From 91dd7274f486b84c18a937a8437ad72f845e0a61 Mon Sep 17 00:00:00 2001
From: pca006132 <john.lck40@gmail.com>
Date: Mon, 9 Dec 2024 12:44:54 +0800
Subject: [PATCH] better checks

---
 src/csg_tree.cpp   | 25 ++++++++++++++-----------
 src/properties.cpp | 19 +++++++++++++++++++
 2 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/src/csg_tree.cpp b/src/csg_tree.cpp
index 4c5082f76..4c9bf343e 100644
--- a/src/csg_tree.cpp
+++ b/src/csg_tree.cpp
@@ -115,17 +115,7 @@ std::shared_ptr<CsgLeafNode> ImplToLeaf(Manifold::Impl &&impl) {
 std::shared_ptr<CsgLeafNode> SimpleBoolean(const Manifold::Impl &a,
                                            const Manifold::Impl &b, OpType op) {
 #ifdef MANIFOLD_DEBUG
-  try {
-    Boolean3 boolean(a, b, op);
-    auto impl = boolean.Result(op);
-    if (ManifoldParams().intermediateChecks && impl.IsSelfIntersecting()) {
-      dump_lock.lock();
-      std::cout << "self-intersection detected" << std::endl;
-      dump_lock.unlock();
-      throw logicErr("self intersection detected");
-    }
-    return ImplToLeaf(std::move(impl));
-  } catch (logicErr &err) {
+  auto dump = [&]() {
     if (ManifoldParams().verbose) {
       dump_lock.lock();
       if (op == OpType::Add)
@@ -139,6 +129,19 @@ std::shared_ptr<CsgLeafNode> SimpleBoolean(const Manifold::Impl &a,
       std::cout << b;
       dump_lock.unlock();
     }
+  };
+  try {
+    Boolean3 boolean(a, b, op);
+    auto impl = boolean.Result(op);
+    if (ManifoldParams().intermediateChecks && impl.IsSelfIntersecting()) {
+      throw logicErr("self intersection detected");
+    }
+    return ImplToLeaf(std::move(impl));
+  } catch (logicErr &err) {
+    dump();
+    throw err;
+  } catch (geometryErr &err) {
+    dump();
     throw err;
   }
 #else
diff --git a/src/properties.cpp b/src/properties.cpp
index c40b9d578..a54666602 100644
--- a/src/properties.cpp
+++ b/src/properties.cpp
@@ -234,6 +234,25 @@ bool Manifold::Impl::IsSelfIntersecting() const {
         if (distance2(tri_x[i], tri_y[j]) <= epsilonSq) return true;
 
     if (DistanceTriangleTriangleSquared(tri_x, tri_y) == 0.0) {
+      // try to move the triangles around the normal of the other face
+      std::array<vec3, 3> tmp_x, tmp_y;
+      for (int i : {0, 1, 2})
+        tmp_x[i] = tri_x[i] + epsilon_ * faceNormal_[y];
+      if (DistanceTriangleTriangleSquared(tmp_x, tri_y) > 0.0)
+        return true;
+      for (int i : {0, 1, 2})
+        tmp_x[i] = tri_x[i] - epsilon_ * faceNormal_[y];
+      if (DistanceTriangleTriangleSquared(tmp_x, tri_y) > 0.0)
+        return true;
+      for (int i : {0, 1, 2})
+        tmp_y[i] = tri_y[i] + epsilon_ * faceNormal_[x];
+      if (DistanceTriangleTriangleSquared(tri_x, tmp_y) > 0.0)
+        return true;
+      for (int i : {0, 1, 2})
+        tmp_y[i] = tri_y[i] - epsilon_ * faceNormal_[x];
+      if (DistanceTriangleTriangleSquared(tri_x, tmp_y) > 0.0)
+        return true;
+
 #ifdef MANIFOLD_DEBUG
       if (verbose) {
         dump_lock.lock();