlyphs (IntPtr str, int strlen, SKEncoding encoding, out ushort[] glyphs) =>
+			GetGlyphs (str, strlen, encoding, out glyphs);
+
+		// Properties
 
 		public string FamilyName => (string)GetObject<SKString> (SkiaApi.sk_typeface_get_family_name (Handle));
 
@@ -173,6 +186,10 @@ namespace SkiaSharp
 
 		public int UnitsPerEm => SkiaApi.sk_typeface_get_units_per_em (Handle);
 
+		public int GlyphCount => SkiaApi.sk_typeface_count_glyphs (Handle);
+
+		// GetTableTags
+
 		public int TableCount => SkiaApi.sk_typeface_count_tables (Handle);
 
 		public UInt32[] GetTableTags ()
@@ -196,9 +213,13 @@ namespace SkiaSharp
 			return true;
 		}
 
+		// GetTableSize
+
 		public int GetTableSize (UInt32 tag) =>
 			(int)SkiaApi.sk_typeface_get_table_size (Handle, tag);
 
+		// GetTableData
+
 		public byte[] GetTableData (UInt32 tag)
 		{
 			if (!TryGetTableData (tag, out var result)) {
@@ -227,102 +248,174 @@ namespace SkiaSharp
 			return actual != IntPtr.Zero;
 		}
 
-		public int CountGlyphs (string str) => CountGlyphs (str, SKEncoding.Utf16);
+		// CountGlyphs (string/char)
 
-		public int CountGlyphs (string str, SKEncoding encoding)
+		public int CountGlyphs (string str) =>
+			CountGlyphs (str.AsSpan ());
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use CountGlyphs(string) instead.")]
+		public int CountGlyphs (string str, SKEncoding encoding) =>
+			CountGlyphs (str.AsSpan ());
+
+		public int CountGlyphs (ReadOnlySpan<char> str)
 		{
-			if (str == null)
-				throw new ArgumentNullException (nameof (str));
-
-			var bytes = StringUtilities.GetEncodedText (str, encoding);
-			return CountGlyphs (bytes, encoding);
+			var bytes = StringUtilities.GetEncodedText (str, SKTextEncoding.Utf16);
+			return CountGlyphs (bytes, SKTextEncoding.Utf16);
 		}
 
+		// CountGlyphs (byte[])
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use CountGlyphs(byte[], SKTextEncoding) instead.")]
 		public int CountGlyphs (byte[] str, SKEncoding encoding) =>
-			CountGlyphs (new ReadOnlySpan<byte> (str), encoding);
+			CountGlyphs (str.AsSpan (), encoding.ToTextEncoding ());
 
-		public int CountGlyphs (ReadOnlySpan<byte> str, SKEncoding encoding)
+		public int CountGlyphs (byte[] str, SKTextEncoding encoding) =>
+			CountGlyphs (str.AsSpan (), encoding);
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use CountGlyphs(ReadOnlySpan<byte>, SKTextEncoding) instead.")]
+		public int CountGlyphs (ReadOnlySpan<byte> str, SKEncoding encoding) =>
+			CountGlyphs (str, encoding.ToTextEncoding ());
+
+		public int CountGlyphs (ReadOnlySpan<byte> str, SKTextEncoding encoding)
 		{
-			if (str == null)
-				throw new ArgumentNullException (nameof (str));
-
 			fixed (byte* p = str) {
 				return CountGlyphs ((IntPtr)p, str.Length, encoding);
 			}
 		}
 
-		public int CountGlyphs (IntPtr str, int strLen, SKEncoding encoding)
+		// CountGlyphs (IntPtr)
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use CountGlyphs(ReadOnlySpan<byte>, SKTextEncoding) instead.")]
+		public int CountGlyphs (IntPtr str, int strLen, SKEncoding encoding) =>
+			CountGlyphs (str, strLen, encoding.ToTextEncoding ());
+
+		public int CountGlyphs (IntPtr str, int strLen, SKTextEncoding encoding)
 		{
 			if (str == IntPtr.Zero && strLen != 0)
 				throw new ArgumentNullException (nameof (str));
 
-			return SkiaApi.sk_typeface_chars_to_glyphs (Handle, (byte*)str, encoding, null, strLen);
+			return SkiaApi.sk_typeface_chars_to_glyphs (Handle, (byte*)str, encoding.ToEncoding (), null, strLen);
 		}
 
-		public int GetGlyphs (string text, out ushort[] glyphs) => GetGlyphs (text, SKEncoding.Utf16, out glyphs);
+		// GetGlyphs (string/char, out)
 
-		public int GetGlyphs (string text, SKEncoding encoding, out ushort[] glyphs)
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use GetGlyphs(string) instead.")]
+		public int GetGlyphs (string text, out ushort[] glyphs)
 		{
-			if (text == null)
-				throw new ArgumentNullException (nameof (text));
-
-			var bytes = StringUtilities.GetEncodedText (text, encoding);
-			return GetGlyphs (bytes, encoding, out glyphs);
+			glyphs = GetGlyphs (text);
+			return glyphs.Length;
 		}
 
-		public int GetGlyphs (byte[] text, SKEncoding encoding, out ushort[] glyphs) =>
-			GetGlyphs (new ReadOnlySpan<byte> (text), encoding, out glyphs);
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use GetGlyphs(string) instead.")]
+		public int GetGlyphs (string text, SKEncoding encoding, out ushort[] glyphs) =>
+			GetGlyphs (text, out glyphs);
 
+		// GetGlyphs (byte[], out)
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use GetGlyphs(byte[], SKTextEncoding) instead.")]
+		public int GetGlyphs (byte[] text, SKEncoding encoding, out ushort[] glyphs) =>
+			GetGlyphs (text.AsSpan (), encoding, out glyphs);
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use GetGlyphs(ReadOnlySpan<byte>, SKTextEncoding) instead.")]
 		public int GetGlyphs (ReadOnlySpan<byte> text, SKEncoding encoding, out ushort[] glyphs)
 		{
-			if (text == null)
-				throw new ArgumentNullException (nameof (text));
+			glyphs = GetGlyphs (text, encoding);
+			return glyphs.Length;
+		}
 
-			fixed (byte* p = text) {
-				return GetGlyphs ((IntPtr)p, text.Length, encoding, out glyphs);
+		// GetGlyphs (IntPtr, out)
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use GetGlyphs(IntPtr, int, SKTextEncoding) instead.")]
+		public int GetGlyphs (IntPtr text, int length, SKEncoding encoding, out ushort[] glyphs)
+		{
+			glyphs = GetGlyphs (text, length, encoding);
+			return glyphs.Length;
+		}
+
+		// GetGlyphs (string/char, out)
+
+		public ushort[] GetGlyphs (string text) =>
+			GetGlyphs (text.AsSpan ());
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use GetGlyphs(string) instead.")]
+		public ushort[] GetGlyphs (string text, SKEncoding encoding) =>
+			GetGlyphs (text.AsSpan ());
+
+		public ushort[] GetGlyphs (ReadOnlySpan<char> text)
+		{
+			fixed (void* t = text) {
+				return GetGlyphs ((IntPtr)t, text.Length, SKTextEncoding.Utf16);
 			}
 		}
 
-		public int GetGlyphs (IntPtr text, int length, SKEncoding encoding, out ushort[] glyphs)
+		// GetGlyphs (byte[], out)
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use GetGlyphs(ReadOnlySpan<byte>, SKTextEncoding) instead.")]
+		public ushort[] GetGlyphs (byte[] text, SKEncoding encoding) =>
+			GetGlyphs (text.AsSpan (), encoding.ToTextEncoding ());
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use GetGlyphs(ReadOnlySpan<byte>, SKTextEncoding) instead.")]
+		public ushort[] GetGlyphs (ReadOnlySpan<byte> text, SKEncoding encoding) =>
+			GetGlyphs (text, encoding.ToTextEncoding ());
+
+		public ushort[] GetGlyphs (ReadOnlySpan<byte> text, SKTextEncoding encoding)
+		{
+			fixed (void* t = text) {
+				return GetGlyphs ((IntPtr)t, text.Length, encoding);
+			}
+		}
+
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use GetGlyphs(IntPtr, int, SKTextEncoding) instead.")]
+		public ushort[] GetGlyphs (IntPtr text, int length, SKEncoding encoding) =>
+			GetGlyphs (text, length, encoding.ToTextEncoding ());
+
+		public ushort[] GetGlyphs (IntPtr text, int length, SKTextEncoding encoding)
 		{
 			if (text == IntPtr.Zero && length != 0)
 				throw new ArgumentNullException (nameof (text));
 
-			var n = SkiaApi.sk_typeface_chars_to_glyphs (Handle, (void*)text, encoding, null, length);
+			var n = SkiaApi.sk_typeface_chars_to_glyphs (Handle, (void*)text, encoding.ToEncoding (), null, length);
+			if (n <= 0)
+				return new ushort[0];
 
-			if (n <= 0) {
-				glyphs = new ushort[0];
-				return 0;
-			}
-
-			glyphs = new ushort[n];
+			var glyphs = new ushort[n];
 			fixed (ushort* gp = glyphs) {
-				return SkiaApi.sk_typeface_chars_to_glyphs (Handle, (void*)text, encoding, gp, n);
+				SkiaApi.sk_typeface_chars_to_glyphs (Handle, (void*)text, encoding.ToEncoding (), gp, n);
 			}
-		}
-
-		public ushort[] GetGlyphs (string text) => GetGlyphs (text, SKEncoding.Utf16);
-
-		public ushort[] GetGlyphs (string text, SKEncoding encoding)
-		{
-			GetGlyphs (text, encoding, out var glyphs);
 			return glyphs;
 		}
 
-		public ushort[] GetGlyphs (byte[] text, SKEncoding encoding) =>
-			GetGlyphs (new ReadOnlySpan<byte> (text), encoding);
+		// ContainsGlyphs
 
-		public ushort[] GetGlyphs (ReadOnlySpan<byte> text, SKEncoding encoding)
-		{
-			GetGlyphs (text, encoding, out var glyphs);
-			return glyphs;
-		}
+		public bool ContainsGlyphs (string text) =>
+			ContainsGlyphs (GetGlyphs (text));
 
-		public ushort[] GetGlyphs (IntPtr text, int length, SKEncoding encoding)
-		{
-			GetGlyphs (text, length, encoding, out var glyphs);
-			return glyphs;
-		}
+		public bool ContainsGlyphs (ReadOnlySpan<char> text) =>
+			ContainsGlyphs (GetGlyphs (text));
+
+		public bool ContainsGlyphs (ReadOnlySpan<byte> text, SKTextEncoding encoding) =>
+			ContainsGlyphs (GetGlyphs (text, encoding));
+
+		public bool ContainsGlyphs (IntPtr text, int length, SKTextEncoding encoding) =>
+			ContainsGlyphs (GetGlyphs (text, length, encoding));
+
+		private bool ContainsGlyphs (ushort[] glyphs) =>
+			Array.IndexOf (glyphs, 0) != -1;
+
+		// OpenStream
 
 		public SKStreamAsset OpenStream () =>
 			OpenStream (out _);
@@ -334,6 +427,20 @@ namespace SkiaSharp
 			}
 		}
 
+		// GetKerningPairAdjustments
+
+		public int[] GetKerningPairAdjustments (ReadOnlySpan<ushort> glyphs)
+		{
+			var adjustments = new int[glyphs.Length];
+			fixed (ushort* gp = glyphs)
+			fixed (int* ap = adjustments) {
+				SkiaApi.sk_typeface_get_kerning_pair_adjustments (Handle, gp, glyphs.Length, ap);
+			}
+			return adjustments;
+		}
+
+		//
+
 		private sealed class SKTypefaceStatic : SKTypeface
 		{
 			internal SKTypefaceStatic (IntPtr x)

binding/Binding/SkiaApi.generated.cs

@@ -1658,6 +1658,10 @@ namespace SkiaSharp
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern void sk_matrix44_set (sk_matrix44_t matrix, Int32 row, Int32 col, Single value);
 
+		// void sk_matrix44_set_3x3_row_major(sk_matrix44_t* matrix, float* dst)
+		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
+		internal static extern void sk_matrix44_set_3x3_row_major (sk_matrix44_t matrix, Single* dst);
+
 		// void sk_matrix44_set_col_major(sk_matrix44_t* matrix, float* dst)
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern void sk_matrix44_set_col_major (sk_matrix44_t matrix, Single* dst);
@@ -2318,6 +2322,10 @@ namespace SkiaSharp
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern void sk_path_transform (sk_path_t cpath, SKMatrix* cmatrix);
 
+		// void sk_path_transform_to_dest(sk_path_t* cpath, const sk_matrix_t* cmatrix, sk_path_t* destination)
+		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
+		internal static extern void sk_path_transform_to_dest (sk_path_t cpath, SKMatrix* cmatrix, sk_path_t destination);
+
 		// void sk_pathmeasure_destroy(sk_pathmeasure_t* pathMeasure)
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern void sk_pathmeasure_destroy (sk_pathmeasure_t pathMeasure);
@@ -2490,10 +2498,10 @@ namespace SkiaSharp
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern void sk_color_unpremultiply_array (UInt32* pmcolors, Int32 size, UInt32* colors);
 
-		// bool sk_jpegencoder_encode(sk_wstream_t* dst, const sk_pixmap_t* src, sk_jpegencoder_options_t options)
+		// bool sk_jpegencoder_encode(sk_wstream_t* dst, const sk_pixmap_t* src, const sk_jpegencoder_options_t* options)
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		[return: MarshalAs (UnmanagedType.I1)]
-		internal static extern bool sk_jpegencoder_encode (sk_wstream_t dst, sk_pixmap_t src, SKJpegEncoderOptions options);
+		internal static extern bool sk_jpegencoder_encode (sk_wstream_t dst, sk_pixmap_t src, SKJpegEncoderOptions* options);
 
 		// void sk_pixmap_destructor(sk_pixmap_t* cpixmap)
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
@@ -2565,19 +2573,19 @@ namespace SkiaSharp
 		[return: MarshalAs (UnmanagedType.I1)]
 		internal static extern bool sk_pixmap_scale_pixels (sk_pixmap_t cpixmap, sk_pixmap_t dst, SKFilterQuality quality);
 
-		// bool sk_pngencoder_encode(sk_wstream_t* dst, const sk_pixmap_t* src, sk_pngencoder_options_t options)
+		// bool sk_pngencoder_encode(sk_wstream_t* dst, const sk_pixmap_t* src, const sk_pngencoder_options_t* options)
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		[return: MarshalAs (UnmanagedType.I1)]
-		internal static extern bool sk_pngencoder_encode (sk_wstream_t dst, sk_pixmap_t src, SKPngEncoderOptions options);
+		internal static extern bool sk_pngencoder_encode (sk_wstream_t dst, sk_pixmap_t src, SKPngEncoderOptions* options);
 
