ID3D12GraphicsCommandList：:D rawIndexedInstanced 方法 (d3d12.h)

绘制索引的实例化基元。

语法

void DrawIndexedInstanced(
  [in] UINT IndexCountPerInstance,
  [in] UINT InstanceCount,
  [in] UINT StartIndexLocation,
  [in] INT  BaseVertexLocation,
  [in] UINT StartInstanceLocation
);

参数

[in] IndexCountPerInstance

类型： UINT

从每个实例的索引缓冲区读取的索引数。

[in] InstanceCount

类型： UINT

要绘制的实例数。

[in] StartIndexLocation

类型： UINT

GPU 从索引缓冲区读取的第一个索引的位置。

[in] BaseVertexLocation

类型： INT

从顶点缓冲区读取顶点之前添加到每个索引的值。

[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

绘图 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。 实例化需要多个顶点缓冲区：每个顶点数据至少有一个，每个实例数据至少有一个缓冲区。

示例

D3D12Bundles 示例使用 ID3D12GraphicsCommandList：:D rawIndexedInstanced，如下所示：

void FrameResource::PopulateCommandList(ID3D12GraphicsCommandList* pCommandList, ID3D12PipelineState* pPso1, ID3D12PipelineState* pPso2,
    UINT frameResourceIndex, UINT numIndices, D3D12_INDEX_BUFFER_VIEW* pIndexBufferViewDesc, D3D12_VERTEX_BUFFER_VIEW* pVertexBufferViewDesc,
    ID3D12DescriptorHeap* pCbvSrvDescriptorHeap, UINT cbvSrvDescriptorSize, ID3D12DescriptorHeap* pSamplerDescriptorHeap, ID3D12RootSignature* pRootSignature)
{
    // If the root signature matches the root signature of the caller, then
    // bindings are inherited, otherwise the bind space is reset.
    pCommandList->SetGraphicsRootSignature(pRootSignature);

    ID3D12DescriptorHeap* ppHeaps[] = { pCbvSrvDescriptorHeap, pSamplerDescriptorHeap };
    pCommandList->SetDescriptorHeaps(_countof(ppHeaps), ppHeaps);
    pCommandList->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST);

    pCommandList->IASetIndexBuffer(pIndexBufferViewDesc);

    pCommandList->IASetVertexBuffers(0, 1, pVertexBufferViewDesc);

    pCommandList->SetGraphicsRootDescriptorTable(0, pCbvSrvDescriptorHeap->GetGPUDescriptorHandleForHeapStart());
    pCommandList->SetGraphicsRootDescriptorTable(1, pSamplerDescriptorHeap->GetGPUDescriptorHandleForHeapStart());

    // Calculate the descriptor offset due to multiple frame resources.
    // 1 SRV + how many CBVs we have currently.
    UINT frameResourceDescriptorOffset = 1 + (frameResourceIndex * m_cityRowCount * m_cityColumnCount);
    CD3DX12_GPU_DESCRIPTOR_HANDLE cbvSrvHandle(pCbvSrvDescriptorHeap->GetGPUDescriptorHandleForHeapStart(), frameResourceDescriptorOffset, cbvSrvDescriptorSize);

    BOOL usePso1 = TRUE;
    for (UINT i = 0; i < m_cityRowCount; i++)
    {
        for (UINT j = 0; j < m_cityColumnCount; j++)
        {
            // Alternate which PSO to use; the pixel shader is different on 
            // each just as a PSO setting demonstration.
            pCommandList->SetPipelineState(usePso1 ? pPso1 : pPso2);
            usePso1 = !usePso1;

            // Set this city's CBV table and move to the next descriptor.
            pCommandList->SetGraphicsRootDescriptorTable(2, cbvSrvHandle);
            cbvSrvHandle.Offset(cbvSrvDescriptorSize);

            pCommandList->DrawIndexedInstanced(numIndices, 1, 0, 0, 0);
        }
    }
}

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