feat: strengthen modeling, configuration, and assembly workflows

Preserve linked sketch identities through deterministic face projection and resizing. Fix origin-corner picking, persistent inline navigation, appearance editing, configuration styles, component properties, contact sweeps, sheet exports, analytic STEP offsets, and bounded rolling-ball fit accuracy.

Validated with full cargo xtask ci, native workflow screenshots, repeated enclosure replays, and analytic geometry regressions.

crates/doc/src/config.rs

@@ -1,6 +1,6 @@
 //! Configurations: a table whose rows are variants of the design. Each column is a parameter
-//! (its expression per row) or a feature (suppressed or not per row); activating a row sets
-//! those values in the design, which then rebuilds as usual.
+//! expression, feature suppression, body material or body appearance. Activating a row sets
+//! those values in the design atomically, which then rebuilds as usual.
 
 use serde::{Deserialize, Serialize};
 
@@ -13,12 +13,16 @@ pub enum Column {
     Param(String),
     /// A feature's suppression (by feature id).
     Suppress(u64),
+    /// A body's physical material (library name, or Default to clear).
+    Material(String),
+    /// A body's appearance (library name, serialized Look, or empty to clear).
+    Appearance(String),
 }
 
 #[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
 pub struct ConfigRow {
     pub name: String,
-    /// One cell per column: an expression, or "true"/"false" for suppression.
+    /// One cell per column: expression, suppression, material name or appearance look.
     pub cells: Vec<String>,
 }
 
@@ -39,28 +43,69 @@ impl ConfigTable {
     }
 }
 
+/// Parse an appearance cell. Empty/Default follows the body's material; named library looks
+/// and JSON Look objects support both convenient editing and lossless custom colours.
+pub fn appearance_cell(value: &str) -> Result<Option<crate::appearance::Look>> {
+    let value = value.trim();
+    if value.is_empty() || value.eq_ignore_ascii_case("default") {
+        return Ok(None);
+    }
+    if value.len() > 4096 {
+        return Err(DocError::Invalid("appearance value too long".into()));
+    }
+    if let Some(look) = crate::appearance::library(value) {
+        return Ok(Some(look));
+    }
+    let look: crate::appearance::Look =
+        serde_json::from_str(value).map_err(|_| DocError::Invalid(format!("unknown configuration appearance `{value}`")))?;
+    if look.name.chars().count() > 128 || !look.opacity.is_finite() || !(0.0..=1.0).contains(&look.opacity) {
+        return Err(DocError::Invalid("appearance requires a name up to 128 characters and opacity in 0..1".into()));
+    }
+    Ok(Some(look))
+}
+
+/// Parse a physical material cell, returning None for the default material.
+pub fn material_cell(value: &str) -> Result<Option<String>> {
+    let name = crate::MATERIALS
+        .iter()
+        .find(|(n, _)| n.eq_ignore_ascii_case(value.trim()))
+        .map(|(n, _)| *n)
+        .ok_or_else(|| DocError::Invalid(format!("unknown configuration material `{value}`")))?;
+    Ok((name != "Default").then(|| name.to_string()))
+}
+
 impl Document {
     /// A column's current value in the design.
     pub fn config_current(&self, c: &Column) -> Option<String> {
         match c {
             Column::Param(n) => self.all_param_exprs().into_iter().find(|(m, _, _)| m == n).map(|(_, e, _)| e),
             Column::Suppress(id) => self.feature(*id).map(|f| f.suppressed.to_string()),
+            Column::Material(body) => Some(self.materials.get(body).cloned().unwrap_or_else(|| "Default".into())),
+            Column::Appearance(body) => Some(self.appearances.bodies.get(body).and_then(|look| serde_json::to_string(look).ok()).unwrap_or_default()),
         }
     }
 
-    /// A column's display key: `param:<name>` or `suppress:<feature name>`.
+    /// A column's display key, prefixed by its kind to distinguish targets with equal names.
     pub fn config_key(&self, c: &Column) -> String {
         match c {
             Column::Param(n) => format!("param:{n}"),
             Column::Suppress(id) => format!("suppress:{}", self.feature(*id).map(|f| f.name.clone()).unwrap_or_else(|| id.to_string())),
+            Column::Material(body) => format!("material:{body}"),
+            Column::Appearance(body) => format!("appearance:{body}"),
         }
     }
 
