bevy/examples/ecs/fixed_timestep.rs
bjorn3 6d6bc2a8b4 Merge AppBuilder into App (#2531)
This is extracted out of eb8f973646476b4a4926ba644a77e2b3a5772159 and includes some additional changes to remove all references to AppBuilder and fix examples that still used App::build() instead of App::new(). In addition I didn't extract the sub app feature as it isn't ready yet.

You can use `git diff --diff-filter=M eb8f973646476b4a4926ba644a77e2b3a5772159` to find all differences in this PR. The `--diff-filtered=M` filters all files added in the original commit but not in this commit away.

Co-Authored-By: Carter Anderson <mcanders1@gmail.com>
2021-07-27 20:21:06 +00:00

51 lines
1.5 KiB
Rust

use bevy::{
core::{FixedTimestep, FixedTimesteps},
prelude::*,
};
const LABEL: &str = "my_fixed_timestep";
#[derive(Debug, Hash, PartialEq, Eq, Clone, StageLabel)]
struct FixedUpdateStage;
fn main() {
App::new()
.add_plugins(DefaultPlugins)
// this system will run once every update (it should match your screen's refresh rate)
.add_system(frame_update.system())
// add a new stage that runs twice a second
.add_stage_after(
CoreStage::Update,
FixedUpdateStage,
SystemStage::parallel()
.with_run_criteria(
FixedTimestep::step(0.5)
// labels are optional. they provide a way to access the current
// FixedTimestep state from within a system
.with_label(LABEL),
)
.with_system(fixed_update.system()),
)
.run();
}
fn frame_update(mut last_time: Local<f64>, time: Res<Time>) {
info!("update: {}", time.seconds_since_startup() - *last_time);
*last_time = time.seconds_since_startup();
}
fn fixed_update(mut last_time: Local<f64>, time: Res<Time>, fixed_timesteps: Res<FixedTimesteps>) {
info!(
"fixed_update: {}",
time.seconds_since_startup() - *last_time,
);
let fixed_timestep = fixed_timesteps.get(LABEL).unwrap();
info!(
" overstep_percentage: {}",
fixed_timestep.overstep_percentage()
);
*last_time = time.seconds_since_startup();
}