bevy/examples/transforms/translation.rs
ira 4847f7e3ad Update codebase to use IntoIterator where possible. (#5269)
Remove unnecessary calls to `iter()`/`iter_mut()`.
Mainly updates the use of queries in our code, docs, and examples.

```rust
// From
for _ in list.iter() {
for _ in list.iter_mut() {

// To
for _ in &list {
for _ in &mut list {
```

We already enable the pedantic lint [clippy::explicit_iter_loop](https://rust-lang.github.io/rust-clippy/stable/) inside of Bevy. However, this only warns for a few known types from the standard library.

## Note for reviewers
As you can see the additions and deletions are exactly equal.
Maybe give it a quick skim to check I didn't sneak in a crypto miner, but you don't have to torture yourself by reading every line.
I already experienced enough pain making this PR :) 


Co-authored-by: devil-ira <justthecooldude@gmail.com>
2022-07-11 15:28:50 +00:00

73 lines
2.2 KiB
Rust

//! Illustrates how to move an object along an axis.
use bevy::prelude::*;
// Define a struct to keep some information about our entity.
// Here it's an arbitrary movement speed, the spawn location, and a maximum distance from it.
#[derive(Component)]
struct Movable {
spawn: Vec3,
max_distance: f32,
speed: f32,
}
// Implement a utility function for easier Movable struct creation.
impl Movable {
fn new(spawn: Vec3) -> Self {
Movable {
spawn,
max_distance: 5.0,
speed: 2.0,
}
}
}
fn main() {
App::new()
.add_plugins(DefaultPlugins)
.add_startup_system(setup)
.add_system(move_cube)
.run();
}
// Startup system to setup the scene and spawn all relevant entities.
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<StandardMaterial>>,
) {
// Add a cube to visualize translation.
let entity_spawn = Vec3::ZERO;
commands
.spawn_bundle(PbrBundle {
mesh: meshes.add(Mesh::from(shape::Cube { size: 1.0 })),
material: materials.add(Color::WHITE.into()),
transform: Transform::from_translation(entity_spawn),
..default()
})
.insert(Movable::new(entity_spawn));
// Spawn a camera looking at the entities to show what's happening in this example.
commands.spawn_bundle(Camera3dBundle {
transform: Transform::from_xyz(0.0, 10.0, 20.0).looking_at(entity_spawn, Vec3::Y),
..default()
});
// Add a light source for better 3d visibility.
commands.spawn_bundle(PointLightBundle {
transform: Transform::from_translation(Vec3::ONE * 3.0),
..default()
});
}
// This system will move all Movable entities with a Transform
fn move_cube(mut cubes: Query<(&mut Transform, &mut Movable)>, timer: Res<Time>) {
for (mut transform, mut cube) in &mut cubes {
// Check if the entity moved too far from its spawn, if so invert the moving direction.
if (cube.spawn - transform.translation).length() > cube.max_distance {
cube.speed *= -1.0;
}
let direction = transform.local_x();
transform.translation += direction * cube.speed * timer.delta_seconds();
}
}