Support Warning
WebGPU is currently only supported on Chrome starting with version 113, and only on desktop. If they don't work on your configuration, you can check the WebGL2 examples here.text.rs:
//! This example illustrates how to create UI text and update it in a system.
//!
//! It displays the current FPS in the top left corner, as well as text that changes color
//! in the bottom right. For text within a scene, please see the text2d example.
use bevy::{
color::palettes::css::GOLD,
diagnostic::{DiagnosticsStore, FrameTimeDiagnosticsPlugin},
prelude::*,
};
fn main() {
App::new()
.add_plugins((DefaultPlugins, FrameTimeDiagnosticsPlugin))
.add_systems(Startup, setup)
.add_systems(Update, (text_update_system, text_color_system))
.run();
}
// A unit struct to help identify the FPS UI component, since there may be many Text components
#[derive(Component)]
struct FpsText;
// A unit struct to help identify the color-changing Text component
#[derive(Component)]
struct ColorText;
fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
// UI camera
commands.spawn(Camera2dBundle::default());
// Text with one section
commands.spawn((
// Create a TextBundle that has a Text with a single section.
TextBundle::from_section(
// Accepts a `String` or any type that converts into a `String`, such as `&str`
"hello\nbevy!",
TextStyle {
// This font is loaded and will be used instead of the default font.
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
font_size: 100.0,
..default()
},
) // Set the justification of the Text
.with_text_justify(JustifyText::Center)
// Set the style of the TextBundle itself.
.with_style(Style {
position_type: PositionType::Absolute,
bottom: Val::Px(5.0),
right: Val::Px(5.0),
..default()
}),
ColorText,
));
// Text with multiple sections
commands.spawn((
// Create a TextBundle that has a Text with a list of sections.
TextBundle::from_sections([
TextSection::new(
"FPS: ",
TextStyle {
// This font is loaded and will be used instead of the default font.
font: asset_server.load("fonts/FiraSans-Bold.ttf"),
font_size: 60.0,
..default()
},
),
TextSection::from_style(if cfg!(feature = "default_font") {
TextStyle {
font_size: 60.0,
color: GOLD.into(),
// If no font is specified, the default font (a minimal subset of FiraMono) will be used.
..default()
}
} else {
// "default_font" feature is unavailable, load a font to use instead.
TextStyle {
font: asset_server.load("fonts/FiraMono-Medium.ttf"),
font_size: 60.0,
color: GOLD.into(),
}
}),
]),
FpsText,
));
#[cfg(feature = "default_font")]
commands.spawn(
// Here we are able to call the `From` method instead of creating a new `TextSection`.
// This will use the default font (a minimal subset of FiraMono) and apply the default styling.
TextBundle::from("From an &str into a TextBundle with the default font!").with_style(
Style {
position_type: PositionType::Absolute,
bottom: Val::Px(5.0),
left: Val::Px(15.0),
..default()
},
),
);
#[cfg(not(feature = "default_font"))]
commands.spawn(
TextBundle::from_section(
"Default font disabled",
TextStyle {
font: asset_server.load("fonts/FiraMono-Medium.ttf"),
..default()
},
)
.with_style(Style {
position_type: PositionType::Absolute,
bottom: Val::Px(5.0),
left: Val::Px(15.0),
..default()
}),
);
}
fn text_color_system(time: Res<Time>, mut query: Query<&mut Text, With<ColorText>>) {
for mut text in &mut query {
let seconds = time.elapsed_seconds();
// Update the color of the first and only section.
text.sections[0].style.color = Color::srgb(
(1.25 * seconds).sin() / 2.0 + 0.5,
(0.75 * seconds).sin() / 2.0 + 0.5,
(0.50 * seconds).sin() / 2.0 + 0.5,
);
}
}
fn text_update_system(
diagnostics: Res<DiagnosticsStore>,
mut query: Query<&mut Text, With<FpsText>>,
) {
for mut text in &mut query {
if let Some(fps) = diagnostics.get(&FrameTimeDiagnosticsPlugin::FPS) {
if let Some(value) = fps.smoothed() {
// Update the value of the second section
text.sections[1].value = format!("{value:.2}");
}
}
}
}