Generates a copy of the swapchain's front buffer and places that copy in a system memory buffer provided by the application.
HRESULT GetFrontBufferData( IDirect3DSurface9 * pDestSurface );
If the method succeeds, the return value is D3D_OK. If BackBuffer exceeds or equals the total number of back buffers, the function fails and returns D3DERR_INVALIDCALL.
Calling this method will increase the internal reference count on the IDirect3DSurface9 interface. Failure to call IUnknown::Release when finished using this IDirect3DSurface9 interface results in a memory leak.
Header: Declared in D3d9.h.