     /// Set the design to a row's values (all or nothing).
     pub fn apply_configuration(&mut self, row: &str) -> Result<()> {
         let r = self.configs.rows.iter().find(|r| r.name == row).cloned().ok_or_else(|| DocError::Unknown(format!("configuration `{row}`")))?;
+        if self.configs.columns.len() > MAX_COLUMNS || self.configs.rows.len() > MAX_ROWS || r.cells.len() != self.configs.columns.len() {
+            return Err(DocError::Invalid("configuration table exceeds limits or has incomplete rows".into()));
+        }
         let mut next = self.clone();
         for (c, v) in self.configs.columns.iter().zip(&r.cells) {
+            if v.len() > 4096 {
+                return Err(DocError::Invalid("configuration value too long".into()));
+            }
             match c {
                 Column::Param(n) => {
                     if next.config_current(c).as_deref() != Some(v.as_str()) {
@@ -76,6 +121,22 @@ impl Document {
                     let f = next.feature_mut(*id).ok_or_else(|| DocError::Unknown(format!("configuration `{row}`: feature {id} is gone")))?;
                     f.suppressed = on;
                 }
+                Column::Material(body) => match material_cell(v)? {
+                    Some(material) => {
+                        next.materials.insert(body.clone(), material);
+                    }
+                    None => {
+                        next.materials.remove(body);
+                    }
+                },
+                Column::Appearance(body) => match appearance_cell(v)? {
+                    Some(look) => {
+                        next.appearances.bodies.insert(body.clone(), look);
+                    }
+                    None => {
+                        next.appearances.bodies.remove(body);
+                    }
+                },
             }
         }
         next.configs.active = Some(row.to_string());
@@ -86,9 +147,14 @@ impl Document {
     /// The active row's values all hold in the design.
     pub fn configuration_matches(&self) -> bool {
         let Some(r) = self.configs.active.as_ref().and_then(|a| self.configs.rows.iter().find(|r| r.name == *a)) else { return false };
+        if r.cells.len() != self.configs.columns.len() {
+            return false;
+        }
         self.configs.columns.iter().zip(&r.cells).all(|(c, v)| match c {
             Column::Suppress(_) => self.config_current(c).as_deref() == Some(v.trim()),
             Column::Param(_) => self.config_current(c).is_some_and(|x| x.replace(' ', "") == v.replace(' ', "")),
+            Column::Material(body) => material_cell(v).is_ok_and(|m| self.materials.get(body) == m.as_ref()),
+            Column::Appearance(body) => appearance_cell(v).is_ok_and(|look| self.appearances.bodies.get(body) == look.as_ref()),
         })
     }
 }
@@ -114,4 +180,21 @@ mod tests {
         assert!(d.apply_configuration("Bad").is_err());
         assert_eq!(d, before, "all or nothing");
     }
+
+    #[test]
+    fn invalid_saved_appearance_rolls_back_material_and_parameters() {
+        let mut d = Document::new("A");
+        d.set_param("width", "10 mm", None, None).unwrap();
+        d.configs.columns = vec![Column::Param("width".into()), Column::Material("Body".into()), Column::Appearance("Body".into())];
+        d.configs.rows.push(ConfigRow {
+            name: "Broken".into(),
+            cells: vec!["20 mm".into(), "Steel".into(), r#"{"name":"Invalid","color":[1,2,3],"opacity":2}"#.into()],
+        });
+        let before = d.clone();
+        assert!(d.apply_configuration("Broken").is_err());
+        assert_eq!(d, before);
+        assert!(appearance_cell(r#"{"name":"Invalid","color":[1,2,3],"opacity":1e999}"#).is_err());
+        assert!(appearance_cell(&"a".repeat(4097)).is_err());
+        assert!(appearance_cell("default").unwrap().is_none());
+    }
 }

crates/doc/src/format.rs

@@ -20,13 +20,16 @@
 //!   "don't mate". Older joints keep their placement: their `flip` is inverted.
 //! - 6: XZ origin planes use sketch y = -Z and normal +Y. Older XZ references become
 //!   explicit planes retaining their previous axes, including offset-plane expressions.
+//! - 7: configuration tables can include body material and appearance columns. Version 6
+//!   rows need no transformation; the version stamp lets older readers request an update
+//!   instead of encountering an unknown column variant.
 
