Speed up cold document geometry rebuilds

crates/kernel/src/refine_cache_tests.rs

@@ -0,0 +1,53 @@
+use super::*;
+
+fn bits(v: Vec3) -> [u64; 3] {
+    [v.x.to_bits(), v.y.to_bits(), v.z.to_bits()]
+}
+
+fn check_body(body: &Body) -> usize {
+    let meshes = mesh_shells(&body.solid, 0.5);
+    let mut changed = 0;
+    for (face, meshed) in body.solid.face_iter().zip(meshes.iter().flat_map(|shell| shell.face_iter())) {
+        let Some(mesh) = meshed.surface() else { continue };
+        let surface = face.surface();
+        let cached = refined_with_cache(&mesh, &surface, 0.002, true);
+        let original = refined_with_cache(&mesh, &surface, 0.002, false);
+        match (cached, original) {
+            (None, None) => {}
+            (Some(cached), Some(original)) => {
+                changed += 1;
+                assert_eq!(cached.len(), original.len(), "triangle count/winding must not change");
+                for (cached, original) in cached.into_iter().zip(original) {
+                    for ((point, normal), (old_point, old_normal)) in cached.into_iter().zip(original) {
+                        assert_eq!(bits(point), bits(old_point), "every refined coordinate must remain bit-identical");
+                        assert_eq!(bits(normal), bits(old_normal), "every refined normal must remain bit-identical");
+                    }
+                }
+            }
+            _ => panic!("memoization changed the refine/no-refine decision"),
+        }
+    }
+    changed
+}
+
+#[test]
+fn exact_refinement_cache_preserves_periodic_seams_and_normals() {
+    let cylinder = crate::cylinder(Vec3::ZERO, Vec3::Z, 15., 8.).unwrap();
+    let torus = crate::torus(Vec3::ZERO, 18., 4.).unwrap();
+    assert!(check_body(&cylinder) > 0, "the fixture must actually refine");
+    assert!(check_body(&torus) > 0, "the periodic fixture must actually refine");
+}
+
+#[test]
+fn exact_refinement_cache_preserves_singular_poles_and_placed_surfaces() {
+    let sphere = crate::sphere(Vec3::ZERO, 12.).unwrap();
+    assert!(check_body(&sphere) > 0, "the polar fixture must actually refine");
+    let placed = crate::transform(&sphere, Vec3::new(120., -85., 40.), Vec3::ZERO, Vec3::new(1., 2., 3.), 0.371).unwrap();
+    assert!(check_body(&placed) > 0);
+}
+
+#[test]
+fn exact_refinement_cache_keeps_unnecessary_planar_refinement_absent() {
+    let body = crate::box_solid(Vec3::ZERO, Vec3::new(10., 20., 30.)).unwrap();
+    assert_eq!(check_body(&body), 0);
+}