ID3D12Device：：GetDescriptorHandleIncrementSize 方法 (d3d12.h)

取得指定類型描述項堆積的控制碼遞增大小。 這個值通常用來依正確的數量將控制碼遞增至描述項陣列。

語法

UINT GetDescriptorHandleIncrementSize(
  [in] D3D12_DESCRIPTOR_HEAP_TYPE DescriptorHeapType
);

參數

[in] DescriptorHeapType

D3D12_DESCRIPTOR_HEAP_TYPE型別值，指定要取得控制碼遞增之描述元堆積的類型。

傳回值

傳回指定類型描述項堆積的控制碼遞增大小，包括任何必要的填補。

備註

這個方法所傳回的描述元大小是用來做為協助程式結構的一個輸入 ，CD3DX12_CPU_DESCRIPTOR_HANDLE 和 CD3DX12_GPU_DESCRIPTOR_HANDLE。

範例

D3D12PredicationQueries範例使用ID3D12Device：：GetDescriptorHandleIncrementSize，如下所示：

為資源建立描述項堆積。 變數 m_rtvDescriptorSize 會儲存轉譯目標檢視描述項控制碼遞增大小，並用於程式碼的 [建立框架資源 ] 區段中。

// 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])));
    }    
}

請參閱 D3D12 參考中的範例程式碼。

需求

目標平台	Windows
標頭	d3d12.h
程式庫	D3D12.lib
Dll	D3D12.dll

另請參閱

ID3D12Device