> ## Documentation Index
> Fetch the complete documentation index at: https://devdocs.xbox.com/llms.txt
> Use this file to discover all available pages before exploring further.

# DrawInstanced

> 绘制未建立索引的实例化图元。

绘制未建立索引的实例化图元。

## 语法

```cpp theme={null}
void DrawInstanced(
    UINT VertexCountPerInstance,
    UINT InstanceCount,
    UINT StartVertexLocation,
    UINT StartInstanceLocation
)
```

### 参数

*VertexCountPerInstance \[in]*\
类型：UINT

要绘制的顶点数。

*InstanceCount \[in]*\
类型：UINT

要绘制的实例数。

*StartVertexLocation \[in]*\
类型：UINT

第一个顶点的索引。

*StartInstanceLocation \[in]*\
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

类型：void

无。

## 备注

绘制 API 将工作提交到渲染管道。

实例化可能通过重用相同的几何图形来绘制场景中的多个对象来提高性能。实例化的一个示例是使用不同的位置和颜色绘制同一对象。

实例化绘制调用的顶点数据通常来自绑定到管道的顶点缓冲区。但是，您也可以从着色器提供顶点数据，该着色器使用系统值语义 (SV\_InstanceID) 标识实例化数据。

#### 示例

[D3D12HelloTriangle](https://learn.microsoft.com/en-us/windows/desktop/direct3d12/working-samples) 示例按以下方式使用 **ID3D12GraphicsCommandList::DrawInstanced**：

```cpp theme={null}
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;

```

```cpp theme={null}
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 [Direct3D 12 参考中的示例代码](https://learn.microsoft.com/en-us/windows/desktop/direct3d12/notes-on-example-code)。

<div class="code" />

## 要求

**头文件：** d3d12\_xs.h 或 d3d12\_x.h\
**库：** d3d12\_xs.lib 或 d3d12\_x.lib\
**支持的平台**：XBOX Series 主机和 XBOX One 系列

## 另请参阅

[ID3D12GraphicsCommandList](/reference/graphics/d3d12_xs/interfaces/ID3D12GraphicsCommandList/id3d12graphicscommandlist_xs)


## Related topics

- [D3D12_DRAW_ARGUMENTS](/zh-CN/reference/graphics/d3d12/structs/d3d12_draw_arguments_public.md)
- [DrawIndexedInstanced](/zh-CN/reference/graphics/d3d12/interfaces/id3d12graphicscommandlist/methods/id3d12graphicscommandlist_drawindexedinstanced_public.md)
- [D3D12_DRAW_INDEXED_ARGUMENTS](/zh-CN/reference/graphics/d3d12/structs/d3d12_draw_indexed_arguments_public.md)
- [XblTournamentGameResult](/zh-CN/reference/live/xsapi-c/multiplayer_c/enums/xbltournamentgameresult.md)
- [ID3D12MetaCommand](/zh-CN/reference/graphics/d3d12/interfaces/id3d12metacommand/id3d12metacommand_public.md)