Merge branch 'gpu-support' into merge-m54

# Conflicts:
#	binding/Binding/Definitions.cs
#	binding/Binding/SKCanvas.cs
#	binding/Binding/SkiaApi.cs

binding/Binding/Binding.projitems

@@ -10,6 +10,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(MSBuildThisFileDirectory)Definitions.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)GRGlInterface.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SKColorTable.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SkiaApi.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SKObject.cs" />
@@ -18,6 +19,7 @@
     <Compile Include="$(MSBuildThisFileDirectory)SKPaint.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SKDocument.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SKPathEffect.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)GRContext.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SKSurface.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SKCanvas.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SKShader.cs" />

binding/Binding/Definitions.cs

@@ -1,4 +1,4 @@
-//
+//
 // Skia Definitions, enumerations and interop structures
 //
 // Author:
@@ -42,6 +42,9 @@ using System;
 using System.Runtime.InteropServices;
 using System.Globalization;
 
+using GRBackendObject = System.IntPtr;
+using GRBackendContext = System.IntPtr;
+ 	
 namespace SkiaSharp
 {
 	public enum SKCodecResult {
@@ -522,6 +525,14 @@ namespace SkiaSharp
 		BgrVertical
 	}
 
+	[Flags]
+	public enum SKSurfacePropsFlags {
+		DisallowAntiAlias = 1 << 0,
+		DisallowDither = 1 << 1,
+		UseDeviceIndependentFonts = 1 << 2,
+		GammaCorrect = 1 << 3,
+	}
+
 	public enum SKEncoding {
 		Utf8, Utf16, Utf32
 	}
@@ -749,11 +760,17 @@ namespace SkiaSharp
 	[StructLayout(LayoutKind.Sequential)]
 	public struct SKSurfaceProps {
 		private SKPixelGeometry pixelGeometry;
+		private SKSurfacePropsFlags flags;
 
 		public SKPixelGeometry PixelGeometry {
 			get { return pixelGeometry; }
 			set { pixelGeometry = value; }
 		}
+
+		public SKSurfacePropsFlags Flags {
+			get { return flags; }
+			set { flags = value; }
+		}
 	}
 
 	public enum SKZeroInitialized {
@@ -2256,5 +2273,191 @@ typeMask = Mask.Scale | Mask.RectStaysRect
 			}
 		}
 	}
+
+	public enum GRSurfaceOrigin {
+		TopLeft,
+		BottomLeft,
+	}
+
+	public enum GRPixelConfig {
+		Unknown,
+		Alpha8,
+		Index8,
+		Rgb565,
+		Rgba4444,
+		Rgba8888,
+		Bgra8888,
+		Srgba8888,
+		Sbgra8888,
+		Etc1,
+		Latc,
+		R11Eac,
+		Astc12x12,
+		RgbaFloat,
+		AlphaHalf,
+		RgbaHalf,
+	}
+
+	[StructLayout(LayoutKind.Sequential)]
+	public struct GRBackendRenderTargetDesc {
+		private int width;
+		private int height;
+		private GRPixelConfig config;
+		private GRSurfaceOrigin origin;
+		private int sampleCount;
+		private int stencilBits;
+		private GRBackendObject renderTargetHandle;
+
+		public int Width {
+			get { return width; }
+			set { width = value; }
+		}
+		public int Height {
+			get { return height; }
+			set { height = value; }
+		}
+		public GRPixelConfig Config {
+			get { return config; }
+			set { config = value; }
+		}
+		public GRSurfaceOrigin Origin {
+			get { return origin; }
+			set { origin = value; }
+		}
+		public int SampleCount {
+			get { return sampleCount; }
+			set { sampleCount = value; }
+		}
+		public int StencilBits {
+			get { return stencilBits; }
+			set { stencilBits = value; }
+		}
+		public GRBackendObject RenderTargetHandle {
+			get { return renderTargetHandle; }
+			set { renderTargetHandle = value; }
+		}
+	}
+	
+	public enum GRBackend {
+		OpenGL,
+		Vulkan,
+	}
+
+	[Flags]
+	public enum GRBackendTextureDescFlags {
+		None = 0,
+		RenderTarget = 1,
+	}
+
+	[StructLayout(LayoutKind.Sequential)]
+	public struct GRBackendTextureDesc {
+		private GRBackendTextureDescFlags flags;
+		private GRSurfaceOrigin origin;
+		private int width;
+		private int height;
+		private GRPixelConfig config;
+		private int sampleCount;
+		private GRBackendObject textureHandle;
+		
+		public GRBackendTextureDescFlags Flags {
+			get { return flags; }
+			set { flags = value; }
+		}
+		public GRSurfaceOrigin Origin {
+			get { return origin; }
+			set { origin = value; }
+		}
+		public int Width {
+			get { return width; }
+			set { width = value; }
+		}
+		public int Height {
+			get { return height; }
+			set { height = value; }
+		}
+		public GRPixelConfig Config {
+			get { return config; }
+			set { config = value; }
+		}
+		public int SampleCount {
+			get { return sampleCount; }
+			set { sampleCount = value; }
+		}
+		public GRBackendObject TextureHandle {
+			get { return textureHandle; }
+			set { textureHandle = value; }
+		}
+	}
+
+	[StructLayout(LayoutKind.Sequential)]
+	public struct GRContextOptions {
+		private bool suppressPrints;
+		private int maxTextureSizeOverride;
+		private int maxTileSizeOverride;
+		private bool suppressDualSourceBlending;
+		private int bufferMapThreshold;
+		private bool useDrawInsteadOfPartialRenderTargetWrite;
+		private bool immediateMode;
+		private bool clipBatchToBounds;
+		private bool drawBatchBounds;
+		private int maxBatchLookback;
+		private int maxBatchLookahead;
+		private bool useShaderSwizzling;
+		private bool doManualMipmapping;
+
+		public bool SuppressPrints {
+			get { return suppressPrints; }
+			set { suppressPrints = value; }
+		}
+		public int MaxTextureSizeOverride {
+			get { return maxTextureSizeOverride; }
+			set { maxTextureSizeOverride = value; }
+		}
+		public int MaxTileSizeOverride {
+			get { return maxTileSizeOverride; }
+			set { maxTileSizeOverride = value; }
+		}
+		public bool SuppressDualSourceBlending {
+			get { return suppressDualSourceBlending; }
+			set { suppressDualSourceBlending = value; }
+		}
+		public int BufferMapThreshold {
+			get { return bufferMapThreshold; }
+			set { bufferMapThreshold = value; }
+		}
+		public bool UseDrawInsteadOfPartialRenderTargetWrite {
+			get { return useDrawInsteadOfPartialRenderTargetWrite; }
+			set { useDrawInsteadOfPartialRenderTargetWrite = value; }
+		}
+		public bool ImmediateMode {
+			get { return immediateMode; }
+			set { immediateMode = value; }
+		}
+		public bool ClipBatchToBounds {
+			get { return clipBatchToBounds; }
+			set { clipBatchToBounds = value; }
+		}
+		public bool DrawBatchBounds {
+			get { return drawBatchBounds; }
+			set { drawBatchBounds = value; }
+		}
+		public int MaxBatchLookback {
+			get { return maxBatchLookback; }
+			set { maxBatchLookback = value; }
+		}
+		public int MaxBatchLookahead {
+			get { return maxBatchLookahead; }
+			set { maxBatchLookahead = value; }
+		}
+		public bool UseShaderSwizzling {
+			get { return useShaderSwizzling; }
+			set { useShaderSwizzling = value; }
+		}
+		public bool DoManualMipmapping {
+			get { return doManualMipmapping; }
+			set { doManualMipmapping = value; }
+		}
+	}
+	
 }
 

binding/Binding/GRContext.cs

@@ -0,0 +1,90 @@
+//
+// Bindings for GRContext
+//
+// Author:
+//   Matthew Leibowitz
+//
+// Copyright 2016 Xamarin Inc
+//
+
+using System;
+
+namespace SkiaSharp
+{
+	public class GRContext : SKObject
+	{
+		[Preserve]
+		internal GRContext (IntPtr h, bool owns)
+			: base (h, owns)
+		{
+		}
+		
+		public static GRContext Create (GRBackend backend)
+		{
+			return Create (backend, IntPtr.Zero);
+		}
+
+		public static GRContext Create (GRBackend backend, IntPtr backendContext)
+		{
+			return GetObject<GRContext> (SkiaApi.gr_context_create_with_defaults (backend, backendContext));
+		}
+
+		public static GRContext Create (GRBackend backend, GRGlInterface backendContext)
+		{
+			return GetObject<GRContext> (SkiaApi.gr_context_create_with_defaults (backend, backendContext.Handle));
+		}
+
+		public static GRContext Create (GRBackend backend, IntPtr backendContext, GRContextOptions options)
+		{
+			return GetObject<GRContext> (SkiaApi.gr_context_create (backend, backendContext, ref options));
+		}
+
+		public static GRContext Create (GRBackend backend, GRGlInterface backendContext, GRContextOptions options)
+		{
+			return GetObject<GRContext> (SkiaApi.gr_context_create (backend, backendContext.Handle, ref options));
+		}
+
+		public void AbandonContext (bool releaseResources = false)
+		{
+			if (releaseResources) {
+				SkiaApi.gr_context_release_resources_and_abandon_context (Handle);
+			} else {
+				SkiaApi.gr_context_abandon_context (Handle);
+			}
+		}
+
+		public void GetResourceCacheLimits (out int maxResources, out long maxResourceBytes)
+		{
+			IntPtr maxResourceBytesPtr;
+			SkiaApi.gr_context_get_resource_cache_limits (Handle, out maxResources, out maxResourceBytesPtr);
+			maxResourceBytes = (long)maxResourceBytesPtr;
+		}
+
+		public void SetResourceCacheLimits (int maxResources, long maxResourceBytes)
+		{
+			SkiaApi.gr_context_set_resource_cache_limits (Handle, maxResources, (IntPtr)maxResourceBytes);
+		}
+
+		public void GetResourceCacheUsage (out int maxResources, out long maxResourceBytes)
+		{
+			IntPtr maxResourceBytesPtr;
+			SkiaApi.gr_context_get_resource_cache_usage (Handle, out maxResources, out maxResourceBytesPtr);
+			maxResourceBytes = (long)maxResourceBytesPtr;
+		}
+		
+		public int GetRecommendedSampleCount (GRPixelConfig config, float dpi)
+		{
+			return SkiaApi.gr_context_get_recommended_sample_count (Handle, config, dpi);
+		}
+
+		protected override void Dispose (bool disposing)
+		{
+			if (Handle != IntPtr.Zero && OwnsHandle) {
+				SkiaApi.gr_context_unref (Handle);
+			}
+
+			base.Dispose (disposing);
+		}
+	}
+}
+

