644bd5dbc6
# Objective Reduce the catch-all grab-bag of functionality in bevy_core by minimally splitting off time functionality into bevy_time. Functionality like that provided by #3002 would increase the complexity of bevy_time, so this is a good candidate for pulling into its own unit. A step in addressing #2931 and splitting bevy_core into more specific locations. ## Solution Pull the time module of bevy_core into a new crate, bevy_time. # Migration guide - Time related types (e.g. `Time`, `Timer`, `Stopwatch`, `FixedTimestep`, etc.) should be imported from `bevy::time::*` rather than `bevy::core::*`. - If you were adding `CorePlugin` manually, you'll also want to add `TimePlugin` from `bevy::time`. - The `bevy::core::CorePlugin::Time` system label is replaced with `bevy::time::TimeSystem`. Co-authored-by: Carter Anderson <mcanders1@gmail.com>
53 lines
1.6 KiB
Rust
53 lines
1.6 KiB
Rust
//! Shows how to create systems that run every fixed timestep, rather than every tick.
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use bevy::{
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prelude::*,
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time::{FixedTimestep, FixedTimesteps},
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};
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const LABEL: &str = "my_fixed_timestep";
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#[derive(Debug, Hash, PartialEq, Eq, Clone, StageLabel)]
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struct FixedUpdateStage;
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fn main() {
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App::new()
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.add_plugins(DefaultPlugins)
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// this system will run once every update (it should match your screen's refresh rate)
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.add_system(frame_update)
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// add a new stage that runs twice a second
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.add_stage_after(
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CoreStage::Update,
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FixedUpdateStage,
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SystemStage::parallel()
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.with_run_criteria(
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FixedTimestep::step(0.5)
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// labels are optional. they provide a way to access the current
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// FixedTimestep state from within a system
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.with_label(LABEL),
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)
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.with_system(fixed_update),
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)
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.run();
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}
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fn frame_update(mut last_time: Local<f64>, time: Res<Time>) {
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info!("update: {}", time.seconds_since_startup() - *last_time);
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*last_time = time.seconds_since_startup();
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}
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fn fixed_update(mut last_time: Local<f64>, time: Res<Time>, fixed_timesteps: Res<FixedTimesteps>) {
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info!(
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"fixed_update: {}",
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time.seconds_since_startup() - *last_time,
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);
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let fixed_timestep = fixed_timesteps.get(LABEL).unwrap();
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info!(
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" overstep_percentage: {}",
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fixed_timestep.overstep_percentage()
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);
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*last_time = time.seconds_since_startup();
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}
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