PFND3DDDI_PRESENT callback function (d3dumddi.h)
The Present function notifies the user-mode display driver that an application finished rendering and requests that the driver display the source surface by either copying or flipping or that the driver perform a color-fill operation.
Syntax
PFND3DDDI_PRESENT Pfnd3dddiPresent;
HRESULT Pfnd3dddiPresent(
HANDLE hDevice,
const D3DDDIARG_PRESENT *unnamedParam2
)
{...}
Parameters
hDevice
A handle to the display device (graphics context).
unnamedParam2
pData [in]
A pointer to a D3DDDIARG_PRESENT structure that describes the resource to display.
Return value
Present returns one of the following values:
| Return code | Description |
|---|---|
| S_OK | The resource is successfully displayed. |
| E_OUTOFMEMORY | Present could not allocate the required memory for it to complete. |
Remarks
The Microsoft Direct3D runtime calls the user-mode display driver's Present function to notify the user-mode display driver that an application finished rendering and to request that the driver display out the source surface or that the driver perform a color-fill operation. If the hSrcResource member of the D3DDDIARG_PRESENT structure that the pData parameter points to is non-NULL, Present requests that the user-mode display driver display new content to the screen; if hSrcResource is NULL, Present requests that the user-mode display driver perform a color-fill operation to the screen.
If the hDstResource member of the D3DDDIARG_PRESENT structure is NULL, the destination surface is unknown. In addition, the destination surface and a list of clipping rectangles are determined in kernel mode before sending the hardware command stream through DMA to the graphics processor.
As a result, the user-mode display driver cannot generate hardware instructions to perform the present operation. These hardware instructions must be generated by the display miniport driver. However, when the hSrcResource member of D3DDDIARG_PRESENT is non-NULL, the user-mode display driver must derive the allocation handle to the source surface and insert this handle in the hSrcAllocation member of the D3DDDICB_PRESENT structure in a call to the pfnPresentCb function. The display miniport driver can then successfully generate the hardware instructions. The user-mode display driver typically derives the allocation handle from the resource information in the D3DDDIARG_PRESENT structure.
If the hDstResource member of D3DDDIARG_PRESENT is non-NULL, the destination surface for the present is known and the user-mode display driver must fill in the hDstAllocation member of D3DDDICB_PRESENT with the corresponding allocation handle.
If a user-mode display driver exposes a DDI version of less than 0x0000000C (the driver returns this value in the DriverVersion member of the D3D10DDIARG_OPENADAPTER structure in a call to the driver's OpenAdapter function), the Direct3D runtime first calls the user-mode display driver's Flush function to submit any outstanding hardware commands in the command buffer before the runtime calls the user-mode display driver's Present function. In this way, the user-mode display driver's Present function is serialized with render operations (that is, calls to the pfnRenderCb function). If a user-mode display driver exposes a DDI version of 0x0000000C or greater and the calling application runs in windowed mode, the runtime also calls Flush before it calls Present. If a user-mode display driver exposes a DDI version of 0x0000000C or greater and the calling application runs in full-screen mode, the runtime will not call Flush before it calls Present. This behavior allows drivers that implement their own threading to queue present calls. A driver that exposes a DDI version of 0x0000000C or greater must call pfnRenderCb to internally flush any outstanding command buffers before the driver calls the pfnPresentCb function.
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) |