binding/Binding/GRGlInterface.cs

@@ -0,0 +1,169 @@
+//
+// Bindings for GRContext
+//
+// Author:
+//   Matthew Leibowitz
+//
+// Copyright 2016 Xamarin Inc
+//
+
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+
+namespace SkiaSharp
+{
+	// public delegates
+	public delegate IntPtr GRGlGetProcDelegate (object context, string name);
+
+	// internal proxy delegates
+	[UnmanagedFunctionPointer (CallingConvention.Cdecl)]
+	internal delegate IntPtr GRGlGetProcDelegateInternal (IntPtr context, string name);
+
+	public class GRGlInterface : SKObject
+	{
+		// so the GC doesn't collect the delegate
+		private static readonly GRGlGetProcDelegateInternal getProcDelegate;
+		static GRGlInterface ()
+		{
+			getProcDelegate = new GRGlGetProcDelegateInternal (GrGLGetProcInternal);
+		}
+
+		[Preserve]
+		internal GRGlInterface (IntPtr h, bool owns)
+			: base (h, owns)
+		{
+		}
+		
+		public static GRGlInterface CreateDefaultInterface ()
+		{
+			return GetObject<GRGlInterface> (SkiaApi.gr_glinterface_default_interface ());
+		}
+
+		public static GRGlInterface CreateNativeInterface ()
+		{
+			return GetObject<GRGlInterface> (SkiaApi.gr_glinterface_create_native_interface ());
+		}
+
+		public static GRGlInterface AssembleInterface (GRGlGetProcDelegate get)
+		{
+			return AssembleInterface (null, get);
+		}
+
+		public static GRGlInterface AssembleInterface (object context, GRGlGetProcDelegate get)
+		{
+			var del = Marshal.GetFunctionPointerForDelegate (getProcDelegate);
+
+			var ctx = new GRGlGetProcDelegateContext (context, get);
+			var ptr = ctx.Wrap ();
+			var glInterface = GetObject<GRGlInterface> (SkiaApi.gr_glinterface_assemble_interface (ptr, del));
+			GRGlGetProcDelegateContext.Free (ptr);
+			return glInterface;
+		}
+
+		public static GRGlInterface AssembleGlInterface (GRGlGetProcDelegate get)
+		{
+			return AssembleGlInterface (null, get);
+		}
+
+		public static GRGlInterface AssembleGlInterface (object context, GRGlGetProcDelegate get)
+		{
+			var del = Marshal.GetFunctionPointerForDelegate (getProcDelegate);
+
+			var ctx = new GRGlGetProcDelegateContext (context, get);
+			var ptr = ctx.Wrap ();
+			var glInterface = GetObject<GRGlInterface> (SkiaApi.gr_glinterface_assemble_gl_interface (ptr, del));
+			GRGlGetProcDelegateContext.Free (ptr);
+			return glInterface;
+		}
+
+		public static GRGlInterface AssembleGlesInterface (GRGlGetProcDelegate get)
+		{
+			return AssembleGlesInterface (null, get);
+		}
+
+		public static GRGlInterface AssembleGlesInterface (object context, GRGlGetProcDelegate get)
+		{
+			var del = Marshal.GetFunctionPointerForDelegate (getProcDelegate);
+
+			var ctx = new GRGlGetProcDelegateContext (context, get);
+			var ptr = ctx.Wrap ();
+			var glInterface = GetObject<GRGlInterface> (SkiaApi.gr_glinterface_assemble_gles_interface (ptr, del));
+			GRGlGetProcDelegateContext.Free (ptr);
+			return glInterface;
+		}
+
+		public GRGlInterface Clone ()
+		{
+			return GetObject<GRGlInterface> (SkiaApi.gr_glinterface_clone (Handle));
+		}
+
+		public bool Validate ()
+		{
+			return SkiaApi.gr_glinterface_validate (Handle);
+		}
+
+		public bool HasExtension (string extension)
+		{
+			return SkiaApi.gr_glinterface_has_extension (Handle, extension);
+		}
+
+		protected override void Dispose (bool disposing)
+		{
+			if (Handle != IntPtr.Zero && OwnsHandle) {
+				SkiaApi.gr_context_unref (Handle);
+			}
+
+			base.Dispose (disposing);
+		}
+
+		// internal proxy
+		#if __IOS__
+		[ObjCRuntime.MonoPInvokeCallback (typeof (GRGlGetProcDelegateInternal))]
+		#endif
+		private static IntPtr GrGLGetProcInternal (IntPtr context, string name)
+		{
+			var ctx = GRGlGetProcDelegateContext.Unwrap (context);
+			return ctx.GetProc (ctx.Context, name);
+		}
+
+		// This is the actual context passed to native code.
+		// Instead of marshalling the user's data as an IntPtr and requiring 
+		// him to wrap/unwarp, we do it via a proxy class. This also prevents 
+		// us from having to marshal the user's callback too. 
+		private struct GRGlGetProcDelegateContext
+		{
+			// the "managed version" of the callback 
+			public readonly GRGlGetProcDelegate GetProc;
+			public readonly object Context;
+
+			public GRGlGetProcDelegateContext (object context, GRGlGetProcDelegate get)
+			{
+				Context = context;
+				GetProc = get;
+			}
+
+			// wrap this context into a "native" pointer
+			public IntPtr Wrap ()
+			{
+				var gc = GCHandle.Alloc (this, GCHandleType.Pinned);
+				return GCHandle.ToIntPtr (gc);
+			}
+
+			// unwrap the "native" pointer into a managed context
+			public static GRGlGetProcDelegateContext Unwrap (IntPtr ptr)
+			{
+				var gchandle = GCHandle.FromIntPtr (ptr);
+				return (GRGlGetProcDelegateContext) gchandle.Target;
+			}
+
+			// unwrap and free the context
+			public static void Free (IntPtr ptr)
+			{
+				var gchandle = GCHandle.FromIntPtr (ptr);
+				gchandle.Free ();
+			}
+		}
+	}
+}
+

binding/Binding/SKCanvas.cs

@@ -1,4 +1,4 @@
-//
+//
 // Bindings for SKCanvas
 //
 // Author:
@@ -357,6 +357,11 @@ namespace SkiaSharp
 			SkiaApi.sk_canvas_draw_text_on_path (Handle, bytes, bytes.Length, path.Handle, hOffset, vOffset, paint.Handle);
 		}
 
+		public void Flush ()
+		{
+			SkiaApi.sk_canvas_flush (Handle);
+		}
+
 		public void DrawBitmapNinePatch (SKBitmap bitmap, SKRectI center, SKRect dst, SKPaint paint = null)
 		{
 			if (bitmap == null)

binding/Binding/SKSurface.cs

@@ -44,6 +44,51 @@ namespace SkiaSharp
 			return GetObject<SKSurface> (SkiaApi.sk_surface_new_raster_direct (ref info, pixels, (IntPtr)rowBytes, ref props));
 		}
 		
+		public static SKSurface Create (GRContext context, GRBackendRenderTargetDesc desc, SKSurfaceProps props)
+		{
+			return GetObject<SKSurface> (SkiaApi.sk_surface_new_backend_render_target (context.Handle, ref desc, ref props));
+		}
+		
+		public static SKSurface Create (GRContext context, GRBackendRenderTargetDesc desc)
+		{
+			return GetObject<SKSurface> (SkiaApi.sk_surface_new_backend_render_target (context.Handle, ref desc, IntPtr.Zero));
+		}
+		
+		public static SKSurface Create (GRContext context, GRBackendTextureDesc desc, SKSurfaceProps props)
+		{
+			return GetObject<SKSurface> (SkiaApi.sk_surface_new_backend_texture (context.Handle, ref desc, ref props));
+		}
+		
+		public static SKSurface Create (GRContext context, GRBackendTextureDesc desc)
+		{
+			return GetObject<SKSurface> (SkiaApi.sk_surface_new_backend_texture (context.Handle, ref desc, IntPtr.Zero));
+		}
+		
+		public static SKSurface CreateAsRenderTarget (GRContext context, GRBackendTextureDesc desc, SKSurfaceProps props)
+		{
+			return GetObject<SKSurface> (SkiaApi.sk_surface_new_backend_texture_as_render_target (context.Handle, ref desc, ref props));
+		}
+		
+		public static SKSurface CreateAsRenderTarget (GRContext context, GRBackendTextureDesc desc)
+		{
+			return GetObject<SKSurface> (SkiaApi.sk_surface_new_backend_texture_as_render_target (context.Handle, ref desc, IntPtr.Zero));
+		}
+		
+		public static SKSurface Create (GRContext context, bool budgeted, SKImageInfo info, int sampleCount, SKSurfaceProps props)
+		{
+			return GetObject<SKSurface> (SkiaApi.sk_surface_new_render_target (context.Handle, budgeted, ref info, sampleCount, ref props));
+		}
+		
+		public static SKSurface Create (GRContext context, bool budgeted, SKImageInfo info, int sampleCount)
+		{
+			return GetObject<SKSurface> (SkiaApi.sk_surface_new_render_target (context.Handle, budgeted, ref info, sampleCount, IntPtr.Zero));
+		}
+		
+		public static SKSurface Create (GRContext context, bool budgeted, SKImageInfo info)
+		{
+			return GetObject<SKSurface> (SkiaApi.sk_surface_new_render_target (context.Handle, budgeted, ref info, 0, IntPtr.Zero));
+		}
+		
 		protected override void Dispose (bool disposing)
 		{
 			if (Handle != IntPtr.Zero && OwnsHandle) {

binding/Binding/SkiaApi.cs

@@ -9,6 +9,9 @@
 using System;
 using System.Runtime.InteropServices;
 
