IDirect3DRMViewport::ForceUpdate
HRESULT ForceUpdate(DWORD dwX1, DWORD dwY1, DWORD dwX2,
DWORD dwY2);
Forces an area of the viewport to be updated. The specified area will be copied to the screen at the next call to the IDirect3DRMDevice::Update method.
·Returns D3DRM_OK if successful, or an error otherwise. For a list of possible return codes, see Direct3D Retained-Mode Return Values.
dwX1 and dwY1
Upper-left corner of area to be updated.
dwX2 and dwY2
Lower-right corner of area to be updated.
The system might update any region that is larger than the specified rectangle, including possibly the entire window.