Added a member to swizzle the R and B

binding/Binding/Binding.projitems

@@ -55,5 +55,6 @@
     <Compile Include="$(MSBuildThisFileDirectory)SKVertices.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SKManagedPixelSerializer.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)SKPixelSerializer.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)SKSwizzle.cs" />
   </ItemGroup>
 </Project>

binding/Binding/SKSwizzle.cs

@@ -0,0 +1,28 @@
+//
+// Bindings for Skia's swizzle features
+//
+// Author:
+//   Matthew Leibowitz
+//
+// Copyright 2017 Xamarin Inc
+//
+
+using System;
+
+namespace SkiaSharp
+{
+	public static class SKSwizzle
+	{
+		public static void SwapRedBlue (IntPtr dest, IntPtr src, int count)
+		{
+			if (dest == IntPtr.Zero) {
+				throw new ArgumentException (nameof (dest));
+			}
+			if (src == IntPtr.Zero) {
+				throw new ArgumentException (nameof (src));
+			}
+
+			SkiaApi.sk_swizzle_swap_rb (dest, src, count);
+		}
+	}
+}

binding/Binding/SkiaApi.cs

@@ -1398,6 +1398,9 @@ namespace SkiaSharp
 		[return: MarshalAs(UnmanagedType.I1)]
 		public extern static bool sk_pixmap_read_pixels(sk_pixmap_t cpixmap, ref SKImageInfoNative dstInfo, IntPtr dstPixels, IntPtr dstRowBytes, int srcX, int srcY);
 
+		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
+		public extern static void sk_swizzle_swap_rb(IntPtr dest, IntPtr src, int count);
+
 		// Mask
 		[DllImport(SKIA, CallingConvention = CallingConvention.Cdecl)]
 		public extern static IntPtr sk_mask_alloc_image(IntPtr bytes);

externals/skia

@@ -1 +1 @@
-Subproject commit ddeb7dcf52e6099a8192adbdbd442a517b5d25c9
+Subproject commit 7dd04f34629f406059aa22daecb673fef4561577

tests/Tests/SKBitmapTest.cs

@@ -389,5 +389,21 @@ namespace SkiaSharp.Tests
 			}
 		}
 
+		[Test]
+		public void SwizzleRedBlueTest()
+		{
+			var info = new SKImageInfo(1, 1);
+
+			using (var bmp = new SKBitmap(info))
+			{
+				bmp.Erase((uint)0xFACEB004);
+
+				Assert.AreEqual((uint)0xFACEB004, (uint)bmp.GetPixel(0, 0));
+
+				SKSwizzle.SwapRedBlue(bmp.GetPixels(), bmp.GetPixels(), 1);
+
+				Assert.AreEqual((uint)0xFA04B0CE, (uint)bmp.GetPixel(0, 0));
+			}
+		}
 	}
 }