Hi, is NV_DX_interop2 missing for WGL.Extensions?

[jcyuan]

I found Silk.NET.WGL.Extensions.NV.NVDXInterop only, but there is no extension for NV_DX_interop2.
or maybe there is, but i missed it?
by the way, what does those Overloads mean? for example NVDXInteropOverloads, is this actually the NV_DX_interop2?
thank you so much.

[Perksey]

NV_DX_interop2 does not add any new functions therefore it does not have a class generated. For more info see the specification: https://registry.khronos.org/OpenGL/extensions/NV/WGL_NV_DX_interop2.txt

[jcyuan]

NV_DX_interop2 does not add any new functions therefore it does not have a class generated. For more info see the specification: https://registry.khronos.org/OpenGL/extensions/NV/WGL_NV_DX_interop2.txt

thanks for reply, yeah i know that, actually it was the usage confused me, so how can i use NV_DX_interop2 with Silk.WGL? i assume that the Overloads will be auto used for those changes in NV_DX_interop2?

[Perksey]

Yes that's correct.

[jcyuan]

Yes that's correct.

Hi sir, sorry for bothering again,

i just found 2 problems:

1, this method is not implemented in WGL.cs:

so, if (wgl.TryGetExtension<NVDXInterop>(out var ext)) will fail.

2, NV_DX_interop does not exist in the extension string list. but i can still use wglGetProcAddress("wglDXOpenDeviceNV") to use those methods, not sure why, it's strange to me...

if i try to use the ext with a 'normal' way just like other extensions:

by this test code:

var wgl = WGL.GetApi();
var ext = new NVDXInterop(wgl.Context);
ext.DxopenDevice(out IntPtr device);
 ext.DxcloseDevice(device);

it will fail....

and if i just use it by using DllImport even it does not exist in the extension string list:

it just works....

[Perksey]

oops

[Perksey]

This will now be fixed as part of #2115 (the next update), and the fix is contained in commit dfb4225. If you would like to work around this in your own code, feel free to use this commit as inspiration.

[jcyuan]

This will now be fixed as part of #2115 (the next update), and the fix is contained in commit dfb4225. If you would like to work around this in your own code, feel free to use this commit as inspiration.

👏thanks so much.

[jcyuan]

hi @Perksey

i had applied your changes into my logic (as the official release is not ready yet),
i found that i can create NVDXInterop extension in my 'primary' context, once i try to create with any context created later (shared with the primary context), the creating will fail.

ex info: i manage all the created DCs in a single thread.

maybe i should wait for new official release?

[Perksey]

2.21 should have fixed this.

[jcyuan]

so fast! thanks so much @Perksey
but just had a try and it didn't work, here is the code:

[MethodImpl(MethodImplOptions.AggressiveInlining)]
    [SupportedOSPlatform("windows")]
    private INativeContext CreateNativeContext()
    {
        return WGL.CreateDefaultContext(["Opengl32"]);
    }

// ------

 var nativeContext = CreateNativeContext();
        
        using (MakeCurrent())
        {
            _gl = GL.GetApi(nativeContext);
            _wgl= WGL.GetApi();   // new WGL(nativeContext) not work too.
        }

// test
var test = _wgl.TryGetExtension(out NVDXInterop ext);

it throws exception:

[Perksey]

Please ensure that you're using WGL.GetApi. Please note that the snippet you gave is using GL.GetApi incorrectly - this will only work for OpenGL 1.1 - you need to use a native context that uses wgl.GetProcAddress for the others.

I'm not sure why this isn't working, I'll reopen this issue until a community member can investigate further.

[jcyuan]

thanks for your suggestion,
i have changed my code like this:

    [MethodImpl(MethodImplOptions.AggressiveInlining)]
    private static IntPtr GetProcAddress(string proc)
    {
        var p = NativeMethods.wglGetProcAddress(proc);
        return p != IntPtr.Zero ? p : NativeMethods.GetProcAddress(OpenGl32Handle, proc);
    }

        using (MakeCurrent())
        {
            _gl = GL.GetApi(GetProcAddress);
            _wgl = WGL.GetApi();  // way auto create `MultiNativeContext`
        }

i think for _gl it's fine now, but for _wgl, still the same exception.

[jcyuan]

update:

i tried to create WGL with new WGL(new LamdaNativeContext(GetProcAddress)); (the GetProcAddress is the same one the _gl uses.

now it has exception, the _extensions is null:

so i think

private static IntPtr GetProcAddress(string proc)
    {
        var p = NativeMethods.wglGetProcAddress(proc);
        return p != IntPtr.Zero ? p : NativeMethods.GetProcAddress(OpenGl32Handle, proc);
    }

this should be the right way. @Perksey

[jcyuan]

update:

still failed, even the getProcAddress works for NVDXInterop extension to get those APIs, but those API call only works with the primary context, not sure why...

works fine now, i have manually written a binding for NVDXInterop because it only has a few APIs, and it works with all context now.
hope Silk could fix these problems soon, and thanks so much for official team for your efforts. ❤

[Perksey]

Awesome stuff @jcyuan. I had hoped that this is what the LambdaNativeContext is essentially doing, but it looks like for some reason it's not rolling over to the default context.

The null thing is a big oops, feel free to use unsafe accessors to rectify that:

[UnsafeAccessor(UnsafeAccessorKind.Field, Name = "_extensions")]
extern static ref ConcurrentDictionary<nint, HashSet<string>>? Exts(WGL wgl);

Exts(wgl) = new();

[qian-o]

This is a way I tried, I hope it can help you.

Use TryGetProcAddress instead of GetProcAddress in the GetProcAddress function of MultiNativeContext.

public nint GetProcAddress(string proc, int? slot = null)
{
    INativeContext[] contexts = Contexts;
    for (int i = 0; i < contexts.Length; i++)
    {
        if (contexts[i]?.TryGetProcAddress(proc, out IntPtr intPtr, slot) ?? false)
        {
            return intPtr;
        }
    }

    return 0;
}

Initialize and assign _extensions in WGL.

This can effectively solve the extension problem of WGL.