CODEWITHSUNDEEP
c#screenshotscreen-scrapingdirectx-11dxgi
MakesYT
MakesYT

Reputation: 1

Take a screenshot using directx11 under c#

I used directx11 in c# to take a screenshot, but in the end I only got 0 in span, I don't know why, there is no error in the middle and the execution returns 0, the code uses the silk.net.direct3d11 library

I also tried this by creating an intermediate Texture2D, then copying my desktopTexture to this intermediate Texture2D, and then copying from the intermediate Texture2D to stagingResource

//....
        ID3D11Device* device=null;
        ID3D11DeviceContext* context=null;
        D3DFeatureLevel featureLevel=D3DFeatureLevel.Level101;
        D3DFeatureLevel[] featureLevels =
        [
            D3DFeatureLevel.Level111, D3DFeatureLevel.Level110, D3DFeatureLevel.Level101,D3DFeatureLevel.Level100
        ];
        fixed (D3DFeatureLevel* pFeatureLevels = &featureLevels[0])
        {
            D3D11 d3D11 = new D3D11(new DefaultNativeContext("d3d11"));
            if (d3D11.CreateDevice((IDXGIAdapter*)adapter1, D3DDriverType.Unknown, IntPtr.Zero,
                    (uint)CreateDeviceFlag.None,pFeatureLevels,(uint)featureLevels.Length, D3D11.SdkVersion, ref device,
&featureLevel, ref context)!=0){/*..*/}
        }
        ID3D11DeviceContext* immediateContext = null;
        device->GetImmediateContext(ref immediateContext);
        IDXGIOutputDuplication *outputDuplication = null;
        if (output5.DuplicateOutput((IUnknown*)device, ref outputDuplication)!=0){/*..*/}
        OutduplFrameInfo outduplFrameInfo = new OutduplFrameInfo();
        IDXGIResource* desktopResource = null;
        if (outputDuplication->AcquireNextFrame(1000, &outduplFrameInfo, &desktopResource)!=0{/*..*/}
        if (desktopResource->QueryInterface<ID3D11Resource>(out var desktopTexture)!=0){/*..*/}
        Texture2DDesc stagingTextureDesc = new()
        {
            CPUAccessFlags = (uint)CpuAccessFlag.Read,
            BindFlags = (uint)(BindFlag.None),
            Format = Format.FormatB8G8R8A8Unorm,
            Width = (uint)desc.DesktopCoordinates.Size.X,
            Height = (uint)desc.DesktopCoordinates.Size.Y,
            MiscFlags = (uint)ResourceMiscFlag.None,
            MipLevels = 1,
            ArraySize = 1,
            SampleDesc = { Count = 1, Quality = 0 },
            Usage = Usage.Staging
        };
        ID3D11Texture2D* stagingTexture = null;
        if (device->CreateTexture2D(&stagingTextureDesc,null,ref stagingTexture )!=0){/*..*/}
        stagingTexture->QueryInterface<ID3D11Resource>(out var stagingResource);
immediateContext->CopyResource(stagingResource, desktopTexture);
        MappedSubresource mappedSubresource=new MappedSubresource();
        if (immediateContext->Map(stagingResource, 0, Map.Read, 0, &mappedSubresource)!=0){/*..*/}
        var span = new ReadOnlySpan<byte>(mappedSubresource.PData,
            (int)mappedSubresource.DepthPitch);

What am i doing wrong?

Upvotes: -2

Views: 143

Answers (1)

Roman Ryltsov
Roman Ryltsov

Reputation: 69724

AcquireNextFrame has no promise to give you a screenshot right away. You might need to call it a few times before the texture is ready.

See more in this answer: AcquireNextFrame not working (Desktop Duplication API & D3D11).

Upvotes: 0

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