 		// void sk_swizzle_swap_rb(uint32_t* dest, const uint32_t* src, int count)
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern void sk_swizzle_swap_rb (UInt32* dest, UInt32* src, Int32 count);
 
-		// bool sk_webpencoder_encode(sk_wstream_t* dst, const sk_pixmap_t* src, sk_webpencoder_options_t options)
+		// bool sk_webpencoder_encode(sk_wstream_t* dst, const sk_pixmap_t* src, const sk_webpencoder_options_t* options)
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		[return: MarshalAs (UnmanagedType.I1)]
-		internal static extern bool sk_webpencoder_encode (sk_wstream_t dst, sk_pixmap_t src, SKWebpEncoderOptions options);
+		internal static extern bool sk_webpencoder_encode (sk_wstream_t dst, sk_pixmap_t src, SKWebpEncoderOptions* options);
 
 		#endregion
 
@@ -3301,9 +3309,13 @@ namespace SkiaSharp
 
 		#region sk_svg.h
 
-		// sk_canvas_t* sk_svgcanvas_create(const sk_rect_t* bounds, sk_xmlwriter_t* writer)
+		// sk_canvas_t* sk_svgcanvas_create_with_stream(const sk_rect_t* bounds, sk_wstream_t* stream)
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
-		internal static extern sk_canvas_t sk_svgcanvas_create (SKRect* bounds, sk_xmlwriter_t writer);
+		internal static extern sk_canvas_t sk_svgcanvas_create_with_stream (SKRect* bounds, sk_wstream_t stream);
+
+		// sk_canvas_t* sk_svgcanvas_create_with_writer(const sk_rect_t* bounds, sk_xmlwriter_t* writer)
+		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
+		internal static extern sk_canvas_t sk_svgcanvas_create_with_writer (SKRect* bounds, sk_xmlwriter_t writer);
 
 		#endregion
 
@@ -3453,6 +3465,10 @@ namespace SkiaSharp
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern Int32 sk_typeface_chars_to_glyphs (sk_typeface_t typeface, /* char */ void* chars, SKEncoding encoding, UInt16* glyphs, Int32 glyphCount);
 
+		// int sk_typeface_count_glyphs(sk_typeface_t* typeface)
+		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
+		internal static extern Int32 sk_typeface_count_glyphs (sk_typeface_t typeface);
+
 		// int sk_typeface_count_tables(sk_typeface_t* typeface)
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern Int32 sk_typeface_count_tables (sk_typeface_t typeface);
@@ -3493,6 +3509,11 @@ namespace SkiaSharp
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern sk_fontstyle_t sk_typeface_get_fontstyle (sk_typeface_t typeface);
 
+		// bool sk_typeface_get_kerning_pair_adjustments(sk_typeface_t* typeface, const uint16_t* glyphs, int count, int32_t* adjustments)
+		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
+		[return: MarshalAs (UnmanagedType.I1)]
+		internal static extern bool sk_typeface_get_kerning_pair_adjustments (sk_typeface_t typeface, UInt16* glyphs, Int32 count, Int32* adjustments);
+
 		// size_t sk_typeface_get_table_data(sk_typeface_t* typeface, sk_font_table_tag_t tag, size_t offset, size_t length, void* data)
 		[DllImport (SKIA, CallingConvention = CallingConvention.Cdecl)]
 		internal static extern /* size_t */ IntPtr sk_typeface_get_table_data (sk_typeface_t typeface, UInt32 tag, /* size_t */ IntPtr offset, /* size_t */ IntPtr length, void* data);

binding/Binding/Util.cs

@@ -1,112 +1,139 @@
 using System;
-using System.Collections.Generic;
-using System.Runtime.InteropServices;
+using System.ComponentModel;
 using System.Text;
 
 namespace SkiaSharp
 {
-	internal static class Utils
+	internal unsafe static class Utils
 	{
-		internal const float NearlyZero = (1.0f / (1 << 12));
+		internal const float NearlyZero = 1.0f / (1 << 12);
 
-		internal static bool NearlyEqual (float a, float b, float tolerance)
+		internal static Span<byte> AsSpan (this IntPtr ptr, int size) =>
+			new Span<byte> ((void*)ptr, size);
+
+		internal static ReadOnlySpan<byte> AsReadOnlySpan (this IntPtr ptr, int size) =>
+			new ReadOnlySpan<byte> ((void*)ptr, size);
+
+		internal static bool NearlyEqual (float a, float b, float tolerance) =>
+			Math.Abs (a - b) <= tolerance;
+
+		internal static byte[] GetBytes (this Encoding encoding, ReadOnlySpan<char> text)
 		{
-			return Math.Abs (a - b) <= tolerance;
+			if (text.Length == 0)
+				return new byte[0];
+
+			fixed (char* t = text) {
+				var byteCount = encoding.GetByteCount (t, text.Length);
+				if (byteCount == 0)
+					return new byte[0];
+
+				var bytes = new byte[byteCount];
+				fixed (byte* b = bytes) {
+					encoding.GetBytes (t, text.Length, b, byteCount);
+				}
+				return bytes;
+			}
 		}
 	}
 
 	public unsafe static class StringUtilities
 	{
-		private static int GetUnicodeStringLength(SKTextEncoding encoding)
-		{
-			switch (encoding)
+		// GetUnicodeStringLength
+
+		private static int GetUnicodeStringLength (SKTextEncoding encoding) =>
+			encoding switch
 			{
-				case SKTextEncoding.Utf8:
-				case SKTextEncoding.Utf16:
-					return 1;
-				case SKTextEncoding.Utf32:
-					return 2;
-				default:
-					throw new ArgumentOutOfRangeException(nameof(encoding), $"Encoding {encoding} is not supported.");
-			}
+				SKTextEncoding.Utf8 => 1,
+				SKTextEncoding.Utf16 => 1,
+				SKTextEncoding.Utf32 => 2,
+				_ => throw new ArgumentOutOfRangeException (nameof (encoding), $"Encoding {encoding} is not supported.")
+			};
+
+		// GetUnicodeCharacterCode
+
+		public static int GetUnicodeCharacterCode (string character, SKTextEncoding encoding)
+		{
+			if (character == null)
+				throw new ArgumentNullException (nameof (character));
+			if (GetUnicodeStringLength (encoding) != character.Length)
+				throw new ArgumentException (nameof (character), $"Only a single character can be specified.");
+
+			var bytes = GetEncodedText (character, encoding);
+			return BitConverter.ToInt32 (bytes, 0);
 		}
 
-		public static int GetUnicodeCharacterCode(string character, SKTextEncoding encoding)
-		{
-			if (GetUnicodeStringLength(encoding) != character.Length)
-				throw new ArgumentException(nameof(character), $"Only a single character can be specified.");
+		// GetEncodedText
 
-			var bytes = GetEncodedText(character, encoding);
-			return BitConverter.ToInt32(bytes, 0);
-		}
+		[EditorBrowsable (EditorBrowsableState.Never)]
+		[Obsolete ("Use GetEncodedText(string, SKTextEncoding) instead.")]
+		public static byte[] GetEncodedText (string text, SKEncoding encoding) =>
+			GetEncodedText (text.AsSpan (), encoding.ToTextEncoding ());
 
-		public static byte[] GetEncodedText(string text, SKEncoding encoding)
-		{
-			if (text == null)
-				throw new ArgumentNullException (nameof (text));
+		public static byte[] GetEncodedText (string text, SKTextEncoding encoding) =>
+			GetEncodedText (text.AsSpan (), encoding);
 
-			switch (encoding)
+		public static byte[] GetEncodedText (ReadOnlySpan<char> text, SKTextEncoding encoding) =>
+			encoding switch
 			{
-				case SKEncoding.Utf8:
-					return Encoding.UTF8.GetBytes(text);
-				case SKEncoding.Utf16:
-					return Encoding.Unicode.GetBytes(text);
-				case SKEncoding.Utf32:
-					return Encoding.UTF32.GetBytes(text);
-				default:
-					throw new ArgumentOutOfRangeException(nameof(encoding), $"Encoding {encoding} is not supported.");
-			}
-		}
+				SKTextEncoding.Utf8 => Encoding.UTF8.GetBytes (text),
+				SKTextEncoding.Utf16 => Encoding.Unicode.GetBytes (text),
+				SKTextEncoding.Utf32 => Encoding.UTF32.GetBytes (text),
+				_ => throw new ArgumentOutOfRangeException (nameof (encoding), $"Encoding {encoding} is not supported."),
+			};
 
-		public static byte[] GetEncodedText(string text, SKTextEncoding encoding)
+		// GetString
+
+		public static string GetString (IntPtr data, int dataLength, SKTextEncoding encoding) =>
+			GetString (data.AsReadOnlySpan (dataLength), 0, dataLength, encoding);
+
+		public static string GetString (byte[] data, SKTextEncoding encoding) =>
+			GetString (data, 0, data.Length, encoding);
+
+		public static string GetString (byte[] data, int index, int count, SKTextEncoding encoding)
 		{
-			if (text == null)
-				throw new ArgumentNullException (nameof (text));
+			if (data == null)
+				throw new ArgumentNullException (nameof (data));
 
-			switch (encoding)
+			return encoding switch
 			{
-				case SKTextEncoding.Utf8:
-					return Encoding.UTF8.GetBytes(text);
-				case SKTextEncoding.Utf16:
-					return Encoding.Unicode.GetBytes(text);
-				case SKTextEncoding.Utf32:
-					return Encoding.UTF32.GetBytes(text);
-				default:
-					throw new ArgumentOutOfRangeException(nameof(encoding), $"Encoding {encoding} is not supported.");
-			}
+				SKTextEncoding.Utf8 => Encoding.UTF8.GetString (data, index, count),
+				SKTextEncoding.Utf16 => Encoding.Unicode.GetString (data, index, count),
+				SKTextEncoding.Utf32 => Encoding.UTF32.GetString (data, index, count),
+				_ => throw new ArgumentOutOfRangeException (nameof (encoding), $"Encoding {encoding} is not supported."),
+			};
 		}
 
-		internal static string GetString(void* data, int dataLength, SKTextEncoding encoding) =>
-			GetString((IntPtr)data, dataLength, encoding);
+		public static string GetString (ReadOnlySpan<byte> data, SKTextEncoding encoding) =>
+			GetString (data, 0, data.Length, encoding);
 
-		public static string GetString(IntPtr data, int dataLength, SKTextEncoding encoding)
+		public static string GetString (ReadOnlySpan<byte> data, int index, int count, SKTextEncoding encoding)
 		{
-			if (data == IntPtr.Zero || dataLength <= 0)
-				return "";
+			data = data.Slice (index, count);
 
-			byte[] result = new byte[dataLength];
-			Marshal.Copy(data, result, 0, dataLength);
-			return GetString(result, encoding);
-		}
+			if (data.Length == 0)
+				return string.Empty;
 
-		public static string GetString(byte[] data, SKTextEncoding encoding)
-		{
-			return GetString(data, 0, data.Length, encoding);
-		}
-
-		public static string GetString(byte[] data, int index, int count, SKTextEncoding encoding)
-		{
-			switch (encoding)
+#if __DESKTOP__
+			// TODO: improve this copy for old .NET 4.5
+			var array = data.ToArray ();
+			return encoding switch
 			{
-				case SKTextEncoding.Utf8:
-					return Encoding.UTF8.GetString(data, index, count);
-				case SKTextEncoding.Utf16:
-					return Encoding.Unicode.GetString(data, index, count);
-				case SKTextEncoding.Utf32:
-					return Encoding.UTF32.GetString(data, index, count);
-				default:
-					throw new ArgumentOutOfRangeException(nameof(encoding), $"Encoding {encoding} is not supported.");
+				SKTextEncoding.Utf8 => Encoding.UTF8.GetString (array),
+				SKTextEncoding.Utf16 => Encoding.Unicode.GetString (array),
+				SKTextEncoding.Utf32 => Encoding.UTF32.GetString (array),
+				_ => throw new ArgumentOutOfRangeException (nameof (encoding), $"Encoding {encoding} is not supported."),
+			};
+#else
+			fixed (byte* bp = data) {
+				return encoding switch
+				{
+					SKTextEncoding.Utf8 => Encoding.UTF8.GetString (bp, data.Length),
+					SKTextEncoding.Utf16 => Encoding.Unicode.GetString (bp, data.Length),
+					SKTextEncoding.Utf32 => Encoding.UTF32.GetString (bp, data.Length),
+					_ => throw new ArgumentOutOfRangeException (nameof (encoding), $"Encoding {encoding} is not supported."),
+				};
 			}
+#endif
 		}
 	}
 }

binding/HarfBuzzSharp/HarfBuzzSharp.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netstandard1.3;netstandard2.0;net45</TargetFrameworks>
+    <TargetFrameworks>netstandard1.3;netstandard2.0;net45;net462</TargetFrameworks>
     <RootNamespace>HarfBuzzSharp</RootNamespace>
     <AssemblyName>HarfBuzzSharp</AssemblyName>
     <PackagingGroup>HarfBuzzSharp</PackagingGroup>
@@ -9,7 +9,7 @@
   <PropertyGroup Condition="$(TargetFramework.StartsWith('netstandard'))">
     <DefineConstants>$(DefineConstants);NET_STANDARD</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition="$(TargetFramework.StartsWith('net4'))">
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('net45'))">
     <DefineConstants>$(DefineConstants);__DESKTOP__</DefineConstants>
   </PropertyGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard1.3'">

binding/SkiaSharp/SkiaSharp.csproj

@@ -1,6 +1,6 @@
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <TargetFrameworks>netstandard1.3;netstandard2.0;net45</TargetFrameworks>
+    <TargetFrameworks>netstandard1.3;netstandard2.0;net45;net462</TargetFrameworks>
     <RootNamespace>SkiaSharp</RootNamespace>
     <AssemblyName>SkiaSharp</AssemblyName>
     <PackagingGroup>SkiaSharp</PackagingGroup>
@@ -8,7 +8,7 @@
   <PropertyGroup Condition="$(TargetFramework.StartsWith('netstandard'))">
     <DefineConstants>$(DefineConstants);NET_STANDARD</DefineConstants>
   </PropertyGroup>
-  <PropertyGroup Condition="$(TargetFramework.StartsWith('net4'))">
+  <PropertyGroup Condition="$(TargetFramework.StartsWith('net45'))">
     <DefineConstants>$(DefineConstants);__DESKTOP__</DefineConstants>
   </PropertyGroup>
   <ItemGroup Condition="'$(TargetFramework)' == 'netstandard1.3'">

binding/libSkiaSharp.json

@@ -9,6 +9,10 @@
     "include/c": [ "sk_*", "gr_*" ],
     "include/xamarin": [ "sk_*" ]
   },
+  "source": {
+    "src/c": [ "sk_*", "gr_*" ],
+    "src/xamarin": [ "sk_*" ]
+  },
   "mappings": {
     "types": {
       // type aliases

cake/UpdateDocs.cake

@@ -23,8 +23,10 @@ void CopyChangelogs (DirectoryPath diffRoot, string id, string version)
             var dllName = file.GetFilenameWithoutExtension ().GetFilenameWithoutExtension ().GetFilenameWithoutExtension ();
             if (file.GetFilenameWithoutExtension ().GetExtension () == ".breaking") {
                 // skip over breaking changes without any breaking changes
-                if (!FindTextInFiles (file.FullPath, "###").Any ())
+                if (!FindTextInFiles (file.FullPath, "###").Any ()) {
+                    DeleteFile (file);
                     continue;
+                }
 
                 dllName += ".breaking";
             }
@@ -68,9 +70,14 @@ Task ("docs-download-output")
 Task ("docs-api-diff")
     .Does (async () =>
 {
+    // working version
     var baseDir = $"{OUTPUT_NUGETS_PATH}/api-diff";
     CleanDirectories (baseDir);
 
