ID3D12GraphicsCommandList::Dispatch method (d3d12.h)
Executes a command list from a thread group.
Syntax
void Dispatch(
[in] UINT ThreadGroupCountX,
[in] UINT ThreadGroupCountY,
[in] UINT ThreadGroupCountZ
);
Parameters
[in] ThreadGroupCountX
Type: UINT
The number of groups dispatched in the x direction. ThreadGroupCountX must be less than or equal to D3D11_CS_DISPATCH_MAX_THREAD_GROUPS_PER_DIMENSION (65535).
[in] ThreadGroupCountY
Type: UINT
The number of groups dispatched in the y direction. ThreadGroupCountY must be less than or equal to D3D11_CS_DISPATCH_MAX_THREAD_GROUPS_PER_DIMENSION (65535).
[in] ThreadGroupCountZ
Type: UINT
The number of groups dispatched in the z direction. ThreadGroupCountZ must be less than or equal to D3D11_CS_DISPATCH_MAX_THREAD_GROUPS_PER_DIMENSION (65535). In feature level 10 the value for ThreadGroupCountZ must be 1.
Return value
None
Remarks
You call the Dispatch method to execute commands in a compute shader. A compute shader can be run on many threads in parallel, within a thread group. Index a particular thread, within a thread group using a 3D vector given by (x,y,z).
Examples
The D3D12nBodyGravity sample uses ID3D12GraphicsCommandList::Dispatch as follows:
// Run the particle simulation using the compute shader.
void D3D12nBodyGravity::Simulate(UINT threadIndex)
{
ID3D12GraphicsCommandList* pCommandList = m_computeCommandList[threadIndex].Get();
UINT srvIndex;
UINT uavIndex;
ID3D12Resource *pUavResource;
if (m_srvIndex[threadIndex] == 0)
{
srvIndex = SrvParticlePosVelo0;
uavIndex = UavParticlePosVelo1;
pUavResource = m_particleBuffer1[threadIndex].Get();
}
else
{
srvIndex = SrvParticlePosVelo1;
uavIndex = UavParticlePosVelo0;
pUavResource = m_particleBuffer0[threadIndex].Get();
}
pCommandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(pUavResource, D3D12_RESOURCE_STATE_NON_PIXEL_SHADER_RESOURCE, D3D12_RESOURCE_STATE_UNORDERED_ACCESS));
pCommandList->SetPipelineState(m_computeState.Get());
pCommandList->SetComputeRootSignature(m_computeRootSignature.Get());
ID3D12DescriptorHeap* ppHeaps[] = { m_srvUavHeap.Get() };
pCommandList->SetDescriptorHeaps(_countof(ppHeaps), ppHeaps);
CD3DX12_GPU_DESCRIPTOR_HANDLE srvHandle(m_srvUavHeap->GetGPUDescriptorHandleForHeapStart(), srvIndex + threadIndex, m_srvUavDescriptorSize);
CD3DX12_GPU_DESCRIPTOR_HANDLE uavHandle(m_srvUavHeap->GetGPUDescriptorHandleForHeapStart(), uavIndex + threadIndex, m_srvUavDescriptorSize);
pCommandList->SetComputeRootConstantBufferView(RootParameterCB, m_constantBufferCS->GetGPUVirtualAddress());
pCommandList->SetComputeRootDescriptorTable(RootParameterSRV, srvHandle);
pCommandList->SetComputeRootDescriptorTable(RootParameterUAV, uavHandle);
pCommandList->Dispatch(static_cast<int>(ceil(ParticleCount / 128.0f)), 1, 1);
pCommandList->ResourceBarrier(1, &CD3DX12_RESOURCE_BARRIER::Transition(pUavResource, D3D12_RESOURCE_STATE_UNORDERED_ACCESS, D3D12_RESOURCE_STATE_NON_PIXEL_SHADER_RESOURCE));
}
See Example Code in the D3D12 Reference.
Requirements
Requirement | Value |
---|---|
Target Platform | Windows |
Header | d3d12.h |
Library | D3d12.lib |
DLL | D3d12.dll |