+using GRBackendObject = System.IntPtr;
+using GRBackendContext = System.IntPtr;
+
 using sk_surface_t = System.IntPtr;
 using sk_canvas_t = System.IntPtr;
 using sk_image_t = System.IntPtr;
@@ -42,6 +45,8 @@ using sk_path_iterator_t = System.IntPtr;
 using sk_path_effect_t = System.IntPtr;
 using sk_pixelref_factory_t = System.IntPtr;
 using sk_colortable_t = System.IntPtr;
+using gr_context_t = System.IntPtr;
+using gr_glinterface_t = System.IntPtr;
 
 namespace SkiaSharp
 {
@@ -77,6 +82,26 @@ namespace SkiaSharp
 		public extern static sk_canvas_t sk_surface_get_canvas(sk_surface_t t);
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static sk_image_t sk_surface_new_image_snapshot(sk_surface_t t);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static sk_surface_t sk_surface_new_backend_render_target (gr_context_t context, ref GRBackendRenderTargetDesc desc, ref SKSurfaceProps props);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static sk_surface_t sk_surface_new_backend_render_target (gr_context_t context, ref GRBackendRenderTargetDesc desc, IntPtr propsZero);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static sk_surface_t sk_surface_new_backend_texture (gr_context_t context, ref GRBackendTextureDesc desc, ref SKSurfaceProps props);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static sk_surface_t sk_surface_new_backend_texture (gr_context_t context, ref GRBackendTextureDesc desc, IntPtr propsZero);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static sk_surface_t sk_surface_new_backend_texture_as_render_target (gr_context_t context, ref GRBackendTextureDesc desc, ref SKSurfaceProps props);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static sk_surface_t sk_surface_new_backend_texture_as_render_target (gr_context_t context, ref GRBackendTextureDesc desc, IntPtr propsZero);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static sk_surface_t sk_surface_new_render_target (gr_context_t context, bool budgeted, ref SKImageInfo info, int sampleCount, ref SKSurfaceProps props);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static sk_surface_t sk_surface_new_render_target (gr_context_t context, bool budgeted, ref SKImageInfo info, int sampleCount, IntPtr propsZero);
+
+
+		// Canvas
+
 
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static int sk_canvas_save(sk_canvas_t t);
@@ -178,10 +203,14 @@ namespace SkiaSharp
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static sk_canvas_t sk_canvas_new_from_bitmap(sk_bitmap_t bitmap);
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void sk_canvas_flush (sk_canvas_t canvas);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static void sk_canvas_draw_bitmap_lattice(sk_canvas_t t, sk_bitmap_t bitmap, int[] xDivs, int xCount, int[] yDivs, int yCount, ref SKRect dst, sk_paint_t paint);
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static void sk_canvas_draw_image_lattice(sk_canvas_t t, sk_image_t image, int[] xDivs, int xCount, int[] yDivs, int yCount, ref SKRect dst, sk_paint_t paint);
 
+		// Paint
+
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static sk_paint_t sk_paint_new();
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
@@ -1013,6 +1042,51 @@ namespace SkiaSharp
 		public extern static void sk_colortable_read_colors (sk_colortable_t ctable, [Out] SKColor[] colors);
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static void sk_colortable_read_colors (sk_colortable_t ctable, out IntPtr colors);
+
+		// GRContext
+
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static gr_context_t gr_context_create (GRBackend backend, GRBackendContext backendContext, ref GRContextOptions options);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static gr_context_t gr_context_create_with_defaults (GRBackend backend, GRBackendContext backendContext);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void gr_context_unref (gr_context_t context);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void gr_context_abandon_context (gr_context_t context);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void gr_context_release_resources_and_abandon_context (gr_context_t context);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void gr_context_get_resource_cache_limits (gr_context_t context, out int maxResources, out IntPtr maxResourceBytes);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void gr_context_set_resource_cache_limits (gr_context_t context, int maxResources, IntPtr maxResourceBytes);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void gr_context_get_resource_cache_usage (gr_context_t context, out int maxResources, out IntPtr maxResourceBytes);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static int gr_context_get_recommended_sample_count (gr_context_t context, GRPixelConfig config, float dpi);
+		
+		// GLInterface
+		
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static gr_glinterface_t gr_glinterface_assemble_interface (IntPtr ctx, IntPtr get);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static gr_glinterface_t gr_glinterface_assemble_gl_interface (IntPtr ctx, IntPtr get);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static gr_glinterface_t gr_glinterface_assemble_gles_interface (IntPtr ctx, IntPtr get);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static gr_glinterface_t gr_glinterface_default_interface ();
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static gr_glinterface_t gr_glinterface_create_native_interface ();
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void gr_glinterface_interface_unref (gr_glinterface_t glInterface);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static gr_glinterface_t gr_glinterface_clone (gr_glinterface_t glInterface);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		[return: MarshalAs(UnmanagedType.I1)]
+		public extern static bool gr_glinterface_validate (gr_glinterface_t glInterface);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		[return: MarshalAs(UnmanagedType.I1)]
+		public extern static bool gr_glinterface_has_extension (gr_glinterface_t glInterface, string extension);
+
 	}
 }
 

build.cake

@@ -385,7 +385,7 @@ Task ("externals-windows")
     .Does (() =>  
 {
     var buildArch = new Action<string, string, string> ((platform, skiaArch, dir) => {
-        RunGyp ("skia_arch_type='" + skiaArch + "'", "ninja,msvs");
+        RunGyp ("skia_arch_type='" + skiaArch + "' skia_gpu=1", "ninja,msvs");
         VisualStudioPathFixup ();
         DotNetBuild ("native-builds/libSkiaSharp_windows/libSkiaSharp_" + dir + ".sln", c => { 
             c.Configuration = "Release"; 
@@ -544,7 +544,7 @@ Task ("externals-osx")
     .Does (() =>  
 {
     var buildArch = new Action<string, string> ((arch, skiaArch) => {
-        RunGyp ("skia_arch_type='" + skiaArch + "'", "ninja,xcode");
+        RunGyp ("skia_arch_type='" + skiaArch + "' skia_gpu=1", "ninja,xcode");
         
         XCodeBuild (new XCodeBuildSettings {
             Project = "native-builds/libSkiaSharp_osx/libSkiaSharp.xcodeproj",
@@ -596,7 +596,7 @@ Task ("externals-ios")
     // set up the gyp environment variables
     AppendEnvironmentVariable ("PATH", DEPOT_PATH.FullPath);
     
-    RunGyp ("skia_os='ios' skia_arch_type='arm' armv7=1 arm_neon=0", "ninja,xcode");
+    RunGyp ("skia_os='ios' skia_arch_type='arm' armv7=1 arm_neon=0 skia_gpu=1", "ninja,xcode");
     
     buildArch ("iphonesimulator", "i386");
     buildArch ("iphonesimulator", "x86_64");
@@ -647,7 +647,7 @@ Task ("externals-tvos")
     // set up the gyp environment variables
     AppendEnvironmentVariable ("PATH", DEPOT_PATH.FullPath);
     
-    RunGyp ("skia_os='ios' skia_arch_type='arm' armv7=1 arm_neon=0", "ninja,xcode");
+    RunGyp ("skia_os='ios' skia_arch_type='arm' armv7=1 arm_neon=0 skia_gpu=1", "ninja,xcode");
     convertIOSToTVOS();
     
     buildArch ("appletvsimulator", "x86_64");
@@ -691,13 +691,13 @@ Task ("externals-android")
     SetEnvironmentVariable ("ANDROID_SDK_ROOT", ANDROID_SDK_ROOT);
     SetEnvironmentVariable ("ANDROID_NDK_HOME", ANDROID_NDK_HOME);
     
-    SetEnvironmentVariable ("GYP_DEFINES", "");
+    SetEnvironmentVariable ("GYP_DEFINES", "skia_gpu=1");
     buildArch ("x86", "x86");
-    SetEnvironmentVariable ("GYP_DEFINES", "");
+    SetEnvironmentVariable ("GYP_DEFINES", "skia_gpu=1");
     buildArch ("x86_64", "x86_64");
-    SetEnvironmentVariable ("GYP_DEFINES", "arm_neon=1 arm_version=7");
+    SetEnvironmentVariable ("GYP_DEFINES", "arm_neon=1 arm_version=7 skia_gpu=1");
     buildArch ("arm_v7_neon", "armeabi-v7a");
-    SetEnvironmentVariable ("GYP_DEFINES", "arm_neon=0 arm_version=8");
+    SetEnvironmentVariable ("GYP_DEFINES", "arm_neon=0 arm_version=8 skia_gpu=1");
     buildArch ("arm64", "arm64-v8a");
         
     var ndkbuild = MakeAbsolute (Directory (ANDROID_NDK_HOME)).CombineWithFilePath ("ndk-build").FullPath;
@@ -859,6 +859,10 @@ Task ("samples")
             c.Configuration = "Release"; 
             c.Properties ["Platform"] = new [] { "iPhoneSimulator" };
         });
+        RunNuGetRestore ("./samples/Skia.OSX.GLDemo/Skia.OSX.GLDemo.sln");
+        DotNetBuild ("./samples/Skia.OSX.GLDemo/Skia.OSX.GLDemo.sln", c => { 
+            c.Configuration = "Release"; 
+        });
     }
     
     if (IsRunningOnWindows ()) {
@@ -875,6 +879,11 @@ Task ("samples")
         DotNetBuild ("./samples/Skia.Forms.Demo/Skia.Forms.Demo.Windows.sln", c => { 
             c.Configuration = "Release"; 
         });
+        RunNuGetRestore ("./samples/Skia.WindowsDesktop.GLDemo/Skia.WindowsDesktop.GLDemo.sln");
+        DotNetBuild ("./samples/Skia.WindowsDesktop.GLDemo/Skia.WindowsDesktop.GLDemo.sln", c => { 
+            c.Configuration = "Release"; 
+            c.Properties ["Platform"] = new [] { "x86" };
+        });
     }
     
