ID3D12GraphicsCommandList：：ClearRenderTargetView 方法 (d3d12.h)

将呈现器目标中的所有元素设置为一个值。

语法

void ClearRenderTargetView(
  [in] D3D12_CPU_DESCRIPTOR_HANDLE RenderTargetView,
  [in] const FLOAT [4]             ColorRGBA,
  [in] UINT                        NumRects,
  [in] const D3D12_RECT            *pRects
);

参数

[in] RenderTargetView

类型： D3D12_CPU_DESCRIPTOR_HANDLE

指定D3D12_CPU_DESCRIPTOR_HANDLE结构，该结构描述 CPU 描述符句柄，该句柄表示要清除的呈现器目标的堆的开头。

[in] ColorRGBA

类型： const FLOAT[4]

一个由 4 分量构成的数组，表示要填充呈现器目标时使用的颜色。

[in] NumRects

类型： UINT

pRects 参数指定的数组中的矩形数。

[in] pRects

类型： const D3D12_RECT*

要清除的资源视图中矩形的 D3D12_RECT 结构的数组。 如果 为NULL，ClearRenderTargetView 将清除整个资源视图。

返回值

无

备注

ClearRenderTargetView 可用于初始化同一堆内存别名的资源。 有关更多详细信息 ，请参阅 CreatePlacedResource 。

运行时验证

对于浮点输入，运行时会将非规范化值设置为 0 (，同时保留 NAN) 。

验证失败将导致调用 Close 返回 E_INVALIDARG。

调试层

如果输入颜色非规范化，调试层将发出错误。

如果视图引用的子资源未处于适当的状态，则调试层将发出错误。 对于 ClearRenderTargetView，状态必须为 D3D12_RESOURCE_STATE_RENDER_TARGET。

示例

D3D12HelloTriangle 示例使用 ID3D12GraphicsCommandList：：ClearRenderTargetView，如下所示：

D3D12_VIEWPORT m_viewport;
D3D12_RECT m_scissorRect;
ComPtr<IDXGISwapChain3> m_swapChain;
ComPtr<ID3D12Device> m_device;
ComPtr<ID3D12Resource> m_renderTargets[FrameCount];
ComPtr<ID3D12CommandAllocator> m_commandAllocator;
ComPtr<ID3D12CommandQueue> m_commandQueue;
ComPtr<ID3D12RootSignature> m_rootSignature;
ComPtr<ID3D12DescriptorHeap> m_rtvHeap;
ComPtr<ID3D12PipelineState> m_pipelineState;
ComPtr<ID3D12GraphicsCommandList> m_commandList;
UINT m_rtvDescriptorSize;

void D3D12HelloTriangle::PopulateCommandList()
{
    // Command list allocators can only be reset when the associated 
    // command lists have finished execution on the GPU; apps should use 
    // fences to determine GPU execution progress.
    ThrowIfFailed(m_commandAllocator->Reset());

    // However, when ExecuteCommandList() is called on a particular command 
    // list, that command list can then be reset at any time and must be before 
    // re-recording.
    ThrowIfFailed(m_commandList->Reset(m_commandAllocator.Get(), m_pipelineState.Get()));

    // Set necessary state.
    m_commandList->SetGraphicsRootSignature(m_rootSignature.Get());
    m_commandList->RSSetViewports(1, &m_viewport);
    m_commandList->RSSetScissorRects(1, &m_scissorRect);

    // Indicate that the back buffer will be used as a render target.
    m_commandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(m_renderTargets[m_frameIndex].Get(), D3D12_RESOURCE_STATE_PRESENT, D3D12_RESOURCE_STATE_RENDER_TARGET));

    CD3DX12_CPU_DESCRIPTOR_HANDLE rtvHandle(m_rtvHeap->GetCPUDescriptorHandleForHeapStart(), m_frameIndex, m_rtvDescriptorSize);
    m_commandList->OMSetRenderTargets(1, &rtvHandle, FALSE, nullptr);

    // Record commands.
    const float clearColor[] = { 0.0f, 0.2f, 0.4f, 1.0f };
    m_commandList->ClearRenderTargetView(rtvHandle, clearColor, 0, nullptr);
    m_commandList->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
    m_commandList->IASetVertexBuffers(0, 1, &m_vertexBufferView);
    m_commandList->DrawInstanced(3, 1, 0, 0);

    // Indicate that the back buffer will now be used to present.
    m_commandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(m_renderTargets[m_frameIndex].Get(), D3D12_RESOURCE_STATE_RENDER_TARGET, D3D12_RESOURCE_STATE_PRESENT));

    ThrowIfFailed(m_commandList->Close());
}

D3D12Multithreading 示例使用 ID3D12GraphicsCommandList：：ClearRenderTargetView，如下所示：

// Frame resources.
FrameResource* m_frameResources[FrameCount];
FrameResource* m_pCurrentFrameResource;
int m_currentFrameResourceIndex;

// Assemble the CommandListPre command list.
void D3D12Multithreading::BeginFrame()
{
    m_pCurrentFrameResource->Init();

    // Indicate that the back buffer will be used as a render target.
    m_pCurrentFrameResource->m_commandLists[CommandListPre]->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(m_renderTargets[m_frameIndex].Get(), D3D12_RESOURCE_STATE_PRESENT, D3D12_RESOURCE_STATE_RENDER_TARGET));

    // Clear the render target and depth stencil.
    const float clearColor[] = { 0.0f, 0.0f, 0.0f, 1.0f };
    CD3DX12_CPU_DESCRIPTOR_HANDLE rtvHandle(m_rtvHeap->GetCPUDescriptorHandleForHeapStart(), m_frameIndex, m_rtvDescriptorSize);
    m_pCurrentFrameResource->m_commandLists[CommandListPre]->ClearRenderTargetView(rtvHandle, clearColor, 0, nullptr);
    m_pCurrentFrameResource->m_commandLists[CommandListPre]->ClearDepthStencilView(m_dsvHeap->GetCPUDescriptorHandleForHeapStart(), D3D12_CLEAR_FLAG_DEPTH, 1.0f, 0, 0, nullptr);

    ThrowIfFailed(m_pCurrentFrameResource->m_commandLists[CommandListPre]->Close());
}

// Assemble the CommandListMid command list.
void D3D12Multithreading::MidFrame()
{
    // Transition our shadow map from the shadow pass to readable in the scene pass.
    m_pCurrentFrameResource->SwapBarriers();

    ThrowIfFailed(m_pCurrentFrameResource->m_commandLists[CommandListMid]->Close());
}

请参阅 D3D12 参考中的示例代码。

要求

要求	值
目标平台	Windows
标头	d3d12.h
Library	D3d12.lib
DLL	D3d12.dll

另请参阅

ID3D12GraphicsCommandList