starfield

Author: mockersf

assets/starfield.wgsl

@@ -45,17 +45,10 @@ fn fragment(in: VertexOutput) -> @location(0) vec4<f32> {
     var result = vec3<f32>(0.0, 0.0, 0.0);
     let coords = vec2<f32>(-material.coords.x, material.coords.y);
     let move_factor = 1000.0;
-    let time_factor = 0.05;
 
-    let intensity = clamp(rand(in.uv * globals.time), 0.4, 1.0);
+    result = result + vec3<f32>(stars(in.uv - coords / (move_factor * 1.2), 3.0, 0.025, 2.0));
+    result = result + vec3<f32>(stars(in.uv - coords / (move_factor * 1.4), 10.0, 0.018, 1.0));
+    result = result + vec3<f32>(stars(in.uv - coords / (move_factor * 2.0), 30.0, 0.015, 0.5));
 
-//    result = result + vec3<f32>(stars(in.uv - coords / (move_factor * 1.2), 3.0, 0.025, 2.0)) * intensity;
-//    result = result + vec3<f32>(stars(in.uv - coords / (move_factor * 1.4), 10.0, 0.018, 1.0)) * intensity;
-//    result = result + vec3<f32>(stars(in.uv - coords / (move_factor * 2.0), 30.0, 0.015, 0.5)) * intensity;
-
-    result = result + stars(in.uv + vec2<f32>(material.seeds.x, 0.0) - coords / (move_factor * 1.2), 3.0, 0.025, 2.0) * vec3<f32>(3.6, 3.6, 3.6) * intensity;
-    result = result + stars(in.uv + vec2<f32>(material.seeds.y, 0.0) - coords / (move_factor * 1.4), 10.0, 0.018, 1.0) * vec3<f32>(6.7, 6.7, 6.7) * intensity;
-    result = result + stars(in.uv + vec2<f32>(material.seeds.x, material.seeds.y) - coords / (move_factor * 2.0), 30.0, 0.015, 0.5) * vec3<f32>(.75, .75, .75) * intensity;
-
-    return vec4<f32>(result * 6.0, 1.0);
+    return vec4<f32>(result, 1.0);
 }

src/main.rs

@@ -8,6 +8,7 @@ mod game;
 mod hud;
 mod level;
 mod splash;
+mod starfield;
 mod start_menu;
 mod won;
 
@@ -32,6 +33,7 @@ fn main() {
             hud::hud_plugin,
             won::won_plugin,
             audio::audio_plugin,
+            starfield::starfield_plugin,
         ))
         .run();
 }

src/starfield.rs

@@ -0,0 +1,84 @@
+use bevy::{
+    prelude::*,
+    render::render_resource::{AsBindGroup, ShaderRef, ShaderType},
+    sprite::{Material2d, Material2dPlugin},
+    window::WindowResized,
+};
+use rand::Rng;
+
+use crate::GameState;
+
+pub fn starfield_plugin(app: &mut bevy::prelude::App) {
+    app.add_plugins(Material2dPlugin::<StarfieldMaterial>::default())
+        .add_systems(OnEnter(GameState::Game), setup)
+        .add_systems(
+            PostUpdate,
+            update_starfield.run_if(in_state(GameState::Game)),
+        );
+}
+
+#[derive(Asset, TypePath, AsBindGroup, ShaderType, Debug, Clone)]
+#[uniform(0, StarfieldMaterial)]
+pub struct StarfieldMaterial {
+    position: Vec2,
+    seeds: Vec2,
+}
+
+impl<'a> From<&'a StarfieldMaterial> for StarfieldMaterial {
+    fn from(material: &'a StarfieldMaterial) -> Self {
+        material.clone()
+    }
+}
+
+impl Material2d for StarfieldMaterial {
+    fn fragment_shader() -> bevy::render::render_resource::ShaderRef {
+        ShaderRef::Path("starfield.wgsl".into())
+    }
+}
+
+fn setup(
+    mut commands: Commands,
+    mut meshes: ResMut<Assets<Mesh>>,
+    mut materials: ResMut<Assets<StarfieldMaterial>>,
+    windows: Query<&Window>,
+) {
+    let window = windows.single().unwrap();
+    let size = window.width().max(window.height());
+
+    commands.spawn((
+        Mesh2d(meshes.add(Rectangle::default())),
+        MeshMaterial2d(materials.add(StarfieldMaterial {
+            position: Vec2::ZERO,
+            seeds: Vec2::new(
+                rand::thread_rng().gen_range(0.0..1000.0),
+                rand::thread_rng().gen_range(0.0..1000.0),
+            ),
+        })),
+        Transform::from_scale(Vec3::new(size, size, 1.0)),
+        StateScoped(GameState::Game),
+    ));
+}
+
+fn update_starfield(
+    mut starfield: Query<(&mut Transform, &MeshMaterial2d<StarfieldMaterial>), Without<Camera2d>>,
+    camera: Query<Ref<Transform>, With<Camera2d>>,
+    mut materials: ResMut<Assets<StarfieldMaterial>>,
+    mut resized: EventReader<WindowResized>,
+) {
+    let camera_transform = camera.single().unwrap();
+    if camera_transform.is_changed() {
+        let (mut starfield_transform, material) = starfield.single_mut().unwrap();
+
+        starfield_transform.translation = camera_transform.translation.with_z(-2.0);
+
+        let material = materials.get_mut(&material.0).unwrap();
+        material.position = camera_transform.translation.xy();
+    }
+
+    if let Some(resized) = resized.read().last() {
+        let (mut starfield_transform, _) = starfield.single_mut().unwrap();
+
+        starfield_transform.scale.x = resized.width.max(resized.height);
+        starfield_transform.scale.y = resized.width.max(resized.height);
+    }
+}