     RunNuGetRestore ("./samples/Skia.WindowsDesktop.Demo/Skia.WindowsDesktop.Demo.sln");

native-builds/libSkiaSharp_android/jni/SkiaSharp.mk

@@ -26,7 +26,9 @@ LOCAL_C_INCLUDES       := ../../skia/src/c           \
                           ../../skia/include/core    \
                           ../../skia/include/codec   \
                           ../../skia/include/effects \
+                          ../../skia/include/gpu     \
                           ../../skia/include/config  \
+                          ../../skia/include/utils   \
                           ../../skia/include/images
 
 LOCAL_CFLAGS           := -DSK_INTERNAL -DSK_GAMMA_APPLY_TO_A8                                   \

native-builds/libSkiaSharp_ios/libSkiaSharp.xcodeproj/project.pbxproj

@@ -1935,6 +1935,8 @@
 					../../skia/include/core,
 					../../skia/include/codec,
 					../../skia/include/effects,
+					../../skia/include/utils,
+					../../skia/include/gpu,
 					../../skia/include/config,
 				);
 				INFOPLIST_FILE = libSkiaSharp/Info.plist;
@@ -1968,6 +1970,8 @@
 					../../skia/include/core,
 					../../skia/include/codec,
 					../../skia/include/effects,
+					../../skia/include/utils,
+					../../skia/include/gpu,
 					../../skia/include/config,
 				);
 				INFOPLIST_FILE = libSkiaSharp/Info.plist;

native-builds/libSkiaSharp_osx/libSkiaSharp.xcodeproj/project.pbxproj

@@ -1633,6 +1633,8 @@
 					../../skia/include/core,
 					../../skia/include/codec,
 					../../skia/include/effects,
+					../../skia/include/gpu,
+					../../skia/include/utils,
 					../../skia/include/config,
 				);
 				OTHER_CPLUSPLUSFLAGS = (
@@ -1657,6 +1659,8 @@
 					../../skia/include/core,
 					../../skia/include/codec,
 					../../skia/include/effects,
+					../../skia/include/gpu,
+					../../skia/include/utils,
 					../../skia/include/config,
 				);
 				OTHER_CPLUSPLUSFLAGS = (

native-builds/libSkiaSharp_tvos/libSkiaSharp.xcodeproj/project.pbxproj

@@ -1930,6 +1930,8 @@
 					../../skia/include/core,
 					../../skia/include/codec,
 					../../skia/include/effects,
+					../../skia/include/gpu,
+					../../skia/include/utils,
 					../../skia/include/config,
 				);
 				INFOPLIST_FILE = libSkiaSharp/Info.plist;
@@ -1962,6 +1964,8 @@
 					../../skia/include/core,
 					../../skia/include/codec,
 					../../skia/include/effects,
+					../../skia/include/utils,
+					../../skia/include/gpu,
 					../../skia/include/config,
 				);
 				INFOPLIST_FILE = libSkiaSharp/Info.plist;

native-builds/src/SkiaKeeper.c

@@ -29,6 +29,7 @@
 #include "sk_string.h"
 #include "sk_surface.h"
 #include "sk_typeface.h"
+#include "gr_context.h"
 
 // Xamarin
 #include "sk_managedstream.h"
@@ -80,6 +81,7 @@ void** KeepSkiaCSymbols ()
         (void*)sk_matrix_map_radius,
         (void*)sk_matrix_try_invert,
         (void*)sk_colortable_new,
+        (void*)gr_context_unref,
 
         // Xamarin
         (void*)sk_managedstream_new,

samples/SharedDemo/SkiaSharp.Demos.cs

@@ -1079,7 +1079,8 @@ namespace SkiaSharp
 			WindowsDesktop = 8,
 			UWP = 16,
 			tvOS = 32,
-			All = 0xFFFF,
+			OpenGL = 64,
+			All = iOS | Android | OSX | WindowsDesktop | UWP | tvOS | OpenGL,
 		}
 
 		public class Sample 
@@ -1092,7 +1093,7 @@ namespace SkiaSharp
 
 		public static string [] SamplesForPlatform (Platform platform)
 		{
-			return sampleList.Where (s => 0 != (s.Platform & platform)).Select (s => s.Title).ToArray ();
+			return sampleList.Where (s => s.Platform.HasFlag (platform)).Select (s => s.Title).ToArray ();
 		}
 
 		public static Sample GetSample (string title)
@@ -1124,7 +1125,7 @@ namespace SkiaSharp
 			new Sample {Title="Turbulence Perlin Noise Shader", Method = TurbulencePerlinNoiseShader, Platform = Platform.All},
 			new Sample {Title="Compose Shader", Method = ComposeShader, Platform = Platform.All},
 			new Sample {Title="Blur Mask Filter", Method = BlurMaskFilter, Platform = Platform.All},
-			new Sample {Title="Emboss Mask Filter", Method = EmbossMaskFilter, Platform = Platform.All},
+			new Sample {Title="Emboss Mask Filter", Method = EmbossMaskFilter, Platform = Platform.All & ~Platform.OpenGL},
 			new Sample {Title="Color Matrix Color Filter", Method = ColorMatrixColorFilter, Platform = Platform.All},
 			new Sample {Title="Color Table Color Filter", Method = ColorTableColorFilter, Platform = Platform.All},
 			new Sample {Title="Luma Color Filter", Method = LumaColorFilter, Platform = Platform.All},

samples/Skia.OSX.GLDemo/AppDelegate.cs

@@ -0,0 +1,29 @@
+using AppKit;
+using Foundation;
+
+namespace Skia.OSX.Demo
+{
+	[Register ("AppDelegate")]
+	public partial class AppDelegate : NSApplicationDelegate
+	{
+		public AppDelegate ()
+		{
+		}
+
+		public override void DidFinishLaunching (NSNotification notification)
+		{
+			// Insert code here to initialize your application
+		}
+
+		public override void WillTerminate (NSNotification notification)
+		{
+			// Insert code here to tear down your application
+		}
+
+		public override bool ApplicationShouldTerminateAfterLastWindowClosed (NSApplication sender)
+		{
+			return true;
+		}
+	}
+}
+

samples/Skia.OSX.GLDemo/AppDelegate.designer.cs

@@ -0,0 +1,19 @@
+// WARNING
+//
+// This file has been generated automatically by Xamarin Studio to store outlets and
+// actions made in the UI designer. If it is removed, they will be lost.
+// Manual changes to this file may not be handled correctly.
+//
+using Foundation;
+using System.CodeDom.Compiler;
+
+namespace Skia.OSX.Demo
+{
+	partial class AppDelegate
+	{
+		
+		void ReleaseDesignerOutlets ()
+		{
+		}
+	}
+}

samples/Skia.OSX.GLDemo/Info.plist

@@ -0,0 +1,33 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleName</key>
+	<string>Skia.OSX.Demo</string>
+	<key>CFBundleIdentifier</key>
+	<string>com.xamarin.skia-osx-demo</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSMinimumSystemVersion</key>
+	<string>10.10</string>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>en</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>NSHumanReadableCopyright</key>
+	<string>billholmes</string>
+	<key>NSPrincipalClass</key>
+	<string>NSApplication</string>
+	<key>NSMainStoryboardFile</key>
+	<string>Main</string>
+	<key>XSAppIconAssets</key>
+	<string>Resources/Images.xcassets/AppIcons.appiconset</string>
+	
+</dict>
+</plist>

samples/Skia.OSX.GLDemo/Main.cs

@@ -0,0 +1,13 @@
+using AppKit;
+
+namespace Skia.OSX.Demo
+{
+	static class MainClass
+	{
+		static void Main (string[] args)
+		{
+			NSApplication.Init ();
+			NSApplication.Main (args);
+		}
+	}
+}

