pub(crate) fn frame_rate_readout(ui: &mut Ui, text: &str)Expand description
Draw the frame-rate readout, showing text, centred along the top edge of
ui’s screen.
The label is set to [egui::Label::extend], so the readout grows to fit its
text instead of wrapping it. An anchored area lays its contents out against
the size it remembered from the previous pass, so a reading that is wider
than the last one — the first real reading after the empty placeholder, or
any reading after the rate changes — would otherwise be broken across lines
in a narrow window.
A free function rather than the body of the panel’s closure so a test can
drive it against a bare [egui::Context]: what it has to get right — one
line, whatever the previous reading was — is a property of the widget tree,
not of the world.