{

std::cout << "\n=================== triangle_mesh_area() ===================" << std::endl;

struct Data

{

std::vector<Eigen::Vector3d> vertices;

std::vector<std::array<int, 3>> triangles;

} data;

auto mesh = generate_triangle_grid(Eigen::Vector2d{0.5, 0.5}, {10, 10});

data.vertices = mesh.vertices;

data.triangles = mesh.triangles;

// Create MappedWorkspace

auto [mws, element] = MappedWorkspace<double>::create(data.triangles);

// Spawn symbols from data

std::vector<Vector> v = mws->make_vectors(data.vertices, element);

// Expression

Vector cross = (v[1] - v[0]).cross3(v[2] - v[0]);

Scalar area = 0.5*cross.norm();

// Compilation

const std::string codegen_dir = symx::get_codegen_dir();

auto loop = CompiledInLoop<double>::create(mws, {area}, "tri_area", codegen_dir);

// Evaluation

double total_area = 0.0;

const int n_threads = 1;

loop->run(n_threads,

[&](const View<double> out, const int32_t elem_idx, const int32_t thread_id, const View<int32_t> elem_conn)

{

total_area += out[0];

}

);

// Print

std::cout << "Total triangle mesh area: " << total_area << std::endl;

loop->get_info().print();