fix: more /* */ inside doxygen blocks in octree/boolean_mesh

src/curves/nurbs_operations.cpp

@@ -143,7 +143,7 @@ NurbsCurve extract_boundary_curve(const NurbsSurface& surf, int edge) {
 }
 
 // ---------------------------------------------------------------------------
-//  offset a curve by moving its control points along surface normals
+//  offset a boundary curve along the surface tangent ("inward") direction
 // ---------------------------------------------------------------------------
 static NurbsCurve offset_boundary_curve(const NurbsSurface& surf,
                                          int edge, double dist) {
@@ -159,59 +159,49 @@ static NurbsCurve offset_boundary_curve(const NurbsSurface& surf,
     auto gu = greville_abscissae(ku, du);
     auto gv = greville_abscissae(kv, dv);
 
-    // Negative normal = inward offset
-    double sign = -1.0;
-
     std::vector<Point3D> curve_cp;
     std::vector<double> curve_w;
     std::vector<double> curve_knots;
     int curve_deg;
 
-    if (edge == 0) { // u=0
-        curve_cp = cp[0];
-        curve_w  = w.empty() ? std::vector<double>(nv, 1.0) : w[0];
+    if (edge == 0 || edge == 1) {
+        // u-edge: curve runs along v, offset along ±u tangent
+        double u_val  = (edge == 0) ? gu[0] : gu[nu - 1];
+        double inward = (edge == 0) ? 1.0 : -1.0; // +du for umin, -du for umax
+        int idx       = (edge == 0) ? 0 : nu - 1;
+
+        curve_cp    = cp[idx];
+        curve_w     = w.empty() ? std::vector<double>(nv, 1.0) : w[idx];
         curve_knots = kv;
         curve_deg   = dv;
+
         for (int j = 0; j < nv; ++j) {
-            Vector3D n = surf.normal(gu[0], gv[j]);
-            curve_cp[j] = Point3D(curve_cp[j].x() + sign * dist * n.x(),
-                                  curve_cp[j].y() + sign * dist * n.y(),
-                                  curve_cp[j].z() + sign * dist * n.z());
+            Vector3D tan = surf.derivative_u(u_val, gv[j]);
+            double len = tan.norm();
+            if (len > 1e-12) tan = (inward * dist / len) * tan;
+            else           tan = Vector3D::Zero();
+            curve_cp[j] = Point3D(curve_cp[j].x() + tan.x(),
+                                  curve_cp[j].y() + tan.y(),
+                                  curve_cp[j].z() + tan.z());
         }
-    } else if (edge == 1) { // u=1
-        curve_cp = cp[nu - 1];
-        curve_w  = w.empty() ? std::vector<double>(nv, 1.0) : w[nu - 1];
-        curve_knots = kv;
-        curve_deg   = dv;
-        for (int j = 0; j < nv; ++j) {
-            Vector3D n = surf.normal(gu[nu - 1], gv[j]);
-            curve_cp[j] = Point3D(curve_cp[j].x() + sign * dist * n.x(),
-                                  curve_cp[j].y() + sign * dist * n.y(),
-                                  curve_cp[j].z() + sign * dist * n.z());
-        }
-    } else if (edge == 2) { // v=0
+    } else {
+        // v-edge: curve runs along u, offset along ±v tangent
+        double v_val  = (edge == 2) ? gv[0] : gv[nv - 1];
+        double inward = (edge == 2) ? 1.0 : -1.0; // +dv for vmin, -dv for vmax
+        int idx       = (edge == 2) ? 0 : nv - 1;
+
         curve_cp.reserve(nu);
         curve_w.reserve(nu);
         for (int i = 0; i < nu; ++i) {
-            Vector3D n = surf.normal(gu[i], gv[0]);
-            Point3D pt = cp[i][0];
-            curve_cp.push_back(Point3D(pt.x() + sign * dist * n.x(),
-                                       pt.y() + sign * dist * n.y(),
-                                       pt.z() + sign * dist * n.z()));
-            curve_w.push_back(w.empty() ? 1.0 : w[i][0]);
-        }
-        curve_knots = ku;
-        curve_deg   = du;
-    } else { // v=1 (edge == 3)
-        curve_cp.reserve(nu);
-        curve_w.reserve(nu);
-        for (int i = 0; i < nu; ++i) {
-            Vector3D n = surf.normal(gu[i], gv[nv - 1]);
-            Point3D pt = cp[i][nv - 1];
-            curve_cp.push_back(Point3D(pt.x() + sign * dist * n.x(),
-                                       pt.y() + sign * dist * n.y(),
-                                       pt.z() + sign * dist * n.z()));
-            curve_w.push_back(w.empty() ? 1.0 : w[i][nv - 1]);
+            Vector3D tan = surf.derivative_v(gu[i], v_val);
+            double len = tan.norm();
+            if (len > 1e-12) tan = (inward * dist / len) * tan;
+            else           tan = Vector3D::Zero();
+            Point3D pt = cp[i][idx];
+            curve_cp.push_back(Point3D(pt.x() + tan.x(),
+                                       pt.y() + tan.y(),
+                                       pt.z() + tan.z()));
+            curve_w.push_back(w.empty() ? 1.0 : w[i][idx]);
         }
         curve_knots = ku;
         curve_deg   = du;
@@ -283,12 +273,6 @@ NurbsSurface coons_patch(const NurbsCurve& curve_u0,
     std::vector<std::vector<Point3D>> grid(nu, std::vector<Point3D>(nv));
     std::vector<std::vector<double>> w(nu, std::vector<double>(nv, 1.0));
 
-    // Corners
-    Point3D P00 = curve_u0.evaluate(gu[0]);              // u=0, v=0
-    Point3D P10 = curve_u0.evaluate(gu[nu - 1]);         // u=1, v=0
-    Point3D P01 = curve_u1.evaluate(gu[0]);              // u=0, v=1
-    Point3D P11 = curve_u1.evaluate(gu[nu - 1]);         // u=1, v=1
-
     // Edge control points (from boundary curves)
     // u=0 edge: v0 curve CPs
     // u=1 edge: v1 curve CPs