Added `Bitmap(PixelFormat format, IntPtr data, int width, int height, int stride)` constructor

src/Avalonia.Controls/Avalonia.Controls.csproj

@@ -60,7 +60,6 @@
     <Compile Include="Platform\IWindowBaseImpl.cs" />
     <Compile Include="Platform\Surfaces\IFramebufferPlatformSurface.cs" />
     <Compile Include="Platform\Surfaces\ILockedFramebuffer.cs" />
-    <Compile Include="Platform\Surfaces\PixelFormat.cs" />
     <Compile Include="PointEventArgs.cs" />
     <Compile Include="Embedding\EmbeddableControlRoot.cs" />
     <Compile Include="Platform\IEmbeddableWindowImpl.cs" />

src/Avalonia.Controls/Platform/Surfaces/ILockedFramebuffer.cs

@@ -1,4 +1,5 @@
 using System;
+using Avalonia.Platform;
 
 namespace Avalonia.Controls.Platform.Surfaces
 {

src/Avalonia.Controls/Platform/Surfaces/PixelFormat.cs

@@ -1,15 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-
-namespace Avalonia.Controls.Platform.Surfaces
-{
-    public enum PixelFormat
-    {
-        Rgb565,
-        Rgba8888,
-        Bgra8888
-    }
-}

src/Avalonia.Visuals/Avalonia.Visuals.csproj

@@ -103,6 +103,7 @@
     <Compile Include="Media\IDrawingContext.cs" />
     <Compile Include="Platform\ExportRenderingSubsystemAttribute.cs" />
     <Compile Include="Platform\IModuleEnvironmentChecker.cs" />
+    <Compile Include="Platform\PixelFormat.cs" />
     <Compile Include="Rendering\IRenderer.cs" />
     <Compile Include="Rendering\IRendererFactory.cs" />
     <Compile Include="Rendering\IRenderLoop.cs" />

src/Avalonia.Visuals/Media/Imaging/Bitmap.cs

@@ -41,6 +41,20 @@ namespace Avalonia.Media.Imaging
             PlatformImpl = impl;
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="Bitmap"/> class.
+        /// </summary>
+        /// <param name="format">Pixel format</param>
+        /// <param name="data">Pointer to source bytes</param>
+        /// <param name="width">Bitmap width</param>
+        /// <param name="height">Bitmap height</param>
+        /// <param name="stride">Bytes per row</param>
+        public Bitmap(PixelFormat format, IntPtr data, int width, int height, int stride)
+        {
+            PlatformImpl = AvaloniaLocator.Current.GetService<IPlatformRenderInterface>()
+                .LoadBitmap(format, data, width, height, stride);
+        }
+
         /// <summary>
         /// Gets the width of the bitmap, in pixels.
         /// </summary>

src/Avalonia.Visuals/Platform/IPlatformRenderInterface.cs

@@ -1,6 +1,7 @@
 // Copyright (c) The Avalonia Project. All rights reserved.
 // Licensed under the MIT license. See licence.md file in the project root for full license information.
 
+using System;
 using System.Collections.Generic;
 using System.IO;
 using Avalonia.Media;
@@ -68,5 +69,16 @@ namespace Avalonia.Platform
         /// <param name="stream">The stream to read the bitmap from.</param>
         /// <returns>An <see cref="IBitmapImpl"/>.</returns>
         IBitmapImpl LoadBitmap(Stream stream);
+
+        /// <summary>
+        /// Loads a bitmap implementation from a pixels in memory..
+        /// </summary>
+        /// <param name="format">Pixel format</param>
+        /// <param name="data">Pointer to source bytes</param>
+        /// <param name="width">Bitmap width</param>
+        /// <param name="height">Bitmap height</param>
+        /// <param name="stride">Bytes per row</param>
+        /// <returns>An <see cref="IBitmapImpl"/>.</returns>
+        IBitmapImpl LoadBitmap(PixelFormat format, IntPtr data, int width, int height, int stride);
     }
 }

src/Avalonia.Visuals/Platform/PixelFormat.cs

@@ -0,0 +1,9 @@
+namespace Avalonia.Platform
+{
+    public enum PixelFormat
+    {
+        Rgb565,
+        Rgba8888,
+        Bgra8888
+    }
+}

src/Gtk/Avalonia.Cairo/CairoPlatform.cs

@@ -91,5 +91,10 @@ namespace Avalonia.Cairo
             Gtk.Application.Init();
             return new Gtk.Invisible().CreatePangoContext();
         }
+
+        public IBitmapImpl LoadBitmap(PixelFormat format, IntPtr data, int width, int height, int stride)
+        {
+            throw new NotSupportedException("No proper control over pixel format with Cairo, use Skia backend instead");
+        }
     }
 }

src/Skia/Avalonia.Skia/FramebufferRenderTarget.cs

@@ -22,19 +22,6 @@ namespace Avalonia.Skia
             //Nothing to do here, since we don't own framebuffer
         }
 
