PFND3D11DDI_COPYSTRUCTURECOUNT callback function (d3d10umddi.h)

Article
04/01/2021

The CopyStructureCount function copies the number of items in the filled portion (that is, the filled-size value) of an append buffer unordered access view (UAV) to an offset into a destination buffer.

Syntax

PFND3D11DDI_COPYSTRUCTURECOUNT Pfnd3d11ddiCopystructurecount;

void Pfnd3d11ddiCopystructurecount(
  D3D10DDI_HDEVICE unnamedParam1,
  D3D10DDI_HRESOURCE unnamedParam2,
  UINT unnamedParam3,
  D3D11DDI_HUNORDEREDACCESSVIEW unnamedParam4
)
{...}

Parameters

unnamedParam1

hDevice [in]

A handle to the display device (graphics context).

unnamedParam2

hDstBuffer [in]

A handle to a destination buffer to copy the filled-size value of an UAV to. To create this destination buffer, the runtime must have previously called the driver's CreateResource(D3D11) function with the ResourceDimension member of the D3D11DDIARG_CREATERESOURCE structure set to the D3D10DDIRESOURCE_BUFFER value.

unnamedParam3

DstAlignedByteOffset [in]

The 4-byte aligned offset, in bytes, into the destination buffer that the hDstBuffer parameter specifies. CopyStructureCount copies the filled-size value of the append buffer view that the hSrcView parameter specifies to this offset in hDstBuffer. DstAlignedByteOffset must be a multiple of four.

unnamedParam4

hSrcView [in]

A handle to the source append UAV, which must be an append buffer view. CopyStructureCount copies the filled-size value of this view to the destination buffer that the hDstBuffer parameter specifies. To create this append buffer view, the runtime must have previously called the driver's CreateUnorderedAccessView function with the D3D11_DDI_BUFFER_UAV_FLAG_APPEND flag set.

Return value

None

Remarks

The driver can use the pfnSetErrorCb callback function to set an error code.

The driver should not encounter any error, except for D3DDDIERR_DEVICEREMOVED. Therefore, if the driver passes any error, except for D3DDDIERR_DEVICEREMOVED, in a call to the pfnSetErrorCb function, the Direct3D runtime determines that the error is critical. Even if the device is removed, the driver is not required to return D3DDDIERR_DEVICEREMOVED; however, if the device removal interferes with the operation of CopyStructureCount (which typically should not happen), the driver can return D3DDDIERR_DEVICEREMOVED.

CopyStructureCount takes the filled-size value of the append buffer UAV (a UAV that supports push and pop-up operations on structures like on a stack) and copies this value to an offset into the destination buffer. The graphics hardware uses a 4-byte filled-size value to keep track of how much data is filled in the append buffer UAV.

Requirements

Requirement	Value
Minimum supported client	CopyStructureCount is supported beginning with the Windows 7 operating system.
Target Platform	Desktop
Header	d3d10umddi.h (include D3d10umddi.h)