Create Render Target View [138][140] need to Bind the back buffer to the render target view DirectX 11

Question

This is the error

D3D11 ERROR: ID3D11Device::CreateRenderTargetView: A RenderTargetView cannot be created of a Resource that did not specify the RENDER_TARGET BindFlag. [ STATE_CREATION ERROR #138: CREATERENDERTARGETVIEW_INVALIDRESOURCE]
D3D11 ERROR: ID3D11Device::CreateRenderTargetView: Returning E_INVALIDARG, meaning invalid parameters were passed. [ STATE_CREATION ERROR #140: CREATERENDERTARGETVIEW_INVALIDARG_RETURN]

So as i see here i need to set the BindFlag of the backBuffer to D3D11_BIND_RENDER_TARGET, but in all the tutorial i saw nobody is doing it, they all create the render target view by using this code

hr=m_swapChain->GetBuffer(0, __uuidof(ID3D11Texture2D), reinterpret_cast<void**>(&m_backBuffer)); 
if (FAILED(hr)) MessageBox(0, L"Failed get buffer", 0, 0); 
hr=m_device->CreateRenderTargetView(m_backBuffer, NULL, &m_renderTargetView); 
if (FAILED(hr)) MessageBox(0, L"Failed to create rendertargetview", 0, 0);

And nobody, nowhere is doing as the msdn site says, that the render target view must be created with this specific flag: D3D11_BIND_RENDER_TARGET

So I tried doing it by myself.

I created a texture2d desc like this for the back buffer:

D3D11_TEXTURE2D_DESC backBufferDescription;
    backBufferDescription.BindFlags = D3D11_BIND_RENDER_TARGET;
    backBufferDescription.ArraySize = 1;
    backBufferDescription.CPUAccessFlags = 0;
    backBufferDescription.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    backBufferDescription.Height = 600;
    backBufferDescription.Width = 800;
    backBufferDescription.MipLevels = 1;
    backBufferDescription.MiscFlags = 0;
    backBufferDescription.SampleDesc.Quality = 0;
    backBufferDescription.SampleDesc.Count = 1;
    backBufferDescription.Usage = D3D11_USAGE_DEFAULT;
    m_device->CreateTexture2D(&backBufferDescription, NULL, &m_backBuffer);
    if (FAILED(hr))
        MessageBox(0, L"Fallito back buffer desc", 0, 0);

And it doesn't work the same.

Help please

Answer 1

The code you are referring to from MSDN is using the Texture2D resources created for the swap chain, which are only usable as render targets (i.e. D3D11_BIND_RENDER_TARGET is implicit).

In this DirectX Tool Kit tutorial, I'm creating my own render target textures that can also be used as a texture.

// Full-size render target for scene
CD3D11_TEXTURE2D_DESC sceneDesc(backBufferFormat, backBufferWidth, backBufferHeight,
    1, 1, D3D11_BIND_RENDER_TARGET | D3D11_BIND_SHADER_RESOURCE);
DX::ThrowIfFailed(m_d3dDevice->CreateTexture2D(&sceneDesc, nullptr,
    m_sceneTex.GetAddressOf()));
DX::ThrowIfFailed(m_d3dDevice->CreateRenderTargetView(m_sceneTex.Get(), nullptr,
    m_sceneRT.ReleaseAndGetAddressOf()));
DX::ThrowIfFailed(m_d3dDevice->CreateShaderResourceView(m_sceneTex.Get(), nullptr,
    m_sceneSRV.ReleaseAndGetAddressOf()));

// Half-size blurring render targets
CD3D11_TEXTURE2D_DESC rtDesc(backBufferFormat, backBufferWidth / 2, backBufferHeight / 2,
    1, 1, D3D11_BIND_RENDER_TARGET | D3D11_BIND_SHADER_RESOURCE);
Microsoft::WRL::ComPtr<ID3D11Texture2D> rtTexture1;
DX::ThrowIfFailed(m_d3dDevice->CreateTexture2D(&rtDesc, nullptr,
    rtTexture1.GetAddressOf()));
DX::ThrowIfFailed(m_d3dDevice->CreateRenderTargetView(rtTexture1.Get(), nullptr,
    m_rt1RT.ReleaseAndGetAddressOf()));
DX::ThrowIfFailed(m_d3dDevice->CreateShaderResourceView(rtTexture1.Get(), nullptr,
    m_rt1SRV.ReleaseAndGetAddressOf()));

Microsoft::WRL::ComPtr<ID3D11Texture2D> rtTexture2;
DX::ThrowIfFailed(m_d3dDevice->CreateTexture2D(&rtDesc, nullptr,
    rtTexture2.GetAddressOf()));
DX::ThrowIfFailed(m_d3dDevice->CreateRenderTargetView(rtTexture2.Get(), nullptr,
    m_rt2RT.ReleaseAndGetAddressOf()));
DX::ThrowIfFailed(m_d3dDevice->CreateShaderResourceView(rtTexture2.Get(), nullptr,
    m_rt2SRV.ReleaseAndGetAddressOf()));

See this link for the full source example.

Of course the key thing to note is that you can't see or Present render targets that are not part of the swap chain. You have to copy them to the swapchain buffer or render with them into the swapchain render target at some point.