+    // pretty version
+    var diffDir = "./output/api-diff";
+    CleanDirectories (diffDir);
+
     Information ($"Creating comparer...");
     var comparer = await CreateNuGetDiffAsync ();
     comparer.SaveAssemblyApiInfo = true;
@@ -104,6 +111,16 @@ Task ("docs-api-diff")
         }
         CopyChangelogs (diffRoot, id, version);
 
+        // copy pretty version
+        foreach (var md in GetFiles ($"{diffRoot}/*/*.md")) {
+            var tfm = md.GetDirectory ().GetDirectoryName();
+            var prettyPath = ((DirectoryPath)diffDir).CombineWithFilePath ($"{id}/{tfm}/{md.GetFilename ()}");
+            if (!FindTextInFiles (md.FullPath, "No changes").Any ()) {
+                EnsureDirectoryExists (prettyPath.GetDirectory ());
+                CopyFile (md, prettyPath);
+            }
+        }
+
         Information ($"Diff complete of '{id}'.");
     }
 });

cake/shared.cake

@@ -35,7 +35,7 @@ void RunCake(FilePath cake, string target = null, Dictionary<string, string> arg
     });
 }
 
-void RunProcess(FilePath process, string args)
+void RunProcess(FilePath process, string args = "")
 {
     var result = StartProcess(process, args);
     if (result != 0) {

externals/skia

@@ -1 +1 @@
-Subproject commit 2411fe768b0e3d16a1e59839f65b4d802b74499a
+Subproject commit 2eb536d04142b5fb3c7ce605f8efd4f08c7e6760

nuget/HarfbuzzSharp.nuspec

@@ -30,6 +30,9 @@ Please visit https://go.microsoft.com/fwlink/?linkid=868517 to view the release
       <group targetFramework="net45">
         <dependency id="System.Memory" version="4.5.3" />
       </group>
+      <group targetFramework="net462">
+        <dependency id="System.Memory" version="4.5.3" />
+      </group>
       <group targetFramework="netstandard1.3">
         <dependency id="System.IO.UnmanagedMemoryStream" version="4.3.0" />
         <dependency id="System.Memory" version="4.5.3" />
@@ -64,6 +67,8 @@ Please visit https://go.microsoft.com/fwlink/?linkid=868517 to view the release
     <!-- HarfBuzzSharp.dll -->
     <file src="lib/net45/HarfBuzzSharp.dll" />
     <file src="lib/net45/HarfBuzzSharp.xml" />
+    <file src="lib/net462/HarfBuzzSharp.dll" />
+    <file src="lib/net462/HarfBuzzSharp.xml" />
     <file src="lib/netstandard1.3/HarfBuzzSharp.dll" />
     <file src="lib/netstandard1.3/HarfBuzzSharp.xml" />
     <file src="lib/netstandard2.0/HarfBuzzSharp.dll" />
@@ -88,6 +93,8 @@ Please visit https://go.microsoft.com/fwlink/?linkid=868517 to view the release
     <!-- the build bits -->
     <file src="build/net45/HarfBuzzSharp.targets" />
     <file src="build/net45/HarfBuzzSharp.targets" target="buildTransitive/net45/HarfBuzzSharp.targets" />
+    <file src="build/net462/HarfBuzzSharp.targets" />
+    <file src="build/net462/HarfBuzzSharp.targets" target="buildTransitive/net462/HarfBuzzSharp.targets" />
     <file src="build/tizen40/HarfBuzzSharp.targets" />
 
     <!-- harfbuzz.dll and other native files -->

nuget/SkiaSharp.nuspec

@@ -31,6 +31,9 @@ Please visit https://go.microsoft.com/fwlink/?linkid=868517 to view the release
       <group targetFramework="net45">
         <dependency id="System.Memory" version="4.5.3" />
       </group>
+      <group targetFramework="net462">
+        <dependency id="System.Memory" version="4.5.3" />
+      </group>
       <group targetFramework="netstandard1.3">
         <dependency id="System.IO.UnmanagedMemoryStream" version="4.3.0" />
         <dependency id="System.Memory" version="4.5.3" />
@@ -65,6 +68,8 @@ Please visit https://go.microsoft.com/fwlink/?linkid=868517 to view the release
     <!-- SkiaSharp.dll -->
     <file src="lib/net45/SkiaSharp.dll" />
     <file src="lib/net45/SkiaSharp.xml" />
+    <file src="lib/net462/SkiaSharp.dll" />
+    <file src="lib/net462/SkiaSharp.xml" />
     <file src="lib/netstandard1.3/SkiaSharp.dll" />
     <file src="lib/netstandard1.3/SkiaSharp.xml" />
     <file src="lib/netstandard2.0/SkiaSharp.dll" />
@@ -89,6 +94,8 @@ Please visit https://go.microsoft.com/fwlink/?linkid=868517 to view the release
     <!-- the build bits -->
     <file src="build/net45/SkiaSharp.targets" />
     <file src="build/net45/SkiaSharp.targets" target="buildTransitive/net45/SkiaSharp.targets" />
+    <file src="build/net462/SkiaSharp.targets" />
+    <file src="build/net462/SkiaSharp.targets" target="buildTransitive/net462/SkiaSharp.targets" />
     <file src="build/tizen40/SkiaSharp.targets" />
 
     <!-- libSkiaSharp.dll and other native files -->

scripts/azure-pipelines.yml

@@ -24,9 +24,6 @@ variables:
   VM_IMAGE_LINUX: Hosted Ubuntu 1604
   DOTNET_SKIP_FIRST_TIME_EXPERIENCE: true
 
-  # # To speed up builds when debugging DevOps
-  # DOWNLOAD_EXTERNALS: ''
-
 resources:
   repositories:
     - repository: xamarin-templates
@@ -299,7 +296,7 @@ stages:
           vmImage: $(VM_IMAGE_WINDOWS)
           target: nuget
           additionalArgs: --packall=true --exclusive
-          shouldPublish: false
+          shouldPublish: true
           requiredArtifacts:
             - managed_linux
             - managed_macos
@@ -316,6 +313,35 @@ stages:
                 artifactName: nuget
                 pathToPublish: 'output/nugets'
 
+  - stage: api_diff
+    displayName: API Diff
+    dependsOn: package
+    jobs:
+      - template: azure-templates-bootstrapper.yml # API Diff
+        parameters:
+          name: api_diff_windows
+          displayName: API Diff
+          vmImage: $(VM_IMAGE_WINDOWS_NATIVE)
+          target: docs-api-diff
+          shouldPublish: false
+          requiredArtifacts:
+            - package_windows
+          preBuildSteps:
+            - pwsh: |
+                $p = "$env:BUILD_SOURCESDIRECTORY\output\nugets\api-diff"
+                New-Item -ItemType Directory -Force -Path $p | Out-Null
+                $uri = 'https://xamarin.azureedge.net/GTKforWindows/Windows/gtk-sharp-2.12.45.msi'
+                .\scripts\download-file.ps1 -Uri $uri -OutFile gtk-sharp.msi
+                msiexec /i gtk-sharp.msi /norestart /quiet /l* $p\gtk-sharp-install.log
+              displayName: Install GTK# 2.12
+          postBuildSteps:
+            - task: PublishBuildArtifacts@1
+              displayName: Publish the API diffs
+              condition: always()
+              inputs:
+                artifactName: api-diff
+                pathToPublish: '$(Build.SourcesDirectory)\output\api-diff'
+
   - ${{ if eq(variables['System.TeamProject'], 'devdiv') }}:
     - stage: signing
       displayName: Sign NuGets

scripts/azure-templates-bootstrapper.yml

@@ -14,7 +14,7 @@ parameters:
   condition: succeeded()                        # whether or not to run this template
   shouldPublish: true                           # whether or not to publish the artifacts
   configuration: $(CONFIGURATION)               # the build configuration
-  buildExternals: $(DOWNLOAD_EXTERNALS)         # the build number to download externals from
+  buildExternals: ''                            # the build number to download externals from
   verbosity: $(VERBOSITY)                       # the level of verbosity to use when building
   docker: ''                                    # the Docker image to build and use
 
@@ -26,6 +26,7 @@ jobs:
 #       displayName: ${{ parameters.displayName }}
 #       vmImage: ${{ parameters.vmImage }}
 #       condition: ${{ parameters.condition }}
+#       buildExternals: ${{ parameters.buildExternals }}
 
 # - ${{ if or(eq(parameters.buildExternals, ''), not(startsWith(parameters.name, 'native_'))) }}:
   - job: ${{ parameters.name }}

scripts/azure-templates-download.yml

@@ -3,7 +3,7 @@ parameters:
   displayName: ''                               # the human name
   vmImage: ''                                   # the VM image
   condition: succeeded()                        # whether or not to run this template
-  buildExternals: $(DOWNLOAD_EXTERNALS)         # the build number to download externals from
+  buildExternals: ''                            # the build number to download externals from
 
 jobs:
   - job: ${{ parameters.name }}

tests/SkiaSharp.Desktop.Tests/SkiaSharp.Desktop.Tests.csproj

@@ -18,7 +18,7 @@
     <DebugType>full</DebugType>
     <Optimize>false</Optimize>
     <OutputPath>bin\AnyCPU\Debug\</OutputPath>
-    <DefineConstants>$(DefineConstants);DEBUG;TRACE</DefineConstants>
+    <DefineConstants>$(DefineConstants);DEBUG;TRACE;SYSTEM_DRAWING</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
@@ -26,14 +26,14 @@
     <DebugType>pdbonly</DebugType>
     <Optimize>true</Optimize>
     <OutputPath>bin\AnyCPU\Release\</OutputPath>
-    <DefineConstants>$(DefineConstants);TRACE</DefineConstants>
+    <DefineConstants>$(DefineConstants);TRACE;SYSTEM_DRAWING</DefineConstants>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
     <DebugSymbols>true</DebugSymbols>
     <OutputPath>bin\x64\Debug\</OutputPath>
-    <DefineConstants>$(DefineConstants);DEBUG;TRACE</DefineConstants>
+    <DefineConstants>$(DefineConstants);DEBUG;TRACE;SYSTEM_DRAWING</DefineConstants>
     <DebugType>full</DebugType>
     <PlatformTarget>x64</PlatformTarget>
     <ErrorReport>prompt</ErrorReport>
@@ -42,7 +42,7 @@
     <DebugType>pdbonly</DebugType>
     <Optimize>true</Optimize>
     <OutputPath>bin\x64\Release\</OutputPath>
-    <DefineConstants>$(DefineConstants);TRACE</DefineConstants>
+    <DefineConstants>$(DefineConstants);TRACE;SYSTEM_DRAWING</DefineConstants>
     <PlatformTarget>x64</PlatformTarget>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
@@ -50,7 +50,7 @@
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
     <DebugSymbols>true</DebugSymbols>
     <OutputPath>bin\x86\Debug\</OutputPath>
-    <DefineConstants>$(DefineConstants);DEBUG;TRACE</DefineConstants>
+    <DefineConstants>$(DefineConstants);DEBUG;TRACE;SYSTEM_DRAWING</DefineConstants>
     <DebugType>full</DebugType>
     <PlatformTarget>x86</PlatformTarget>
     <ErrorReport>prompt</ErrorReport>
@@ -59,7 +59,7 @@
     <DebugType>pdbonly</DebugType>
     <Optimize>true</Optimize>
     <OutputPath>bin\x86\Release\</OutputPath>
-    <DefineConstants>$(DefineConstants);TRACE</DefineConstants>
+    <DefineConstants>$(DefineConstants);TRACE;SYSTEM_DRAWING</DefineConstants>
     <PlatformTarget>x86</PlatformTarget>
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>

tests/Tests/GRContextTest.cs

@@ -19,6 +19,15 @@ namespace SkiaSharp.Tests
 			}
 		}
 
+		[SkippableFact]
+		public void ToGlSizedFormat()
+		{
+			foreach (GRPixelConfig value in Enum.GetValues(typeof(GRPixelConfig)))
+			{
+				value.ToGlSizedFormat();
+			}
+		}
+
 		[Trait(CategoryKey, GpuCategory)]
 		[SkippableFact]
 		public void CreateSpecificContextIsValid()

tests/Tests/SKBasicTypesTest.cs

@@ -7,9 +7,6 @@ namespace SkiaSharp.Tests
 {
 	public class SKBasicTypesTest : SKTest
 	{
-		private const float EPSILON = 0.0001f;
-		private const int PRECISION = 4;
-
 		[SkippableFact]
 		public void ImageInfoMethodsDoNotModifySource()
 		{

tests/Tests/SKBitmapTest.cs

@@ -1,28 +1,107 @@
 using System;
 using System.Collections.Generic;
 using System.IO;
-using System.Threading.Tasks;
 using System.Runtime.InteropServices;
+using System.Threading.Tasks;
 using Xunit;
 
 namespace SkiaSharp.Tests
 {
 	public class SKBitmapTest : SKTest
 	{
-		[SkippableFact]
-		public void BitmapCanCopyIsCorrect()
+		public static IEnumerable<object[]> GetAllColorTypes()
 		{
-			var bmp = CreateTestBitmap();
+			foreach (SKColorType ct in Enum.GetValues(typeof(SKColorType)))
+				yield return new object[] { ct };
+		}
 
-			Assert.True(bmp.CanCopyTo(SKColorType.Alpha8));
-			Assert.True(bmp.CanCopyTo(SKColorType.Rgb565));
-			Assert.True(bmp.CanCopyTo(SKColorType.Argb4444));
-			Assert.True(bmp.CanCopyTo(SKColorType.Bgra8888));
-			Assert.True(bmp.CanCopyTo(SKColorType.Rgba8888));
-			Assert.True(bmp.CanCopyTo(SKColorType.RgbaF16));
+		[SkippableTheory]
+		[MemberData(nameof(GetAllColorTypes))]
+		public void CanCopyToIsCorrect(SKColorType colorType)
+		{
+			using var bmp = CreateTestBitmap();
 
