7989cb2650
# Objective - Make `Time` API more consistent. - Support time accel/decel/pause. ## Solution This is just the `Time` half of #3002. I was told that part isn't controversial. - Give the "delta time" and "total elapsed time" methods `f32`, `f64`, and `Duration` variants with consistent naming. - Implement accelerating / decelerating the passage of time. - Implement stopping time. --- ## Changelog - Changed `time_since_startup` to `elapsed` because `time.time_*` is just silly. - Added `relative_speed` and `set_relative_speed` methods. - Added `is_paused`, `pause`, `unpause` , and methods. (I'd prefer `resume`, but `unpause` matches `Timer` API.) - Added `raw_*` variants of the "delta time" and "total elapsed time" methods. - Added `first_update` method because there's a non-zero duration between startup and the first update. ## Migration Guide - `time.time_since_startup()` -> `time.elapsed()` - `time.seconds_since_startup()` -> `time.elapsed_seconds_f64()` - `time.seconds_since_startup_wrapped_f32()` -> `time.elapsed_seconds_wrapped()` If you aren't sure which to use, most systems should continue to use "scaled" time (e.g. `time.delta_seconds()`). The realtime "unscaled" time measurements (e.g. `time.raw_delta_seconds()`) are mostly for debugging and profiling.
103 lines
3.4 KiB
Rust
103 lines
3.4 KiB
Rust
//! This example illustrates how to create UI text and update it in a system.
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//!
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//! It displays the current FPS in the top left corner, as well as text that changes color
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//! in the bottom right. For text within a scene, please see the text2d example.
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use bevy::{
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diagnostic::{Diagnostics, FrameTimeDiagnosticsPlugin},
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prelude::*,
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};
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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.add_plugin(FrameTimeDiagnosticsPlugin::default())
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.add_startup_system(setup)
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.add_system(text_update_system)
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.add_system(text_color_system)
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.run();
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}
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// A unit struct to help identify the FPS UI component, since there may be many Text components
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#[derive(Component)]
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struct FpsText;
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// A unit struct to help identify the color-changing Text component
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#[derive(Component)]
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struct ColorText;
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fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
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// UI camera
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commands.spawn(Camera2dBundle::default());
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// Text with one section
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commands.spawn((
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// Create a TextBundle that has a Text with a single section.
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TextBundle::from_section(
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// Accepts a `String` or any type that converts into a `String`, such as `&str`
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"hello\nbevy!",
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TextStyle {
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font: asset_server.load("fonts/FiraSans-Bold.ttf"),
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font_size: 100.0,
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color: Color::WHITE,
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},
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) // Set the alignment of the Text
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.with_text_alignment(TextAlignment::TOP_CENTER)
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// Set the style of the TextBundle itself.
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.with_style(Style {
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position_type: PositionType::Absolute,
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position: UiRect {
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bottom: Val::Px(5.0),
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right: Val::Px(15.0),
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..default()
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},
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..default()
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}),
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ColorText,
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));
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// Text with multiple sections
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commands.spawn((
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// Create a TextBundle that has a Text with a list of sections.
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TextBundle::from_sections([
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TextSection::new(
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"FPS: ",
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TextStyle {
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font: asset_server.load("fonts/FiraSans-Bold.ttf"),
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font_size: 60.0,
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color: Color::WHITE,
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},
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),
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TextSection::from_style(TextStyle {
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font: asset_server.load("fonts/FiraMono-Medium.ttf"),
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font_size: 60.0,
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color: Color::GOLD,
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}),
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]),
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FpsText,
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));
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}
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fn text_color_system(time: Res<Time>, mut query: Query<&mut Text, With<ColorText>>) {
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for mut text in &mut query {
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let seconds = time.elapsed_seconds();
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// Update the color of the first and only section.
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text.sections[0].style.color = Color::Rgba {
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red: (1.25 * seconds).sin() / 2.0 + 0.5,
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green: (0.75 * seconds).sin() / 2.0 + 0.5,
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blue: (0.50 * seconds).sin() / 2.0 + 0.5,
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alpha: 1.0,
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};
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}
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}
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fn text_update_system(diagnostics: Res<Diagnostics>, mut query: Query<&mut Text, With<FpsText>>) {
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for mut text in &mut query {
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if let Some(fps) = diagnostics.get(FrameTimeDiagnosticsPlugin::FPS) {
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if let Some(average) = fps.average() {
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// Update the value of the second section
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text.sections[1].value = format!("{average:.2}");
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}
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}
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}
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}
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