From e67b758566633fdf80916db471d4344c7a347154 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=8C=82=E4=B9=8B=E9=92=B3?= <claw@hdtime.space>
Date: Fri, 24 Jul 2026 11:42:13 +0000
Subject: [PATCH] =?UTF-8?q?fix:=203MF=20multi-object=20parsing=20=E2=80=94?=
 =?UTF-8?q?=20flush=20per=20object?=
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---
 src/foundation/io_3mf.cpp | 86 ++++++++++++++-------------------------
 1 file changed, 31 insertions(+), 55 deletions(-)

diff --git a/src/foundation/io_3mf.cpp b/src/foundation/io_3mf.cpp
index 2b14850..51e7905 100644
--- a/src/foundation/io_3mf.cpp
+++ b/src/foundation/io_3mf.cpp
@@ -328,14 +328,33 @@ static std::vector<ThreeMFMesh> parse_model_xml(const std::string& xml) {
     std::istringstream iss(xml);
     std::string line;
 
-    // Parse all <object> blocks in the XML
+    // Per-object state
     std::vector<std::array<double, 3>> verts;
     std::vector<std::array<int, 3>> tris;
     bool in_vertices = false, in_triangles = false;
     std::string object_name;
 
+    auto add_current_object = [&]() {
+        if (verts.empty()) return;
+        std::vector<mesh::Point3D> pts;
+        pts.reserve(verts.size());
+        for (const auto& v : verts) pts.emplace_back(v[0], v[1], v[2]);
+        std::vector<std::array<int, 3>> faces;
+        for (const auto& t : tris) {
+            if (t[0]>=0 && (size_t)t[0]<verts.size()
+             && t[1]>=0 && (size_t)t[1]<verts.size()
+             && t[2]>=0 && (size_t)t[2]<verts.size())
+                faces.push_back(t);
+        }
+        ThreeMFMesh m;
+        m.mesh.build_from_triangles(pts, faces);
+        m.name = object_name;
+        results.push_back(std::move(m));
+        verts.clear();
+        tris.clear();
+    };
+
     while (std::getline(iss, line)) {
-        // Trim whitespace
         size_t start = 0;
         while (start < line.size() && (line[start] == ' ' || line[start] == '\t' || line[start] == '\r'))
             ++start;
@@ -344,79 +363,36 @@ static std::vector<ThreeMFMesh> parse_model_xml(const std::string& xml) {
             if (!line.empty() && line.back() == '\r') line.pop_back();
         }
 
+        // New object: flush previous
         if (line.find("<object ") != std::string::npos) {
+            add_current_object();
             object_name = xml_get_attr(line, "name");
         }
 
-        if (line.find("<vertices>") != std::string::npos) {
-            in_vertices = true;
-            continue;
-        }
-        if (line.find("</vertices>") != std::string::npos) {
-            in_vertices = false;
-            continue;
-        }
-        if (line.find("<triangles>") != std::string::npos) {
-            in_triangles = true;
-            continue;
-        }
-        if (line.find("</triangles>") != std::string::npos) {
-            in_triangles = false;
-            continue;
-        }
+        if (line.find("<vertices>") != std::string::npos) { in_vertices = true; continue; }
+        if (line.find("</vertices>") != std::string::npos) { in_vertices = false; continue; }
+        if (line.find("<triangles>") != std::string::npos) { in_triangles = true; continue; }
+        if (line.find("</triangles>") != std::string::npos) { in_triangles = false; continue; }
 
         if (in_vertices && line.find("<vertex ") != std::string::npos) {
             auto xs = xml_get_attr(line, "x");
             auto ys = xml_get_attr(line, "y");
             auto zs = xml_get_attr(line, "z");
-            if (!xs.empty() && !ys.empty() && !zs.empty()) {
+            if (!xs.empty() && !ys.empty() && !zs.empty())
                 verts.push_back({std::stod(xs), std::stod(ys), std::stod(zs)});
-            }
         }
 
         if (in_triangles && line.find("<triangle ") != std::string::npos) {
             auto v1s = xml_get_attr(line, "v1");
             auto v2s = xml_get_attr(line, "v2");
             auto v3s = xml_get_attr(line, "v3");
-            if (!v1s.empty() && !v2s.empty() && !v3s.empty()) {
+            if (!v1s.empty() && !v2s.empty() && !v3s.empty())
                 tris.push_back({std::stoi(v1s), std::stoi(v2s), std::stoi(v3s)});
-            }
         }
     }
 
-    // Build mesh
-    std::vector<mesh::Point3D> pts;
-    pts.reserve(verts.size());
-    for (const auto& v : verts) {
-        pts.emplace_back(v[0], v[1], v[2]);
-    }
-
-    std::vector<std::array<int, 3>> faces;
-    faces.reserve(tris.size());
-    for (const auto& t : tris) {
-        // Validate indices
-        if (t[0] >= 0 && static_cast<size_t>(t[0]) < verts.size() &&
-            t[1] >= 0 && static_cast<size_t>(t[1]) < verts.size() &&
-            t[2] >= 0 && static_cast<size_t>(t[2]) < verts.size()) {
-            faces.push_back(t);
-        }
-    }
-
-    ThreeMFMesh m;
-    m.mesh.build_from_triangles(pts, faces);
-    m.name = object_name;
-    results.push_back(m);
-
-    // Reset for next object
-    verts.clear();
-    tris.clear();
-    object_name.clear();
-    pts.clear();
-    faces.clear();
-    
-    // Re-parse for next objects? No, the function ends here.
-    // Actually this only works for the first object.
-    // For multi-object, need to detect <object> boundaries
+    // Flush final object
+    add_current_object();
     return results;
 }