-			Assert.False(bmp.CanCopyTo(SKColorType.Unknown));
-			Assert.False(bmp.CanCopyTo(SKColorType.Gray8));
+			var canCopy = bmp.CanCopyTo(colorType);
+
+			if (colorType == SKColorType.Unknown)
+				Assert.False(canCopy);
+			else
+				Assert.True(canCopy);
+		}
+
+		[SkippableTheory]
+		[MemberData(nameof(GetAllColorTypes))]
+		public void CopyToSucceeds(SKColorType colorType)
+		{
+			var alphaType = colorType.GetAlphaType();
+
+			using var bmp = CreateTestBitmap();
+
+			using var copy = bmp.Copy(colorType);
+
+			if (colorType == SKColorType.Unknown)
+			{
+				Assert.Null(copy);
+			}
+			else
+			{
+				Assert.NotNull(copy);
+				Assert.Equal(colorType, copy.ColorType);
+				Assert.Equal(alphaType, copy.AlphaType);
+
+				var color = copy.GetPixel(10, 10);
+				Assert.NotEqual(SKColors.Empty, color);
+				if (colorType == SKColorType.Gray8)
+					Assert.Equal(0xFF353535, color);
+				else if (colorType == SKColorType.Alpha8)
+					Assert.Equal(0xFF000000, color);
+				else
+					Assert.Equal(0xFFFF0000, color);
+			}
+		}
+
+		[SkippableTheory]
+		[MemberData(nameof(GetAllColorTypes))]
+		public void CopyWithAlphaToSucceeds(SKColorType colorType)
+		{
+			var alphaType = colorType.GetAlphaType();
+
+			using var bmp = CreateTestBitmap(170);
+
+			using var copy = bmp.Copy(colorType);
+
+			if (colorType == SKColorType.Unknown)
+			{
+				Assert.Null(copy);
+			}
+			else
+			{
+				Assert.NotNull(copy);
+				Assert.Equal(colorType, copy.ColorType);
+				Assert.Equal(alphaType, copy.AlphaType);
+
+				var color = copy.GetPixel(10, 10);
+				Assert.NotEqual(SKColors.Empty, color);
+
+				if (colorType == SKColorType.Gray8)
+				{
+					Assert.Equal((SKColor)0xFF232323, color);
+				}
+				else if (alphaType == SKAlphaType.Opaque)
+				{
+					Assert.True(color.Red > color.Green);
+					Assert.True(color.Red > color.Blue);
+					Assert.Equal(255, color.Alpha);
+				}
+				else if (colorType == SKColorType.Alpha8)
+				{
+					Assert.Equal((SKColor)0xAA000000, color);
+				}
+				else
+				{
+					Assert.Equal((SKColor)0xAAFF0000, color);
+				}
+			}
 		}
 
 		[SkippableFact]
@@ -63,15 +142,21 @@ namespace SkiaSharp.Tests
 			var bmp = CreateTestBitmap();
 
 			var alpha8 = bmp.Copy(SKColorType.Alpha8);
+
 			Assert.Equal(SKColors.Black, alpha8.GetPixel(10, 10));
 			Assert.Equal(SKColors.Black, alpha8.GetPixel(30, 10));
 			Assert.Equal(SKColors.Black, alpha8.GetPixel(10, 30));
 			Assert.Equal(SKColors.Black, alpha8.GetPixel(30, 30));
 			Assert.Equal(SKColorType.Alpha8, alpha8.ColorType);
+		}
 
-			bmp = CreateTestBitmap(127);
+		[SkippableFact]
+		public void BitmapWithAlphaCopyToAlpha8PreservesData()
+		{
+			var bmp = CreateTestBitmap(127);
+
+			var alpha8 = bmp.Copy(SKColorType.Alpha8);
 
-			alpha8 = bmp.Copy(SKColorType.Alpha8);
 			Assert.Equal(SKColors.Black.WithAlpha(127), alpha8.GetPixel(10, 10));
 			Assert.Equal(SKColors.Black.WithAlpha(127), alpha8.GetPixel(30, 10));
 			Assert.Equal(SKColors.Black.WithAlpha(127), alpha8.GetPixel(10, 30));
@@ -85,17 +170,23 @@ namespace SkiaSharp.Tests
 			var bmp = CreateTestBitmap();
 
 			var argb4444 = bmp.Copy(SKColorType.Argb4444);
+
 			Assert.Equal((SKColor)0xffff0000, argb4444.GetPixel(10, 10));
-			Assert.Equal((SKColor)0xff007700, argb4444.GetPixel(30, 10));
+			Assert.Equal((SKColor)0xff008800, argb4444.GetPixel(30, 10));
 			Assert.Equal((SKColor)0xff0000ff, argb4444.GetPixel(10, 30));
 			Assert.Equal((SKColor)0xffffff00, argb4444.GetPixel(30, 30));
 			Assert.Equal(SKColorType.Argb4444, argb4444.ColorType);
+		}
 
-			bmp = CreateTestBitmap(127);
+		[SkippableFact]
+		public void BitmapWithAlphaCopyToArgb4444PreservesData()
+		{
+			var bmp = CreateTestBitmap(127);
+
+			var argb4444 = bmp.Copy(SKColorType.Argb4444);
 
-			argb4444 = bmp.Copy(SKColorType.Argb4444);
 			Assert.Equal((SKColor)0x77ff0000, argb4444.GetPixel(10, 10));
-			Assert.Equal((SKColor)0x77006d00, argb4444.GetPixel(30, 10));
+			Assert.Equal((SKColor)0x77009200, argb4444.GetPixel(30, 10));
 			Assert.Equal((SKColor)0x770000ff, argb4444.GetPixel(10, 30));
 			Assert.Equal((SKColor)0x77ffff00, argb4444.GetPixel(30, 30));
 			Assert.Equal(SKColorType.Argb4444, argb4444.ColorType);
@@ -107,15 +198,21 @@ namespace SkiaSharp.Tests
 			var bmp = CreateTestBitmap();
 
 			var rgb565 = bmp.Copy(SKColorType.Rgb565);
+
 			Assert.Equal((SKColor)0xffff0000, rgb565.GetPixel(10, 10));
 			Assert.Equal((SKColor)0xff008200, rgb565.GetPixel(31, 10));
 			Assert.Equal((SKColor)0xff0000ff, rgb565.GetPixel(10, 30));
 			Assert.Equal((SKColor)0xffffff00, rgb565.GetPixel(30, 30));
 			Assert.Equal(SKColorType.Rgb565, rgb565.ColorType);
+		}
 
-			bmp = CreateTestBitmap(127);
+		[SkippableFact]
+		public void BitmapWithAlphaCopyToRgb565PreservesData()
+		{
+			var bmp = CreateTestBitmap(127);
+
+			var rgb565 = bmp.Copy(SKColorType.Rgb565);
 
-			rgb565 = bmp.Copy(SKColorType.Rgb565);
 			Assert.Equal((SKColor)0xff7b0000, rgb565.GetPixel(10, 10));
 			Assert.Equal((SKColor)0xff004100, rgb565.GetPixel(31, 10));
 			Assert.Equal((SKColor)0xff00007b, rgb565.GetPixel(10, 30));
@@ -129,19 +226,25 @@ namespace SkiaSharp.Tests
 			var bmp = CreateTestBitmap();
 
 			var rgbaF16 = bmp.Copy(SKColorType.RgbaF16);
+
 			Assert.Equal((SKColor)0xffff0000, rgbaF16.GetPixel(10, 10));
-			Assert.Equal((SKColor)0xff003700, rgbaF16.GetPixel(30, 10));
+			Assert.Equal((SKColor)0xff008000, rgbaF16.GetPixel(30, 10));
 			Assert.Equal((SKColor)0xff0000ff, rgbaF16.GetPixel(10, 30));
 			Assert.Equal((SKColor)0xffffff00, rgbaF16.GetPixel(30, 30));
 			Assert.Equal(SKColorType.RgbaF16, rgbaF16.ColorType);
+		}
 
-			bmp = CreateTestBitmap(127);
+		[SkippableFact]
+		public void BitmapWithAlphaCopyToRgbaF16PreservesData()
+		{
+			var bmp = CreateTestBitmap(127);
 
-			rgbaF16 = bmp.Copy(SKColorType.RgbaF16);
-			Assert.Equal((SKColor)0x7f6d0000, rgbaF16.GetPixel(10, 10));
-			Assert.Equal((SKColor)0x7f001a00, rgbaF16.GetPixel(30, 10));
-			Assert.Equal((SKColor)0x7f00006d, rgbaF16.GetPixel(10, 30));
-			Assert.Equal((SKColor)0x7f6d6d00, rgbaF16.GetPixel(30, 30));
+			var rgbaF16 = bmp.Copy(SKColorType.RgbaF16);
+
+			Assert.Equal((SKColor)0x7fff0000, rgbaF16.GetPixel(10, 10));
+			Assert.Equal((SKColor)0x7f008100, rgbaF16.GetPixel(30, 10));
+			Assert.Equal((SKColor)0x7f0000ff, rgbaF16.GetPixel(10, 30));
+			Assert.Equal((SKColor)0x7fffff00, rgbaF16.GetPixel(30, 30));
 			Assert.Equal(SKColorType.RgbaF16, rgbaF16.ColorType);
 		}
 
@@ -154,12 +257,6 @@ namespace SkiaSharp.Tests
 			ValidateTestBitmap(bmp.Copy(SKImageInfo.PlatformColorType));
 
 			Assert.Null(bmp.Copy(SKColorType.Unknown));
-			Assert.Null(bmp.Copy(SKColorType.Gray8));
-
-			// alpha to non-alpha is not supported
-			Assert.Null(bmp
-				.Copy(SKColorType.Alpha8)
-				.Copy(SKImageInfo.PlatformColorType));
 		}
 
 		[SkippableFact]
@@ -167,13 +264,15 @@ namespace SkiaSharp.Tests
 		{
 			bool released = false;
 
-			var onRelease = new SKBitmapReleaseDelegate((addr, ctx) => {
+			var onRelease = new SKBitmapReleaseDelegate((addr, ctx) =>
+			{
 				Marshal.FreeCoTaskMem(addr);
 				released = true;
 				Assert.Equal("RELEASING!", ctx);
 			});
 
-			using (var bitmap = new SKBitmap()) {
+			using (var bitmap = new SKBitmap())
+			{
 				var info = new SKImageInfo(1, 1);
 				var pixels = Marshal.AllocCoTaskMem(info.BytesSize);
 
@@ -187,7 +286,8 @@ namespace SkiaSharp.Tests
 		public void ImageCreateDoesNotThrow()
 		{
 			var info = new SKImageInfo(1, 1);
-			using (var image = SKImage.Create(info)) {
+			using (var image = SKImage.Create(info))
+			{
 				Assert.False(image.IsTextureBacked);
 				Assert.Equal(image, image.ToRasterImage());
 			}
@@ -199,7 +299,8 @@ namespace SkiaSharp.Tests
 			var info = new SKImageInfo(1, 1);
 			var pixels = Marshal.AllocCoTaskMem(info.BytesSize);
 
-			using (var bitmap = new SKBitmap()) {
+			using (var bitmap = new SKBitmap())
+			{
 				bitmap.InstallPixels(info, pixels, info.RowBytes);
 			}
 
@@ -215,7 +316,8 @@ namespace SkiaSharp.Tests
 			var alpha = new SKBitmap();
 
 			SKPointI offset;
-			SKPaint paint = new SKPaint {
+			SKPaint paint = new SKPaint
+			{
 				MaskFilter = SKMaskFilter.CreateBlur(SKBlurStyle.Normal, 5.0f)
 			};
 
@@ -230,13 +332,15 @@ namespace SkiaSharp.Tests
 			var path = Path.Combine(PathToImages, "color-wheel.png");
 
 			using (var bitmap = SKBitmap.Decode(path))
-			using (var surface = SKSurface.Create(new SKImageInfo(200, 200))) {
+			using (var surface = SKSurface.Create(new SKImageInfo(200, 200)))
+			{
 				var canvas = surface.Canvas;
 				canvas.Clear(SKColors.White);
 				canvas.DrawBitmap(bitmap, 0, 0);
 
 				using (var img = surface.Snapshot())
-				using (var bmp = SKBitmap.FromImage(img)) {
+				using (var bmp = SKBitmap.FromImage(img))
+				{
 					Assert.Equal(new SKColor(2, 255, 42), bmp.GetPixel(20, 20));
 					Assert.Equal(new SKColor(1, 83, 255), bmp.GetPixel(108, 20));
 					Assert.Equal(new SKColor(255, 166, 1), bmp.GetPixel(20, 108));
@@ -249,7 +353,8 @@ namespace SkiaSharp.Tests
 		public void BitmapAndPixmapAreValid()
 		{
 			var info = new SKImageInfo(10, 10);
-			using (var bitmap = new SKBitmap(info)) {
+			using (var bitmap = new SKBitmap(info))
+			{
 				Assert.Equal(10, bitmap.Width);
 				Assert.Equal(10, bitmap.Height);
 
@@ -275,7 +380,8 @@ namespace SkiaSharp.Tests
 			var srcBmp = new SKBitmap(srcInfo);
 
 			using (var canvas = new SKCanvas(srcBmp))
-			using (var paint = new SKPaint { Color = SKColors.Green }) {
+			using (var paint = new SKPaint { Color = SKColors.Green })
+			{
 				canvas.Clear(SKColors.Blue);
 				canvas.DrawRect(new SKRect(0, 0, 100, 200), paint);
 			}
@@ -299,7 +405,8 @@ namespace SkiaSharp.Tests
 			var srcBmp = new SKBitmap(srcInfo);
 
 			using (var canvas = new SKCanvas(srcBmp))
-			using (var paint = new SKPaint { Color = SKColors.Green }) {
+			using (var paint = new SKPaint { Color = SKColors.Green })
+			{
 				canvas.Clear(SKColors.Blue);
 				canvas.DrawRect(new SKRect(0, 0, 100, 200), paint);
 			}
@@ -351,7 +458,7 @@ namespace SkiaSharp.Tests
 			{
 				Assert.Equal(255, pixel.Alpha);
 			}
-			
+
 			var maskBuffer = new byte[]
 			{
 				128, 127, 126, 125,
@@ -461,5 +568,26 @@ namespace SkiaSharp.Tests
 				Assert.NotNull(bitmap);
 			}
 		}
+
+		[SkippableFact]
+		public void CanCreateUsingRowBytes()
+		{
+			using var src = CreateTestBitmap();
+
+			var xOffset = 19 * src.BytesPerPixel;
+			var yOffset = 19 * src.RowBytes;
+			var offset = yOffset + xOffset;
+
+			using var bmp = new SKBitmap();
+			bmp.InstallPixels(new SKImageInfo(2, 2), src.GetPixels() + offset, src.RowBytes);
+
+			Assert.Equal(2, bmp.Width);
+			Assert.Equal(2, bmp.Height);
+
+			Assert.Equal(SKColors.Red, bmp.GetPixel(0, 0));
+			Assert.Equal(SKColors.Green, bmp.GetPixel(1, 0));
+			Assert.Equal(SKColors.Blue, bmp.GetPixel(0, 1));
+			Assert.Equal(SKColors.Yellow, bmp.GetPixel(1, 1));
+		}
 	}
 }

tests/Tests/SKCanvasTest.cs

@@ -393,6 +393,47 @@ namespace SkiaSharp.Tests
 		{
 			var stream = new MemoryStream();
 
