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Example Code in the D3D12 Reference

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Explains the use of example code in the Direct3D 12 documentation.

Example snippet code

The example code shown in the Direct3D 12 reference is not compilable or run-able code, it is simply a snippet of code giving an example of how the API is called. Some examples list the global variables and class members used by the calls, for example:

Global pipeline objects.

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;

Populating command lists.

// 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.
auto barrier = CD3DX12_RESOURCE_BARRIER::Transition(m_renderTargets[m_frameIndex].Get(), D3D12_RESOURCE_STATE_PRESENT, D3D12_RESOURCE_STATE_RENDER_TARGET);
m_commandList->ResourceBarrier(1, &barrier);

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, &barrier);
barrier = CD3DX12_RESOURCE_BARRIER::Transition(m_renderTargets[m_frameIndex].Get(), D3D12_RESOURCE_STATE_RENDER_TARGET, D3D12_RESOURCE_STATE_PRESENT);
ThrowIfFailed(m_commandList->Close());

Creating a basic Direct3D 12 component

Direct3D 12 Reference

D3D12 Code Walk-Throughs

Working Samples