Merge pull request #1206 from Ramox81/codex/fix-region-measurement-persistence-20260911

src/entities/solid3d.rs

@@ -260,17 +260,26 @@ fn position_section(prefix: &str, p: &acadrust::types::Vector3) -> PropSection {
     }
 }
 
-/// Approximate a region's enclosed area and boundary perimeter from its
-/// wireframe loops. Perimeter is the total edge length across every wire.
-/// Area accumulates the Newell area vector of each loop (opposite-wound
-/// holes subtract) and halves its magnitude — exact for a single planar
-/// loop, approximate for multi-loop or curved regions. Returns zeros when
-/// there is nothing to measure.
-/// The area and perimeter of a region's boundary wires.
-///
-/// Measured in space rather than in projection: a region need not lie in a
-/// coordinate plane, and flattening it to XY first would report its shadow.
-fn region_area_perimeter(wires: &[acadrust::entities::Wire]) -> (f64, f64) {
+/// Measure decoded planar curves in a unit frame, retaining legacy wire-only input.
+fn region_area_perimeter(region: &Region) -> (f64, f64) {
+    let exact = (|| {
+        let (plane, loops, true) = crate::scene::model::presspull_model::profile_geometry(
+            &EntityType::Region(region.clone()),
+        )? else { return None; };
+        let unit = cadkernel::space::Plane::orthonormal(plane.origin, plane.x_axis, plane.normal()?)?;
+        let transform = cadkernel::geom2d::Transform {
+            origin: unit.project(plane.origin)?.into(),
+            x_axis: unit.project_vector(plane.x_axis)?.into(),
+            y_axis: unit.project_vector(plane.y_axis)?.into(),
+        };
+        let curves = loops.iter().flatten().map(|curve| curve.transformed(&transform))
+            .collect::<Option<Vec<_>>>()?;
+        let area = curves.iter().map(|curve| curve.enclosed_area()).sum::<f64>().abs();
+        let perimeter = curves.iter().map(|curve| curve.length()).sum::<f64>();
+        (area.is_finite() && perimeter.is_finite()).then_some((area, perimeter))
+    })();
+    if let Some(measurements) = exact { return measurements; }
+    let wires = &region.wires;
     let mut area_vector = [0.0f64; 3];
     let mut perimeter = 0.0;
     for wire in wires {
@@ -351,7 +360,7 @@ impl Grippable for Region {
 
 impl PropertyEditable for Region {
     fn geometry_properties(&self, _text_style_names: &[String]) -> Vec<PropSection> {
-        let (area, perimeter) = region_area_perimeter(&self.wires);
+        let (area, perimeter) = region_area_perimeter(self);
         let mut sections =
             acis_sections(&self.acis_data, &self.wires, &self.silhouettes, self.history_handle);
         sections[0]
@@ -912,3 +921,36 @@ pub fn tessellate_volume(
         _ => None,
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use cadkernel::geom2d::{Curve, Line};
+
+    fn ring(points: &[[f64; 2]]) -> Vec<Curve> {
+        points.iter().copied().zip(points.iter().copied().cycle().skip(1))
+            .take(points.len()).map(|(start, end)| Curve::Line(Line { start, end })).collect()
+    }
+
+    #[test]
+    fn decoded_region_reports_exact_hole_area_perimeter_and_bounds() {
+        let loops = vec![
+            ring(&[[0.0, 0.0], [10.0, 0.0], [10.0, 10.0], [0.0, 10.0]]),
+            ring(&[[2.0, 2.0], [2.0, 4.0], [4.0, 4.0], [4.0, 2.0]]),
+        ];
+        let EntityType::Region(mut region) =
+            crate::scene::model::presspull_model::region_from_loops(
+                &loops,
+                crate::command::WorkingPlane::default(),
+            ).unwrap()
+        else { unreachable!() };
+        region.wires.clear();
+
+        let (area, perimeter) = region_area_perimeter(&region);
+        assert!((area - 96.0).abs() < 1e-8, "{area}");
+        assert!((perimeter - 48.0).abs() < 1e-8, "{perimeter}");
+        let (min, max) = crate::scene::convert::tess::entity_bounds(&EntityType::Region(region));
+        assert_eq!(min, [0.0, 0.0, 0.0]);
+        assert_eq!(max, [10.0, 10.0, 0.0]);
+    }
+}