samples/Skia.OSX.GLDemo/Main.storyboard

@@ -0,0 +1,107 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<document type="com.apple.InterfaceBuilder3.Cocoa.Storyboard.XIB" version="3.0" toolsVersion="10116" systemVersion="15E65" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES" initialViewController="B8D-0N-5wS">
+    <dependencies>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="10116"/>
+    </dependencies>
+    <scenes>
+        <!--Application-->
+        <scene sceneID="JPo-4y-FX3">
+            <objects>
+                <application id="hnw-xV-0zn" sceneMemberID="viewController">
+                    <menu key="mainMenu" title="Main Menu" systemMenu="main" id="AYu-sK-qS6">
+                        <items>
+                            <menuItem title="Skia.OSX.Demo" id="1Xt-HY-uBw">
+                                <modifierMask key="keyEquivalentModifierMask"/>
+                                <menu key="submenu" title="Skia.OSX.Demo" systemMenu="apple" id="uQy-DD-JDr">
+                                    <items>
+                                        <menuItem title="About Skia.OSX.Demo" id="5kV-Vb-QxS">
+                                            <modifierMask key="keyEquivalentModifierMask"/>
+                                            <connections>
+                                                <action selector="orderFrontStandardAboutPanel:" target="Ady-hI-5gd" id="Exp-CZ-Vem"/>
+                                            </connections>
+                                        </menuItem>
+                                        <menuItem isSeparatorItem="YES" id="eHP-pT-vMg"/>
+                                        <menuItem title="Quit Skia.OSX.Demo" keyEquivalent="q" id="4sb-4s-VLi">
+                                            <connections>
+                                                <action selector="terminate:" target="Ady-hI-5gd" id="Te7-pn-YzF"/>
+                                            </connections>
+                                        </menuItem>
+                                    </items>
+                                </menu>
+                            </menuItem>
+                        </items>
+                    </menu>
+                    <connections>
+                        <outlet property="delegate" destination="Voe-Tx-rLC" id="PrD-fu-P6m"/>
+                    </connections>
+                </application>
+                <customObject id="Voe-Tx-rLC" customClass="AppDelegate"/>
+                <customObject id="Ady-hI-5gd" userLabel="First Responder" customClass="NSResponder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="75" y="0.0"/>
+        </scene>
+        <!--Window Controller-->
+        <scene sceneID="R2V-B0-nI4">
+            <objects>
+                <windowController id="B8D-0N-5wS" sceneMemberID="viewController">
+                    <window key="window" title="Window" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" oneShot="NO" releasedWhenClosed="NO" showsToolbarButton="NO" visibleAtLaunch="NO" animationBehavior="default" id="IQv-IB-iLA">
+                        <windowStyleMask key="styleMask" titled="YES" closable="YES" miniaturizable="YES" resizable="YES"/>
+                        <windowPositionMask key="initialPositionMask" leftStrut="YES" rightStrut="YES" topStrut="YES" bottomStrut="YES"/>
+                        <rect key="contentRect" x="196" y="240" width="480" height="270"/>
+                        <rect key="screenRect" x="0.0" y="0.0" width="1680" height="1027"/>
+                    </window>
+                    <connections>
+                        <segue destination="XfG-lQ-9wD" kind="relationship" relationship="window.shadowedContentViewController" id="cq2-FE-JQM"/>
+                    </connections>
+                </windowController>
+                <customObject id="Oky-zY-oP4" userLabel="First Responder" customClass="NSResponder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="75" y="250"/>
+        </scene>
+        <!--View Controller-->
+        <scene sceneID="hIz-AP-VOD">
+            <objects>
+                <viewController id="XfG-lQ-9wD" customClass="ViewController" sceneMemberID="viewController">
+                    <customView key="view" id="QUA-QF-Q3f">
+                        <rect key="frame" x="0.0" y="0.0" width="450" height="300"/>
+                        <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+                        <subviews>
+                            <view translatesAutoresizingMaskIntoConstraints="NO" id="m2S-Jp-Qdl" customClass="SkiaView">
+                                <rect key="frame" x="0.0" y="0.0" width="450" height="300"/>
+                            </view>
+                            <popUpButton verticalHuggingPriority="750" translatesAutoresizingMaskIntoConstraints="NO" id="mnJ-8z-WRI">
+                                <rect key="frame" x="228" y="17" width="205" height="26"/>
+                                <constraints>
+                                    <constraint firstAttribute="width" constant="200" id="3Ya-mE-NFc"/>
+                                    <constraint firstAttribute="height" constant="21" id="PW1-2o-QII"/>
+                                </constraints>
+                                <popUpButtonCell key="cell" type="push" bezelStyle="rounded" alignment="left" lineBreakMode="truncatingTail" borderStyle="borderAndBezel" imageScaling="proportionallyDown" inset="2" id="5te-c2-WKW">
+                                    <behavior key="behavior" lightByBackground="YES" lightByGray="YES"/>
+                                    <font key="font" metaFont="menu"/>
+                                    <menu key="menu" id="LKv-bG-q8C"/>
+                                </popUpButtonCell>
+                                <connections>
+                                    <action selector="PopUpButtonAction:" target="XfG-lQ-9wD" id="lmM-6c-sIb"/>
+                                </connections>
+                            </popUpButton>
+                        </subviews>
+                        <constraints>
+                            <constraint firstAttribute="bottom" secondItem="mnJ-8z-WRI" secondAttribute="bottom" constant="20" id="A3L-Bb-rlF"/>
+                            <constraint firstAttribute="trailing" secondItem="mnJ-8z-WRI" secondAttribute="trailing" constant="20" id="DYI-UX-Zkb"/>
+                            <constraint firstAttribute="bottom" secondItem="m2S-Jp-Qdl" secondAttribute="bottom" id="Gw9-r7-0Df"/>
+                            <constraint firstItem="m2S-Jp-Qdl" firstAttribute="top" secondItem="QUA-QF-Q3f" secondAttribute="top" id="Uut-tC-oBU"/>
+                            <constraint firstItem="m2S-Jp-Qdl" firstAttribute="leading" secondItem="QUA-QF-Q3f" secondAttribute="leading" id="Xcr-Wg-5ia"/>
+                            <constraint firstAttribute="trailing" secondItem="m2S-Jp-Qdl" secondAttribute="trailing" id="rZp-9d-Lpb"/>
+                        </constraints>
+                    </customView>
+                    <connections>
+                        <outlet property="PopUpButton" destination="mnJ-8z-WRI" id="mEQ-lK-fod"/>
+                        <outlet property="SkiaView" destination="m2S-Jp-Qdl" id="8ta-WW-AHG"/>
+                    </connections>
+                </viewController>
+                <customObject id="rPt-NT-nkU" userLabel="First Responder" customClass="NSResponder" sceneMemberID="firstResponder"/>
+            </objects>
+            <point key="canvasLocation" x="75" y="655"/>
+        </scene>
+    </scenes>
+</document>

samples/Skia.OSX.GLDemo/Resources/Images.xcassets/AppIcons.appiconset/Contents.json

@@ -0,0 +1,222 @@
+{
+  "images": [
+    {
+      "size": "29x29",
+      "scale": "1x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "29x29",
+      "scale": "2x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "29x29",
+      "scale": "3x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "40x40",
+      "scale": "2x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "40x40",
+      "scale": "3x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "57x57",
+      "scale": "1x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "57x57",
+      "scale": "2x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "60x60",
+      "scale": "2x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "60x60",
+      "scale": "3x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "29x29",
+      "scale": "1x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "29x29",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "40x40",
+      "scale": "1x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "40x40",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "50x50",
+      "scale": "1x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "50x50",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "83.5x83.5",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "72x72",
+      "scale": "1x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "72x72",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "76x76",
+      "scale": "1x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "76x76",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "role": "notificationCenter",
+      "size": "24x24",
+      "subtype": "38mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "notificationCenter",
+      "size": "27.5x27.5",
+      "subtype": "42mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "companionSettings",
+      "size": "29x29",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "companionSettings",
+      "size": "29x29",
+      "scale": "3x",
+      "idiom": "watch"
+    },
+    {
+      "role": "appLauncher",
+      "size": "40x40",
+      "subtype": "38mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "longLook",
+      "size": "44x44",
+      "subtype": "42mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "quickLook",
+      "size": "86x86",
+      "subtype": "38mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "quickLook",
+      "size": "98x98",
+      "subtype": "42mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "filename": "skia_16x16.png",
+      "size": "16x16",
+      "scale": "1x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "skia_32x32.png",
+      "size": "16x16",
+      "scale": "2x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "skia_32x32.png",
+      "size": "32x32",
+      "scale": "1x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "skia_64x64.png",
+      "size": "32x32",
+      "scale": "2x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "skia_128x128.png",
+      "size": "128x128",
+      "scale": "1x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "skia_256x256.png",
+      "size": "128x128",
+      "scale": "2x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "skia_256x256.png",
+      "size": "256x256",
+      "scale": "1x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "skia_512x512.png",
+      "size": "256x256",
+      "scale": "2x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "skia_512x512.png",
+      "size": "512x512",
+      "scale": "1x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "skia_1024x1024.png",
+      "size": "512x512",
+      "scale": "2x",
+      "idiom": "mac"
+    }
+  ],
+  "info": {
+    "version": 1,
+    "author": "xcode"
+  }
+}

