From d99c9f1dba04389059127d4af2838c38a9971f19 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 09:13:18 +0000
Subject: [PATCH] fix: inline tessellation in io_gltf to avoid circular dep

---
 src/foundation/io_gltf.cpp | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/src/foundation/io_gltf.cpp b/src/foundation/io_gltf.cpp
index f1d20c9..e9fa81c 100644
--- a/src/foundation/io_gltf.cpp
+++ b/src/foundation/io_gltf.cpp
@@ -296,13 +296,32 @@ bool write_brep_gltf(const std::string& filepath, const brep::BrepModel& model,
 
         const auto& surf = model.surface(surf_id);
 
-        // Tessellate using the surface evaluator
+        // Inline tessellation: sample surface uniformly, create quad mesh
         int res = std::max(4, tessellation_res);
-        auto eval = [&surf](double u, double v) -> core::Point3D {
-            return surf.evaluate(u, v);
-        };
+        std::vector<core::Point3D> verts;
+        std::vector<std::array<int, 3>> tris;
 
-        auto [verts, tris] = curves::tessellate(eval, res, res);
+        auto [u_min, u_max] = surf.domain_u();
+        auto [v_min, v_max] = surf.domain_v();
+
+        for (int j = 0; j <= res; ++j) {
+            double v = v_min + (v_max - v_min) * static_cast<double>(j) / res;
+            for (int i = 0; i <= res; ++i) {
+                double u = u_min + (u_max - u_min) * static_cast<double>(i) / res;
+                verts.push_back(surf.evaluate(u, v));
+            }
+        }
+
+        for (int j = 0; j < res; ++j) {
+            for (int i = 0; i < res; ++i) {
+                int a = j * (res + 1) + i;
+                int b = a + 1;
+                int c = a + (res + 1);
+                int d = c + 1;
+                tris.push_back({a, b, d});
+                tris.push_back({a, d, c});
+            }
+        }
 
         // Offset indices
         int base = static_cast<int>(all_verts.size());