|Microsoft DirectX 9.0|
If the method succeeds, the return value is D3D_OK.
If the method fails, the return value can be one of the following values.
D3DERR_INVALIDCALL The method call is invalid. For example, a method's parameter may have an invalid value. D3DXERR_INVALIDDATA The data is invalid.
Calling Begin is optional. If called outside of a Begin/ID3DXLine::End sequence, the draw functions will internally call Begin and End. To avoid extra overhead, this method should be used if more than one draw function will be called successively.
Begin cannot be used as a substitute for either IDirect3DDevice9::BeginScene or ID3DXRenderToSurface::BeginScene.