Added the pieces for the simplest GPU sample

binding/Binding/Binding.projitems

@@ -18,6 +18,7 @@
     <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

@@ -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 {
@@ -265,6 +268,14 @@ 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
 	}
@@ -457,6 +468,7 @@ namespace SkiaSharp
 	[StructLayout(LayoutKind.Sequential)]
 	public struct SKSurfaceProps {
 		public SKPixelGeometry PixelGeometry;
+		public SKSurfacePropsFlags Flags;
 	}
 
 	public enum SKZeroInitialized {
@@ -1141,6 +1153,9 @@ namespace SkiaSharp
 			Bottom = bottom;
 		}
 
+		public float Height => Bottom - Top;
+		public float Width => Right - Left;
+
 		public static SKRectI Create (int width, int height)
 		{
 			return new SKRectI (0, 0, width, height);
@@ -1163,6 +1178,9 @@ namespace SkiaSharp
 			Bottom = bottom;
 		}
 
+		public float Height => Bottom - Top;
+		public float Width => Right - Left;
+
 		public static SKRect Create (float width, float height)
 		{
 			return new SKRect (0, 0, width, height);
@@ -1614,5 +1632,45 @@ 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 {
+		public int Width;
+		public int Height;
+		public GRPixelConfig Config;
+		public GRSurfaceOrigin Origin;
+		public int SampleCount;
+		public int StencilBits;
+		public GRBackendObject RenderTargetHandle;
+	}
+	
+	public enum GRBackend {
+		OpenGL,
+		Vulkan,
+	}
 }
 

binding/Binding/GRContext.cs

@@ -0,0 +1,42 @@
+//
+// 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));
+		}
+
+		protected override void Dispose (bool disposing)
+		{
+			if (Handle != IntPtr.Zero && OwnsHandle) {
+				SkiaApi.gr_context_unref (Handle);
+			}
+
+			base.Dispose (disposing);
+		}
+	}
+}
+

binding/Binding/SKCanvas.cs

@@ -349,6 +349,10 @@ 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 ResetMatrix ()
 		{

binding/Binding/SKSurface.cs

@@ -44,6 +44,16 @@ 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));
+		}
+		
 		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 +45,7 @@ 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;
 
 namespace SkiaSharp
 {
@@ -77,6 +81,10 @@ 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 int sk_canvas_save(sk_canvas_t t);
@@ -173,6 +181,10 @@ namespace SkiaSharp
 		public extern static bool sk_canvas_get_clip_device_bounds(sk_canvas_t t, ref SKRectI cbounds);
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static bool sk_canvas_get_clip_bounds(sk_canvas_t t, ref SKRect cbounds);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void sk_canvas_flush (sk_canvas_t canvas);
+
+		// Paint
 
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static sk_paint_t sk_paint_new();
@@ -910,6 +922,13 @@ 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_with_defaults (GRBackend backend, GRBackendContext backendContext);
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void gr_context_unref (gr_context_t context);
 	}
 }
 

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,

skia

@@ -1 +1 @@
-Subproject commit 3343ae587f9da023dfd43ed1ab12dcddf0bd097b
+Subproject commit e83f322d4ccfd5cbf5bdfbd973aa951b7171504e