pub fn set_density(d: f32)Expand description
Set the process-wide pixel density used by Length::dp (the
WidgetScaling::Physical mode). The runtime sets it to the main
surface’s buffer scale right before crate::App::on_scale_changed,
so dp( n ) is n logical px by default; an app that wants a
DPI-derived density overrides it from that callback. Default: 1.0.