-
-        SKColorType TranslatePixelFormat(PixelFormat fmt)
-        {
-            if(fmt == PixelFormat.Rgb565)
-                return SKColorType.Rgb565;
-            if(fmt == PixelFormat.Bgra8888)
-                return SKColorType.Bgra8888;
-            if (fmt == PixelFormat.Rgba8888)
-                return SKColorType.Rgba8888;
-            throw new ArgumentException("Unknown pixel format: " + fmt);
-        }
-
-
         class PixelFormatShim : IDisposable
         {
             private readonly SKImageInfo _nfo;
@@ -73,8 +60,8 @@ namespace Avalonia.Skia
         {
             var fb = _surface.Lock();
             PixelFormatShim shim = null;
-            SKImageInfo framebuffer = new SKImageInfo(fb.Width, fb.Height, TranslatePixelFormat(fb.Format),
+            SKImageInfo framebuffer = new SKImageInfo(fb.Width, fb.Height, fb.Format.ToSkColorType(),
-                SKAlphaType.Opaque);
+                SKAlphaType.Premul);
             var surface = SKSurface.Create(framebuffer, fb.Address, fb.RowBytes) ??
                           (shim = new PixelFormatShim(framebuffer, fb.Address, fb.RowBytes))
                           .CreateSurface();

src/Skia/Avalonia.Skia/PlatformRenderInterface.cs

@@ -52,6 +52,16 @@ namespace Avalonia.Skia
             }
         }
 
+        public IBitmapImpl LoadBitmap(PixelFormat format, IntPtr data, int width, int height, int stride)
+        {
+            using (var tmp = new SKBitmap())
+            {
+                tmp.InstallPixels(new SKImageInfo(width, height, format.ToSkColorType(), SKAlphaType.Premul)
+                    , data, stride);
+                return new BitmapImpl(tmp.Copy());
+            }
+        }
+
         public IRenderer CreateRenderer(IRenderRoot root, IRenderLoop renderLoop)
         {
             return new Renderer(root, renderLoop);

src/Skia/Avalonia.Skia/SkiaSharpExtensions.cs

@@ -1,4 +1,6 @@
+using System;
 using Avalonia.Media;
+using Avalonia.Platform;
 using SkiaSharp;
 
 
@@ -44,6 +46,17 @@ namespace Avalonia.Skia
             return new SKColor(c.R, c.G, c.B, c.A);
         }
 
+        public static SKColorType ToSkColorType(this PixelFormat fmt)
+        {
+            if (fmt == PixelFormat.Rgb565)
+                return SKColorType.Rgb565;
+            if (fmt == PixelFormat.Bgra8888)
+                return SKColorType.Bgra8888;
+            if (fmt == PixelFormat.Rgba8888)
+                return SKColorType.Rgba8888;
+            throw new ArgumentException("Unknown pixel format: " + fmt);
+        }
+
         public static SKShaderTileMode ToSKShaderTileMode(this Media.GradientSpreadMethod m)
         {
             switch (m)

src/Windows/Avalonia.Direct2D1/Direct2D1Platform.cs

@@ -133,5 +133,10 @@ namespace Avalonia.Direct2D1
         {
             return new WicBitmapImpl(s_imagingFactory, stream);
         }
+
+        public IBitmapImpl LoadBitmap(PixelFormat format, IntPtr data, int width, int height, int stride)
+        {
+            return new WicBitmapImpl(s_imagingFactory, format, data, width, height, stride);
+        }
     }
 }

src/Windows/Avalonia.Direct2D1/Media/Imaging/WicBitmapImpl.cs

@@ -4,6 +4,9 @@
 using System;
 using System.IO;
 using Avalonia.Platform;
+using Avalonia.Win32.Interop;
+using PixelFormat  = SharpDX.WIC.PixelFormat;
+using APixelFormat  = Avalonia.Platform.PixelFormat;
 using SharpDX.WIC;
 
 namespace Avalonia.Direct2D1.Media
@@ -64,6 +67,28 @@ namespace Avalonia.Direct2D1.Media
                 BitmapCreateCacheOption.CacheOnLoad);
         }
 
