HRESULT GetPlane(D3DVALUE *lpd3dvLeft, D3DVALUE *lpd3dvRight,
D3DVALUE *lpd3dvBottom, D3DVALUE *lpd3dvTop);
Retrieves the dimensions of the viewport on the front clipping plane.
·Returns D3DRM_OK if successful, or an error otherwise. For a list of possible return codes, see Direct3D Retained-Mode Return Values.
lpd3dvLeft, lpd3dvRight, lpd3dvBottom, and lpd3dvTop
Addresses of variables that will be filled to represent the dimensions of the viewport on the front clipping plane.