 use serde_json::Value;
 
 use crate::{DocError, Document, Result};
 
 /// The format this build writes.
-pub const FORMAT: u32 = 6;
+pub const FORMAT: u32 = 7;
 
 pub fn format_string(n: u32) -> String {
     format!("solvecraft/{n}")
@@ -39,7 +42,7 @@ pub fn version_of(s: &str) -> Option<u32> {
 
 /// JSON-level upgrades: entry `i` turns format `i + 1` into `i + 2`.
 type JsonStep = fn(&mut Value) -> Result<()>;
-const JSON_STEPS: [JsonStep; 5] = [|_| Ok(()), v2_to_v3, v3_to_v4, v4_to_v5, v5_to_v6];
+const JSON_STEPS: [JsonStep; 6] = [|_| Ok(()), v2_to_v3, v3_to_v4, v4_to_v5, v5_to_v6, |_| Ok(())];
 
 /// Old XZ references retain their exact frame, including nested offset and angled planes.
 /// New origin references use +Y; freezing the old frame avoids changing sketch coordinates,
@@ -210,6 +213,65 @@ fn normalise(d: &mut Document) -> Result<()> {
 mod tests {
     use super::*;
 
+    #[test]
+    fn version_six_configuration_rows_upgrade_without_changing_values_or_features() {
+        use crate::config::{Column, ConfigRow};
+        let mut d = Document::new("legacy configurations");
+        d.set_param("width", "10 mm", None, None).unwrap();
+        let feature = d
+            .add_feature(
+                crate::FeatureKind::Box {
+                    corner: ["0".into(), "0".into(), "0".into()],
+                    length: "width".into(),
+                    width: "20".into(),
+                    height: "5".into(),
+                    operation: crate::Operation::NewBody,
+                },
+                None,
+            )
+            .unwrap();
+        d.configs.columns = vec![Column::Param("width".into()), Column::Suppress(feature)];
+        d.configs.rows = vec![
+            ConfigRow { name: "Default".into(), cells: vec!["10 mm".into(), "false".into()] },
+            ConfigRow { name: "Alternate".into(), cells: vec!["width / 2 + 5 mm".into(), "yes".into()] },
+        ];
+        d.configs.active = Some("Default".into());
+        let mut legacy: Value = serde_json::from_str(&d.to_json()).unwrap();
+        legacy["format"] = Value::from("solvecraft/6");
+        let original_table = legacy["configs"].clone();
+        let upgraded = read(&legacy.to_string()).unwrap();
+        assert_eq!(upgraded, d, "the identity migration preserves the complete design");
+        assert_eq!(serde_json::to_value(&upgraded.configs).unwrap(), original_table);
+        assert_eq!(upgraded.format, "solvecraft/7");
+        assert!(upgraded.configuration_matches());
+        legacy.as_object_mut().unwrap().remove("configs");
+        assert!(read(&legacy.to_string()).unwrap().configs.is_empty());
+        legacy["configs"] = serde_json::json!({"columns":[],"rows":[]});
+        assert!(read(&legacy.to_string()).unwrap().configs.is_empty());
+    }
+
+    #[test]
+    fn version_seven_styles_roundtrip_and_newer_versions_are_refused_before_columns() {
+        use crate::config::{Column, ConfigRow};
+        let mut d = Document::new("configured styles");
+        d.configs.columns = vec![Column::Material("Body".into()), Column::Appearance("Body".into())];
+        d.configs.rows = vec![ConfigRow {
+            name: "Blue steel".into(),
+            cells: vec!["Steel".into(), r#"{"name":"Custom blue","color":[40,90,186],"opacity":0.4}"#.into()],
+        }];
+        d.apply_configuration("Blue steel").unwrap();
+        let mut value: Value = serde_json::from_str(&d.to_json()).unwrap();
+        assert_eq!(value["format"], "solvecraft/7");
+        let roundtrip = read(&value.to_string()).unwrap();
+        assert_eq!(roundtrip, d);
+        assert!(roundtrip.configuration_matches());
+        value["format"] = Value::from(format_string(FORMAT + 1));
+        value["configs"]["columns"] = serde_json::json!([{"unknown_future_column":"Body"}]);
+        let error = read(&value.to_string()).unwrap_err().to_string();
+        assert!(error.contains("newer SolveCraft") && error.contains("update SolveCraft"), "{error}");
+        assert!(!error.contains("unknown variant"), "format refusal precedes decoding new variants");
+    }
+
     #[test]
     fn bulk_input_repair_preserves_existing_names_and_reuses_surplus_names() {
         let mut d = Document::new("input repair");

