Merge pull request #45 from thombruce/feat/ship-orbit

add simple gravitational impulse attracting ship to orbitables

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- Simple gravitational impulse attracting ship to orbitables (star and planets)
 - Add and use KDNode instead of Orbitable for nearest neighbour mapping
 
 ### Changed

src/player/dynamic_orbit.rs

@@ -0,0 +1,33 @@
+use bevy::{math::Vec3Swizzles, prelude::*};
+use bevy_rapier2d::prelude::ExternalImpulse;
+use bevy_spatial::{kdtree::KDTree2, SpatialAccess};
+
+use crate::{core::resources::state::GameState, world::spatial::KDNode};
+
+use super::ship::Ship;
+
+pub struct DynamicOrbitPlugin;
+impl Plugin for DynamicOrbitPlugin {
+    fn build(&self, app: &mut App) {
+        app.add_systems(
+            Update,
+            dynamic_orbital_positioning_system.run_if(in_state(GameState::Active)),
+        );
+    }
+}
+
+pub fn dynamic_orbital_positioning_system(
+    tree: Res<KDTree2<KDNode>>,
+    mut query: Query<(&Transform, &mut ExternalImpulse), With<Ship>>,
+) {
+    let (transform, mut impulse) = query.single_mut();
+
+    // From Nav
+    let player_translation = transform.translation.xy();
+
+    if let Some((pos, _entity)) = tree.nearest_neighbour(player_translation) {
+        if pos.distance(player_translation) < 1500. {
+            impulse.impulse += (pos - player_translation).normalize() * 2000.;
+        }
+    }
+}

src/player/mod.rs

@@ -1,16 +1,18 @@
 use bevy::prelude::*;
 use bevy_rapier2d::prelude::*;
 
+pub mod dynamic_orbit;
 pub mod ship;
 
-use self::ship::ShipPlugin;
+use self::{dynamic_orbit::DynamicOrbitPlugin, ship::ShipPlugin};
 
 pub struct PlayerPlugin;
 impl Plugin for PlayerPlugin {
     fn build(&self, app: &mut App) {
         app.add_plugins((
             RapierPhysicsPlugin::<NoUserData>::pixels_per_meter(1.0),
             ShipPlugin,
+            DynamicOrbitPlugin,
         ));
 
         app.add_systems(Startup, setup);

src/player/ship.rs

@@ -65,7 +65,7 @@ fn setup(mut commands: Commands, sprites: Res<SpriteAssets>) {
         SpriteBundle {
             texture: sprites.player_ship.clone(),
             transform: Transform {
-                translation: Vec3::new(0., 0., 100.0),
+                translation: Vec3::new(200., 0., 100.0),
                 scale: Vec3::splat(0.5),
                 ..default()
             },
@@ -129,5 +129,5 @@ pub fn ship_flight_system(
         velocity.angvel += rotation_factor * ship.rotation / 60.0;
     }
 
-    impulse.impulse = (transform.rotation * (Vec3::Y * thrust_factor * ship.thrust)).truncate();
+    impulse.impulse += (transform.rotation * (Vec3::Y * thrust_factor * ship.thrust)).truncate();
 }

src/world/astronomy/orbit.rs

@@ -2,7 +2,7 @@ use bevy::prelude::*;
 
 use crate::core::resources::{game_time::GameTime, state::GameState};
 
-const ORBITAL_PERIOD_SCALING_FACTOR: f32 = 1.0;
+pub const ORBITAL_PERIOD_SCALING_FACTOR: f32 = 1.0;
 
 #[derive(Component, Clone, Debug)]
 pub struct Orbit {