From 6c9482a3efa6c68c5c58062647eb26d2a6f77fa0 Mon Sep 17 00:00:00 2001
From: Oliver Scherer <github@oli-obk.de>
Date: Fri, 22 Dec 2023 21:53:57 +0100
Subject: [PATCH] Reorient "up" axis when moving

---
 src/lib.rs | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index fa60235..314d646 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -316,14 +316,21 @@ fn reposition_compass(
 
 fn update_camera_orientations(
     mut movement_settings: ResMut<MovementSettings>,
-    fly_cam: Query<GalacticTransform, With<FlyCam>>,
+    mut fly_cam: Query<GalacticTransform, With<FlyCam>>,
     space: Res<FloatingOriginSettings>,
 ) {
-    movement_settings.up = fly_cam
-        .single() // the only FlyCam's calactic position <grid,f32>
+    // the only FlyCam's calactic position <grid,f32>
+    let mut fly_cam = fly_cam.single_mut();
+
+    let up = fly_cam
         .position_double(&space)
         .normalize() // direction from galactic NULL = from the Earth center
         .as_vec3();
+    movement_settings.up = up;
+
+    // Reorient "up" axis without introducing other rotations.
+    let forward = fly_cam.transform.forward();
+    fly_cam.transform.look_to(forward, up);
 }
 
 fn pull_to_ground(