+			using (var svg = SKSvgCanvas.Create(SKRect.Create(100, 100), stream))
+			{
+				var paint = new SKPaint
+				{
+					Color = SKColors.Red,
+					Style = SKPaintStyle.Fill
+				};
+				svg.DrawRect(SKRect.Create(10, 10, 80, 80), paint);
+			}
+
+			stream.Position = 0;
+
+			using (var reader = new StreamReader(stream))
+			{
+				var xml = reader.ReadToEnd();
+				var xdoc = XDocument.Parse(xml);
+
+				var svg = xdoc.Root;
+				var ns = svg.Name.Namespace;
+
+				Assert.Equal(ns + "svg", svg.Name);
+				Assert.Equal("100", svg.Attribute("width")?.Value);
+				Assert.Equal("100", svg.Attribute("height")?.Value);
+
+				var rect = svg.Element(ns + "rect");
+				Assert.Equal(ns + "rect", rect.Name);
+				Assert.Equal("rgb(255,0,0)", rect.Attribute("fill")?.Value);
+				Assert.Equal("none", rect.Attribute("stroke")?.Value);
+				Assert.Equal("10", rect.Attribute("x")?.Value);
+				Assert.Equal("10", rect.Attribute("y")?.Value);
+				Assert.Equal("80", rect.Attribute("width")?.Value);
+				Assert.Equal("80", rect.Attribute("height")?.Value);
+			}
+		}
+
+		[Obsolete]
+		[SkippableFact]
+		public void SvgCanvasSavesFileUsingWriter()
+		{
+			var stream = new MemoryStream();
+
 			using (var wstream = new SKManagedWStream(stream))
 			using (var writer = new SKXmlStreamWriter(wstream))
 			using (var svg = SKSvgCanvas.Create(SKRect.Create(100, 100), writer))

tests/Tests/SKColorSpaceStructsTest.cs

@@ -0,0 +1,52 @@
+using Xunit;
+
+namespace SkiaSharp.Tests
+{
+	public class SKColorSpaceStructsTest : SKTest
+	{
+		// SKColorSpacePrimaries
+
+		[SkippableFact]
+		public void PrimariesGoFullCircle()
+		{
+			var primaries = new float[] { 1, 2, 3, 4, 5, 6, 7, 8 };
+
+			var csp = new SKColorSpacePrimaries(primaries);
+
+			Assert.Equal(primaries, csp.Values);
+		}
+
+		[SkippableFact]
+		public void PrimariesToMatrix44()
+		{
+			var primaries = new float[] {
+				0.64f, 0.33f,
+				0.30f, 0.60f,
+				0.15f, 0.06f,
+				0.3127f, 0.3290f
+			};
+			var csp = new SKColorSpacePrimaries(primaries);
+
+			var matrix44 = csp.ToXyzD50();
+			Assert.NotNull(matrix44);
+
+			using var srgb = SKColorSpace.CreateSrgb();
+			var srgb44 = srgb.ToXyzD50();
+
+			AssertSimilar(srgb44.ToRowMajor(), matrix44.ToRowMajor(), PRECISION);
+		}
+
+		// SKColorSpaceTransferFn
+
+		[SkippableFact]
+		public void TransferFnIsFullCircle()
+		{
+			var values = new float[7] { 1, 2, 3, 4, 5, 6, 7 };
+
+			var tf = new SKColorSpaceTransferFn(values);
+			var tfValues = tf.Values;
+
+			Assert.Equal(values, tfValues);
+		}
+	}
+}

tests/Tests/SKDocumentTest.cs

@@ -177,7 +177,7 @@ namespace SkiaSharp.Tests
 
 			Assert.False(SKObject.GetInstance<SKDynamicMemoryWStream>(handle, out _));
 
-			void DoWork(out IntPtr streamHandle)
+			static void DoWork(out IntPtr streamHandle)
 			{
 				using (var document = CreateDocument(out streamHandle))
 				{
@@ -188,15 +188,15 @@ namespace SkiaSharp.Tests
 
 					CollectGarbage();
 
-					Assert.True(SKObject.GetInstance<SKDynamicMemoryWStream>(handle, out _));
+					Assert.True(SKObject.GetInstance<SKDynamicMemoryWStream>(streamHandle, out _));
 
 					document.Close();
 				}
 
-				Assert.True(SKObject.GetInstance<SKDynamicMemoryWStream>(handle, out _));
+				Assert.True(SKObject.GetInstance<SKDynamicMemoryWStream>(streamHandle, out _));
 			}
 
-			SKDocument CreateDocument(out IntPtr streamHandle)
+			static SKDocument CreateDocument(out IntPtr streamHandle)
 			{
 				var stream = new SKDynamicMemoryWStream();
 				streamHandle = stream.Handle;

tests/Tests/SKManagedWStreamTest.cs

@@ -0,0 +1,152 @@
+using System;
+using System.IO;
+using Xunit;
+
+namespace SkiaSharp.Tests
+{
+	public class SKManagedWStreamTest : SKTest
+	{
+		[SkippableFact]
+		public void DotNetStreamIsCollected()
+		{
+			var dotnet = new MemoryStream();
+			var stream = new SKManagedWStream(dotnet, true);
+
+			Assert.Equal(0, dotnet.Position);
+
+			stream.Dispose();
+
+			Assert.Throws<ObjectDisposedException>(() => dotnet.Position);
+		}
+
+		[SkippableFact]
+		public void DotNetStreamIsNotCollected()
+		{
+			var dotnet = new MemoryStream();
+			var stream = new SKManagedWStream(dotnet, false);
+
+			Assert.Equal(0, dotnet.Position);
+
+			stream.Dispose();
+
+			Assert.Equal(0, dotnet.Position);
+		}
+
+		[SkippableFact]
+		public unsafe void StreamIsNotDisposedWhenReferencedIsDisposed()
+		{
+			var stream = new SKManagedWStream(new MemoryStream(), true);
+			var handle = stream.Handle;
+
+			var document = SKDocument.CreatePdf(stream);
+			document.Dispose();
+
+			Assert.True(SKObject.GetInstance<SKManagedWStream>(handle, out _));
+		}
+
+		[SkippableFact]
+		public void StreamIsCollectedEvenWhenNotProperlyDisposed()
+		{
+			VerifyImmediateFinalizers();
+
+			var handle = DoWork();
+
+			CollectGarbage();
+
+			var exists = SKObject.GetInstance<SKManagedWStream>(handle, out _);
+			Assert.False(exists);
+
+			static IntPtr DoWork()
+			{
+				var dotnet = new MemoryStream();
+				var stream = new SKManagedWStream(dotnet, true);
+				return stream.Handle;
+			}
+		}
+
+		[SkippableFact]
+		public void ManagedStreamWritesByteCorrectly()
+		{
+			var dotnet = new MemoryStream();
+			var stream = new SKManagedWStream(dotnet);
+
+			Assert.Equal(0, dotnet.Position);
+			Assert.Equal(0, stream.BytesWritten);
+
+			stream.Write8(123);
+
+			Assert.Equal(1, dotnet.Position);
+			Assert.Equal(1, stream.BytesWritten);
+			Assert.Equal(new byte[] { 123 }, dotnet.ToArray());
+
+			stream.Write8(246);
+
+			Assert.Equal(2, dotnet.Position);
+			Assert.Equal(2, stream.BytesWritten);
+			Assert.Equal(new byte[] { 123, 246 }, dotnet.ToArray());
+		}
+
+		[SkippableFact]
+		public void ManagedStreamWritesChunkCorrectly()
+		{
+			var data = new byte[1024];
+			for (var i = 0; i < data.Length; i++)
+			{
+				data[i] = (byte)(i % byte.MaxValue);
+			}
+
+			var dotnet = new MemoryStream();
+			var stream = new SKManagedWStream(dotnet);
+
+			Assert.Equal(0, dotnet.Position);
+			Assert.Equal(0, stream.BytesWritten);
+
+			stream.Write(data, data.Length);
+
+			Assert.Equal(data.Length, dotnet.Position);
+			Assert.Equal(data.Length, stream.BytesWritten);
+			Assert.Equal(data, dotnet.ToArray());
+		}
+
+		[SkippableFact]
+		public unsafe void StreamIsReferencedAndNotDisposedPrematurely()
+		{
+			VerifyImmediateFinalizers();
+
+			DoWork(out var docH, out var streamH);
+
+			CollectGarbage();
+
+			Assert.False(SKObject.GetInstance<SKManagedWStream>(streamH, out _));
+			Assert.False(SKObject.GetInstance<SKDocument>(docH, out _));
+
+			static void DoWork(out IntPtr documentHandle, out IntPtr streamHandle)
+			{
+				var document = CreateDocument(out streamHandle);
+				documentHandle = document.Handle;
+
+				CollectGarbage();
+
+				Assert.NotNull(document.BeginPage(100, 100));
+				document.EndPage();
+				document.Close();
+
+				Assert.True(SKObject.GetInstance<SKManagedWStream>(streamHandle, out var stream));
+				Assert.True(stream.OwnsHandle);
+				Assert.False(stream.IgnorePublicDispose);
+			}
+
+			static SKDocument CreateDocument(out IntPtr streamHandle)
+			{
+				var stream = new SKManagedWStream(new MemoryStream(), true);
+				streamHandle = stream.Handle;
+
+				Assert.True(stream.OwnsHandle);
+				Assert.False(stream.IgnorePublicDispose);
+				Assert.True(SKObject.GetInstance<SKManagedWStream>(streamHandle, out _));
+
+				return SKDocument.CreatePdf(stream);
+			}
+		}
+	}
+}

tests/Tests/SKMaskTest.cs

@@ -8,9 +8,6 @@ namespace SkiaSharp.Tests
 {
 	public class SKMaskTest : SKTest
 	{
-		private const float EPSILON = 0.0001f;
-		private const int PRECISION = 4;
-
 		[SkippableFact]
 		public unsafe void FixedImageMaskIsHandledCorrectly()
 		{
@@ -20,12 +17,11 @@ namespace SkiaSharp.Tests
 			UInt32 rowBytes = 1;
 			var format = SKMaskFormat.BW;
 
-			fixed (void* bufferPtr = buffer)
-			{
-				var mask = SKMask.Create(buffer, bounds, rowBytes, format);
+			var mask = SKMask.Create(buffer, bounds, rowBytes, format);
 
-				Assert.Equal(rawMask, mask.GetAddr1(0, 0));
-			}
+			Assert.Equal(rawMask, mask.GetAddr1(0, 0));
+
+			mask.FreeImage();
 		}
 
 		[SkippableFact]

