off import/export

src/polymesh/formats/off.cc

+#include "off.hh"
+
+#include <fstream>
+#include <sstream>
+
+namespace polymesh
+{
+void write_off(const std::string &filename, const Mesh &mesh, const vertex_attribute<glm::vec3> &position)
+{
+    std::ofstream file(filename);
+    write_off(file, mesh, position);
+}
+void write_off(std::ostream &out, const Mesh &mesh, const vertex_attribute<glm::vec3> &position)
+{
+    out << "OFF\n";
+    out << mesh.vertices().size() << " " << mesh.faces().size() << " " << mesh.edges().size() << "\n";
+
+    for (auto v : mesh.all_vertices())
+    {
+        auto pos = v[position];
+        out << pos.x << " " << pos.y << " " << pos.z << "\n";
+    }
+
+    for (auto f : mesh.faces())
+    {
+        out << f.vertices().size();
+        for (auto v : f.vertices())
+            out << " " << v.idx.value;
+        out << "\n";
+    }
+}
+
+bool read_off(const std::string &filename, Mesh &mesh, vertex_attribute<glm::vec3> &position)
+{
+    std::ifstream file(filename);
+    if (!file.good())
+        return false;
+
+    return read_off(file, mesh, position);
+}
+
+bool read_off(std::istream &input, Mesh &mesh, vertex_attribute<glm::vec3> &position)
+{
+    std::string str;
+    input >> str;
+    if (str != "OFF")
+        return false;
+
+    // read counts
+    int v_cnt, f_cnt, e_cnt;
+    input >> v_cnt >> f_cnt >> e_cnt;
+    (void)e_cnt; // unused
+
+    // read vertices
+    for (auto i = 0; i < v_cnt; ++i)
+    {
+        auto v = mesh.vertices().add();
+        auto &pos = v[position];
+        input >> pos.x >> pos.y >> pos.z;
+    }
+
+    // read faces
+    std::vector<vertex_handle> vs;
+    for (auto i = 0; i < f_cnt; ++i)
+    {
+        int valence;
+        input >> valence;
+        vs.resize(valence);
+        for (auto vi = 0; vi < valence; ++vi)
+        {
+            int v;
+            input >> v;
+            vs[vi] = mesh[vertex_index(v)];
+        }
+
+        mesh.faces().add(vs);
+    }
+
+    return true;
+}
+}

src/polymesh/formats/off.hh

+#pragma once
+
+#include <glm/glm.hpp>
+
+#include <iostream>
+#include <string>
+
+#include "../Mesh.hh"
+
+namespace polymesh
+{
+void write_off(std::string const& filename, Mesh const& mesh, vertex_attribute<glm::vec3> const& position);
+void write_off(std::ostream& out, Mesh const& mesh, vertex_attribute<glm::vec3> const& position);
+bool read_off(std::string const& filename, Mesh& mesh, vertex_attribute<glm::vec3>& position);
+bool read_off(std::istream& input, Mesh& mesh, vertex_attribute<glm::vec3>& position);
+}