+        public WicBitmapImpl(ImagingFactory factory, Platform.PixelFormat format, IntPtr data, int width, int height, int stride)
+        {
+            Guid fmt;
+            if (format == APixelFormat.Rgb565)
+                fmt = PixelFormat.Format16bppBGR565;
+            else if (format == APixelFormat.Bgra8888)
+                fmt = PixelFormat.Format32bppPBGRA;
+            else if (format == APixelFormat.Rgba8888)
+                fmt = PixelFormat.Format32bppPRGBA;
+            else throw new ArgumentException("Unknown pixel format");
+
+            WicImpl = new Bitmap(factory, width, height, fmt, BitmapCreateCacheOption.CacheOnDemand);
+            using (var l = WicImpl.Lock(BitmapLockFlags.Write))
+            {
+                for (var row = 0; row < height; row++)
+                {
+                    UnmanagedMethods.CopyMemory(new IntPtr(l.Data.DataPointer.ToInt64() + row * l.Stride),
+                        new IntPtr(data.ToInt64() + row * stride), (uint) l.Data.Pitch);
+                }
+            }
+        }
+
         /// <summary>
         /// Gets the width of the bitmap, in pixels.
         /// </summary>

src/Windows/Avalonia.Direct2D1/SwapChainRenderTarget.cs

@@ -9,6 +9,7 @@ using Avalonia.Win32.Interop;
 using SharpDX;
 using SharpDX.Direct2D1;
 using SharpDX.DXGI;
+using PixelFormat = SharpDX.Direct2D1.PixelFormat;
 using AlphaMode = SharpDX.Direct2D1.AlphaMode;
 using Device = SharpDX.Direct2D1.Device;
 using Factory = SharpDX.Direct2D1.Factory;

src/Windows/Avalonia.Win32/Interop/UnmanagedMethods.cs

@@ -909,6 +909,9 @@ namespace Avalonia.Win32.Interop
             uint dwMaximumSizeLow,
             string lpName);
 
+        [DllImport("kernel32.dll", EntryPoint = "CopyMemory", SetLastError = false)]
+        public static extern void CopyMemory(IntPtr dest, IntPtr src, uint count);
+
         public enum MONITOR
         {
             MONITOR_DEFAULTTONULL = 0x00000000,

src/Windows/Avalonia.Win32/WindowFramebuffer.cs

@@ -2,7 +2,7 @@
 using System.Runtime.InteropServices;
 using Avalonia.Controls.Platform.Surfaces;
 using Avalonia.Win32.Interop;
-using PixelFormat = Avalonia.Controls.Platform.Surfaces.PixelFormat;
+using PixelFormat = Avalonia.Platform.PixelFormat;
 
 namespace Avalonia.Win32
 {

tests/Avalonia.Input.UnitTests/InputElement_HitTesting.cs

@@ -365,6 +365,11 @@ namespace Avalonia.Input.UnitTests
                 throw new NotImplementedException();
             }
 
+            public IBitmapImpl LoadBitmap(PixelFormat format, IntPtr data, int width, int height, int stride)
+            {
+                throw new NotImplementedException();
+            }
+
             class MockStreamGeometry : Avalonia.Platform.IStreamGeometryImpl
             {
                 private MockStreamGeometryContext _impl = new MockStreamGeometryContext();

tests/Avalonia.RenderTests/Avalonia.RenderTests.projitems

@@ -10,6 +10,7 @@
   </PropertyGroup>
   <ItemGroup>
     <Compile Include="$(MSBuildThisFileDirectory)GeometryClippingTests.cs" />
+    <Compile Include="$(MSBuildThisFileDirectory)Media\BitmapTests.cs" />
     <Compile Include="$(MSBuildThisFileDirectory)OpacityMaskTests.cs" />
     <Compile Include="Media\FormattedTextImplTests.cs" />
     <Compile Include="Controls\ImageTests.cs" />

