fix typo

code/src/apps/v0/conformallab_cli.cpp

@@ -0,0 +1,93 @@
+#include <CGAL/Simple_cartesian.h>
+#include <CGAL/Surface_mesh.h>
+#include <CGAL/IO/polygon_mesh_io.h>
+
+#include <CGAL/Polygon_mesh_processing/triangulate_faces.h>
+
+#include <CLI11.hpp>
+#include <iostream>
+#include <string>
+
+#include <igl/opengl/glfw/Viewer.h>
+#include <Eigen/Core>
+
+
+using Kernel = CGAL::Simple_cartesian<double>;
+using Point  = Kernel::Point_3;
+using Mesh   = CGAL::Surface_mesh<Point>;
+namespace PMP = CGAL::Polygon_mesh_processing;
+
+int main(int argc, char* argv[])
+{
+    CLI::App app{"demo of conformallab"};
+    std::string input_file;
+    std::string output_file; // default output file name
+
+    app.add_option("-i,--input",  input_file,  "Input OFF file")->required();
+    app.add_option("-o,--output", output_file, "Output OFF file (optional)");
+    CLI11_PARSE(app, argc, argv);
+
+    if (input_file.empty()) {
+        std::cerr << "Input file is required.\n";
+        return EXIT_FAILURE;
+    }
+
+    if (input_file.substr(input_file.find_last_of('.') + 1) != "off") {
+        std::cerr << "Unsupported file format. Please provide an OFF file.\n";
+        return EXIT_FAILURE;
+    }
+
+    Mesh surface_mesh;
+    if (!CGAL::IO::read_polygon_mesh(input_file, surface_mesh) || surface_mesh.is_empty()) {
+        std::cerr << "Invalid input file: " << input_file << "\n";
+        return EXIT_FAILURE;
+    }
+  
+    // #TODO: later: here we would call the unwrapping code, e.g.:
+    // UnwrapSettings settings;
+    // settings.target_geometry = TargetGeometry::Euclidean;
+    // UnwrapJob job(surface_mesh, settings);
+    // auto result = job.run();
+    // Mesh unwrapped = result.surface_unwrapped;
+
+
+    // CGAL -> libigl
+    PMP::triangulate_faces(surface_mesh);
+    //todo : we should check if the mesh is already triangulated, and only call this if it isn't, to avoid unnecessary processing. CGAL::Polygon_mesh_processing::is_triangulated() can be used for this check.
+    Eigen::MatrixXd Vertices;
+    Eigen::MatrixXi Faces;
+    Vertices.resize(surface_mesh.number_of_vertices(), 3);
+    Faces.resize(surface_mesh.number_of_faces(),    3);
+    
+        for (auto v : surface_mesh.vertices()) {
+            const auto& p = surface_mesh.point(v);
+            Vertices(v.idx(), 0) = p.x();
+            Vertices(v.idx(), 1) = p.y();
+            Vertices(v.idx(), 2) = p.z();
+        }
+    
+        int f_i = 0;
+        for (auto f : surface_mesh.faces()) {
+            int k = 0;
+            for (auto hv : CGAL::halfedges_around_face(surface_mesh.halfedge(f), surface_mesh)) {
+                auto v = surface_mesh.target(hv);
+                Faces(f_i, k) = v.idx();
+                ++k;
+            }
+            ++f_i;
+        }
+    
+        igl::opengl::glfw::Viewer viewer;
+        viewer.data().set_mesh(Vertices, Faces);
+        viewer.launch();
+
+
+    
+    // for now, we just write the input mesh to the output file as a placeholder
+    if (!output_file.empty() && !CGAL::IO::write_polygon_mesh(output_file, surface_mesh)) {
+        std::cerr << "Failed to write output file: " << output_file << "\n";
+        return EXIT_FAILURE;
+    }
+
+    return EXIT_SUCCESS;
+}