Prepare to support other curves besides lines

experiments/2025-03-18/src/geometry/curve.rs

@@ -0,0 +1,3 @@
+pub trait CurveGeometry {}
+
+impl CurveGeometry for () {}

experiments/2025-03-18/src/geometry/mod.rs

@@ -1,5 +1,9 @@
+mod curve;
 mod sketch;
 mod surface;
 mod tri_mesh;
 
-pub use self::{sketch::Sketch, surface::SurfaceGeometry, tri_mesh::ToTriMesh};
+pub use self::{
+    curve::CurveGeometry, sketch::Sketch, surface::SurfaceGeometry,
+    tri_mesh::ToTriMesh,
+};

experiments/2025-03-18/src/operations/translate.rs

@@ -22,8 +22,12 @@ impl TranslateExt for Curve {
         // 3D space, which means we have to do the actual translation here.
         // We'll see how it shakes out.
 
-        let Curve {} = self;
+        let Curve { geometry } = self;
-        Curve {}
+        let _ = geometry;
+
+        Curve {
+            geometry: Box::new(()),
+        }
     }
 }
 

experiments/2025-03-18/src/topology/curve.rs

@@ -1,9 +1,15 @@
+use crate::geometry::CurveGeometry;
+
 use super::vertex::Vertex;
 
-pub struct Curve {}
+pub struct Curve {
+    pub geometry: Box<dyn CurveGeometry>,
+}
 
 impl Curve {
     pub fn line_from_vertices(_: [&Vertex; 2]) -> Self {
-        Curve {}
+        Self {
+            geometry: Box::new(()),
+        }
     }
 }