fn round_layout(
    nodes: &mut [NodeData],
    children: &[sys::ChildrenVec<NodeId>],
    root: NodeId,
    abs_x: f32,
    abs_y: f32,
) {
    let layout = &mut nodes[root].layout;
    let abs_x = abs_x + layout.location.x;
    let abs_y = abs_y + layout.location.y;

    layout.location.x = sys::round(layout.location.x);
    layout.location.y = sys::round(layout.location.y);

    layout.size.width = sys::round(abs_x + layout.size.width) - sys::round(abs_x);
    layout.size.height = sys::round(abs_y + layout.size.height) - sys::round(abs_y);

    for child in &children[root] {
        Self::round_layout(nodes, children, *child, abs_x, abs_y);
    }
}