Support AABB calculation for arcs

crates/fj-core/src/algorithms/bounding_volume/edge.rs

@@ -1,15 +1,21 @@
-use fj_math::Aabb;
+use fj_math::{Aabb, Vector};
 
 use crate::{geometry::curve::Curve, objects::HalfEdge};
 
 impl super::BoundingVolume<2> for HalfEdge {
     fn aabb(&self) -> Option<Aabb<2>> {
         match self.curve() {
-            Curve::Circle(_) => {
-                // I don't currently have an example model to test this with.
-                // This should change soon, and then this will panic  and can be
-                // addressed.
-                todo!("Computing AABB of arc is not supported yet")
+            Curve::Circle(circle) => {
+                // Just calculate the AABB of the whole circle. This is not the
+                // most precise, but it should do for now.
+
+                let center_to_min_max =
+                    Vector::from([circle.radius(), circle.radius()]);
+
+                Some(Aabb {
+                    min: circle.center() - center_to_min_max,
+                    max: circle.center() + center_to_min_max,
+                })
             }
             Curve::Line(_) => {
                 let points = self.boundary().map(|point_curve| {