crates/doc/src/params.rs

@@ -829,8 +829,10 @@ impl Document {
         }
         // Configuration cells refer to parameters too.
         for r in &mut self.configs.rows {
-            for cell in &mut r.cells {
-                *cell = expr::rename_reference(cell, old, new);
+            for (column, cell) in self.configs.columns.iter().zip(&mut r.cells) {
+                if matches!(column, crate::config::Column::Param(_)) {
+                    *cell = expr::rename_reference(cell, old, new);
+                }
             }
         }
         if let Some(c) = self.param_comments.remove(old) {

crates/doc/src/project.rs

@@ -20,6 +20,9 @@ const AXIS_HALF: f64 = 100.0;
 /// Points in one fitted chain at most (longer chains are thinned).
 const MAX_CHAIN: usize = 4000;
 
+#[path = "project_order.rs"]
+mod order;
+
 /// A resolved link: its geometry in sketch coordinates and the (possibly moved) reference.
 #[derive(Clone, Debug)]
 pub struct Resolved {
@@ -133,7 +136,7 @@ fn resolve_uncached(
                 LinkKind::Intersect => section(plane, &mesh, Some(f)),
                 _ => {
                     let mut g = Vec::new();
-                    for e in mesh.face_edges(f) {
+                    for e in order::face_edges(&mesh, f, plane)? {
                         if mesh.seams.get(e).copied().unwrap_or(false) {
                             continue;
                         }

