D3DDDI_ESCAPEFLAGS structure (d3dukmdt.h)
The D3DDDI_ESCAPEFLAGS structure identifies how the user-mode display driver (UMD) (or client driver) shares information with the kernel-mode display miniport driver (KMD).
Syntax
typedef struct _D3DDDI_ESCAPEFLAGS {
union {
struct {
UINT HardwareAccess : 1;
UINT DeviceStatusQuery : 1;
UINT ChangeFrameLatency : 1;
UINT NoAdapterSynchronization : 1;
#if ...
UINT Reserved : 1;
UINT VirtualMachineData : 1;
UINT DriverKnownEscape : 1;
UINT DriverCommonEscape : 1;
#if ...
UINT Reserved2 : 24;
#else
UINT Reserved2 : 26;
#endif
#elif
UINT Reserved : 28;
#elif
UINT Reserved : 29;
#else
UINT Reserved : 31;
#endif
};
UINT Value;
};
} D3DDDI_ESCAPEFLAGS;
Members
HardwareAccess
A UINT value that specifies whether the OS performs the second level of synchronization into the KMD for the DxgkDdiEscape call. If the driver requires the second level of synchronization and the HardwareAccess flag isn't set, the call to the driver's DxgkDdiEscape function should fail.
Starting in Windows 8.1, if this member is set, DeviceStatusQuery and ChangeFrameLatency must be set to zero.
DeviceStatusQuery
If set, when the pfnEscapeCb function is called and the D3DDDICB_ESCAPE.PrivateDriverDataSize member is sizeof(D3DDDI_EXECUTIONSTATEESCAPE), the Direct3D runtime interprets the D3DDDICB_ESCAPE.pPrivateDriverData member as a pointer to a buffer that contains a D3DDDI_EXECUTIONSTATEESCAPE structure. In addition, the runtime processes the pfnEscapeCb as a status query by writing the requested info into the provided buffer instead of sending a DxgkDdiEscape call to the KMD.
If this member is set, HardwareAccess and ChangeFrameLatency must be set to zero.
Supported starting with Windows 8.1.
The operating system ignores this member if it is prior to Windows 8.1, or if the user-mode driver was initialized with an OpenAdapterXxx call where the pOpenData->Interface member indicates Direct3D version 8 or earlier.
ChangeFrameLatency
If set, when the pfnEscapeCb function is called, the D3DDDICB_ESCAPE.PrivateDriverDataSize member is sizeof(D3DDDI_FRAMELATENCYESCAPE) and conditions in Remarks are also met, the Direct3D runtime interprets the D3DDDICB_ESCAPE.pPrivateDriverData member as a pointer to a buffer that contains a D3DDDI_FRAMELATENCYESCAPE structure. In addition, the runtime processes the pfnEscapeCb as a request to change the DirectX graphics kernel subsystem's maximum frame latency by writing the requested info into the provided buffer instead of sending a DxgkDdiEscape call to the KMD.
If this member is set, HardwareAccess and DeviceStatusQuery must be set to zero.
Supported starting with Windows 8.1.
The operating system ignores this member if it is prior to Windows 8.1, or if the user-mode driver was initialized with an OpenAdapterXxx call where the pOpenData->Interface member indicates Direct3D version 8 or earlier.
NoAdapterSynchronization
Reserved
This member is reserved and should be set to zero.
VirtualMachineData
Indicates that DxgkDdiEscape is called from a virtual machine. This flag can't be set from user mode. Supported starting with WDDM 2.2.
DriverKnownEscape
The driver private data points to a well known structure.
DriverCommonEscape
The private data points to a D3D runtime-defined structure.
Reserved2
This member is reserved and should be set to zero.
Value
A member in the union that is contained in D3DDDI_ESCAPEFLAGS that can hold one 32-bit value that identifies how to share information.
Remarks
If ChangeFrameLatency is set, a pfnEscapeCb call will succeed only if:
- The KMD is responsible for a linked adapter configuration (LDA) provided by a single vendor.
- The app has taken exclusive full-screen ownership of the display at some point in its lifetime.
- The app has not overridden the default maximum frame latency value of 3.
If these conditions are not met, pfnEscapeCb call returns an E_INVALIDARG error code.
Requirements
| Requirement | Value |
|---|---|
| Minimum supported client | Windows Vista (WDDM 1.0) |
| Header | d3dukmdt.h (include D3dumddi.h, D3dkmddi.h) |