nf-d3d12-id3d12device-getdescriptorhandleincrementsize.md

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NF:d3d12.ID3D12Device.GetDescriptorHandleIncrementSize	ID3D12Device::GetDescriptorHandleIncrementSize (d3d12.h)	Gets the size of the handle increment for the given type of descriptor heap. This value is typically used to increment a handle into a descriptor array by the correct amount.	GetDescriptorHandleIncrementSize GetDescriptorHandleIncrementSize method GetDescriptorHandleIncrementSize method ID3D12Device interface ID3D12Device interface GetDescriptorHandleIncrementSize method ID3D12Device.GetDescriptorHandleIncrementSize ID3D12Device::GetDescriptorHandleIncrementSize d3d12/ID3D12Device::GetDescriptorHandleIncrementSize direct3d12.id3d12device_getdescriptorhandleincrementsize	direct3d12\id3d12device_getdescriptorhandleincrementsize.htm	direct3d12	4593C153-913A-49DF-ADDC-6FB1E19D3D17	12/05/2018	GetDescriptorHandleIncrementSize, GetDescriptorHandleIncrementSize method, GetDescriptorHandleIncrementSize method,ID3D12Device interface, ID3D12Device interface,GetDescriptorHandleIncrementSize method, ID3D12Device.GetDescriptorHandleIncrementSize, ID3D12Device::GetDescriptorHandleIncrementSize, d3d12/ID3D12Device::GetDescriptorHandleIncrementSize, direct3d12.id3d12device_getdescriptorhandleincrementsize	d3d12.h		Windows												D3D12.lib	D3D12.dll		Windows			19H1	ID3D12Device::GetDescriptorHandleIncrementSize d3d12/ID3D12Device::GetDescriptorHandleIncrementSize	c++	APIRef kbSyntax	COM	D3D12.dll	ID3D12Device.GetDescriptorHandleIncrementSize

ID3D12Device::GetDescriptorHandleIncrementSize

-description

Gets the size of the handle increment for the given type of descriptor heap. This value is typically used to increment a handle into a descriptor array by the correct amount.

-parameters

-param DescriptorHeapType [in]

The D3D12_DESCRIPTOR_HEAP_TYPE-typed value that specifies the type of descriptor heap to get the size of the handle increment for.

-returns

Returns the size of the handle increment for the given type of descriptor heap, including any necessary padding.

-remarks

The descriptor size returned by this method is used as one input to the helper structures CD3DX12_CPU_DESCRIPTOR_HANDLE and CD3DX12_GPU_DESCRIPTOR_HANDLE.

Examples

The D3D12PredicationQueries sample uses ID3D12Device::GetDescriptorHandleIncrementSize as follows:

Create the descriptor heap for the resources. The m_rtvDescriptorSize variable stores the render target view descriptor handle increment size, and is used in the Create frame resources section of the code.

// Create descriptor heaps.
{
    // Describe and create a render target view (RTV) descriptor heap.
    D3D12_DESCRIPTOR_HEAP_DESC rtvHeapDesc = {};
    rtvHeapDesc.NumDescriptors = FrameCount;
    rtvHeapDesc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_RTV;
    rtvHeapDesc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
    ThrowIfFailed(m_device->CreateDescriptorHeap(&rtvHeapDesc, IID_PPV_ARGS(&m_rtvHeap)));

    // Describe and create a depth stencil view (DSV) descriptor heap.
    D3D12_DESCRIPTOR_HEAP_DESC dsvHeapDesc = {};
    dsvHeapDesc.NumDescriptors = 1;
    dsvHeapDesc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_DSV;
    dsvHeapDesc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
    ThrowIfFailed(m_device->CreateDescriptorHeap(&dsvHeapDesc, IID_PPV_ARGS(&m_dsvHeap)));

    // Describe and create a constant buffer view (CBV) descriptor heap.
    D3D12_DESCRIPTOR_HEAP_DESC cbvHeapDesc = {};
    cbvHeapDesc.NumDescriptors = CbvCountPerFrame * FrameCount;
    cbvHeapDesc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV;
    cbvHeapDesc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE;
    ThrowIfFailed(m_device->CreateDescriptorHeap(&cbvHeapDesc, IID_PPV_ARGS(&m_cbvHeap)));

    // Describe and create a heap for occlusion queries.
    D3D12_QUERY_HEAP_DESC queryHeapDesc = {};
    queryHeapDesc.Count = 1;
    queryHeapDesc.Type = D3D12_QUERY_HEAP_TYPE_OCCLUSION;
    ThrowIfFailed(m_device->CreateQueryHeap(&queryHeapDesc, IID_PPV_ARGS(&m_queryHeap)));

    m_rtvDescriptorSize = m_device->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_RTV);
    m_cbvSrvDescriptorSize = m_device->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV);
}

// Create frame resources.
{
    CD3DX12_CPU_DESCRIPTOR_HANDLE rtvHandle(m_rtvHeap->GetCPUDescriptorHandleForHeapStart());

    // Create a RTV and a command allocator for each frame.
    for (UINT n = 0; n < FrameCount; n++)
    {
        ThrowIfFailed(m_swapChain->GetBuffer(n, IID_PPV_ARGS(&m_renderTargets[n])));
        m_device->CreateRenderTargetView(m_renderTargets[n].Get(), nullptr, rtvHandle);
        rtvHandle.Offset(1, m_rtvDescriptorSize);

        ThrowIfFailed(m_device->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&m_commandAllocators[n])));
    }    
}

Refer to the Example Code in the D3D12 Reference.

-see-also

ID3D12Device