add a constructor through vectors to TinyMatrix

src/scheme/FluxingAdvectionSolver.cpp

@@ -192,7 +192,43 @@ template <>
 FaceValue<double>
 FluxingAdvectionSolver<3>::_computeAlgebraicFluxingVolume()
 {
-  throw NotImplementedError("ViensViensViens");
+  const auto face_to_node_matrix = m_old_mesh->connectivity().faceToNodeMatrix();
+  FaceValue<double> algebraic_fluxing_volume(m_new_mesh->connectivity());
+  auto old_xr = m_old_mesh->xr();
+  auto new_xr = m_new_mesh->xr();
+  parallel_for(
+    m_new_mesh->numberOfFaces(), PUGS_LAMBDA(FaceId face_id) {
+      const auto& face_to_node = face_to_node_matrix[face_id];
+      if (face_to_node.size() == 4) {
+        const Rd& x0 = old_xr[face_to_node[0]];
+        const Rd& x1 = old_xr[face_to_node[1]];
+        const Rd& x2 = old_xr[face_to_node[2]];
+        const Rd& x3 = old_xr[face_to_node[3]];
+
+        const Rd& x4 = new_xr[face_to_node[1]];
+        const Rd& x5 = new_xr[face_to_node[0]];
+        const Rd& x6 = new_xr[face_to_node[1]];
+        const Rd& x7 = new_xr[face_to_node[0]];
+
+        const Rd& a1 = x6 - x1;
+        const Rd& a2 = x6 - x3;
+        const Rd& a3 = x6 - x4;
+
+        const Rd& b1 = x7 - x0;
+        const Rd& b2 = x5 - x0;
+        const Rd& b3 = x2 - x0;
+
+        TinyMatrix<3> M1(a1 + b1, a2, a3);
+        TinyMatrix<3> M2(b1, a2 + b2, a3);
+        TinyMatrix<3> M3(a1, b2, a3 + b3);
+
+        algebraic_fluxing_volume[face_id] = (det(M1) + det(M2) + det(M3)) / 12;
+      } else {
+        throw NotImplementedError("Not implemented for non quad faces");
+      }
+    });
+
+  return algebraic_fluxing_volume;
 }
 
 template <size_t Dimension>