ID3D12GraphicsCommandList：:D rawInstanced 方法 (d3d12.h)

绘制未编制索引的实例化基元。

语法

void DrawInstanced(
  [in] UINT VertexCountPerInstance,
  [in] UINT InstanceCount,
  [in] UINT StartVertexLocation,
  [in] UINT StartInstanceLocation
);

参数

[in] VertexCountPerInstance

类型： UINT

要绘制的顶点数。

[in] InstanceCount

类型： UINT

要绘制的实例数。

[in] StartVertexLocation

类型： UINT

第一个顶点的索引。

[in] StartInstanceLocation

类型： UINT

从顶点缓冲区读取每个实例数据之前添加到每个索引的值。

返回值

无

备注

绘制 API 将工作提交到呈现管道。

实例化可以通过重用相同的几何图形在场景中绘制多个对象来扩展性能。 实例化的示例之一是绘制具有不同位置和颜色的同一对象。

实例化绘图调用的顶点数据通常来自绑定到管道的顶点缓冲区。 但是，还可以从着色器提供顶点数据，该着色器具有使用系统值语义 (SV_InstanceID) 标识的实例数据。

示例

D3D12HelloTriangle 示例使用 ID3D12GraphicsCommandList：:D rawInstanced，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());
}

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