feat(v4.6): memory pool + parallel boolean/MC/intersection + GMP exact predicates

M1 — Memory Pool (内存池):
- ObjectPool<T>: O(1) acquire/release with free-list, chunk-based expansion
- ThreadSafeObjectPool<T>: per-thread local pools with global fallback
- CowPtr<T>: copy-on-write smart pointer with shallow/deep copy
- 10 tests: single/multi-thread, CoW detach, reuse rate

M2 — Parallel Boolean (并行布尔):
- parallel_face_face_intersection(): OpenMP face-pair dispatch with AABB culling
- parallel_classify_faces(): thread-safe ray casting classification
- parallel_mesh_union/intersection/difference + B-Rep variants
- Thread count management API
- 12 tests: coverage, empty cases, identity operations

M3 — Parallel Marching Cubes (并行MC):
- parallel_marching_cubes(): Z-slice parallel voxel processing
- parallel_adaptive_mc(): octree-based adaptive resolution
- Complete 256-entry edge table + Möller-Trumbore interpolation
- 5 tests: sphere basic/high-res/empty/adaptive/threaded

M4 — Parallel Surface Intersection (并行求交):
- parallel_curve_intersections(): per-pair parallel dispatch
- parallel_surface_intersection(): recursive subdivision + Newton refinement
- AABB broad-phase culling before narrow-phase
- 4 tests: curve pairs, surface batch

M5 — GMP Exact Predicates (精确谓词):
- exact_orient2d/3d: adaptive precision (double → GMP fallback)
- exact_in_sphere: circumsphere test with degenerate handling
- exact_point_in_polygon/polyhedron: robust ray casting
- PrecisionMode: Fast/Adaptive/Exact with global toggle
- 12 tests: all orientations, boundary cases, mode switching

21 files, +2263 lines

tests/core/CMakeLists.txt

@@ -4,3 +4,5 @@ add_vde_test(test_transform)
 add_vde_test(test_distance)
 add_vde_test(test_polygon)
 add_vde_test(test_cam_toolpath)
+add_vde_test(test_object_pool)
+add_vde_test(test_exact_predicates)

tests/core/test_exact_predicates.cpp

@@ -0,0 +1,73 @@
+#include <gtest/gtest.h>
+#include "vde/core/exact_predicates.h"
+#include <vector>
+#include <cmath>
+
+using namespace vde::core;
+
+TEST(ExactPredicatesTest, Orient2D_CounterClockwise) {
+    double r = exact_orient2d(0, 0, 1, 0, 0, 1);
+    EXPECT_GT(r, 0.0); // CCW
+}
+
+TEST(ExactPredicatesTest, Orient2D_Clockwise) {
+    double r = exact_orient2d(0, 0, 0, 1, 1, 0);
+    EXPECT_LT(r, 0.0);
+}
+
+TEST(ExactPredicatesTest, Orient2D_Collinear) {
+    double r = exact_orient2d(0, 0, 1, 1, 2, 2);
+    EXPECT_NEAR(r, 0.0, 1e-9);
+}
+
+TEST(ExactPredicatesTest, Orient3D_Above) {
+    // Tetrahedron: base on z=0, apex at z=1 → positive volume
+    double r = exact_orient3d(0,0,0, 1,0,0, 0,1,0, 0,0,1);
+    EXPECT_GT(r, 0.0);
+}
+
+TEST(ExactPredicatesTest, Orient3D_Coplanar) {
+    double r = exact_orient3d(0,0,0, 1,0,0, 0,1,0, 0.5,0.5,0);
+    EXPECT_NEAR(r, 0.0, 1e-9);
+}
+
+TEST(ExactPredicatesTest, InSphere_Inside) {
+    // Regular tetrahedron, point at centroid → inside circumsphere
+    double r = exact_in_sphere(0,0,0, 2,0,0, 0,2,0, 0,0,2, 0.2,0.2,0.2);
+    EXPECT_GT(r, 0.0);
+}
+
+TEST(ExactPredicatesTest, InSphere_OnSurface) {
+    double r = exact_in_sphere(0,0,0, 3,0,0, 0,3,0, 0,0,3, 0,0,3);
+    EXPECT_NEAR(r, 0.0, 1e-8);
+}
+
+TEST(ExactPredicatesTest, PointInPolygon_Inside) {
+    std::vector<Point3D> poly = {{0,0,0},{2,0,0},{2,2,0},{0,2,0}};
+    EXPECT_TRUE(exact_point_in_polygon({1,1,0}, poly));
+}
+
+TEST(ExactPredicatesTest, PointInPolygon_Outside) {
+    std::vector<Point3D> poly = {{0,0,0},{2,0,0},{2,2,0},{0,2,0}};
+    EXPECT_FALSE(exact_point_in_polygon({3,3,0}, poly));
+}
+
+TEST(ExactPredicatesTest, PointInPolygon_OnEdge) {
+    std::vector<Point3D> poly = {{0,0,0},{2,0,0},{2,2,0},{0,2,0}};
+    EXPECT_TRUE(exact_point_in_polygon({1,0,0}, poly));
+}
+
+TEST(ExactPredicatesTest, PrecisionMode) {
+    set_precision_mode(PrecisionMode::Fast);
+    EXPECT_EQ(precision_mode(), PrecisionMode::Fast);
+
+    set_precision_mode(PrecisionMode::Adaptive);
+    EXPECT_EQ(precision_mode(), PrecisionMode::Adaptive);
+
+    set_precision_mode(PrecisionMode::Adaptive); // restore default
+}
+
+TEST(ExactPredicatesTest, IsUncertain) {
+    EXPECT_TRUE(is_uncertain(1e-12));
+    EXPECT_FALSE(is_uncertain(1.0));
+}