samples/Skia.OSX.GLDemo/Skia.OSX.GLDemo.csproj

@@ -0,0 +1,130 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project DefaultTargets="Build" ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectTypeGuids>{A3F8F2AB-B479-4A4A-A458-A89E7DC349F1};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
+    <ProjectGuid>{1730229c-f631-4ba9-86b3-d62828d8815b}</ProjectGuid>
+    <OutputType>Exe</OutputType>
+    <RootNamespace>Skia.OSX.GLDemo</RootNamespace>
+    <MonoMacResourcePrefix>Resources</MonoMacResourcePrefix>
+    <AssemblyName>Skia.OSX.GLDemo</AssemblyName>
+    <TargetFrameworkIdentifier>Xamarin.Mac</TargetFrameworkIdentifier>
+    <TargetFrameworkVersion>v2.0</TargetFrameworkVersion>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug</OutputPath>
+    <DefineConstants>DEBUG;</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <ConsolePause>false</ConsolePause>
+    <Profiling>true</Profiling>
+    <UseRefCounting>true</UseRefCounting>
+    <UseSGen>true</UseSGen>
+    <IncludeMonoRuntime>false</IncludeMonoRuntime>
+    <CreatePackage>false</CreatePackage>
+    <CodeSigningKey>Mac Developer</CodeSigningKey>
+    <EnableCodeSigning>false</EnableCodeSigning>
+    <EnablePackageSigning>false</EnablePackageSigning>
+    <XamMacArch>x86_64</XamMacArch>
+    <PackageSigningKey>Developer ID Installer</PackageSigningKey>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <DebugType>full</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release</OutputPath>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+    <ConsolePause>false</ConsolePause>
+    <Profiling>false</Profiling>
+    <UseRefCounting>true</UseRefCounting>
+    <UseSGen>true</UseSGen>
+    <IncludeMonoRuntime>true</IncludeMonoRuntime>
+    <CreatePackage>true</CreatePackage>
+    <CodeSigningKey>Mac Developer</CodeSigningKey>
+    <EnableCodeSigning>true</EnableCodeSigning>
+    <EnablePackageSigning>false</EnablePackageSigning>
+    <XamMacArch>x86_64</XamMacArch>
+    <LinkMode>Full</LinkMode>
+    <PackageSigningKey>Developer ID Installer</PackageSigningKey>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="Xamarin.Mac" />
+    <Reference Include="SkiaSharp">
+      <HintPath>packages\SkiaSharp.1.53.2-gpu2\lib\XamarinMac\SkiaSharp.dll</HintPath>
+      <Private>False</Private>
+    </Reference>
+    <Reference Include="OpenTK" />
+  </ItemGroup>
+  <ItemGroup>
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\Contents.json" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\AppIcon-128.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\AppIcon-128%402x.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\AppIcon-16.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\AppIcon-16%402x.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\AppIcon-256.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\AppIcon-256%402x.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\AppIcon-32.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\AppIcon-32%402x.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\AppIcon-512.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\AppIcon-512%402x.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\skia_16x16.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\skia_32x32.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\skia_64x64.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\skia_128x128.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\skia_256x256.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\skia_512x512.png" />
+    <ImageAsset Include="Resources\Images.xcassets\AppIcons.appiconset\skia_1024x1024.png" />
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="Info.plist" />
+    <None Include="packages.config" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="Main.cs" />
+    <Compile Include="AppDelegate.cs" />
+    <Compile Include="ViewController.cs" />
+    <Compile Include="ViewController.designer.cs">
+      <DependentUpon>ViewController.cs</DependentUpon>
+    </Compile>
+    <Compile Include="SkiaView.cs" />
+    <Compile Include="SkiaView.designer.cs">
+      <DependentUpon>SkiaView.cs</DependentUpon>
+    </Compile>
+    <Compile Include="AppDelegate.designer.cs">
+      <DependentUpon>AppDelegate.cs</DependentUpon>
+    </Compile>
+    <Compile Include="..\SharedDemo\SkiaSharp.Demos.cs">
+      <Link>SkiaSharp.Demos.cs</Link>
+    </Compile>
+  </ItemGroup>
+  <ItemGroup>
+    <InterfaceDefinition Include="Main.storyboard" />
+  </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="..\SharedDemo\embedded-font.ttf">
+      <Link>embedded-font.ttf</Link>
+    </EmbeddedResource>
+    <EmbeddedResource Include="..\SharedDemo\baboon.png">
+      <Link>baboon.png</Link>
+    </EmbeddedResource>
+    <EmbeddedResource Include="..\SharedDemo\color-wheel.png">
+      <Link>color-wheel.png</Link>
+    </EmbeddedResource>
+    <EmbeddedResource Include="..\SharedDemo\adobe-dng.dng">
+      <Link>adobe-dng.dng</Link>
+    </EmbeddedResource>
+  </ItemGroup>
+  <ItemGroup>
+    <BundleResource Include="..\SharedDemo\content-font.ttf">
+      <Link>Resources\content-font.ttf</Link>
+    </BundleResource>
+  </ItemGroup>
+  <Import Project="$(MSBuildExtensionsPath)\Xamarin\Mac\Xamarin.Mac.CSharp.targets" />
+  <Import Project="packages\SkiaSharp.1.53.2-gpu2\build\XamarinMac\SkiaSharp.targets" Condition="Exists('packages\SkiaSharp.1.53.2-gpu2\build\XamarinMac\SkiaSharp.targets')" />
+</Project>

samples/Skia.OSX.GLDemo/Skia.OSX.GLDemo.sln

@@ -0,0 +1,17 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 2012
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Skia.OSX.GLDemo", "Skia.OSX.GLDemo.csproj", "{1730229c-f631-4ba9-86b3-d62828d8815b}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{1730229c-f631-4ba9-86b3-d62828d8815b}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{1730229c-f631-4ba9-86b3-d62828d8815b}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{1730229c-f631-4ba9-86b3-d62828d8815b}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{1730229c-f631-4ba9-86b3-d62828d8815b}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+EndGlobal

samples/Skia.OSX.GLDemo/SkiaView.cs

@@ -0,0 +1,74 @@
+using System;
+using AppKit;
+using OpenTK.Graphics.OpenGL;
+
+using SkiaSharp;
+
+namespace Skia.OSX.Demo
+{
+	public partial class SkiaView : NSOpenGLView
+	{
+		Demos.Sample sample;
+
+		GRContext grContext;
+
+		public SkiaView (IntPtr handle) : base (handle)
+		{
+			AddGestureRecognizer (new NSClickGestureRecognizer (OnClicked));
+		}
+
+		public override void PrepareOpenGL ()
+		{
+			base.PrepareOpenGL ();
+
+			grContext = GRContext.Create (GRBackend.OpenGL);
+		}
+
+		public override void DrawRect (CoreGraphics.CGRect dirtyRect)
+		{
+			base.DrawRect (dirtyRect);
+
+			if (grContext != null)
+			{
+				var sampleCount = grContext.GetRecommendedSampleCount(GRPixelConfig.Rgba8888, 96.0f);
+
+				var desc = new GRBackendRenderTargetDesc
+				{
+					Width = (int)Bounds.Width,
+					Height = (int)Bounds.Height,
+					Config = GRPixelConfig.Rgba8888,
+					Origin = GRSurfaceOrigin.TopLeft,
+					SampleCount = sampleCount,
+					StencilBits = 0,
+					RenderTargetHandle = IntPtr.Zero,
+				};
+
+				using (var surface = SKSurface.Create (grContext, desc))
+				{
+					var skcanvas = surface.Canvas;
+
+					sample.Method (skcanvas, (int)Bounds.Width, (int)Bounds.Height);
+
+					skcanvas.Flush ();
+				}
+
+				GL.Flush();
+			}
+		}
+
+		void OnClicked ()
+		{
+			Sample?.TapMethod?.Invoke ();
+		}
+
+		public Demos.Sample Sample {
+			get {
+				return sample;
+			}
+			set {
+				sample = value;
+				SetNeedsDisplayInRect (Bounds);
+			}
+		}
+	}
+}

samples/Skia.OSX.GLDemo/SkiaView.designer.cs

@@ -0,0 +1,20 @@
+// WARNING
+//
+// This file has been generated automatically by Xamarin Studio to store outlets and
+// actions made in the UI designer. If it is removed, they will be lost.
+// Manual changes to this file may not be handled correctly.
+//
+using Foundation;
+using System.CodeDom.Compiler;
+
+namespace Skia.OSX.Demo
+{
+	[Register ("SkiaView")]
+	partial class SkiaView
+	{
+
+		void ReleaseDesignerOutlets ()
+		{
+		}
+	}
+}

samples/Skia.OSX.GLDemo/ViewController.cs

@@ -0,0 +1,56 @@
+using System;
+
+using AppKit;
+using Foundation;
+using System.IO;
+
+namespace Skia.OSX.Demo
+{
+	public partial class ViewController : NSViewController
+	{
+		public ViewController (IntPtr handle) : base (handle)
+		{
+		}
+
+		public override void ViewDidLoad ()
+		{
+			base.ViewDidLoad ();
+
+			// set up resource paths
+			string fontName = "content-font.ttf";
+			SkiaSharp.Demos.CustomFontPath = NSBundle.MainBundle.PathForResource (Path.GetFileNameWithoutExtension (fontName), Path.GetExtension (fontName));
+			var dir = Path.Combine (Path.GetTempPath (), "SkiaSharp.Demos", Path.GetRandomFileName ());
+			if (!Directory.Exists (dir))
+			{
+				Directory.CreateDirectory (dir);
+			}
+			SkiaSharp.Demos.WorkingDirectory = dir;
+			SkiaSharp.Demos.OpenFileDelegate = path =>
+			{
+				if (!NSWorkspace.SharedWorkspace.OpenFile (Path.Combine (dir, path)))
+				{
+					NSAlert.WithMessage ("SkiaSharp", "OK", null, null, "Unable to open file.").RunSheetModal (View.Window);
+				}
+			};
+
+			PopUpButton.AddItems (SkiaSharp.Demos.SamplesForPlatform (SkiaSharp.Demos.Platform.OSX | SkiaSharp.Demos.Platform.OpenGL));
+			PopUpButton.SelectItem (0);
+			SkiaView.Sample = SkiaSharp.Demos.GetSample (PopUpButton.SelectedItem.Title);
+		}
+
+		partial void PopUpButtonAction (NSObject sender)
+		{
+			SkiaView.Sample = SkiaSharp.Demos.GetSample (PopUpButton.SelectedItem.Title);
+		}
+
+		public override NSObject RepresentedObject {
+			get {
+				return base.RepresentedObject;
+			}
+			set {
+				base.RepresentedObject = value;
+				// Update the view, if already loaded.
+			}
+		}
+	}
+}

samples/Skia.OSX.GLDemo/ViewController.designer.cs

@@ -0,0 +1,37 @@
+// WARNING
+//
+// This file has been generated automatically by Xamarin Studio to store outlets and
+// actions made in the UI designer. If it is removed, they will be lost.
+// Manual changes to this file may not be handled correctly.
+//
+using Foundation;
+using System.CodeDom.Compiler;
+
+namespace Skia.OSX.Demo
+{
+	[Register ("ViewController")]
+	partial class ViewController
+	{
+		[Outlet]
+		AppKit.NSPopUpButton PopUpButton { get; set; }
+
+		[Outlet]
+		Skia.OSX.Demo.SkiaView SkiaView { get; set; }
+
+		[Action ("PopUpButtonAction:")]
+		partial void PopUpButtonAction (Foundation.NSObject sender);
+		
+		void ReleaseDesignerOutlets ()
+		{
+			if (PopUpButton != null) {
+				PopUpButton.Dispose ();
+				PopUpButton = null;
+			}
+
+			if (SkiaView != null) {
+				SkiaView.Dispose ();
+				SkiaView = null;
+			}
+		}
+	}
+}

