ID3D12GraphicsCommandList::RSSetViewports method (d3d12.h)

Bind an array of viewports to the rasterizer stage of the pipeline.

Syntax

void RSSetViewports(
  [in] UINT                 NumViewports,
  [in] const D3D12_VIEWPORT *pViewports
);

Parameters

[in] NumViewports

Type: UINT

Number of viewports to bind. The range of valid values is (0, D3D12_VIEWPORT_AND_SCISSORRECT_OBJECT_COUNT_PER_PIPELINE).

[in] pViewports

Type: const D3D12_VIEWPORT*

An array of D3D12_VIEWPORT structures to bind to the device.

Return value

None

Remarks

All viewports must be set atomically as one operation. Any viewports not defined by the call are disabled.

Which viewport to use is determined by the SV_ViewportArrayIndex semantic output by a geometry shader; if a geometry shader does not specify the semantic, Direct3D will use the first viewport in the array.

Note  Even though you specify float values to the members of the D3D12_VIEWPORT structure for the pViewports array in a call to RSSetViewports for feature levels 9_x, RSSetViewports uses DWORDs internally. Because of this behavior, when you use a negative top left corner for the viewport, the call to RSSetViewports for feature levels 9_x fails. This failure occurs because RSSetViewports for 9_x casts the floating point values into unsigned integers without validation, which results in integer overflow.
 

Examples

The D3D12HelloTriangle sample uses ID3D12GraphicsCommandList::RSSetViewports as follows:

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());
}

See Example Code in the D3D12 Reference.

Requirements

   
Target Platform Windows
Header d3d12.h
Library D3d12.lib
DLL D3d12.dll

See also

ID3D12GraphicsCommandList