tests/core/test_object_pool.cpp

@@ -0,0 +1,99 @@
+#include <gtest/gtest.h>
+#include "vde/core/object_pool.h"
+#include <thread>
+#include <vector>
+
+using namespace vde::core;
+
+struct TestObj { int x = 0; double y = 0.0; };
+
+TEST(ObjectPoolTest, AcquireRelease) {
+    ObjectPool<TestObj> pool;
+    auto* obj = pool.acquire();
+    ASSERT_NE(obj, nullptr);
+    obj->x = 42;
+    pool.release(obj);
+    auto* obj2 = pool.acquire(); // should reuse
+    EXPECT_EQ(obj2->x, 0); // reset to default
+    EXPECT_GT(pool.reuse_rate(), 0.0);
+}
+
+TEST(ObjectPoolTest, AcquireMany) {
+    ObjectPool<TestObj, 64> pool;
+    std::vector<TestObj*> objs;
+    for (int i = 0; i < 1000; ++i) objs.push_back(pool.acquire());
+    for (auto* o : objs) pool.release(o);
+    EXPECT_EQ(pool.total_allocated(), 1000u);
+    EXPECT_GT(pool.total_reused(), 0u);
+}
+
+TEST(ObjectPoolTest, ReleaseNullptr) {
+    ObjectPool<TestObj> pool;
+    pool.release(nullptr); // should not crash
+    EXPECT_EQ(pool.total_allocated(), 0u);
+}
+
+TEST(ObjectPoolTest, ExpandChunk) {
+    ObjectPool<TestObj, 10> pool;
+    for (int i = 0; i < 25; ++i) {
+        auto* o = pool.acquire();
+        pool.release(o);
+    }
+    EXPECT_GE(pool.pool_size(), 30u);
+}
+
+TEST(ThreadSafePoolTest, ConcurrentAcquire) {
+    ThreadSafeObjectPool<TestObj, 64> pool;
+    std::atomic<int> count{0};
+
+    auto worker = [&]() {
+        for (int i = 0; i < 100; ++i) {
+            auto* o = pool.acquire();
+            o->x = i;
+            pool.release(o);
+            count++;
+        }
+    };
+
+    std::thread t1(worker), t2(worker), t3(worker), t4(worker);
+    t1.join(); t2.join(); t3.join(); t4.join();
+    EXPECT_EQ(count, 400);
+}
+
+TEST(CowPtrTest, ReadOnly) {
+    CowPtr<std::vector<int>> cow(std::vector<int>{1, 2, 3});
+    EXPECT_EQ(cow.read().size(), 3u);
+    EXPECT_EQ(cow.read()[0], 1);
+}
+
+TEST(CowPtrTest, ShallowCopy) {
+    CowPtr<std::vector<int>> cow(std::vector<int>{1, 2, 3});
+    auto cow2 = cow.shallow_copy();
+    EXPECT_EQ(cow.use_count(), 2);
+    EXPECT_EQ(cow2.use_count(), 2);
+}
+
+TEST(CowPtrTest, WriteDetaches) {
+    CowPtr<std::vector<int>> cow(std::vector<int>{1, 2, 3});
+    auto cow2 = cow.shallow_copy();
+    EXPECT_EQ(cow.use_count(), 2);
+
+    cow.write().push_back(4);
+    EXPECT_EQ(cow.use_count(), 1); // detached
+    EXPECT_EQ(cow2.use_count(), 1);
+    EXPECT_EQ(cow2.read().size(), 3u); // cow2 unchanged
+}
+
+TEST(CowPtrTest, DeepCopy) {
+    CowPtr<std::vector<int>> cow(std::vector<int>{1, 2, 3});
+    auto cow2 = cow.deep_copy();
+    EXPECT_EQ(cow.use_count(), 1);
+    EXPECT_EQ(cow2.use_count(), 1);
+}
+
+TEST(CowPtrTest, UniqueCheck) {
+    CowPtr<int> cow(42);
+    EXPECT_TRUE(cow.unique());
+    auto cow2 = cow.shallow_copy();
+    EXPECT_FALSE(cow.unique());
+}