Added bevy_spatial for boid interactions

I'm finally starting on the actual Boids flocking algorithm parts.
I don't want to iterate over all the things, and Bevy doesn't seem to
have fast collision testing yet, so I've reached for bevy_spatial to
track my Boids.

Cargo.lock

@@ -308,6 +308,7 @@ name = "bevy-testing"
 version = "0.1.0"
 dependencies = [
  "bevy",
+ "bevy_spatial",
 ]
 
 [[package]]
@@ -903,6 +904,18 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "bevy_spatial"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f0857f70fec5515c9ec93d23f5d4bf9fd9d9863198ce64c5878de5fab1a852d"
+dependencies = [
+ "bevy",
+ "kd-tree",
+ "num-traits",
+ "typenum",
+]
+
 [[package]]
 name = "bevy_sprite"
 version = "0.14.0"
@@ -1521,6 +1534,25 @@ dependencies = [
  "crossbeam-utils",
 ]
 
+[[package]]
+name = "crossbeam-deque"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "613f8cc01fe9cf1a3eb3d7f488fd2fa8388403e97039e2f73692932e291a770d"
+dependencies = [
+ "crossbeam-epoch",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.9.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
+dependencies = [
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "crossbeam-utils"
 version = "0.8.20"
@@ -2178,6 +2210,19 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "kd-tree"
+version = "0.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f89ee4e60e82cf7024e5e94618c646fbf61ce7501dc5898b3d12786442d3682"
+dependencies = [
+ "num-traits",
+ "ordered-float",
+ "paste",
+ "rayon",
+ "typenum",
+]
+
 [[package]]
 name = "khronos-egl"
 version = "6.0.0"
@@ -2808,6 +2853,15 @@ dependencies = [
  "libredox",
 ]
 
+[[package]]
+name = "ordered-float"
+version = "4.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "19ff2cf528c6c03d9ed653d6c4ce1dc0582dc4af309790ad92f07c1cd551b0be"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "overload"
 version = "0.1.1"
@@ -3028,6 +3082,26 @@ version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "20675572f6f24e9e76ef639bc5552774ed45f1c30e2951e1e99c59888861c539"
 
+[[package]]
+name = "rayon"
+version = "1.10.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b418a60154510ca1a002a752ca9714984e21e4241e804d32555251faf8b78ffa"
+dependencies = [
+ "either",
+ "rayon-core",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1465873a3dfdaa8ae7cb14b4383657caab0b3e8a0aa9ae8e04b044854c8dfce2"
+dependencies = [
+ "crossbeam-deque",
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "rectangle-pack"
 version = "0.4.2"
@@ -3512,6 +3586,12 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "059d83cc991e7a42fc37bd50941885db0888e34209f8cfd9aab07ddec03bc9cf"
 
+[[package]]
+name = "typenum"
+version = "1.17.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "42ff0bf0c66b8238c6f3b578df37d0b7848e55df8577b3f74f92a69acceeb825"
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.12"

Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 bevy = "0.14.0"
+bevy_spatial = "0.9.0"
 
 [profile.dev]
 opt-level = 1

src/birdoids_plugin.rs

@@ -1,16 +1,33 @@
+use std::time::Duration;
+
 use bevy::{prelude::*, sprite::MaterialMesh2dBundle};
+use bevy_spatial::{
+    AutomaticUpdate,
+    SpatialAccess,
+    TransformMode,
+    kdtree::KDTree2,
+};
 
 const BACKGROUND_COLOR: Color = Color::srgb(0.4, 0.4, 0.4);
 const PLAYERBOID_COLOR: Color = Color::srgb(1.0, 0.0, 0.0);
 const TURN_FACTOR: f32 = 1.;
-
+const BOID_VIEW_RANGE: f32 = 50.0;
 pub struct BoidsPlugin;
 
 impl Plugin for BoidsPlugin {
     fn build(&self, app: &mut App) {
-        app.insert_resource(ClearColor(BACKGROUND_COLOR))
+        app
+            .add_plugins(AutomaticUpdate::<TrackedByKdTree>::new()
+                .with_frequency(Duration::from_secs_f32(0.3))
+                .with_transform(TransformMode::GlobalTransform))
+            .insert_resource(ClearColor(BACKGROUND_COLOR))
             .add_systems(Startup, (spawn_camera, spawn_boids))
-            .add_systems(FixedUpdate, (apply_velocity, turn_if_edge, check_keyboard));
+            .add_systems(FixedUpdate, (
+                apply_velocity,
+                turn_if_edge,
+                check_keyboard,
+                cohesion,
+            ));
     }
 }
 
@@ -25,10 +42,14 @@ struct PlayerBoid;
 #[derive(Component, Deref, DerefMut)]
 struct Velocity(Vec3);
 
+#[derive(Component)]
+struct TrackedByKdTree;
+
 #[derive(Bundle)]
 struct BoidBundle {
     boid: Boid,
     velocity: Velocity,
+    spatial: TrackedByKdTree,
 }
 
 impl BoidBundle {
@@ -36,6 +57,7 @@ impl BoidBundle {
         Self {
             boid: Boid,
             velocity: Velocity(vel),
+            spatial: TrackedByKdTree,
         }
     }
 }
@@ -132,3 +154,16 @@ fn check_keyboard(
 
     **pvelocity = **pvelocity + dir.extend(0.0);
 }
+
+fn cohesion(
+    spatial_tree: Res<KDTree2<TrackedByKdTree>>,
+    mut query: Query<&mut Boid, With<TrackedByKdTree>>,
+    player: Query<&Transform, With<PlayerBoid>>,
+) {
+    let player_transform = player.get_single().unwrap();
+
+    let neighbors = spatial_tree.within_distance(
+        player_transform.translation.xy(),
+        BOID_VIEW_RANGE
+    );
+}