tests/Tests/SKMatrix44Tests.cs

@@ -0,0 +1,255 @@
+using System;
+using Xunit;
+
+namespace SkiaSharp.Tests
+{
+	public class SKMatrix44Test : SKTest
+	{
+		[SkippableFact]
+		public void Matrix44CreatesIdentity()
+		{
+			var matrix = SKMatrix44.CreateIdentity();
+
+			var expectedRowMajor = new float[] {
+				1, 0, 0, 0,
+				0, 1, 0, 0,
+				0, 0, 1, 0,
+				0, 0, 0, 1,
+			};
+			var rowMajor = matrix.ToRowMajor();
+
+			Assert.Equal(expectedRowMajor, rowMajor);
+		}
+
+		[SkippableFact]
+		public void RowMajorColumnMajorTransposes()
+		{
+			var rowMajor = new float[] {
+				1, 2, 3, 0,
+				0, 1, 4, 0,
+				5, 6, 1, 0,
+				0, 0, 0, 1,
+			};
+			var colMajor = new float[] {
+				1, 0, 5, 0,
+				2, 1, 6, 0,
+				3, 4, 1, 0,
+				0, 0, 0, 1,
+			};
+
+			var rowMajorMatrix = SKMatrix44.FromRowMajor(rowMajor);
+			var colMajorMatrix = rowMajorMatrix.ToColumnMajor();
+
+			Assert.Equal(colMajor, colMajorMatrix);
+		}
+
+		[SkippableFact]
+		public void MatrixGoesFullCircle()
+		{
+			var rowMajor = new float[] {
+				1, 2, 3, 0,
+				0, 1, 4, 0,
+				5, 6, 1, 0,
+				0, 0, 0, 1,
+			};
+
+			var matrix = SKMatrix44.FromRowMajor(rowMajor);
+			var result = matrix.ToRowMajor();
+
+			Assert.Equal(rowMajor, result);
+		}
+
+		[SkippableFact]
+		public void TransposeWorks()
+		{
+			var rowMajor = new float[] {
+				1, 2, 3, 0,
+				0, 1, 4, 0,
+				5, 6, 1, 0,
+				0, 0, 0, 1,
+			};
+			var colMajor = new float[] {
+				1, 0, 5, 0,
+				2, 1, 6, 0,
+				3, 4, 1, 0,
+				0, 0, 0, 1,
+			};
+
+			var rowMajorMatrix = SKMatrix44.FromRowMajor(rowMajor);
+			rowMajorMatrix.Transpose();
+			var colMajorMatrix = rowMajorMatrix.ToRowMajor();
+
+			Assert.Equal(colMajor, colMajorMatrix);
+		}
+
+		[SkippableFact]
+		public void ColumnMajorToRowMajorTransposes()
+		{
+			var rowMajor = new float[] {
+				1, 2, 3, 0,
+				0, 1, 4, 0,
+				5, 6, 1, 0,
+				0, 0, 0, 1,
+			};
+			var colMajor = new float[] {
+				1, 0, 5, 0,
+				2, 1, 6, 0,
+				3, 4, 1, 0,
+				0, 0, 0, 1,
+			};
+
+			var colMajorMatrix = SKMatrix44.FromColumnMajor(colMajor);
+			var rowMajorMatrix = colMajorMatrix.ToRowMajor();
+
+			Assert.Equal(rowMajor, rowMajorMatrix);
+		}
+
+		[SkippableFact]
+		public void Matrix44Inverts()
+		{
+			var rowMajor = new float[] {
+				1, 2, 3, 0,
+				0, 1, 4, 0,
+				5, 6, 1, 0,
+				0, 0, 0, 1,
+			};
+			var expectedRowMajor = new float[] {
+				-11.5f, 8, 2.5f, 0,
+				10, -7, -2, 0,
+				-2.5f, 2, 0.5f, 0,
+				0, 0, 0, 1,
+			};
+			var determinant = 2f;
+
+			var matrix = SKMatrix44.FromRowMajor(rowMajor);
+
+			Assert.Equal(rowMajor, matrix.ToRowMajor());
+			Assert.Equal(determinant, matrix.Determinant());
+
+			var inverted = matrix.Invert();
+
+			Assert.Equal(1f / determinant, inverted.Determinant());
+
+			var actualRowMajor = inverted.ToRowMajor();
+			Assert.Equal(expectedRowMajor, actualRowMajor);
+		}
+
+		[SkippableFact]
+		public void Matrix44ConvertsToMatrix()
+		{
+			var rowMajor44 = new float[] {
+				2, 3, 4, 5,
+				4, 6, 8, 10,
+				6, 9, 12, 15,
+				8, 12, 16, 20,
+			};
+			var rowMajor = new float[] {
+				rowMajor44[0], rowMajor44[1], rowMajor44[3],
+				rowMajor44[4], rowMajor44[5], rowMajor44[7],
+				rowMajor44[12], rowMajor44[13], rowMajor44[15],
+			};
+
+			var matrix44 = SKMatrix44.FromRowMajor(rowMajor44);
+
+			Assert.Equal(rowMajor, matrix44.Matrix.Values);
+		}
+
+		[SkippableFact]
+		public void TransformConvertsToMatrix()
+		{
+			var matrix44 = SKMatrix44.CreateRotationDegrees(0, 0, 1, 45);
+			var matrix = SKMatrix.CreateRotationDegrees(45);
+
+			Assert.Equal(matrix.Values, matrix44.Matrix.Values);
+		}
+
+		[SkippableFact]
+		public void ImplicitFromMatrix()
+		{
+			var matrix = SKMatrix.CreateRotationDegrees(45);
+			var matrix44 = (SKMatrix44)matrix;
+
+			Assert.Equal(matrix.Values, matrix44.Matrix.Values);
+		}
+
+		[SkippableFact]
+		public void ImplicitFromRotationScale()
+		{
+			var rs = SKRotationScaleMatrix.CreateRotationDegrees(45, 0, 0);
+			var matrix = SKMatrix.CreateRotationDegrees(45);
+			var matrix44 = (SKMatrix44)rs.ToMatrix();
+
+			Assert.Equal(matrix.Values, matrix44.Matrix.Values);
+		}
+
+		[SkippableFact]
+		public void TranslationMapsScalars()
+		{
+			var matrixTranslate = SKMatrix44.CreateTranslation(10, 20, 0);
+
+			var resultTranslateZero = matrixTranslate.MapScalars(0, 0, 0, 1);
+			var resultTranslateValue = matrixTranslate.MapScalars(5, 25, 0, 1);
+
+			Assert.Equal(new[] { 10f, 20f, 0f, 1f }, resultTranslateZero);
+			Assert.Equal(new[] { 15f, 45f, 0f, 1f }, resultTranslateValue);
+		}
+
+		[SkippableFact]
+		public void RotationMapsScalars()
+		{
+			var matrixRotate = SKMatrix44.CreateRotationDegrees(0, 1, 0, 90);
+
+			var resultRotateZero = matrixRotate.MapScalars(0, 0, 0, 1);
+			var resultRotateValue = matrixRotate.MapScalars(5, 25, 0, 1);
+
+			Assert.Equal(new[] { 0f, 0f, 0f, 1f }, resultRotateZero);
+			AssertSimilar(new[] { 0f, 25f, -5f, 1f }, resultRotateValue, PRECISION);
+		}
+
+		[SkippableFact]
+		public void TranslationMapsPoints()
+		{
+			var matrixTranslate = SKMatrix44.CreateTranslation(10, 20, 0);
+
+			var resultTranslateZero = matrixTranslate.MapPoint(SKPoint.Empty);
+			var resultTranslateValue = matrixTranslate.MapPoint(new SKPoint(5, 25));
+
+			Assert.Equal(new SKPoint(10f, 20f), resultTranslateZero);
+			Assert.Equal(new SKPoint(15f, 45f), resultTranslateValue);
+		}
+
+		[SkippableFact]
+		public void RotationMapsPoints()
+		{
+			var matrixRotate = SKMatrix44.CreateRotationDegrees(0, 1, 0, 90);
+
+			var resultRotateZero = matrixRotate.MapPoint(SKPoint.Empty);
+			var resultRotateValue = matrixRotate.MapPoint(new SKPoint(5, 25));
+
+			Assert.Equal(new SKPoint(0f, 0f), resultRotateZero);
+			Assert.Equal(0, resultRotateValue.X, PRECISION);
+			Assert.Equal(25, resultRotateValue.Y, PRECISION);
+		}
+
+		[SkippableFact]
+		public void MapsPointsBulk()
+		{
+			var rnd = new Random();
+
+			var matrixTranslate = SKMatrix44.CreateTranslation(10, 25, 0);
+
+			// generate some points
+			var points = new SKPoint[1000];
+			var results = new SKPoint[points.Length];
+			for (var i = 0; i < points.Length; i++)
+			{
+				points[i] = new SKPoint(rnd.Next(1000) / 10f, rnd.Next(1000) / 10f);
+				results[i] = new SKPoint(points[i].X + 10, points[i].Y + 25);
+			}
+
+			var actualResults = matrixTranslate.MapPoints(points);
+
+			Assert.Equal(results, actualResults);
+		}
+	}
+}

tests/Tests/SKMatrixTests.cs

@@ -7,144 +7,6 @@ namespace SkiaSharp.Tests
 {
 	public class SKMatrixTest : SKTest
 	{
-		private const float EPSILON = 0.0001f;
-		private const int PRECISION = 4;
-
-		[SkippableFact]
-		public void Matrix44CreatesIdentity()
-		{
-			var matrix = SKMatrix44.CreateIdentity();
-
-			var expectedRowMajor = new float[] {
-				1, 0, 0, 0,
-				0, 1, 0, 0,
-				0, 0, 1, 0,
-				0, 0, 0, 1,
-			};
-			var rowMajor = matrix.ToRowMajor();
-
-			Assert.Equal(expectedRowMajor, rowMajor);
-		}
-
-		[SkippableFact]
-		public void Matrix44Inverts()
-		{
-			var rowMajor = new float[] {
-				1, 2, 3, 0,
-				0, 1, 4, 0,
-				5, 6, 1, 0,
-				0, 0, 0, 1,
-			};
-			var expectedRowMajor = new float[] {
-				-11.5f, 8, 2.5f, 0,
-				10, -7, -2, 0,
-				-2.5f, 2, 0.5f, 0,
-				0, 0, 0, 1,
-			};
-			var determinant = 2f;
-
-			var matrix = SKMatrix44.FromRowMajor(rowMajor);
-
-			Assert.Equal(rowMajor, matrix.ToRowMajor());
-			Assert.Equal(determinant, matrix.Determinant());
-
-			var inverted = matrix.Invert();
-
-			Assert.Equal(1f / determinant, inverted.Determinant());
-
-			var actualRowMajor = inverted.ToRowMajor();
-			Assert.Equal(expectedRowMajor, actualRowMajor);
-		}
-
-		[SkippableFact]
-		public void Matrix44ConvertsToMatrix()
-		{
-			var rowMajor44 = new float[] {
-				2, 3, 4, 5,
-				4, 6, 8, 10,
-				6, 9, 12, 15,
-				8, 12, 16, 20,
-			};
-			var rowMajor = new float[] {
-				rowMajor44[0], rowMajor44[1], rowMajor44[3],
-				rowMajor44[4], rowMajor44[5], rowMajor44[7],
-				rowMajor44[12], rowMajor44[13], rowMajor44[15],
-			};
-
-			var matrix44 = SKMatrix44.FromRowMajor(rowMajor44);
-
-			Assert.Equal(rowMajor, matrix44.Matrix.Values);
-
-			matrix44 = SKMatrix44.CreateRotationDegrees(0, 0, 1, 45);
-			Assert.Equal(SKMatrix.MakeRotationDegrees(45).Values, matrix44.Matrix.Values);
-		}
-
-		[SkippableFact]
-		public void Matrix44MapsScalars()
-		{
-			// translate
-			var matrixTranslate = SKMatrix44.CreateTranslate(10, 20, 0);
-
-			var resultTranslateZero = matrixTranslate.MapScalars(0, 0, 0, 1);
-			var resultTranslateValue = matrixTranslate.MapScalars(5, 25, 0, 1);
-
-			Assert.Equal(new[] { 10f, 20f, 0f, 1f }, resultTranslateZero);
-			Assert.Equal(new[] { 15f, 45f, 0f, 1f }, resultTranslateValue);
-
-			// rotate
-			var matrixRotate = SKMatrix44.CreateRotationDegrees(0, 1, 0, 90);
-
-			var resultRotateZero = matrixRotate.MapScalars(0, 0, 0, 1);
-			var resultRotateValue = matrixRotate.MapScalars(5, 25, 0, 1);
-
-			Assert.Equal(new[] { 0f, 0f, 0f, 1f }, resultRotateZero);
-			Assert.Equal(new[] { 0f, 25f, -5f, 1f }, resultRotateValue.Select(v => (int)(v / EPSILON) * EPSILON));
-		}
-
-		[SkippableFact]
-		public void Matrix44MapsPoints()
-		{
-			// translate
-			var matrixTranslate = SKMatrix44.CreateTranslate(10, 20, 0);
-
-			var resultTranslateZero = matrixTranslate.MapPoint(SKPoint.Empty);
-			var resultTranslateValue = matrixTranslate.MapPoint(new SKPoint(5, 25));
-
-			Assert.Equal(new SKPoint(10f, 20f), resultTranslateZero);
-			Assert.Equal(new SKPoint(15f, 45f), resultTranslateValue);
-
-			// rotate
-			var matrixRotate = SKMatrix44.CreateRotationDegrees(0, 1, 0, 90);
-
-			var resultRotateZero = matrixRotate.MapPoint(SKPoint.Empty);
-			var resultRotateValue = matrixRotate.MapPoint(new SKPoint(5, 25));
-
-			Assert.Equal(new SKPoint(0f, 0f), resultRotateZero);
-			Assert.Equal(0, resultRotateValue.X, PRECISION);
-			Assert.Equal(25, resultRotateValue.Y, PRECISION);
-		}
-
-		[SkippableFact]
-		public void Matrix44MapsPointsBulk()
-		{
-			var rnd = new Random();
-
-			var matrixTranslate = SKMatrix44.CreateTranslate(10, 25, 0);
-
-			// generate some points
-			var points = new SKPoint[1000];
-			var results = new SKPoint[points.Length];
-			for (int i = 0; i < points.Length; i++)
-			{
-				points[i] = new SKPoint(rnd.Next(1000) / 10f, rnd.Next(1000) / 10f);
-				results[i] = new SKPoint(points[i].X + 10, points[i].Y + 25);
-			}
-
-			var actualResults = matrixTranslate.MapPoints(points);
-
-			Assert.Equal(results, actualResults);
-		}
-
 		[SkippableFact]
 		public void MatrixCanInvert()
 		{
@@ -160,7 +22,7 @@ namespace SkiaSharp.Tests
 			var b = SKMatrix.MakeTranslation(5, 7);
 
 			var c = SKMatrix.Concat(a, b);
-			
+
 			Assert.Equal(SKMatrix.MakeTranslation(15, 27).Values, c.Values);
 		}
 
@@ -171,7 +33,7 @@ namespace SkiaSharp.Tests
 			var b = SKMatrix.MakeTranslation(5, 7);
 
 			var c = a.PreConcat(b);
-			
+
 			Assert.Equal(SKMatrix.MakeTranslation(15, 27).Values, c.Values);
 		}
 
@@ -182,37 +44,10 @@ namespace SkiaSharp.Tests
 			var b = SKMatrix.MakeTranslation(5, 7);
 
 			var c = a.PostConcat(b);
-			
+
 			Assert.Equal(SKMatrix.MakeTranslation(15, 27).Values, c.Values);
 		}
 
-		[SkippableFact]
-		public void SKRotationScaleMatrixTranslationToMatrixIsCorrect()
-		{
-			var m = SKMatrix.MakeTranslation(5, 7);
-			var rsm = SKRotationScaleMatrix.CreateTranslation(5, 7).ToMatrix();
-
-			Assert.Equal(m.Values, rsm.Values);
-		}
-
-		[SkippableFact]
-		public void SKRotationScaleMatrixRotationToMatrixIsCorrect()
-		{
-			var m = SKMatrix.MakeRotationDegrees(45);
-			var rsm = SKRotationScaleMatrix.CreateRotationDegrees(45, 0, 0).ToMatrix();
-
-			Assert.Equal(m.Values, rsm.Values);
-		}
-
-		[SkippableFact]
-		public void SKRotationScaleMatrixScaleToMatrixIsCorrect()
-		{
-			var m = SKMatrix.MakeScale(3.5f, 3.5f);
-			var rsm = SKRotationScaleMatrix.CreateScale(3.5f).ToMatrix();
-
-			Assert.Equal(m.Values, rsm.Values);
-		}
-
 		[SkippableFact]
 		public void MatrixMapsPoints()
 		{

tests/Tests/SKRotationScaleMatrixTests.cs

@@ -0,0 +1,34 @@
+using Xunit;
+
+namespace SkiaSharp.Tests
+{
+	public class SKRotationScaleMatrixTest : SKTest
+	{
+		[SkippableFact]
+		public void TranslationToMatrixIsCorrect()
+		{
+			var m = SKMatrix.CreateTranslation(5, 7);
+			var rsm = SKRotationScaleMatrix.CreateTranslation(5, 7).ToMatrix();
+
+			Assert.Equal(m.Values, rsm.Values);
+		}
+
+		[SkippableFact]
+		public void RotationToMatrixIsCorrect()
+		{
+			var m = SKMatrix.CreateRotationDegrees(45);
+			var rsm = SKRotationScaleMatrix.CreateRotationDegrees(45, 0, 0).ToMatrix();
+
+			Assert.Equal(m.Values, rsm.Values);
+		}
+
+		[SkippableFact]
+		public void ScaleToMatrixIsCorrect()
+		{
+			var m = SKMatrix.CreateScale(3.5f, 3.5f);
+			var rsm = SKRotationScaleMatrix.CreateScale(3.5f).ToMatrix();
+
+			Assert.Equal(m.Values, rsm.Values);
+		}
+	}
+}

tests/Tests/SKSurfaceTest.cs

@@ -1,24 +1,11 @@
-#if NET_STANDARD
-#else
-#define SYSTEM_DRAWING
-#endif
-
-using System;
+using System;
 using System.Runtime.InteropServices;
 using Xunit;
 
