feat: 测试覆盖扩展 + 文档更新

src/foundation/io_obj.cpp

@@ -10,29 +10,76 @@ ObjMeshData read_obj(const std::string& filepath) {
     if (!file) return data;
 
     std::string line;
+    std::string current_material;
+
     while (std::getline(file, line)) {
+        // Trim trailing \r
+        if (!line.empty() && line.back() == '\r') line.pop_back();
+
         if (line.empty() || line[0] == '#') continue;
         std::istringstream iss(line);
         std::string token;
         iss >> token;
+
         if (token == "v") {
             double x, y, z;
             iss >> x >> y >> z;
             data.vertices.emplace_back(x, y, z);
-        } else if (token == "vn") {
+        }
+        else if (token == "vt") {
+            double u, v, w = 0.0;
+            iss >> u >> v;
+            if (iss >> w) { /* 1D/3D texcoord — keep only uv */ }
+            data.texcoords.emplace_back(u, v);
+        }
+        else if (token == "vn") {
             double nx, ny, nz;
             iss >> nx >> ny >> nz;
             data.normals.emplace_back(nx, ny, nz);
-        } else if (token == "f") {
-            std::vector<int> face;
+        }
+        else if (token == "usemtl") {
+            iss >> current_material;
+        }
+        else if (token == "f") {
+            std::vector<int> face_v;
+            std::vector<int> face_vt;
+            std::vector<int> face_vn;
+
             std::string vertex;
             while (iss >> vertex) {
-                std::istringstream viss(vertex);
-                std::string vi_str;
-                std::getline(viss, vi_str, '/');
-                face.push_back(std::stoi(vi_str) - 1);
+                // Parse v/vt/vn, v//vn, v/vt formats
+                int v_idx  = -1;
+                int vt_idx = -1;
+                int vn_idx = -1;
+
+                // Count slashes
+                size_t slash1 = vertex.find('/');
+                if (slash1 == std::string::npos) {
+                    // "v" only
+                    v_idx = std::stoi(vertex) - 1;
+                } else {
+                    v_idx = std::stoi(vertex.substr(0, slash1)) - 1;
+                    size_t slash2 = vertex.find('/', slash1 + 1);
+                    if (slash2 == std::string::npos) {
+                        // "v/vt"
+                        vt_idx = std::stoi(vertex.substr(slash1 + 1)) - 1;
+                    } else {
+                        // "v/vt/vn" or "v//vn"
+                        std::string mid = vertex.substr(slash1 + 1, slash2 - slash1 - 1);
+                        if (!mid.empty()) vt_idx = std::stoi(mid) - 1;
+                        vn_idx = std::stoi(vertex.substr(slash2 + 1)) - 1;
+                    }
+                }
+
+                face_v.push_back(v_idx);
+                face_vt.push_back(vt_idx);
+                face_vn.push_back(vn_idx);
             }
-            data.faces.push_back(std::move(face));
+
+            data.faces.push_back(std::move(face_v));
+            data.face_texcoords.push_back(std::move(face_vt));
+            data.face_normals.push_back(std::move(face_vn));
+            data.face_materials.push_back(current_material);
         }
     }
     return data;
@@ -40,13 +87,57 @@ ObjMeshData read_obj(const std::string& filepath) {
 
 void write_obj(const std::string& filepath, const ObjMeshData& data) {
     std::ofstream file(filepath);
+    if (!file) return;
+
+    file.precision(12);
+
+    // Vertices
     for (const auto& v : data.vertices)
         file << "v " << v.x() << " " << v.y() << " " << v.z() << "\n";
+
+    // Texture coordinates
+    for (const auto& vt : data.texcoords)
+        file << "vt " << vt.x() << " " << vt.y() << "\n";
+
+    // Normals
+    bool has_vt = data.has_texcoords();
+    bool has_vn = !data.normals.empty();
+
     for (const auto& n : data.normals)
         file << "vn " << n.x() << " " << n.y() << " " << n.z() << "\n";
-    for (const auto& f : data.faces) {
+
+    // Faces with material tracking
+    std::string current_mtl;
+    for (size_t fi = 0; fi < data.faces.size(); ++fi) {
+        // Emit material change
+        if (fi < data.face_materials.size() && data.face_materials[fi] != current_mtl) {
+            current_mtl = data.face_materials[fi];
+            if (!current_mtl.empty())
+                file << "usemtl " << current_mtl << "\n";
+        }
+
         file << "f";
-        for (int vi : f) file << " " << (vi + 1);
+        const auto& fv = data.faces[fi];
+        for (size_t vi = 0; vi < fv.size(); ++vi) {
+            file << " " << (fv[vi] + 1);  // 0-based → 1-based
+
+            bool wrote_slash = false;
+            if (has_vt && fi < data.face_texcoords.size() && vi < data.face_texcoords[fi].size()) {
+                int vt = data.face_texcoords[fi][vi];
+                if (vt >= 0) {
+                    if (!wrote_slash) { file << "/"; wrote_slash = true; }
+                    file << (vt + 1);
+                }
+            }
+
+            if (has_vn && fi < data.face_normals.size() && vi < data.face_normals[fi].size()) {
+                int vn = data.face_normals[fi][vi];
+                if (vn >= 0) {
+                    if (!wrote_slash) file << "/";
+                    file << "/" << (vn + 1);
+                }
+            }
+        }
         file << "\n";
     }
 }