use bevy::{
prelude::*,
render::{
camera::RenderTarget,
render_resource::{
Extent3d, TextureDescriptor, TextureDimension, TextureFormat, TextureUsages,
},
view::RenderLayers,
},
window::WindowResized,
};
const RES_WIDTH: u32 = 160;
const RES_HEIGHT: u32 = 90;
const PIXEL_PERFECT_LAYERS: RenderLayers = RenderLayers::layer(0);
const HIGH_RES_LAYERS: RenderLayers = RenderLayers::layer(1);
fn main() {
App::new()
.add_plugins(DefaultPlugins.set(ImagePlugin::default_nearest()))
.add_systems(Startup, (setup_camera, setup_sprite, setup_mesh))
.add_systems(Update, (rotate, fit_canvas))
.run();
}
#[derive(Component)]
struct Canvas;
#[derive(Component)]
struct InGameCamera;
#[derive(Component)]
struct OuterCamera;
#[derive(Component)]
struct Rotate;
fn setup_sprite(mut commands: Commands, asset_server: Res<AssetServer>) {
commands.spawn((
Sprite::from_image(asset_server.load("pixel/bevy_pixel_dark.png")),
Transform::from_xyz(-40., 20., 2.),
Rotate,
PIXEL_PERFECT_LAYERS,
));
commands.spawn((
Sprite::from_image(asset_server.load("pixel/bevy_pixel_light.png")),
Transform::from_xyz(-40., -20., 2.),
Rotate,
HIGH_RES_LAYERS,
));
}
fn setup_mesh(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<ColorMaterial>>,
) {
commands.spawn((
Mesh2d(meshes.add(Capsule2d::default())),
MeshMaterial2d(materials.add(Color::BLACK)),
Transform::from_xyz(40., 0., 2.).with_scale(Vec3::splat(32.)),
Rotate,
PIXEL_PERFECT_LAYERS,
));
}
fn setup_camera(mut commands: Commands, mut images: ResMut<Assets<Image>>) {
let canvas_size = Extent3d {
width: RES_WIDTH,
height: RES_HEIGHT,
..default()
};
let mut canvas = Image {
texture_descriptor: TextureDescriptor {
label: None,
size: canvas_size,
dimension: TextureDimension::D2,
format: TextureFormat::Bgra8UnormSrgb,
mip_level_count: 1,
sample_count: 1,
usage: TextureUsages::TEXTURE_BINDING
| TextureUsages::COPY_DST
| TextureUsages::RENDER_ATTACHMENT,
view_formats: &[],
},
..default()
};
canvas.resize(canvas_size);
let image_handle = images.add(canvas);
commands.spawn((
Camera2d,
Camera {
order: -1,
target: RenderTarget::Image(image_handle.clone()),
..default()
},
Msaa::Off,
InGameCamera,
PIXEL_PERFECT_LAYERS,
));
commands.spawn((Sprite::from_image(image_handle), Canvas, HIGH_RES_LAYERS));
commands.spawn((Camera2d, Msaa::Off, OuterCamera, HIGH_RES_LAYERS));
}
fn rotate(time: Res<Time>, mut transforms: Query<&mut Transform, With<Rotate>>) {
for mut transform in &mut transforms {
let dt = time.delta_secs();
transform.rotate_z(dt);
}
}
fn fit_canvas(
mut resize_events: EventReader<WindowResized>,
mut projection: Single<&mut OrthographicProjection, With<OuterCamera>>,
) {
for event in resize_events.read() {
let h_scale = event.width / RES_WIDTH as f32;
let v_scale = event.height / RES_HEIGHT as f32;
projection.scale = 1. / h_scale.min(v_scale).round();
}
}