Surface walls named after their sketch curves (#757) (#850)

Each wall of a surface built from sketch curves (Surface Extrude, Revolve, Sweep and Loft) is now named after the curve it comes from, exactly rather than from geometry, so references to those faces survive edits.

crates/doc/src/eval_surface.rs

@@ -98,9 +98,9 @@ pub(super) fn eval(doc: &Document, vals: &BTreeMap<String, Value>, f: &Feature,
             let d = val(vals, &extent.distance, Kind::Length)?;
             let off = extent.start_offset.as_deref().map(|e| val(vals, e, Kind::Length)).transpose()?.unwrap_or(0.0);
             let (a, b) = extent_sides(vals, extent, d, extent.direction)?;
-            let body = kernel::extrude_sheet(&ss.plane, &sheet_chains(&ss, profiles.as_ref(), curves)?, a + off, b + off)?;
-            let name = new_name(st, f, 0);
-            st.bodies.push(ModelBody::new(name, body, f.id));
+            let chains = sheet_chains(&ss, profiles.as_ref(), curves)?;
+            let body = kernel::extrude_sheet(&ss.plane, &chains, a + off, b + off)?;
+            push_sheet(st, f, crate::lineage::ChainRoles { sketch: &ss, chains: &chains }.tool(body));
             Ok(())
         }
         FeatureKind::SurfaceRevolve { sketch, profiles, curves, axis, angle, angle2, symmetric } => {
@@ -119,9 +119,9 @@ pub(super) fn eval(doc: &Document, vals: &BTreeMap<String, Value>, f: &Feature,
                 (None, true) => (-a / 2.0, a),
                 (None, false) => (0.0, a),
             };
-            let body = kernel::revolve_sheet(&ss.plane, &sheet_chains(&ss, profiles.as_ref(), curves)?, o, d, start, sweep)?;
-            let name = new_name(st, f, 0);
-            st.bodies.push(ModelBody::new(name, body, f.id));
+            let chains = sheet_chains(&ss, profiles.as_ref(), curves)?;
+            let body = kernel::revolve_sheet(&ss.plane, &chains, o, d, start, sweep)?;
+            push_sheet(st, f, crate::lineage::ChainRoles { sketch: &ss, chains: &chains }.tool(body));
             Ok(())
         }
         FeatureKind::Unstitch { body, faces } => {
@@ -177,12 +177,13 @@ pub(super) fn eval(doc: &Document, vals: &BTreeMap<String, Value>, f: &Feature,
                 Some(pts) => kernel::sweep_sheet_points(&ss.plane, &chains, &pts)?,
                 None => kernel::sweep_sheet(&ss.plane, &chains, &path_segments(ps, path, start)?)?,
             };
-            let name = new_name(st, f, 0);
-            st.bodies.push(ModelBody::new(name, body, f.id));
+            let traced = crate::lineage::ChainRoles { sketch: ss, chains: &chains }.tool(body);
+            push_sheet(st, f, traced);
             Ok(())
         }
         FeatureKind::SurfaceLoft { sections } => {
             let mut secs = Vec::with_capacity(sections.len());
+            let mut sketches = Vec::with_capacity(sections.len());
             for sec in sections {
                 let ss = sketch_in_feature_frame(
                     doc,
@@ -201,16 +202,25 @@ pub(super) fn eval(doc: &Document, vals: &BTreeMap<String, Value>, f: &Feature,
                     ));
                 };
                 secs.push((ss.plane, chain));
+                sketches.push(ss);
             }
             let body = kernel::loft_sheet(&secs)?;
-            let name = new_name(st, f, 0);
-            st.bodies.push(ModelBody::new(name, body, f.id));
+            // Each wall named by the section curves it runs between, as a loft's sides are.
+            let loops: Vec<solidcraft_geom::Loop2> = secs.iter().map(|(_, c)| solidcraft_geom::Loop2 { segs: c.clone() }).collect();
+            let traced = crate::lineage::SectionRoles { sections: sketches.iter().zip(&loops).collect() }.tool(body);
+            push_sheet(st, f, traced);
             Ok(())
         }
         _ => Err(DocError::Invalid("not a surface feature".into())),
     }
 }
 
+/// A surface builder's body, added to the model with what its faces came from.
+fn push_sheet(st: &mut ModelState, f: &Feature, traced: crate::lineage::Traced) {
+    let name = new_name(st, f, 0);
+    st.bodies.push(ModelBody::traced_new(name, traced, f.id));
+}
+
 /// What a surface builder sweeps: the boundary loops of the picked profiles, then the picked
 /// curves chained end to end.
 fn sheet_chains(ss: &SolvedSketch, profiles: Option<&ProfileSel>, curves: &[String]) -> Result<Vec<Vec<Seg2>>> {