Now this. I wonder how to transfer the fuel?
I guess the vessels are docked?
When looking into docking port and fuel management, I would propose like this:
You can get a dockhandle to the docked vessel with
DOCKHANDLE VESSEL::GetDockHandle ( UINT n ) const; Returns a handle to a docking port.
Then retrieve a handle to the docked vessel
OBJHANDLE VESSEL::GetDockStatus ( DOCKHANDLE hDock ) const; Returns a handle to a docked vessel.
Then get a handle to the vessel interface:
OAPIFUNC VESSEL∗oapiGetVesselInterface ( OBJHANDLE hVessel ); Returns a VESSEL class instance for a vessel.
Then you can get the current propellant mass of the vessel,
::GetPropellantMass (PROPELLANT_HANDLE ph)
add to this value what you are willing to transfer and set the new propellant mass of the vessel
::SetPropellantMass (PROPELLANT_HANDLE ph, double mass)
Finally reduce your own propellant mass by the transferred amount.