SharpDX. Unsupported pixel format

Question

I use SharpDX and have a problem with PixelFormat. I want to make it A8_UNorm and use an OpacityMask but I get an UnsupportedPixelFormatException. But according to MSDN everything should be alright. Code:

     PixelFormat PF = new PixelFormat(Format.A8_UNorm, AlphaMode.Straight);  
     var desc = new Texture2DDescription()
            {
                Width = Width,
                Height = Height,
                Format = Format.A8_UNorm,
                SampleDescription = new SampleDescription(1, 0),
                ArraySize = 1,
                CpuAccessFlags = 0,
                Usage = ResourceUsage.Default,
                MipLevels = 1,
                BindFlags = BindFlags.RenderTarget | BindFlags.ShaderResource,
            };

            using (var d = new DataStream(desc.Width * desc.Height, true, true))
            {
                for (var i = 0; i < desc.Width * desc.Height / 4; i++) d.Write(0);
                using (Texture2D tex = new Texture2D(GameControl.Device, desc, new DataRectangle(d.DataPointer, desc.Width)))
                {
                    using (Surface temp = tex.QueryInterface<Surface>())
                    {
                        Target = new RenderTarget(Factory2D, temp, new RenderTargetProperties(PF));
                        OpacityMask = new Bitmap(Target, temp, new BitmapProperties(PF)); //Exception is here
                    }
                }
            }

Answer 1

Pixel format support depends on software and hardware. You can check if your platform supports what you want with CheckFormatSupport(). I use it like this:

var format = Format.A8_UNorm;
var supportRequired = FormatSupport.RenderTarget;
var isSupported = device.CheckFormatSupport(format).HasFlag(supportRequired);

Note that there are many options besides FormatSupport.RenderTarget, so test all of them that you are trying to use.