From 18d91b33562bafd29c848910859ce14180512337 Mon Sep 17 00:00:00 2001
From: ghostly_zsh <ghostly@e3t.cc>
Date: Sat, 29 Nov 2025 13:25:04 -0600
Subject: [PATCH] fix: orbit prediction actually follows hill spheres

---
 crates/unified/src/client/starguide/orbit.rs | 32 ++++++++++++--------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/crates/unified/src/client/starguide/orbit.rs b/crates/unified/src/client/starguide/orbit.rs
index 262c9b57b952f2dc7908abe2a6c27aa29852b633..407a2d60c672d4244bcc46e0399e8ba1caea5097 100644
--- a/crates/unified/src/client/starguide/orbit.rs
+++ b/crates/unified/src/client/starguide/orbit.rs
@@ -1,4 +1,4 @@
-use std::{f32::consts::PI, ops::Range};
+use std::{f32::{self, consts::PI}, ops::Range};
 
 use bevy::window::WindowResized;
 
@@ -30,24 +30,32 @@ fn update_orbits(
     let Projection::Orthographic(ref projection) = camera.2.clone() else { return };
     //image.clear(&(Color::BLACK.to_srgba().to_u8_array()));
 
-    let mut p_mass = 0.0;
-    let mut p_transform = Transform::default();
+    let mut p_mass = None;
+    let mut p_transform = None;
     let (sun_mass, _, sun_transform) = planets.iter().filter(|planet| planet.1.name == "Sun").next().unwrap();
+    let mut closest = f32::INFINITY;
     for (mass, planet, transform) in planets {
         if planet.name == "Sun" { continue }
 
-        let a = sun_transform.translation - transform.translation;
-        let hill_sphere = a.length()*(mass.0/(3.0*(sun_mass.0+mass.0))).powf(1.0/3.0);
-        if hill_sphere > (me.0.translation - transform.translation).length() {
-            p_mass = mass.0;
-            p_transform = *transform;
-            break;
+        let (other_mass, p, other_transform) = planets.iter().filter(|f_planet| f_planet.1.name == planet.orbit.clone().unwrap().orbiting).next().unwrap();
+        let a = other_transform.translation - transform.translation;
+        let hill_sphere = a.length()*(mass.0/(3.0*(other_mass.0+mass.0))).powf(1.0/3.0);
+
+        gizmos.circle_2d(transform.translation.truncate(), hill_sphere, Color::linear_rgb(0.02, 0.02, 0.02));
+
+        let rel_dist = (me.0.translation - transform.translation).length();
+        if rel_dist < closest && hill_sphere > rel_dist {
+            p_mass = Some(mass.0);
+            p_transform = Some(*transform);
+            closest = rel_dist;
         }
     }
-    if p_mass == 0.0 {
-        p_mass = sun_mass.0;
-        p_transform = *sun_transform;
+    if p_mass.is_none()  {
+        p_mass = Some(sun_mass.0);
+        p_transform = Some(*sun_transform);
     }
+    let p_mass = p_mass.unwrap();
+    let p_transform = p_transform.unwrap();
 
     // orbit magic
     let rel_pos = me.0.translation - p_transform.translation;