SlimDX and WPF via D3DImage

Question

I've written some code using SlimDX and WPF where I would expect the end result to be a red screen.

Unfortunately all I get is a black screen.

This is on windows 7.

Can anyone see anything major I'm missing?

The reason I'm using a separate surface as the backbuffer for the D3DImage is that I am going to be needing multiple viewports. I thought that rendering to seperate surfaces instead of the devices initial backbuffer would be the best way to achieve that.

anyway, on with the code..

Disclaimer: Please ignore the bad code, this is written entirely as throw-away code just so I can figure out how to do achieve what I'm after.

Here's my window class:

namespace SlimDXWithWpf
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        SlimDXRenderer controller;

        public MainWindow()
        {
            InitializeComponent();
            controller = new SlimDXRenderer();
            controller.Initialize();

            D3DImage image = new D3DImage();

            image.Lock();
            controller.RenderToSurface();
            image.SetBackBuffer(D3DResourceType.IDirect3DSurface9, controller.SurfacePointer);
            image.AddDirtyRect(new Int32Rect(0, 0, image.PixelWidth, image.PixelHeight));            
            image.Unlock();

            Background = new ImageBrush(image);
        }
    }
}

And heres my "renderer" class

namespace SlimDXWithWpf
{
    public class SlimDXRenderer : IDisposable
    {
        Direct3DEx directX;
        DeviceEx device;
        Surface surface;
        Surface backBuffer;
        IntPtr surfacePointer;

        public IntPtr SurfacePointer
        {
            get
            {
                return surfacePointer;
            }
        }

        public void Initialize()
        {
            directX = new Direct3DEx();

            HwndSource hwnd = new HwndSource(0, 0, 0, 0, 0, 640, 480, "SlimDXControl", IntPtr.Zero);

            PresentParameters pp = new PresentParameters()
            {
                BackBufferCount = 1,
                BackBufferFormat = Format.A8R8G8B8,
                BackBufferWidth = 640,
                BackBufferHeight = 480,
                DeviceWindowHandle = hwnd.Handle,
                PresentationInterval = PresentInterval.Immediate,
                Windowed = true,
                SwapEffect = SwapEffect.Discard              
            };



            device = new DeviceEx(directX, 0, DeviceType.Hardware, hwnd.Handle, CreateFlags.HardwareVertexProcessing, pp);
            backBuffer = device.GetRenderTarget(0); 

            surface = Surface.CreateRenderTarget(device, 1024, 768, Format.A8R8G8B8, MultisampleType.None, 1, false);
            surfacePointer = surface.ComPointer;            
        }

        public void RenderToSurface()
        {
            device.SetRenderTarget(0, surface);
            device.Clear(ClearFlags.Target | ClearFlags.ZBuffer, new Color4(Color.Red), 0f, 0);
            device.BeginScene();            
            device.EndScene();                        
        }

        public void Dispose()
        {
            surface.Dispose();
            device.Dispose();
            directX.Dispose();
        }
    }
}

-- Edit: For a second I had thought I'd solved it, but it seems it will only work when my second render target (the one I'm trying to clear red) is 640x480. Any thoughts?

Have you checked that image.PixelWidth and image.PixelHeight are returning a non-zero value - I can't see where you're setting the size of the D3DImage (I don't think it will get the size from the back-buffer for you, but could be wrong!) — Samuel
It does infact get it from the surface I assign as a backbuffer. One of the first things I checked :) — Sekhat

Unknown Unknown · Accepted Answer · 2011-01-13T17:00:26

Did you base some of this code on the SlimDX WPF sample? It looks like you might have, which is why your Clear() call is using 0.0f for the Z clear value... which is a bug in our sample. It should be 1.0f.

Beyond that, the only potential issue I see is that your surface render target is a different size than your back buffer, but that should not actually cause problems. Have you tried rendering to the device's backbuffer (Device.GetBackBuffer()) instead of a new surface to see what impact that has?

SlimDX and WPF via D3DImage

2 Answers