Function cursor_tooltip_origin 

pub fn cursor_tooltip_origin(
    cursor: Vec2,
    popup: Vec2,
    viewport: Vec2,
    offset: f32,
) -> Vec2

Cursor-relative tooltip origin (Qt QToolTip placement): the popup sits below-right of the cursor hotspot, offset px away on each axis. When the preferred spot would overflow the viewport, each axis flips independently to the cursor’s other side (above / left), saturating at 0 so the popup never leaves the window.