-#if SYSTEM_DRAWING
-using System.Drawing;
-using System.Drawing.Imaging;
-#endif
-
 namespace SkiaSharp.Tests
 {
 	public class SKSurfaceTest : SKTest
 	{
-		private const int width = 100;
-		private const int height = 100;
-
 		private void DrawGpuSurface(Action<SKSurface, SKImageInfo> draw)
 		{
 			using (var ctx = CreateGlContext())
@@ -485,60 +472,5 @@ namespace SkiaSharp.Tests
 				}
 			});
 		}
-
-#if SYSTEM_DRAWING
-		private void DrawBitmap(Action<SKSurface, BitmapData> draw)
-		{
-			using (var bitmap = new Bitmap(width, height, PixelFormat.Format32bppPArgb))
-			{
-				var data = bitmap.LockBits(new Rectangle(0, 0, width, height), ImageLockMode.WriteOnly, bitmap.PixelFormat);
-
-				var info = new SKImageInfo(width, height, SKImageInfo.PlatformColorType, SKAlphaType.Premul);
-				using (var surface = SKSurface.Create(info, data.Scan0, data.Stride))
-				{
-					Assert.NotNull(surface);
-
-					draw(surface, data);
-				}
-
-				bitmap.UnlockBits(data);
-			}
-		}
-
-		[SkippableFact]
-		public void SurfaceCanvasReturnTheSameInstance()
-		{
-			DrawBitmap((surface, data) =>
-			{
-				var skcanvas1 = surface.Canvas;
-				var skcanvas2 = surface.Canvas;
-
-				Assert.NotNull(skcanvas1);
-				Assert.NotNull(skcanvas2);
-
-				Assert.Equal(skcanvas1, skcanvas2);
-				Assert.True(skcanvas1 == skcanvas2);
-
-				Assert.Same(skcanvas1, skcanvas2);
-			});
-		}
-
-		[SkippableFact]
-		public void SecondSurfaceWasCreatedDifferent()
-		{
-			DrawBitmap((surface, data) =>
-			{
-				var info = new SKImageInfo(width, height, SKImageInfo.PlatformColorType, SKAlphaType.Premul);
-				var surface2 = SKSurface.Create(info, data.Scan0, data.Stride);
-
-				Assert.NotNull(surface2);
-
-				Assert.NotEqual(surface, surface2);
-				Assert.NotEqual(surface.Handle, surface2.Handle);
-
-				surface2.Dispose();
-			});
-		}
-#endif
 	}
 }

tests/Tests/SKTest.cs

@@ -1,11 +1,15 @@
 using System;
 using System.IO;
+using System.Linq;
 using Xunit;
 
 namespace SkiaSharp.Tests
 {
 	public abstract class SKTest : BaseTest, IAssemblyFixture<GarbageCleanupFixture>
 	{
+		protected const float EPSILON = 0.0001f;
+		protected const int PRECISION = 4;
+
 		private static readonly Random random = new Random();
 
 		protected static Stream CreateTestStream(int length = 1024)
@@ -15,6 +19,13 @@ namespace SkiaSharp.Tests
 			return new MemoryStream(bytes);
 		}
 
+		protected static byte[] CreateTestData(int length = 1024)
+		{
+			var bytes = new byte[length];
+			random.NextBytes(bytes);
+			return bytes;
+		}
+
 		protected static SKStreamAsset CreateTestSKStream(int length = 1024)
 		{
 			var bytes = new byte[length];
@@ -92,6 +103,17 @@ namespace SkiaSharp.Tests
 			Assert.Equal(SKColors.Yellow.WithAlpha(alpha), pix.GetPixelColor(30, 30));
 		}
 
+		protected static void AssertSimilar(ReadOnlySpan<float> expected, ReadOnlySpan<float> actual, int precision = PRECISION)
+		{
+			var eTrimmed = expected.ToArray()
+				.Select(v => (int)(v * precision) / precision);
+
+			var aTrimmed = actual.ToArray()
+				.Select(v => (int)(v * precision) / precision);
+
+			Assert.Equal(eTrimmed, aTrimmed);
+		}
+
 		protected GlContext CreateGlContext()
 		{
 			try

tests/Tests/SKTypefaceTest.cs

@@ -216,6 +216,25 @@ namespace SkiaSharp.Tests
 			var typeface = SKFontManager.Default.MatchCharacter(emojiChar);
 			Assert.NotNull(typeface);
 
+			var count = typeface.CountGlyphs(text);
+			var glyphs = typeface.GetGlyphs(text);
+
+			Assert.True(count > 0);
+			Assert.True(glyphs.Length > 0);
+			Assert.DoesNotContain((ushort)0, glyphs);
+		}
+
+		[Obsolete]
+		[Trait(CategoryKey, MatchCharacterCategory)]
+		[SkippableFact]
+		public void UnicodeGlyphsReturnsTheCorrectNumberOfCharactersObsolete()
+		{
+			const string text = "🚀";
+			var emojiChar = StringUtilities.GetUnicodeCharacterCode(text, SKTextEncoding.Utf32);
+
+			var typeface = SKFontManager.Default.MatchCharacter(emojiChar);
+			Assert.NotNull(typeface);
+
 			Assert.True(typeface.CountGlyphs(text) > 0);
 			Assert.True(typeface.CountGlyphs(text, SKEncoding.Utf32) > 0);
 			Assert.True(typeface.GetGlyphs(text).Length > 0);

tests/Tests/SystemDrawingTest.cs

@@ -0,0 +1,67 @@
+#if SYSTEM_DRAWING
+
+using System;
+using System.Drawing;
+using System.Drawing.Imaging;
+using Xunit;
+
+namespace SkiaSharp.Tests
+{
+	public class SystemDrawingTest : SKTest
+	{
+		private void DrawBitmap(Action<SKSurface, BitmapData> draw)
+		{
+			using (var bitmap = new Bitmap(100, 100, PixelFormat.Format32bppPArgb))
+			{
+				var data = bitmap.LockBits(new Rectangle(0, 0, 100, 100), ImageLockMode.WriteOnly, bitmap.PixelFormat);
+
+				var info = new SKImageInfo(100, 100, SKImageInfo.PlatformColorType, SKAlphaType.Premul);
+				using (var surface = SKSurface.Create(info, data.Scan0, data.Stride))
+				{
+					Assert.NotNull(surface);
+
+					draw(surface, data);
+				}
+
+				bitmap.UnlockBits(data);
+			}
+		}
+
+		[SkippableFact]
+		public void SurfaceCanvasReturnTheSameInstance()
+		{
+			DrawBitmap((surface, data) =>
+			{
+				var skcanvas1 = surface.Canvas;
+				var skcanvas2 = surface.Canvas;
+
+				Assert.NotNull(skcanvas1);
+				Assert.NotNull(skcanvas2);
+
+				Assert.Equal(skcanvas1, skcanvas2);
+				Assert.True(skcanvas1 == skcanvas2);
+
+				Assert.Same(skcanvas1, skcanvas2);
+			});
+		}
+
+		[SkippableFact]
+		public void SecondSurfaceWasCreatedDifferent()
+		{
+			DrawBitmap((surface, data) =>
+			{
+				var info = new SKImageInfo(100, 100, SKImageInfo.PlatformColorType, SKAlphaType.Premul);
+				var surface2 = SKSurface.Create(info, data.Scan0, data.Stride);
+
+				Assert.NotNull(surface2);
+
+				Assert.NotEqual(surface, surface2);
+				Assert.NotEqual(surface.Handle, surface2.Handle);
+
+				surface2.Dispose();
+			});
+		}
+	}
+}
+
+#endif

utils/README.md

@@ -6,6 +6,8 @@ This directory contains a few tools to help with the binding and development of
 
 This is a small set of tools that help with generating the p/invoke layer from the C header files.
 