samples/Skia.OSX.GLDemo/packages.config

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="SkiaSharp" version="1.53.2-gpu2" targetFramework="xamarinmac20" />
+</packages>

samples/Skia.WindowsDesktop.GLDemo/Form1.Designer.cs

@@ -0,0 +1,74 @@
+namespace Skia.WindowsDesktop.GLDemo
+{
+    partial class Form1
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.comboBox = new System.Windows.Forms.ComboBox();
+            this.skiaView = new Skia.WindowsDesktop.GLDemo.SkiaGLControl();
+            this.SuspendLayout();
+            // 
+            // comboBox
+            // 
+            this.comboBox.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
+            this.comboBox.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
+            this.comboBox.FormattingEnabled = true;
+            this.comboBox.Location = new System.Drawing.Point(466, 504);
+            this.comboBox.Name = "comboBox";
+            this.comboBox.Size = new System.Drawing.Size(300, 28);
+            this.comboBox.TabIndex = 0;
+            this.comboBox.SelectedIndexChanged += new System.EventHandler(this.comboBox1_SelectedIndexChanged);
+            // 
+            // skiaView
+            // 
+            this.skiaView.Dock = System.Windows.Forms.DockStyle.Fill;
+            this.skiaView.Location = new System.Drawing.Point(0, 0);
+            this.skiaView.Name = "skiaView";
+            this.skiaView.Size = new System.Drawing.Size(778, 544);
+            this.skiaView.TabIndex = 1;
+            // 
+            // Form1
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(144F, 144F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Dpi;
+            this.ClientSize = new System.Drawing.Size(778, 544);
+            this.Controls.Add(this.comboBox);
+            this.Controls.Add(this.skiaView);
+            this.Name = "Form1";
+            this.Text = "Form1";
+            this.Load += new System.EventHandler(this.Form1_Load);
+            this.ResumeLayout(false);
+
+        }
+
+        #endregion
+
+        private System.Windows.Forms.ComboBox comboBox;
+        private SkiaGLControl skiaView;
+    }
+}
+

samples/Skia.WindowsDesktop.GLDemo/Form1.cs

@@ -0,0 +1,38 @@
+using System;
+using System.IO;
+using System.Windows.Forms;
+
+namespace Skia.WindowsDesktop.GLDemo
+{
+    public partial class Form1 : Form
+    {
+        public Form1()
+        {
+            InitializeComponent();
+        }
+
+        private void Form1_Load(object sender, EventArgs e)
+        {
+            string fontName = "content-font.ttf";
+            var dir = Path.Combine(Path.GetTempPath(), "SkiaSharp.Demos", Path.GetRandomFileName());
+            if (!Directory.Exists(dir))
+            {
+                Directory.CreateDirectory(dir);
+            }
+            SkiaSharp.Demos.CustomFontPath = Path.Combine(Path.GetDirectoryName(typeof(Form1).Assembly.Location), "Content", fontName);
+            SkiaSharp.Demos.WorkingDirectory = dir;
+            SkiaSharp.Demos.OpenFileDelegate = path =>
+            {
+                System.Diagnostics.Process.Start(Path.Combine(dir, path));
+            };
+            
+            comboBox.Items.AddRange(SkiaSharp.Demos.SamplesForPlatform(SkiaSharp.Demos.Platform.WindowsDesktop | SkiaSharp.Demos.Platform.OpenGL));
+            comboBox.SelectedIndex = 0;
+        }
+
+        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
+        {
+            skiaView.Sample = SkiaSharp.Demos.GetSample((string)comboBox.SelectedItem);
+        }
+    }
+}

samples/Skia.WindowsDesktop.GLDemo/Program.cs

@@ -0,0 +1,22 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace Skia.WindowsDesktop.GLDemo
+{
+    static class Program
+    {
+        /// <summary>
+        /// The main entry point for the application.
+        /// </summary>
+        [STAThread]
+        static void Main()
+        {
+            Application.EnableVisualStyles();
+            Application.SetCompatibleTextRenderingDefault(false);
+            Application.Run(new Form1());
+        }
+    }
+}

samples/Skia.WindowsDesktop.GLDemo/Properties/AssemblyInfo.cs

@@ -0,0 +1,36 @@
+using System.Reflection;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+// General Information about an assembly is controlled through the following 
+// set of attributes. Change these attribute values to modify the information
+// associated with an assembly.
+[assembly: AssemblyTitle("Skia.WindowsDesktop.GLDemo")]
+[assembly: AssemblyDescription("")]
+[assembly: AssemblyConfiguration("")]
+[assembly: AssemblyCompany("")]
+[assembly: AssemblyProduct("Skia.WindowsDesktop.GLDemo")]
+[assembly: AssemblyCopyright("Copyright ©  2016")]
+[assembly: AssemblyTrademark("")]
+[assembly: AssemblyCulture("")]
+
+// Setting ComVisible to false makes the types in this assembly not visible 
+// to COM components.  If you need to access a type in this assembly from 
+// COM, set the ComVisible attribute to true on that type.
+[assembly: ComVisible(false)]
+
+// The following GUID is for the ID of the typelib if this project is exposed to COM
+[assembly: Guid("0315044e-207e-466e-84fd-c6add0c53e2d")]
+
+// Version information for an assembly consists of the following four values:
+//
+//      Major Version
+//      Minor Version 
+//      Build Number
+//      Revision
+//
+// You can specify all the values or you can default the Build and Revision Numbers 
+// by using the '*' as shown below:
+// [assembly: AssemblyVersion("1.0.*")]
+[assembly: AssemblyVersion("1.0.0.0")]
+[assembly: AssemblyFileVersion("1.0.0.0")]

samples/Skia.WindowsDesktop.GLDemo/Skia.WindowsDesktop.GLDemo.csproj

@@ -0,0 +1,148 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
+  <PropertyGroup>
+    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
+    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
+    <ProjectGuid>{0315044E-207E-466E-84FD-C6ADD0C53E2D}</ProjectGuid>
+    <OutputType>WinExe</OutputType>
+    <AppDesignerFolder>Properties</AppDesignerFolder>
+    <RootNamespace>Skia.WindowsDesktop.GLDemo</RootNamespace>
+    <AssemblyName>Skia.WindowsDesktop.GLDemo</AssemblyName>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
+    <FileAlignment>512</FileAlignment>
+    <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+    <TargetFrameworkProfile />
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugSymbols>true</DebugSymbols>
+    <DebugType>full</DebugType>
+    <Optimize>false</Optimize>
+    <OutputPath>bin\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
+    <PlatformTarget>AnyCPU</PlatformTarget>
+    <DebugType>pdbonly</DebugType>
+    <Optimize>true</Optimize>
+    <OutputPath>bin\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <ErrorReport>prompt</ErrorReport>
+    <WarningLevel>4</WarningLevel>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
+    <DebugSymbols>true</DebugSymbols>
+    <OutputPath>bin\x86\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <DebugType>full</DebugType>
+    <PlatformTarget>x86</PlatformTarget>
+    <ErrorReport>prompt</ErrorReport>
+    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+    <Prefer32Bit>true</Prefer32Bit>
+    <WarningLevel>4</WarningLevel>
+    <Optimize>false</Optimize>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x64'">
+    <DebugSymbols>true</DebugSymbols>
+    <OutputPath>bin\x64\Debug\</OutputPath>
+    <DefineConstants>DEBUG;TRACE</DefineConstants>
+    <DebugType>full</DebugType>
+    <PlatformTarget>x64</PlatformTarget>
+    <ErrorReport>prompt</ErrorReport>
+    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+    <Prefer32Bit>true</Prefer32Bit>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x86'">
+    <OutputPath>bin\x86\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <DebugType>pdbonly</DebugType>
+    <PlatformTarget>x86</PlatformTarget>
+    <ErrorReport>prompt</ErrorReport>
+    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+    <Prefer32Bit>true</Prefer32Bit>
+    <WarningLevel>4</WarningLevel>
+    <Optimize>false</Optimize>
+  </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Release|x64'">
+    <OutputPath>bin\x64\Release\</OutputPath>
+    <DefineConstants>TRACE</DefineConstants>
+    <DebugType>pdbonly</DebugType>
+    <PlatformTarget>x64</PlatformTarget>
+    <ErrorReport>prompt</ErrorReport>
+    <CodeAnalysisRuleSet>MinimumRecommendedRules.ruleset</CodeAnalysisRuleSet>
+    <Prefer32Bit>true</Prefer32Bit>
+    <WarningLevel>4</WarningLevel>
+    <Optimize>false</Optimize>
+  </PropertyGroup>
+  <PropertyGroup>
+    <ApplicationManifest>app.manifest</ApplicationManifest>
+  </PropertyGroup>
+  <ItemGroup>
+    <Reference Include="Microsoft.CSharp" />
+    <Reference Include="SkiaSharp">
+      <HintPath>packages\SkiaSharp.1.53.2-gpu2\lib\net45\SkiaSharp.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="OpenTK, Version=1.1.0.0, Culture=neutral, PublicKeyToken=bad199fe84eb3df4, processorArchitecture=MSIL">
+      <HintPath>packages\OpenTK.1.1.2349.61993\lib\NET40\OpenTK.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="OpenTK.GLControl, Version=1.1.0.0, Culture=neutral, PublicKeyToken=bad199fe84eb3df4, processorArchitecture=MSIL">
+      <HintPath>packages\OpenTK.GLControl.1.1.2349.61993\lib\NET40\OpenTK.GLControl.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
+    <Reference Include="System" />
+    <Reference Include="System.Core" />
+    <Reference Include="System.Xml.Linq" />
+    <Reference Include="System.Drawing" />
+    <Reference Include="System.Windows.Forms" />
+    <Reference Include="System.Xml" />
+  </ItemGroup>
+  <ItemGroup>
+    <Compile Include="..\SharedDemo\SkiaSharp.Demos.cs">
+      <Link>SkiaSharp.Demos.cs</Link>
+    </Compile>
+    <Compile Include="Form1.cs">
+      <SubType>Form</SubType>
+    </Compile>
+    <Compile Include="Form1.Designer.cs">
+      <DependentUpon>Form1.cs</DependentUpon>
+    </Compile>
+    <Compile Include="Program.cs" />
+    <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="SkiaGLControl.cs">
+      <SubType>UserControl</SubType>
+    </Compile>
+    <EmbeddedResource Include="..\SharedDemo\color-wheel.png">
+      <Link>color-wheel.png</Link>
+    </EmbeddedResource>
+    <EmbeddedResource Include="..\SharedDemo\baboon.png">
+      <Link>baboon.png</Link>
+    </EmbeddedResource>
+    <EmbeddedResource Include="..\SharedDemo\embedded-font.ttf">
+      <Link>embedded-font.ttf</Link>
+    </EmbeddedResource>
+    <EmbeddedResource Include="..\SharedDemo\adobe-dng.dng">
+      <Link>adobe-dng.dng</Link>
+    </EmbeddedResource>
+    <Content Include="..\SharedDemo\content-font.ttf">
+      <Link>Content\content-font.ttf</Link>
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </Content>
+  </ItemGroup>
+  <ItemGroup>
+    <None Include="app.manifest" />
+    <None Include="packages.config" />
+  </ItemGroup>
+  <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Import Project="packages\SkiaSharp.1.53.2-gpu2\build\net45\SkiaSharp.targets" Condition="Exists('packages\SkiaSharp.1.53.2-gpu2\build\net45\SkiaSharp.targets')" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>This project references NuGet package(s) that are missing on this computer. Use NuGet Package Restore to download them.  For more information, see http://go.microsoft.com/fwlink/?LinkID=322105. The missing file is {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('packages\SkiaSharp.1.53.2-gpu2\build\net45\SkiaSharp.targets')" Text="$([System.String]::Format('$(ErrorText)', 'packages\SkiaSharp.1.53.2-gpu2\build\net45\SkiaSharp.targets'))" />
+  </Target>
+</Project>

