Function plan_scaled 

pub fn plan_scaled(
    offers: &[ScrollOffer],
    roots: &[&dyn Widget],
    _: (f64, f64),
    _: (u32, u32),
) -> CopyPlan

plan for a window drawn at drawn_scale scene pixels per logical pixel into a host target of device_per_scene pixels per scene pixel (an app drawn into a desktop’s logical scene, shown at 200 %): the plan is in those device pixels, for a width × height target of them.