+### Generate
+
 This can be run with:
 
 ```pwsh
@@ -18,3 +20,18 @@ dotnet run --project=utils/SkiaSharpGenerator/SkiaSharpGenerator.csproj -- gener
   The path to the root of the skia source.
 * `--output binding/Binding/SkiaApi.generated.cs`  
   The path to the generated file.
+
+### Verify
+
+This can be run with:
+
+```pwsh
+dotnet run --project=utils/SkiaSharpGenerator/SkiaSharpGenerator.csproj -- verify --config binding/libSkiaSharp.json --skia externals/skia
+```
+
+* `--config binding/libSkiaSharp.json`  
+  The path to the JSON file that help generate a useful set of p/invoke definions and structures.
+* `--skia externals/skia`  
+  The path to the root of the skia source.
+* `--output binding/Binding/SkiaApi.generated.cs`  
+  The path to the generated file.

utils/SkiaSharpGenerator/BaseTool.cs

@@ -0,0 +1,214 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text.Json;
+using System.Threading.Tasks;
+using CppAst;
+
+namespace SkiaSharpGenerator
+{
+	public abstract class BaseTool
+	{
+		protected readonly Dictionary<string, TypeMapping> typeMappings = new Dictionary<string, TypeMapping>();
+		protected readonly Dictionary<string, FunctionMapping> functionMappings = new Dictionary<string, FunctionMapping>();
+		protected readonly Dictionary<string, bool> skiaTypes = new Dictionary<string, bool>();
+
+		protected CppCompilation compilation = new CppCompilation();
+		protected Config config = new Config();
+
+		protected BaseTool(string skiaRoot, string configFile)
+		{
+			SkiaRoot = skiaRoot ?? throw new ArgumentNullException(nameof(skiaRoot));
+			ConfigFile = configFile ?? throw new ArgumentNullException(nameof(configFile));
+		}
+
+		public ILogger? Log { get; set; }
+
+		public string SkiaRoot { get; }
+
+		public string ConfigFile { get; }
+
+		public bool HasErrors =>
+			compilation?.Diagnostics?.HasErrors ?? false;
+
+		public IEnumerable<CppDiagnosticMessage> Messages =>
+			compilation?.Diagnostics?.Messages ?? Array.Empty<CppDiagnosticMessage>();
+
+		protected void ParseSkiaHeaders()
+		{
+			Log?.LogVerbose("Parsing skia headers...");
+
+			var options = new CppParserOptions();
+
+			foreach (var header in config.IncludeDirs)
+			{
+				var path = Path.Combine(SkiaRoot, header);
+				options.IncludeFolders.Add(path);
+			}
+
+			var headers = new List<string>();
+			foreach (var header in config.Headers)
+			{
+				var path = Path.Combine(SkiaRoot, header.Key);
+				options.IncludeFolders.Add(path);
+				foreach (var filter in header.Value)
+				{
+					headers.AddRange(Directory.EnumerateFiles(path, filter));
+				}
+			}
+
+			compilation = CppParser.ParseFiles(headers, options);
+
+			if (compilation == null || compilation.HasErrors)
+			{
+				Log?.LogError("Parsing headers failed.");
+				throw new Exception("Parsing headers failed.");
+			}
+		}
+
+		protected void LoadStandardMappings()
+		{
+			Log?.LogVerbose("Loading standard types...");
+
+			var standardMappings = new Dictionary<string, string>
+			{
+				// stdint.h types:
+				{ "uint8_t",              nameof(Byte) },
+				{ "uint16_t",             nameof(UInt16) },
+				{ "uint32_t",             nameof(UInt32) },
+				{ "uint64_t",             nameof(UInt64) },
+				{ "usize_t" ,             "/* usize_t */ " + nameof(UIntPtr) },
+				{ "uintptr_t" ,           nameof(UIntPtr) },
+				{ "int8_t",               nameof(SByte) },
+				{ "int16_t",              nameof(Int16) },
+				{ "int32_t",              nameof(Int32) },
+				{ "int64_t",              nameof(Int64) },
+				{ "size_t" ,              "/* size_t */ " + nameof(IntPtr) },
+				{ "intptr_t" ,            nameof(IntPtr) },
+
+				// standard types:
+				{ "bool",                 nameof(Byte) },
+				{ "char",                 "/* char */ void" },
+				{ "unsigned char",        "/* unsigned char */ void" },
+				{ "signed char",          "/* signed char */ void" },
+				{ "short",                nameof(Int16) },
+				{ "short int",            nameof(Int16) },
+				{ "signed short",         nameof(Int16) },
+				{ "signed short int",     nameof(Int16) },
+				{ "unsigned short",       nameof(UInt16) },
+				{ "unsigned short int",   nameof(UInt16) },
+				{ "int",                  nameof(Int32) },
+				{ "signed",               nameof(Int32) },
+				{ "signed int",           nameof(Int32) },
+				{ "unsigned",             nameof(UInt32) },
+				{ "unsigned int",         nameof(UInt32) },
+				{ "long",                 nameof(Int64) },
+				{ "long int",             nameof(Int64) },
+				{ "signed long",          nameof(Int64) },
+				{ "signed long int",      nameof(Int64) },
+				{ "unsigned long",        nameof(UInt64) },
+				{ "unsigned long int",    nameof(UInt64) },
+				{ "float",                nameof(Single) },
+				{ "double",               nameof(Double) },
+				// TODO: long double, wchar_t ?
+
+				{ "void",                 "void" },
+			};
+
+			foreach (var mapping in standardMappings)
+			{
+				var map = new TypeMapping { CsType = mapping.Value };
+				typeMappings[mapping.Key] = map;
+			}
+		}
+
+		protected void UpdatingMappings()
+		{
+			// load all the classes/structs
+			var typedefs = compilation.Classes;
+			foreach (var klass in typedefs)
+			{
+				typeMappings[klass.GetDisplayName()] = new TypeMapping();
+			}
+
+			// load all the enums
+			var enums = compilation.Enums;
+			foreach (var enm in enums)
+			{
+				typeMappings[enm.GetDisplayName()] = new TypeMapping();
+			}
+
+			// load the mapping file
+			foreach (var mapping in config.Mappings.Types)
+			{
+				typeMappings[mapping.Key] = mapping.Value;
+			}
+			foreach (var mapping in config.Mappings.Functions)
+			{
+				functionMappings[mapping.Key] = mapping.Value;
+			}
+		}
+
+		protected async Task<Config> LoadConfigAsync(string configPath)
+		{
+			Log?.LogVerbose("Loading configuration...");
+
+			using var configJson = File.OpenRead(configPath);
+
+			return await JsonSerializer.DeserializeAsync<Config>(configJson, new JsonSerializerOptions
+			{
+				AllowTrailingCommas = true,
+				ReadCommentHandling = JsonCommentHandling.Skip,
+			});
+		}
+
+		protected string GetType(CppType type)
+		{
+			var typeName = GetCppType(type);
+
+			// split the type from the pointers
+			var pointerIndex = typeName.IndexOf("*");
+			var pointers = pointerIndex == -1 ? "" : typeName.Substring(pointerIndex);
+			var noPointers = pointerIndex == -1 ? typeName : typeName.Substring(0, pointerIndex);
+
+			if (skiaTypes.TryGetValue(noPointers, out var isStruct))
+			{
+				if (!isStruct)
+					return noPointers + pointers.Substring(1);
+				if (typeMappings.TryGetValue(noPointers, out var map))
+					return (map.CsType ?? Utils.CleanName(noPointers)) + pointers;
+			}
+			else
+			{
+				if (typeMappings.TryGetValue(typeName, out var map))
+					return map.CsType ?? Utils.CleanName(typeName);
+				if (typeMappings.TryGetValue(noPointers, out map))
+					return (map.CsType ?? Utils.CleanName(noPointers)) + pointers;
+				if (functionMappings.TryGetValue(typeName, out var funcMap))
+					return funcMap.CsType ?? Utils.CleanName(typeName);
+				if (functionMappings.TryGetValue(noPointers, out funcMap))
+					return (funcMap.CsType ?? Utils.CleanName(noPointers)) + pointers;
+			}
+
+			return Utils.CleanName(typeName);
+		}
+
+		protected static string GetCppType(CppType type)
+		{
+			var typeName = type.GetDisplayName();
+
+			// remove the const
+			typeName = typeName.Replace("const ", "");
+
+			// replace the [] with a *
+			int start;
+			while ((start = typeName.IndexOf("[")) != -1)
+			{
+				var end = typeName.IndexOf("]");
+				typeName = typeName.Substring(0, start) + "*" + typeName.Substring(end + 1);
+			}
+
+			return typeName;
+		}
+	}
+}

utils/SkiaSharpGenerator/ConfigJson/Config.cs

@@ -11,6 +11,9 @@ namespace SkiaSharpGenerator
 		[JsonPropertyName("headers")]
 		public Dictionary<string, string[]> Headers { get; set; } = new Dictionary<string, string[]>();
 
+		[JsonPropertyName("source")]
+		public Dictionary<string, string[]> Source { get; set; } = new Dictionary<string, string[]>();
+
 		[JsonPropertyName("includeDirs")]
 		public List<string> IncludeDirs { get; set; } = new List<string>();
 

utils/SkiaSharpGenerator/Generate/Generator.cs

@@ -2,42 +2,21 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
-using System.Text.Json;
 using System.Threading.Tasks;
 using CppAst;
 
 namespace SkiaSharpGenerator
 {
-	public class Generator
+	public class Generator : BaseTool
 	{
-		private readonly Dictionary<string, TypeMapping> typeMappings = new Dictionary<string, TypeMapping>();
-		private readonly Dictionary<string, FunctionMapping> functionMappings = new Dictionary<string, FunctionMapping>();
-		private readonly Dictionary<string, bool> skiaTypes = new Dictionary<string, bool>();
-
-		private CppCompilation compilation = new CppCompilation();
-		private Config config = new Config();
-
 		public Generator(string skiaRoot, string configFile, TextWriter outputWriter)
+			: base(skiaRoot, configFile)
 		{
-			SkiaRoot = skiaRoot ?? throw new ArgumentNullException(nameof(skiaRoot));
-			ConfigFile = configFile ?? throw new ArgumentNullException(nameof(configFile));
 			OutputWriter = outputWriter ?? throw new ArgumentNullException(nameof(outputWriter));
 		}
 
-		public ILogger? Log { get; set; }
-
-		public string SkiaRoot { get; }
-
-		public string ConfigFile { get; }
-
 		public TextWriter OutputWriter { get; }
 
-		public bool HasErrors =>
-			compilation?.Diagnostics?.HasErrors ?? false;
-
-		public IEnumerable<CppDiagnosticMessage> Messages =>
-			compilation?.Diagnostics?.Messages ?? Array.Empty<CppDiagnosticMessage>();
-
 		public async Task GenerateAsync()
 		{
 			Log?.Log("Starting C# API generation...");
@@ -55,134 +34,6 @@ namespace SkiaSharpGenerator
 			Log?.Log("C# API generation complete.");
 		}
 
-		private void ParseSkiaHeaders()
-		{
-			Log?.LogVerbose("Parsing skia headers...");
-
-			var options = new CppParserOptions();
-
-			foreach (var header in config.IncludeDirs)
-			{
-				var path = Path.Combine(SkiaRoot, header);
-				options.IncludeFolders.Add(path);
-			}
-
-			var headers = new List<string>();
-			foreach (var header in config.Headers)
-			{
-				var path = Path.Combine(SkiaRoot, header.Key);
-				options.IncludeFolders.Add(path);
-				foreach (var filter in header.Value)
-				{
-					headers.AddRange(Directory.EnumerateFiles(path, filter));
-				}
-			}
-
-			compilation = CppParser.ParseFiles(headers, options);
-
-			if (compilation == null || compilation.HasErrors)
-			{
-				Log?.LogError("Parsing headers failed.");
-				throw new Exception("Parsing headers failed.");
-			}
-		}
-
-		private void LoadStandardMappings()
-		{
-			Log?.LogVerbose("Loading standard types...");
-
-			var standardMappings = new Dictionary<string, string>
-			{
-				// stdint.h types:
-				{ "uint8_t",              nameof(Byte) },
-				{ "uint16_t",             nameof(UInt16) },
-				{ "uint32_t",             nameof(UInt32) },
-				{ "uint64_t",             nameof(UInt64) },
-				{ "usize_t" ,             "/* usize_t */ " + nameof(UIntPtr) },
-				{ "uintptr_t" ,           nameof(UIntPtr) },
-				{ "int8_t",               nameof(SByte) },
-				{ "int16_t",              nameof(Int16) },
-				{ "int32_t",              nameof(Int32) },
-				{ "int64_t",              nameof(Int64) },
-				{ "size_t" ,              "/* size_t */ " + nameof(IntPtr) },
-				{ "intptr_t" ,            nameof(IntPtr) },
-
-				// standard types:
-				{ "bool",                 nameof(Byte) },
-				{ "char",                 "/* char */ void" },
-				{ "unsigned char",        "/* unsigned char */ void" },
-				{ "signed char",          "/* signed char */ void" },
-				{ "short",                nameof(Int16) },
-				{ "short int",            nameof(Int16) },
-				{ "signed short",         nameof(Int16) },
-				{ "signed short int",     nameof(Int16) },
-				{ "unsigned short",       nameof(UInt16) },
-				{ "unsigned short int",   nameof(UInt16) },
-				{ "int",                  nameof(Int32) },
-				{ "signed",               nameof(Int32) },
-				{ "signed int",           nameof(Int32) },
-				{ "unsigned",             nameof(UInt32) },
-				{ "unsigned int",         nameof(UInt32) },
-				{ "long",                 nameof(Int64) },
-				{ "long int",             nameof(Int64) },
-				{ "signed long",          nameof(Int64) },
-				{ "signed long int",      nameof(Int64) },
-				{ "unsigned long",        nameof(UInt64) },
-				{ "unsigned long int",    nameof(UInt64) },
-				{ "float",                nameof(Single) },
-				{ "double",               nameof(Double) },
-				// TODO: long double, wchar_t ?
-
-				{ "void",                 "void" },
-			};
-
-			foreach (var mapping in standardMappings)
-			{
-				var map = new TypeMapping { CsType = mapping.Value };
-				typeMappings[mapping.Key] = map;
-			}
-		}
-
-		private void UpdatingMappings()
-		{
-			// load all the classes/structs
-			var typedefs = compilation.Classes;
-			foreach (var klass in typedefs)
-			{
-				typeMappings[klass.GetDisplayName()] = new TypeMapping();
-			}
-
-			// load all the enums
-			var enums = compilation.Enums;
-			foreach (var enm in enums)
-			{
-				typeMappings[enm.GetDisplayName()] = new TypeMapping();
-			}
-
-			// load the mapping file
-			foreach (var mapping in config.Mappings.Types)
-			{
-				typeMappings[mapping.Key] = mapping.Value;
-			}
-			foreach (var mapping in config.Mappings.Functions)
-			{
-				functionMappings[mapping.Key] = mapping.Value;
-			}
-		}
-
-		private async Task<Config> LoadConfigAsync(string configPath)
-		{
-			Log?.LogVerbose("Loading configuration...");
-
-			using var configJson = File.OpenRead(configPath);
-
-			return await JsonSerializer.DeserializeAsync<Config>(configJson, new JsonSerializerOptions
-			{
-				AllowTrailingCommas = true,
-				ReadCommentHandling = JsonCommentHandling.Skip,
-			});
-		}
-
 		private void WriteApi(TextWriter writer)
 		{
 			Log?.LogVerbose("Writing C# API...");
@@ -520,54 +371,5 @@ namespace SkiaSharpGenerator
 				writer.WriteLine();
 			}
 		}
-
-		private string GetType(CppType type)
-		{
-			var typeName = GetCppType(type);
-
-			// split the type from the pointers
-			var pointerIndex = typeName.IndexOf("*");
-			var pointers = pointerIndex == -1 ? "" : typeName.Substring(pointerIndex);
-			var noPointers = pointerIndex == -1 ? typeName : typeName.Substring(0, pointerIndex);
-
-			if (skiaTypes.TryGetValue(noPointers, out var isStruct))
-			{
-				if (!isStruct)
-					return noPointers + pointers.Substring(1);
-				if (typeMappings.TryGetValue(noPointers, out var map))
-					return (map.CsType ?? Utils.CleanName(noPointers)) + pointers;
-			}
-			else
-			{
-				if (typeMappings.TryGetValue(typeName, out var map))
-					return map.CsType ?? Utils.CleanName(typeName);
-				if (typeMappings.TryGetValue(noPointers, out map))
-					return (map.CsType ?? Utils.CleanName(noPointers)) + pointers;
-				if (functionMappings.TryGetValue(typeName, out var funcMap))
-					return funcMap.CsType ?? Utils.CleanName(typeName);
-				if (functionMappings.TryGetValue(noPointers, out funcMap))
-					return (funcMap.CsType ?? Utils.CleanName(noPointers)) + pointers;
-			}
-
-			return Utils.CleanName(typeName);
-		}
-
-		private static string GetCppType(CppType type)
-		{
-			var typeName = type.GetDisplayName();
-
-			// remove the const
-			typeName = typeName.Replace("const ", "");
-
-			// replace the [] with a *
-			int start;
-			while ((start = typeName.IndexOf("[")) != -1)
-			{
-				var end = typeName.IndexOf("]");
-				typeName = typeName.Substring(0, start) + "*" + typeName.Substring(end + 1);
-			}
-
-			return typeName;
-		}
 	}
 }

utils/SkiaSharpGenerator/Program.cs

@@ -21,6 +21,7 @@ namespace SkiaSharpGenerator
 				"",
 				"Available commands:",
 				new GenerateCommand(),
+				new VerifyCommand(),
 			};
 			return commands.Run(args);
 		}

utils/SkiaSharpGenerator/Verify/Verifier.cs

@@ -0,0 +1,89 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text.RegularExpressions;
+using System.Threading.Tasks;
+using CppAst;
+
+namespace SkiaSharpGenerator
+{
+	public class Verifier : BaseTool
+	{
+		private CppCompilation sourceCompilation = new CppCompilation();
+
+		public Verifier(string skiaRoot, string configFile)
+			: base(skiaRoot, configFile)
+		{
+		}
+
+		public async Task VerifyAsync()
+		{
+			Log?.Log("Starting C API verification...");
+
+			config = await LoadConfigAsync(ConfigFile);
+
+			ParseSkiaHeaders();
+
+			Verify();
+
+			Log?.Log("C API verification complete.");
+		}
+
+		private void Verify()
+		{
+			Log?.LogVerbose("Verifying C API...");
+
+			VerifyImplementations();
+		}
+
+		private void VerifyImplementations()
+		{
+			Log?.LogVerbose("  Making sure all declarations have an implementation...");
+
+			var functionGroups = compilation.Functions
+				.OrderBy(f => f.Name)
+				.GroupBy(f => f.Span.Start.File.ToLower().Replace("\\", "/"))
+				.OrderBy(g => Path.GetDirectoryName(g.Key) + "/" + Path.GetFileName(g.Key));
+
+			var allSources = new List<string>();
+			foreach (var source in config.Source)
+			{
+				var path = Path.Combine(SkiaRoot, source.Key);
+				foreach (var filter in source.Value)
+				{
+					allSources.AddRange(Directory.EnumerateFiles(path, filter));
+				}
+			}
+
+			var sourcesContents = new Dictionary<string, string>();
+
+			foreach (var group in functionGroups)
+			{
+				foreach (var function in group)
+				{
+					Log?.LogVerbose($"    {function.Name}");
+
+					var found = false;
+
+					foreach (var source in allSources)
+					{
+						if (!sourcesContents.TryGetValue(source, out var contents))
+						{
+							contents = File.ReadAllText(source);
+							sourcesContents[source] = contents;
+						}
+
+						if (Regex.IsMatch(contents, $"\\s{function.Name}\\s*\\("))
+						{
+							found = true;
+							break;
+						}
+					}
+
+					if (!found)
+						Log?.LogWarning($"Missing implementation for {function}");
+				}
+			}
+		}
+	}
+}

utils/SkiaSharpGenerator/Verify/VerifyCommand.cs

@@ -0,0 +1,80 @@
+using System.Collections.Generic;
+using System.IO;
+using CppAst;
+using Mono.Options;
+
+namespace SkiaSharpGenerator
+{
+	public class VerifyCommand : BaseCommand
+	{
+		public VerifyCommand()
+			: base("verify", "Verify the C definitions have implementations.")
+		{
+		}
+
+		public string? SourceRoot { get; set; }
+
+		public string? ConfigPath { get; set; }
+
+		protected override OptionSet OnCreateOptions() => new OptionSet
+		{
+			{ "s|skia=", "The root of the skia source", v => SourceRoot = v },
+			{ "c|config=", "The config file path", v => ConfigPath = v },
+		};
+
+		protected override bool OnValidateArguments(IEnumerable<string> extras)
+		{
+			var hasError = false;
+
+			if (string.IsNullOrEmpty(SourceRoot))
+			{
+				Program.Log.LogError($"{Program.Name}: Path to the skia source was not provided: `--skia=<path-to-skia>`.");
+				hasError = true;
+			}
+			else if (!Directory.Exists(SourceRoot))
+			{
+				Program.Log.LogError($"{Program.Name}: Path to the skia source does not exist: `{SourceRoot}`.");
+				hasError = true;
+			}
+
+			if (string.IsNullOrEmpty(ConfigPath))
+			{
+				Program.Log.LogError($"{Program.Name}: Path to config file was not provided: `--config=<path-to-config-json>`.");
+				hasError = true;
+			}
+			else if (!File.Exists(ConfigPath))
+			{
+				Program.Log.LogError($"{Program.Name}: Path to config file does not exist: `{ConfigPath}`.");
+				hasError = true;
+			}
+
+			return !hasError;
+		}
+
+		protected override bool OnInvoke(IEnumerable<string> extras)
+		{
+			var verifier = new Verifier(SourceRoot!, ConfigPath!);
+			verifier.Log = Program.Log;
+
+			try
+			{
+				verifier.VerifyAsync().Wait();
+			}
+			catch
+			{
+				if (verifier.HasErrors)
+				{
+					foreach (var dgn in verifier.Messages)
+					{
+						if (dgn.Type == CppLogMessageType.Error)
+							Program.Log.LogError($"{dgn.Text} at {dgn.Location}");
+					}
+				}
+
+				throw;
+			}
+
+			return true;
+		}
+	}
+}