Metodo ID3D12GraphicsCommandList::SetPredication (d3d12.h)

Articolo
08/23/2023

Imposta un predicato di rendering.

Sintassi

void SetPredication(
  [in, optional] ID3D12Resource       *pBuffer,
  [in]           UINT64               AlignedBufferOffset,
  [in]           D3D12_PREDICATION_OP Operation
);

Parametri

[in, optional] pBuffer

Tipo: ID3D12Resource*

Buffer, come ID3D12Resource, che deve trovarsi nello stato D3D12_RESOURCE_STATE_PREDICATION o D3D21_RESOURCE_STATE_INDIRECT_ARGUMENT (entrambi i valori sono identici e forniti come alias per maggiore chiarezza) o NULL per disabilitare il predicato.

[in] AlignedBufferOffset

Tipo: UINT64

Offset del buffer allineato, come UINT64.

[in] Operation

Tipo: D3D12_PREDICATION_OP

Specifica un D3D12_PREDICATION_OP, ad esempio D3D12_PREDICATION_OP_EQUAL_ZERO o D3D12_PREDICATION_OP_NOT_EQUAL_ZERO.

Valore restituito

nessuno

Osservazioni

Utilizzare questo metodo per indicare che i comandi di rendering e manipolazione delle risorse successivi non vengono effettivamente eseguiti se i dati del predicato risultanti del predicato sono uguali all'operazione specificata.

A differenza di Direct3D 11, nello stato del predicato Direct3D 12 non viene ereditato dagli elenchi di comandi diretti e il predicato viene sempre rispettato (non sono presenti hint di predicazione). Tutti gli elenchi di comandi diretti iniziano con predicazione disabilitata. I bundle ereditano lo stato del predicato. È legale che lo stesso predicato sia associato più volte.

Le chiamate API non valide restituiranno un errore o ID3D12CommandQueue::ExecuteCommandLists eliminando l'elenco di comandi e rimuovendo il dispositivo.

Il livello di debug genera errori ogni volta che la convalida del runtime ha esito negativo.

Per altre informazioni, vedere Predicazione .

Esempio

L'esempio D3D12PredicationQueries usa ID3D12GraphicsCommandList::SetPredication come segue:

// Fill the command list with all the render commands and dependent state.
void D3D12PredicationQueries::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_commandAllocators[m_frameIndex]->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_commandAllocators[m_frameIndex].Get(), m_pipelineState.Get()));

    // Set necessary state.
    m_commandList->SetGraphicsRootSignature(m_rootSignature.Get());

    ID3D12DescriptorHeap* ppHeaps[] = { m_cbvHeap.Get() };
    m_commandList->SetDescriptorHeaps(_countof(ppHeaps), ppHeaps);

    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);
    CD3DX12_CPU_DESCRIPTOR_HANDLE dsvHandle(m_dsvHeap->GetCPUDescriptorHandleForHeapStart());
    m_commandList->OMSetRenderTargets(1, &rtvHandle, FALSE, &dsvHandle);

    // Record commands.
    const float clearColor[] = { 0.0f, 0.2f, 0.4f, 1.0f };
    m_commandList->ClearRenderTargetView(rtvHandle, clearColor, 0, nullptr);
    m_commandList->ClearDepthStencilView(dsvHandle, D3D12_CLEAR_FLAG_DEPTH, 1.0f, 0, 0, nullptr);

    // Draw the quads and perform the occlusion query.
    {
        CD3DX12_GPU_DESCRIPTOR_HANDLE cbvFarQuad(m_cbvHeap->GetGPUDescriptorHandleForHeapStart(), m_frameIndex * CbvCountPerFrame, m_cbvSrvDescriptorSize);
        CD3DX12_GPU_DESCRIPTOR_HANDLE cbvNearQuad(cbvFarQuad, m_cbvSrvDescriptorSize);

        m_commandList->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLESTRIP);
        m_commandList->IASetVertexBuffers(0, 1, &m_vertexBufferView);

        // Draw the far quad conditionally based on the result of the occlusion query
        // from the previous frame.
        m_commandList->SetGraphicsRootDescriptorTable(0, cbvFarQuad);
        m_commandList->SetPredication(m_queryResult.Get(), 0, D3D12_PREDICATION_OP_EQUAL_ZERO);
        m_commandList->DrawInstanced(4, 1, 0, 0);

        // Disable predication and always draw the near quad.
        m_commandList->SetPredication(nullptr, 0, D3D12_PREDICATION_OP_EQUAL_ZERO);
        m_commandList->SetGraphicsRootDescriptorTable(0, cbvNearQuad);
        m_commandList->DrawInstanced(4, 1, 4, 0);

        // Run the occlusion query with the bounding box quad.
        m_commandList->SetGraphicsRootDescriptorTable(0, cbvFarQuad);
        m_commandList->SetPipelineState(m_queryState.Get());
        m_commandList->BeginQuery(m_queryHeap.Get(), D3D12_QUERY_TYPE_BINARY_OCCLUSION, 0);
        m_commandList->DrawInstanced(4, 1, 8, 0);
        m_commandList->EndQuery(m_queryHeap.Get(), D3D12_QUERY_TYPE_BINARY_OCCLUSION, 0);

        // Resolve the occlusion query and store the results in the query result buffer
        // to be used on the subsequent frame.
        m_commandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(m_queryResult.Get(), D3D12_RESOURCE_STATE_PREDICATION, D3D12_RESOURCE_STATE_COPY_DEST));
        m_commandList->ResolveQueryData(m_queryHeap.Get(), D3D12_QUERY_TYPE_BINARY_OCCLUSION, 0, 1, m_queryResult.Get(), 0);
        m_commandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(m_queryResult.Get(), D3D12_RESOURCE_STATE_COPY_DEST, D3D12_RESOURCE_STATE_PREDICATION));
    }

    // 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());
}

Vedere Codice di esempio nel riferimento D3D12.