bevy/examples/transforms/3d_rotation.rs
andristarr 7482a0d26d
aligning public apis of Time,Timer and Stopwatch (#15962)
Fixes #15834

## Migration Guide

The APIs of `Time`, `Timer` and `Stopwatch` have been cleaned up for
consistency with each other and the standard library's `Duration` type.
The following methods have been renamed:

- `Stowatch::paused` -> `Stopwatch::is_paused`
- `Time::elapsed_seconds` -> `Time::elasped_secs` (including `_f64` and
`_wrapped` variants)
2024-10-16 21:09:32 +00:00

55 lines
1.7 KiB
Rust

//! Illustrates how to rotate an object around an axis.
use bevy::prelude::*;
use std::f32::consts::TAU;
// Define a component to designate a rotation speed to an entity.
#[derive(Component)]
struct Rotatable {
speed: f32,
}
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_systems(Startup, setup)
.add_systems(Update, rotate_cube)
.run();
}
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
// Spawn a cube to rotate.
commands.spawn((
Mesh3d(meshes.add(Cuboid::default())),
MeshMaterial3d(materials.add(Color::WHITE)),
Transform::from_translation(Vec3::ZERO),
Rotatable { speed: 0.3 },
));
// Spawn a camera looking at the entities to show what's happening in this example.
commands.spawn((
Camera3d::default(),
Transform::from_xyz(0.0, 10.0, 20.0).looking_at(Vec3::ZERO, Vec3::Y),
));
// Add a light source so we can see clearly.
commands.spawn((
DirectionalLight::default(),
Transform::from_xyz(3.0, 3.0, 3.0).looking_at(Vec3::ZERO, Vec3::Y),
));
}
// This system will rotate any entity in the scene with a Rotatable component around its y-axis.
fn rotate_cube(mut cubes: Query<(&mut Transform, &Rotatable)>, timer: Res<Time>) {
for (mut transform, cube) in &mut cubes {
// The speed is first multiplied by TAU which is a full rotation (360deg) in radians,
// and then multiplied by delta_secs which is the time that passed last frame.
// In other words. Speed is equal to the amount of rotations per second.
transform.rotate_y(cube.speed * TAU * timer.delta_secs());
}
}