Prepare for follow-on change

crates/fj-core/src/algorithms/approx/cycle.rs

@@ -31,7 +31,13 @@ pub fn approx_cycle(
         .map(|half_edge| {
             let boundary = geometry.of_half_edge(half_edge).boundary;
             approx_half_edge(
-                half_edge, surface, boundary, tolerance, cache, geometry,
+                half_edge,
+                surface,
+                boundary,
+                tolerance,
+                &mut cache.vertex,
+                &mut cache.curve,
+                geometry,
             )
         })
         .collect();

crates/fj-core/src/algorithms/approx/half_edge.rs

@@ -13,7 +13,8 @@ use crate::{
 };
 
 use super::{
-    curve::approx_curve_with_cache, vertex::approx_vertex, ApproxCache,
+    curve::{approx_curve_with_cache, CurveApproxCache},
+    vertex::{approx_vertex, VertexApproxCache},
     ApproxPoint, Tolerance,
 };
 
@@ -23,7 +24,8 @@ pub fn approx_half_edge(
     surface: &Handle<Surface>,
     boundary: CurveBoundary<Point<1>>,
     tolerance: impl Into<Tolerance>,
-    cache: &mut ApproxCache,
+    vertex_cache: &mut VertexApproxCache,
+    curve_cache: &mut CurveApproxCache,
     geometry: &Geometry,
 ) -> HalfEdgeApprox {
     let tolerance = tolerance.into();
@@ -35,7 +37,7 @@ pub fn approx_half_edge(
         half_edge.curve(),
         surface,
         start_position_curve,
-        &mut cache.vertex,
+        vertex_cache,
         geometry,
     );
 
@@ -44,7 +46,7 @@ pub fn approx_half_edge(
         surface,
         boundary,
         tolerance,
-        &mut cache.curve,
+        curve_cache,
         geometry,
     );