crates/doc/src/project_order.rs

@@ -0,0 +1,290 @@
+//! Stable face projection order: outer boundary first, then holes by geometry.
+//! B-rep edge indices depend on face enumeration and must not choose sketch curve IDs.
+
+use std::collections::BTreeMap;
+
+use solvecraft_geom::{Mesh, Plane, Vec3};
+
+use crate::{DocError, Result};
+
+type Key = (i64, i64, i64);
+
+pub(super) fn face_edges(mesh: &Mesh, face: u32, plane: &Plane) -> Result<Vec<usize>> {
+    let bounds = mesh.bounds();
+    let origin = bounds.min;
+    let local_origin = plane.to_local(origin);
+    let tol = (bounds.diagonal() * 1e-8).max(1e-9);
+    if !tol.is_finite() {
+        return Err(DocError::Invalid("face projection has invalid bounds".into()));
+    }
+    let key = |p: Vec3| -> Key {
+        let p = p - origin;
+        ((p.x / tol).round() as i64, (p.y / tol).round() as i64, (p.z / tol).round() as i64)
+    };
+    let mut edges: Vec<usize> = mesh.face_edges(face).into_iter().filter(|e| !mesh.seams.get(*e).copied().unwrap_or(false)).collect();
+    if edges.iter().any(|e| !mesh.edges.get(*e).is_some_and(|p| p.len() >= 2 && p.iter().all(|p| p.is_finite()))) {
+        return Err(DocError::Invalid("face projection has an invalid boundary edge".into()));
+    }
+    if edges.len() > solvecraft_sketch::MAX_LINK_ENTITIES {
+        return Err(DocError::Invalid("face projection exceeds the boundary edge limit".into()));
+    }
+    let geometry_key = |e: usize| {
+        let pts = mesh.edges.get(e).map(Vec::as_slice).unwrap_or_default();
+        let lo = pts.iter().copied().fold(Vec3::new(f64::INFINITY, f64::INFINITY, f64::INFINITY), Vec3::min);
+        let hi = pts.iter().copied().fold(Vec3::new(f64::NEG_INFINITY, f64::NEG_INFINITY, f64::NEG_INFINITY), Vec3::max);
+        (key(lo), key(hi))
+    };
+    edges.sort_by_key(|e| geometry_key(*e));
+    let mut at: BTreeMap<Key, Vec<usize>> = BTreeMap::new();
+    for e in &edges {
+        if let Some(pts) = mesh.edges.get(*e) {
+            for point in [pts.first(), pts.last()].into_iter().flatten() {
+                at.entry(key(*point)).or_default().push(*e);
+            }
+        }
+    }
+    let mut used = vec![false; mesh.edges.len()];
+    let mut boundaries = Vec::new();
+    for start_edge in &edges {
+        if used.get(*start_edge).copied().unwrap_or(true) {
+            continue;
+        }
+        let Some(pts) = mesh.edges.get(*start_edge) else { continue };
+        let (Some(a), Some(b)) = (pts.first(), pts.last()) else { continue };
+        let start = if key(*a) <= key(*b) { *a } else { *b };
+        let mut current = start;
+        let mut edge = *start_edge;
+        let mut boundary = Vec::new();
+        let mut twice_area = 0.0;
+        for _ in 0..edges.len() {
+            let Some(pts) = mesh.edges.get(edge) else { break };
+            let (Some(a), Some(b)) = (pts.first(), pts.last()) else { break };
+            let forward = current.dist(*a) <= current.dist(*b);
+            for pair in pts.windows(2) {
+                let (Some(a), Some(b)) = (pair.first(), pair.get(1)) else { continue };
+                let (a, b) = (plane.to_local(*a) - local_origin, plane.to_local(*b) - local_origin);
+                twice_area += if forward { a.cross(b) } else { b.cross(a) };
+            }
+            current = if forward { *b } else { *a };
+            if let Some(slot) = used.get_mut(edge) {
+                *slot = true;
+            }
+            boundary.push(edge);
+            if current.dist(start) <= tol {
+                break;
+            }
+            // Neighbouring quantization cells cover points on either side of a rounding
+            // boundary. Connectivity is checked in world space, not in the projection.
+            let (x, y, z) = key(current);
+            let mut candidates = Vec::new();
+            for dx in -1..=1 {
+                for dy in -1..=1 {
+                    for dz in -1..=1 {
+                        let cell = (x.saturating_add(dx), y.saturating_add(dy), z.saturating_add(dz));
+                        if let Some(list) = at.get(&cell) {
+                            candidates.extend(list.iter().copied().filter(|e| {
+                                !used.get(*e).copied().unwrap_or(true)
+                                    && mesh.edges.get(*e).is_some_and(|p| {
+                                        p.first().is_some_and(|a| a.dist(current) <= tol) || p.last().is_some_and(|b| b.dist(current) <= tol)
+                                    })
+                            }));
+                        }
