ID3D12Device：：GetDescriptorHandleIncrementSize 方法 （d3d12.h）

获取给定类型的描述符堆的句柄增量的大小。 此值通常用于按正确的数量将句柄递增到描述符数组中。

语法

UINT GetDescriptorHandleIncrementSize(
  [in] D3D12_DESCRIPTOR_HEAP_TYPE DescriptorHeapType
);

参数

[in] DescriptorHeapType

D3D12_DESCRIPTOR_HEAP_TYPE类型化值，指定描述符堆的类型以获取句柄增量的大小。

返回值

返回给定类型的描述符堆的句柄增量的大小，包括任何必要的填充。

言论

此方法返回的描述符大小用作帮助程序结构的一个输入，CD3DX12_CPU_DESCRIPTOR_HANDLE 和 CD3DX12_GPU_DESCRIPTOR_HANDLE。

例子

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

为资源创建描述符堆。 m_rtvDescriptorSize 变量存储呈现目标视图描述符句柄增量大小，并在代码 创建帧资源 节中使用。

// 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])));
    }    
}

请参阅 D3D12 参考 中的示例代码。

要求

另请参阅

ID3D12Device