With HelixToolkit.SharpDX.Wpf how do I set the DiffuseMap on a PhongMaterial from an ImageSource?

Question

The DiffuseMap property of a PhongMaterial accepts a Stream.

If I have an ImageSource, how do I convert it to something acceptable to the property? Note that I need to be able to do this fast, in memory.

In the examples in the source code I can only find examples of loading images from file:

var image = LoadFileToMemory(new System.Uri(@"test.png", System.UriKind.RelativeOrAbsolute).ToString());
this.ModelMaterial = new PhongMaterial
        {
            AmbientColor = Colors.Gray.ToColor4(),
            DiffuseColor = Colors.White.ToColor4(),
            SpecularColor = Colors.White.ToColor4(),
            SpecularShininess = 100f,
            DiffuseAlphaMap = image,
            DiffuseMap = LoadFileToMemory(new System.Uri(@"TextureCheckerboard2.dds", System.UriKind.RelativeOrAbsolute).ToString()),
            NormalMap = LoadFileToMemory(new System.Uri(@"TextureCheckerboard2_dot3.dds", System.UriKind.RelativeOrAbsolute).ToString()),
        };

LoadFileToMemory simply takes the bytes from a file and returns it as a MemoryStream.

Answer 1

By ImageSource you mean a BitmapSource or DrawingImage? ImageSource is the abstract base class for both of them. If you have a BitmapSource you can convert it to a MemoryStream using:

        private Stream BitmapSourceToStream(BitmapSource writeBmp)
        {
            Stream stream = new MemoryStream();

            //BitmapEncoder enc = new PngBitmapEncoder();
            //BitmapEncoder enc = new JpegBitmapEncoder();
            BitmapEncoder enc = new BmpBitmapEncoder();
            enc.Frames.Add(BitmapFrame.Create(writeBmp));
            enc.Save(stream);                                             

            return stream;
        }