PFND3DDDI_SETPRIORITYCB callback function (d3dumddi.h)

Article
04/01/2021

The pfnSetPriorityCb function sets the priority level of a resource or list of allocations.

Syntax

PFND3DDDI_SETPRIORITYCB Pfnd3dddiSetprioritycb;

HRESULT Pfnd3dddiSetprioritycb(
  HANDLE hDevice,
  D3DDDICB_SETPRIORITY *unnamedParam2
)
{...}

Parameters

hDevice

A handle to the display device (graphics context).

unnamedParam2

pData [in]

A pointer to a D3DDDICB_SETPRIORITY structure that describes the priority level to set a resource or list of allocations to.

Return value

pfnSetPriorityCb returns one of the following values:

Return code	Description
S_OK	The priority level was successfully set.
E_INVALIDARG	Parameters were validated and determined to be incorrect.

This function might also return other HRESULT values.

Remarks

The user-mode display driver can call the pfnSetPriorityCb function to set the priority of the underlying resource or list of allocations. If the priority level of a resource is set, all of the allocations that belong to the resource are set to the specified priority level. Typically, the user-mode display driver sets the priority of a resource or list of allocations after the Microsoft Direct3D runtime calls the user-mode display driver's SetPriority or SetResourcePriorityDXGI function to set the eviction-from-memory priority for a resource. However, the user-mode display driver can set the priority of allocations at any time.

After an application requests to set the priority level of a surface, the user-mode display driver should set the appropriate resource or list of allocations to the priority level that is specified by the application.

Note Priority levels are only a hint to the video memory manager; they can be ignored by the memory manager under various conditions.

An allocation priority defines both the likelihood that the allocation remains resident and the likelihood of how hard the video memory manager will try to respect the driver's preference for the placement of the allocation. The following priority levels are defined in the D3dukmdt.h header file:

The driver can use priority levels other than the preceding defined values when appropriate. For example, marking an allocation with a priority level of 0x78000001 indicates that the allocation is slightly above normal.

Examples

The following code example shows how to set priority level.

HRESULT CD3DContext::SetPriority(CONST D3DDDIARG_SETPRIORITY* pSetPriority) {
    DWORD  dwSurfaceHandle = (DWORD)(DWORD_PTR)pSetPriority->hResource;
    CResource   &res = m_RTbl[dwSurfaceHandle];
    D3DDDICB_SETPRIORITY    setPri;
    UINT                    priority;

    priority = pSetPriority->Priority;

    memset(&setPri, 0, sizeof(setPri));

    setPri.hResource   = res.m_hResRuntime;
    setPri.pPriorities = &priority;

    return (m_d3dCallbacks.pfnSetPriorityCb(m_hD3D, &setPri));
}

Requirements

Requirement	Value
Minimum supported client	Available in Windows Vista and later versions of the Windows operating systems.
Target Platform	Desktop
Header	d3dumddi.h (include D3dumddi.h)

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