+                    }
+                }
+            }
+            candidates.sort_by_key(|e| geometry_key(*e));
+            candidates.dedup();
+            if candidates.len() > 1 {
+                return Err(DocError::Invalid("face projection has a branched boundary".into()));
+            }
+            let Some(next) = candidates.first() else { break };
+            edge = *next;
+        }
+        boundary.sort_by_key(|e| geometry_key(*e));
+        let closed = current.dist(start) <= tol;
+        if !closed || !twice_area.is_finite() {
+            return Err(DocError::Invalid("face projection has an open or invalid boundary".into()));
+        }
+        // Equal-sized holes use their geometric key, not round-off from summing the
+        // same area at different positions or walking their edges in reverse.
+        let area = (twice_area.abs() / (tol * bounds.diagonal().max(tol))).round() as i64;
+        let first = boundary.first().copied().map(geometry_key);
+        boundaries.push((area, first, boundary));
+    }
+    boundaries.sort_by(|a, b| b.0.cmp(&a.0).then(a.1.cmp(&b.1)));
+    Ok(boundaries.into_iter().flat_map(|(_, _, edges)| edges).collect())
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn rectangles() -> Mesh {
+        let mut mesh = Mesh::default();
+        for (x, y) in [(40.0, 30.0), (38.0, 28.0), (4.0, 2.0)] {
+            let pts = [Vec3::new(-x, -y, 0.0), Vec3::new(x, -y, 0.0), Vec3::new(x, y, 0.0), Vec3::new(-x, y, 0.0)];
+            mesh.positions.extend(pts);
+            for i in 0..4 {
+                mesh.edges.push(vec![pts[i], pts[(i + 1) % 4]]);
+                mesh.edge_faces.push(vec![7]);
+            }
+        }
+        mesh
+    }
+
+    #[test]
+    fn boundaries_and_edge_identity_are_independent_of_mesh_enumeration() {
+        let baseline = rectangles();
+        let expected: Vec<_> =
+            face_edges(&baseline, 7, &Plane::XY).unwrap().into_iter().map(|e| super::super::fit_world(&Plane::XY, &baseline.edges[e])).collect();
+        for shift in 0..baseline.edges.len() {
+            for reverse in [false, true] {
+                let mut mesh = baseline.clone();
+                mesh.edges = (0..mesh.edges.len()).map(|i| baseline.edges[(i * 5) % baseline.edges.len()].clone()).collect();
+                mesh.edges.rotate_left(shift);
+                if reverse {
+                    mesh.edges.reverse();
+                    for pts in &mut mesh.edges {
+                        pts.reverse();
+                    }
+                }
+                let actual: Vec<_> = face_edges(&mesh, 7, &Plane::XY)
+                    .unwrap()
+                    .into_iter()
+                    .map(|e| {
+                        let mut pts = mesh.edges[e].clone();
+                        // Lines' direction does not change their geometry.
+                        if pts.first().unwrap().x > pts.last().unwrap().x || pts.first().unwrap().y > pts.last().unwrap().y {
+                            pts.reverse();
+                        }
+                        super::super::fit_world(&Plane::XY, &pts)
+                    })
+                    .collect();
+                let normalized: Vec<_> = expected
+                    .iter()
+                    .map(|g| {
+                        let solvecraft_sketch::LinkGeom::Line(a, b) = g[0] else { panic!("line") };
+                        if a.x > b.x || a.y > b.y { vec![solvecraft_sketch::LinkGeom::Line(b, a)] } else { g.clone() }
+                    })
+                    .collect();
+                assert_eq!(actual, normalized);
+                let ordered = face_edges(&mesh, 7, &Plane::XY).unwrap();
+                for (loop_index, chunk) in ordered.chunks(4).enumerate() {
+                    let want = [40.0, 38.0, 4.0][loop_index];
+                    assert!(chunk.iter().flat_map(|e| &mesh.edges[*e]).all(|p| p.x.abs() <= want));
+                    assert!(chunk.iter().flat_map(|e| &mesh.edges[*e]).any(|p| p.x.abs() == want));
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn rounded_boundary_arc_sweeps_survive_individual_edge_reversal() {
+        use solvecraft_geom::{Seg2, Vec2};
+        use solvecraft_sketch::LinkGeom;
+        let mut mesh = Mesh::default();
+        for (extent, radius) in [(10.0, 3.0), (8.0, 1.0)] {
+            for k in 0..4 {
+                let angle = k as f64 * std::f64::consts::FRAC_PI_2;
+                let rotate = |p: Vec2| (0..k).fold(p, |p, _| p.perp());
+                let centre = rotate(Vec2::new(extent - radius, extent - radius));
