pub fn spacing(surface: &Surface, density: Density) -> SpacingExpand description
egui’s spacing, from the relational scale.
The mapping is nearly one for one. item_spacing separates controls of a
kind, so Gap::Peer across and Gap::Bound down, because a stacked
row sits closer to its neighbour than a side-by-side one does.
button_padding is the distance from a button’s edge to its label, Peer
across and a hair down because a button is wider than it is tall.
window_margin is a panel’s inner margin, which is a group. indent
offsets a child from its parent, a hierarchy rather than a separation, so
it is the width that reads as one pane at this type size.
interact_size.y is the one number here that is not a relationship: it is
the target floor, and it is a minimum rather than a size. The width is
left at egui’s own, which is about DragValue and friends; forcing it on
every control would stretch a one-word button for nothing a reader gains.