Files
bevy-nbody/src/main.rs
2020-08-12 00:57:54 -04:00

84 lines
2.6 KiB
Rust

use bevy::{prelude::*, render::pass::ClearColor};
use bigbang::{Entity, GravTree};
use rand::Rng;
struct Simulation(GravTree<Entity>);
fn main() {
let mut rng = rand::thread_rng();
let mut bodies = vec![];
for _ in 0..100 {
bodies.push(Entity {
x: rng.gen_range(-400., 400.),
y: rng.gen_range(-400., 400.),
z: 0.,
vx: rng.gen_range(-20., 20.),
vy: rng.gen_range(-20., 20.),
vz: 0.,
mass: rng.gen_range(1., 20.),
radius: rng.gen_range(1., 10.),
});
}
App::build()
.add_resource(Msaa { samples: 4 })
.add_default_plugins()
.add_resource(ClearColor(Color::rgb(0.01, 0.01, 0.01)))
.add_resource(Simulation(GravTree::new(&bodies, 0.02)))
.add_startup_system(add_bodies.system())
.add_system(time_step.system())
.add_system(update_bodies.system())
.run();
}
fn add_bodies(
mut commands: Commands,
mut materials: ResMut<Assets<ColorMaterial>>,
mut meshes: ResMut<Assets<Mesh>>,
asset_server: Res<AssetServer>,
grav_tree: Res<Simulation>,
) {
let texture = asset_server.load("assets/circle.png").unwrap();
// TODO: texture transparency not working
commands
.spawn(Camera2dComponents::default())
.spawn(UiCameraComponents::default());
for body in grav_tree.0.as_vec() {
commands
.spawn(SpriteComponents {
mesh: meshes.add(Mesh::from(shape::Quad::new(Vec2::new(
(body.radius / 100.) as f32,
(body.radius / 100.) as f32,
)))),
material: materials.add(texture.into()),
translation: Translation(Vec3::new(body.x as f32, body.y as f32, body.z as f32)),
draw: Draw {
is_transparent: true,
..Default::default()
},
..Default::default()
})
.with(body);
}
}
fn time_step(mut grav_tree: ResMut<Simulation>) {
grav_tree.0 = grav_tree.0.time_step();
}
fn update_bodies(grav_tree: Res<Simulation>, mut body_query: Query<(&Entity, &mut Translation)>) {
let updated_bodies = grav_tree.0.as_vec();
// for body in updated_bodies.iter() {
// println!("body: {}", body.as_string());
// }
let mut index = 0;
for (_, mut translation) in &mut body_query.iter() {
let updated_body = &updated_bodies[index];
translation.0.set_x(updated_body.x as f32);
translation.0.set_y(updated_body.y as f32);
translation.0.set_z(updated_body.z as f32);
index += 1;
}
}