samples/Skia.WindowsDesktop.GLDemo/Skia.WindowsDesktop.GLDemo.sln

@@ -0,0 +1,34 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 14
+VisualStudioVersion = 14.0.25420.1
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Skia.WindowsDesktop.GLDemo", "Skia.WindowsDesktop.GLDemo.csproj", "{0315044E-207E-466E-84FD-C6ADD0C53E2D}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Debug|x64 = Debug|x64
+		Debug|x86 = Debug|x86
+		Release|Any CPU = Release|Any CPU
+		Release|x64 = Release|x64
+		Release|x86 = Release|x86
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Debug|x64.ActiveCfg = Debug|x64
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Debug|x64.Build.0 = Debug|x64
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Debug|x86.ActiveCfg = Debug|x86
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Debug|x86.Build.0 = Debug|x86
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Release|x64.ActiveCfg = Release|x64
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Release|x64.Build.0 = Release|x64
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Release|x86.ActiveCfg = Release|x86
+		{0315044E-207E-466E-84FD-C6ADD0C53E2D}.Release|x86.Build.0 = Release|x86
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal

samples/Skia.WindowsDesktop.GLDemo/SkiaGLControl.cs

@@ -0,0 +1,105 @@
+using System;
+using System.Windows.Forms;
+using OpenTK;
+using OpenTK.Graphics.OpenGL;
+
+using SkiaSharp;
+
+namespace Skia.WindowsDesktop.GLDemo
+{
+    public class SkiaGLControl : GLControl
+    {
+        private Demos.Sample sample;
+        private GRContext grContext = null;
+
+        public SkiaGLControl()
+        {
+            //// something else
+            //var glInterface = GRGlInterface.CreateNativeInterface();
+            //var secondContext = GRContext.Create(GRBackend.OpenGL, glInterface);
+            //var secondSurface = SKSurface.Create(secondContext, false, new SKImageInfo(Width, Height));
+        }
+
+        public Demos.Sample Sample
+        {
+            get { return sample; }
+            set
+            {
+                sample = value;
+                Invalidate();
+            }
+        }
+
+        private void Reshape()
+        {
+            GL.MatrixMode(MatrixMode.Projection);
+            GL.LoadIdentity();
+            GL.Ortho(0, Width, 0, Height, -1, 1);
+            GL.Viewport(0, 0, Width, Height);
+        }
+
+        protected override void Dispose(bool disposing)
+        {
+            grContext.Dispose();
+
+            base.Dispose(disposing);
+        }
+
+        protected override void OnMouseClick(MouseEventArgs e)
+        {
+            base.OnMouseClick(e);
+            sample?.TapMethod?.Invoke();
+        }
+
+        protected override void OnLoad(EventArgs e)
+        {
+            base.OnLoad(e);
+
+            if (DesignMode) return;
+
+            Reshape();
+            grContext = GRContext.Create(GRBackend.OpenGL);
+        }
+
+        protected override void OnResize(EventArgs e)
+        {
+            base.OnResize(e);
+
+            if (grContext != null)
+            {
+                Reshape();
+                Invalidate();
+            }
+        }
+
+        protected override void OnPaint(PaintEventArgs e)
+        {
+            base.OnPaint(e);
+
+            if (grContext != null)
+            {
+                var desc = new GRBackendRenderTargetDesc
+                {
+                    Width = Width,
+                    Height = Height,
+                    Config = GRPixelConfig.Bgra8888,
+                    Origin = GRSurfaceOrigin.TopLeft,
+                    SampleCount = 1,
+                    StencilBits = 0,
+                    RenderTargetHandle = IntPtr.Zero,
+                };
+
+                using (var surface = SKSurface.Create(grContext, desc))
+                {
+                    var skcanvas = surface.Canvas;
+
+                    sample.Method(skcanvas, Width, Height);
+
+                    skcanvas.Flush();
+                }
+
+                SwapBuffers();
+            }
+        }
+    }
+}

samples/Skia.WindowsDesktop.GLDemo/app.manifest

@@ -0,0 +1,74 @@
+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <assemblyIdentity version="1.0.0.0" name="MyApplication.app"/>
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
+    <security>
+      <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3">
+        <!-- UAC Manifest Options
+             If you want to change the Windows User Account Control level replace the 
+             requestedExecutionLevel node with one of the following.
+
+        <requestedExecutionLevel  level="asInvoker" uiAccess="false" />
+        <requestedExecutionLevel  level="requireAdministrator" uiAccess="false" />
+        <requestedExecutionLevel  level="highestAvailable" uiAccess="false" />
+
+            Specifying requestedExecutionLevel element will disable file and registry virtualization. 
+            Remove this element if your application requires this virtualization for backwards
+            compatibility.
+        -->
+        <requestedExecutionLevel level="asInvoker" uiAccess="false" />
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <!-- A list of the Windows versions that this application has been tested on and is
+           is designed to work with. Uncomment the appropriate elements and Windows will 
+           automatically selected the most compatible environment. -->
+
+      <!-- Windows Vista -->
+      <!--<supportedOS Id="{e2011457-1546-43c5-a5fe-008deee3d3f0}" />-->
+
+      <!-- Windows 7 -->
+      <!--<supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}" />-->
+
+      <!-- Windows 8 -->
+      <!--<supportedOS Id="{4a2f28e3-53b9-4441-ba9c-d69d4a4a6e38}" />-->
+
+      <!-- Windows 8.1 -->
+      <!--<supportedOS Id="{1f676c76-80e1-4239-95bb-83d0f6d0da78}" />-->
+
+      <!-- Windows 10 -->
+      <!--<supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />-->
+
+    </application>
+  </compatibility>
+
+  <!-- Indicates that the application is DPI-aware and will not be automatically scaled by Windows at higher
+       DPIs. Windows Presentation Foundation (WPF) applications are automatically DPI-aware and do not need 
+       to opt in. Windows Forms applications targeting .NET Framework 4.6 that opt into this setting, should 
+       also set the 'EnableWindowsFormsHighDpiAutoResizing' setting to 'true' in their app.config. -->
+  <application xmlns="urn:schemas-microsoft-com:asm.v3">
+    <windowsSettings>
+      <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true</dpiAware>
+    </windowsSettings>
+  </application>
+
+  <!-- Enable themes for Windows common controls and dialogs (Windows XP and later) -->
+  <!--
+  <dependency>
+    <dependentAssembly>
+      <assemblyIdentity
+          type="win32"
+          name="Microsoft.Windows.Common-Controls"
+          version="6.0.0.0"
+          processorArchitecture="*"
+          publicKeyToken="6595b64144ccf1df"
+          language="*"
+        />
+    </dependentAssembly>
+  </dependency>
+  -->
+
+</assembly>

samples/Skia.WindowsDesktop.GLDemo/packages.config

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="OpenTK" version="1.1.2349.61993" targetFramework="net45" />
+  <package id="OpenTK.GLControl" version="1.1.2349.61993" targetFramework="net45" />
+  <package id="SkiaSharp" version="1.53.2-gpu2" targetFramework="net45" />
+</packages>

skia

@@ -1 +1 @@
-Subproject commit 66b97f55fe30c3d6b6d9aa10f1dc01ac98ff68b6
+Subproject commit 5a28ee5e40d9f96d005b572beedfb3c199a604b2