fix: solve concentric geometry in kernel

src/entities/circle.rs

@@ -204,14 +204,18 @@ fn apply_geom_prop(circle: &mut Circle, field: &str, value: &str) {
         "area" if v > 0.0 => circle.radius = (v / PI).sqrt(),
         "normal_x" | "normal_y" | "normal_z" => {
             let center = circle.center_wcs();
-            let mut normal = glam::DVec3::new(circle.normal.x, circle.normal.y, circle.normal.z);
+            let mut normal = cadkernel::space::Vec3::new(
+                circle.normal.x,
+                circle.normal.y,
+                circle.normal.z,
+            );
             match field {
                 "normal_x" => normal.x = v,
                 "normal_y" => normal.y = v,
                 "normal_z" => normal.z = v,
                 _ => {}
             }
-            if let Some(normal) = normal.try_normalize() {
+            if let Some(normal) = normal.normalize() {
                 circle.normal = acadrust::types::Vector3::new(normal.x, normal.y, normal.z);
                 let (x, y, z) = crate::scene::view::transform::wcs_point_to_ocs(
                     (center.x, center.y, center.z),
@@ -376,6 +380,19 @@ impl crate::entities::traits::MassPropsCalc for Circle {
 mod tests {
     use super::*;
 
+    #[test]
+    fn editing_normal_preserves_world_center() {
+        let mut circle = Circle::from_coords(2.0, 3.0, 4.0, 5.0);
+        let center = circle.center_wcs();
+
+        apply_geom_prop(&mut circle, "normal_x", "1");
+
+        assert!((circle.center_wcs() - center).length() < 1.0e-9);
+        let normal_length =
+            (circle.normal.x.powi(2) + circle.normal.y.powi(2) + circle.normal.z.powi(2)).sqrt();
+        assert!((normal_length - 1.0).abs() < 1.0e-12);
+    }
+
     #[test]
     fn quadrant_grips_offer_interactive_radius() {
         use crate::entities::traits::Grippable;