+                let arc = Seg2::Arc { center: centre, radius, start: angle, sweep: std::f64::consts::FRAC_PI_2 };
+                let line = Seg2::Line { a: arc.point_at(1.0), b: rotate(Vec2::new(-(extent - radius), extent)) };
+                for seg in [arc, line] {
+                    let pts: Vec<_> = (0..=16).map(|i| Plane::XY.to_world(seg.point_at(i as f64 / 16.0))).collect();
+                    mesh.positions.extend(pts.iter().copied());
+                    mesh.edges.push(pts);
+                    mesh.edge_faces.push(vec![2]);
+                }
+            }
+        }
+        let normalized = |mesh: &Mesh| -> Vec<Vec<LinkGeom>> {
+            face_edges(mesh, 2, &Plane::XY)
+                .unwrap()
+                .into_iter()
+                .map(|e| {
+                    super::super::fit_world(&Plane::XY, &mesh.edges[e])
+                        .into_iter()
+                        .map(|g| match g {
+                            LinkGeom::Line(a, b) if (a.x, a.y) > (b.x, b.y) => LinkGeom::Line(b, a),
+                            g => g,
+                        })
+                        .collect()
+                })
+                .collect()
+        };
+        let expected = normalized(&mesh);
+        for shift in 0..mesh.edges.len() {
+            let mut permuted = mesh.clone();
+            permuted.edges = (0..mesh.edges.len()).map(|i| mesh.edges[(i * 5 + shift) % mesh.edges.len()].clone()).collect();
+            for (i, points) in permuted.edges.iter_mut().enumerate() {
+                if i % 2 == 0 {
+                    points.reverse();
+                }
+            }
+            let actual = normalized(&permuted);
+            for (a, b) in actual.iter().zip(&expected) {
+                assert_eq!(a.len(), b.len());
+                for (a, b) in a.iter().zip(b) {
+                    match (a, b) {
+                        (LinkGeom::Line(a, b), LinkGeom::Line(c, d)) => assert!(a.dist(*c) < 1e-9 && b.dist(*d) < 1e-9),
+                        (LinkGeom::Arc { c, a, b }, LinkGeom::Arc { c: cc, a: aa, b: bb }) => {
+                            assert!(c.dist(*cc) < 1e-9 && a.dist(*aa) < 1e-9 && b.dist(*bb) < 1e-9);
+                        }
+                        _ => panic!("boundary changed kind"),
+                    }
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn incomplete_and_branched_boundaries_are_reported_without_partial_geometry() {
+        let mut open = rectangles();
+        open.edges.pop();
+        open.edge_faces.pop();
+        assert!(face_edges(&open, 7, &Plane::XY).unwrap_err().to_string().contains("open"));
+        let mut branched = rectangles();
+        branched.edges.push(vec![Vec3::new(-40.0, -30.0, 0.0), Vec3::ZERO]);
+        branched.edge_faces.push(vec![7]);
+        assert!(face_edges(&branched, 7, &Plane::XY).is_err());
+        let mut invalid = rectangles();
+        invalid.edges[0].push(Vec3::new(f64::NAN, 0.0, 0.0));
+        assert!(face_edges(&invalid, 7, &Plane::XY).unwrap_err().to_string().contains("invalid"));
+    }
+
+    #[test]
+    fn equal_area_holes_use_geometric_order_after_translation() {
+        let mut baseline = rectangles();
+        baseline.edges.truncate(4);
+        baseline.edge_faces.truncate(4);
+        for x in [-12.0, 12.0] {
+            let pts = [Vec3::new(x - 2.0, -2.0, 0.0), Vec3::new(x + 2.0, -2.0, 0.0), Vec3::new(x + 2.0, 2.0, 0.0), Vec3::new(x - 2.0, 2.0, 0.0)];
+            for i in 0..4 {
+                baseline.edges.push(vec![pts[i], pts[(i + 1) % 4]]);
+                baseline.edge_faces.push(vec![7]);
+            }
+        }
+        let shift = Vec3::new(12345.6789, -23456.7891, 987.0);
+        for p in &mut baseline.positions {
+            *p += shift;
+        }
+        for points in &mut baseline.edges {
+            for p in points {
+                *p += shift;
+            }
+        }
+        for offset in 0..baseline.edges.len() {
+            let mut mesh = baseline.clone();
+            mesh.edges = (0..mesh.edges.len()).map(|i| baseline.edges[(i * 5 + offset) % baseline.edges.len()].clone()).collect();
+            for (i, points) in mesh.edges.iter_mut().enumerate() {
+                if i % 2 == 0 {
+                    points.reverse();
+                }
+            }
+            let order = face_edges(&mesh, 7, &Plane::XY).unwrap();
+            assert!(order[4..8].iter().flat_map(|e| &mesh.edges[*e]).all(|p| p.x < shift.x));
+            assert!(order[8..12].iter().flat_map(|e| &mesh.edges[*e]).all(|p| p.x > shift.x));
+        }
+    }
+}