ID3D11DeviceContext::Dispatch Method

Execute a command list from a thread group.

Syntax

public:
void Dispatch(
         UINT ThreadGroupCountX,
         UINT ThreadGroupCountY,
         UINT ThreadGroupCountZ
)

Parameters

ThreadGroupCountX
Type: UINT

[in] 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).

ThreadGroupCountY
Type: UINT

[in] 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).

ThreadGroupCountZ
Type: UINT

[in] 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).

In the following illustration, assume a thread group with 50 threads where the size of the group is given by (5,5,2). A single thread is identified from a thread group with 50 threads in it, using the vector (4,1,1).

Figure 1. Illustration of a single thread within a thread group of 50 threads

The following illustration shows the relationship between the parameters passed to ID3D11DeviceContext::Dispatch, Dispatch(5,3,2), the values specified in the numthreads attribute, numthreads(10,8,3), and values that will passed to the compute shader for the thread-related system values (SV_GroupIndex, SV_DispatchThreadID, SV_GroupThreadID, SV_GroupID).

Figure 2. Illustration of the relationship between Dispatch, thread groups, and threads

Requirements

Header: Declared in d3d11_x.h (d3d11.h on other Windows platforms).