ID3D12GraphicsCommandList::RSSetViewports method

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

Syntax

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

Parameters

NumViewports

Type: UINT

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

pViewports

Type: const D3D12_VIEWPORT*

An array of D3D12_VIEWPORT structures to bind to the device.

Return Value

This method does not return a value.

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