tests/Avalonia.RenderTests/Media/BitmapTests.cs

@@ -0,0 +1,108 @@
+// Copyright (c) The Avalonia Project. All rights reserved.
+// Licensed under the MIT license. See licence.md file in the project root for full license information.
+
+using System;
+using System.IO;
+using System.Runtime.InteropServices;
+using Avalonia.Controls;
+using Avalonia.Controls.Platform.Surfaces;
+using Avalonia.Controls.Shapes;
+using Avalonia.Layout;
+using Avalonia.Media;
+using Avalonia.Media.Imaging;
+using Avalonia.Platform;
+using Xunit;
+
+#if AVALONIA_CAIRO
+namespace Avalonia.Cairo.RenderTests.Media
+#elif AVALONIA_SKIA
+namespace Avalonia.Skia.RenderTests
+#else
+namespace Avalonia.Direct2D1.RenderTests.Media
+#endif
+{
+    public class BitmapTests : TestBase
+    {
+        public BitmapTests()
+            : base(@"Media\Bitmap")
+        {
+            Directory.CreateDirectory(OutputPath);
+        }
+
+        class Framebuffer : ILockedFramebuffer, IFramebufferPlatformSurface
+        {
+            public Framebuffer(PixelFormat fmt, int width, int height)
+            {
+                Format = fmt;
+                var bpp = fmt == PixelFormat.Rgb565 ? 2 : 4;
+                Width = width;
+                Height = height;
+                RowBytes = bpp * width;
+                Address = Marshal.AllocHGlobal(Height * RowBytes);
+            }
+
+            public IntPtr Address { get; }
+
+            public Size Dpi { get; } = new Size(96, 96);
+
+            public PixelFormat Format { get; }
+
+            public int Height { get; }
+
+            public int RowBytes { get; }
+
+            public int Width { get; }
+
+            public void Dispose()
+            {
+                //no-op
+            }
+
+            public ILockedFramebuffer Lock()
+            {
+                return this;
+            }
+
+            public void Deallocate() => Marshal.FreeHGlobal(Address);
+        }
+
+
+#if AVALONIA_SKIA
+        [Theory]
+#else
+        [Theory(Skip = "Framebuffer not supported")]
+#endif
+        [InlineData(PixelFormat.Rgba8888), InlineData(PixelFormat.Bgra8888), InlineData(PixelFormat.Rgb565)]
+        public void FramebufferRenderResultsShouldBeUsableAsBitmap(PixelFormat fmt)
+        {
+            var testName = nameof(FramebufferRenderResultsShouldBeUsableAsBitmap) + "_" + fmt;
+            var fb = new Framebuffer(fmt, 80, 80);
+            var r = Avalonia.AvaloniaLocator.Current.GetService<IPlatformRenderInterface>();
+            using (var target = r.CreateRenderTarget(new object[] { fb }))
+            using (var ctx = target.CreateDrawingContext())
+            {
+                ctx.PushOpacity(0.8);
+                ctx.FillRectangle(Brushes.Chartreuse, new Rect(0, 0, 20, 100));
+                ctx.FillRectangle(Brushes.Crimson, new Rect(20, 0, 20, 100));
+                ctx.FillRectangle(Brushes.Gold, new Rect(40, 0, 20, 100));
+            }
+
+            var bmp = new Bitmap(fmt, fb.Address, fb.Width, fb.Height, fb.RowBytes);
+            fb.Deallocate();
+            using (var rtb = new RenderTargetBitmap(100, 100))
+            {
+                using (var ctx = rtb.CreateDrawingContext())
+                {
+                    ctx.FillRectangle(Brushes.Blue, new Rect(0, 0, 100, 100));
+                    ctx.FillRectangle(Brushes.Pink, new Rect(0, 20, 100, 10));
+
+                    var rc = new Rect(0, 0, 60, 60);
+                    ctx.DrawImage(bmp, 1, rc, rc);
+                }
+                rtb.Save(System.IO.Path.Combine(OutputPath, testName + ".out.png"));
+            }
+            CompareImages(testName);
+            
+        }
+    }
+}

tests/Avalonia.Visuals.UnitTests/VisualTree/MockRenderInterface.cs

@@ -45,6 +45,11 @@ namespace Avalonia.Visuals.UnitTests.VisualTree
             throw new NotImplementedException();
         }
 
+        public IBitmapImpl LoadBitmap(PixelFormat format, IntPtr data, int width, int height, int stride)
+        {
+            throw new NotImplementedException();
+        }
+
         class MockStreamGeometry : IStreamGeometryImpl
         {
             private MockStreamGeometryContext _impl = new MockStreamGeometryContext();