From 29959d8cf5e78ca6eef1916010a254f0c6ef6629 Mon Sep 17 00:00:00 2001
From: Martin Heistermann <git@mheistermann.de>
Date: Mon, 30 Mar 2020 19:04:26 +0200
Subject: [PATCH 1/2] VectorT: Implement .cross() and .dot() methods.

Aliases for operators % and | for better compatibility with Eigen3.
---
 src/OpenMesh/Core/Geometry/Vector11T.hh | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/src/OpenMesh/Core/Geometry/Vector11T.hh b/src/OpenMesh/Core/Geometry/Vector11T.hh
index c11a77e9..44258377 100644
--- a/src/OpenMesh/Core/Geometry/Vector11T.hh
+++ b/src/OpenMesh/Core/Geometry/Vector11T.hh
@@ -369,7 +369,7 @@ class VectorT {
         }
 
         /// cross product: only defined for Vec3* as specialization
-        /// \see OpenMesh::cross
+        /// \see OpenMesh::cross and .cross()
         template<typename OtherScalar>
         auto operator% (const VectorT<OtherScalar, DIM> &_rhs) const ->
             typename std::enable_if<DIM == 3,
@@ -382,8 +382,18 @@ class VectorT {
             };
         }
 
+        /// cross product: only defined for Vec3* as specialization
+        /// \see OpenMesh::cross and .operator%
+        template<typename OtherScalar>
+        auto cross (const VectorT<OtherScalar, DIM> &_rhs) const ->
+            decltype(*this % _rhs)
+        {
+            return *this % _rhs;
+        }
+
+
         /// compute scalar product
-        /// \see OpenMesh::dot
+        /// \see OpenMesh::dot and .dot()
         template<typename OtherScalar>
         auto operator|(const VectorT<OtherScalar, DIM>& _rhs) const ->
             decltype(*this->data() * *_rhs.data()) {
@@ -392,6 +402,15 @@ class VectorT {
                     *begin() * *_rhs.begin());
         }
 
+        /// compute scalar product
+        /// \see OpenMesh::dot and .operator|
+        template<typename OtherScalar>
+        auto dot(const VectorT<OtherScalar, DIM>& _rhs) const ->
+            decltype(*this | _rhs)
+        {
+            return *this | _rhs;
+        }
+
         //------------------------------------------------------------ euclidean norm
 
         /// \name Euclidean norm calculations

From dfa22839d08e2cab24435c058a6130606bc5909d Mon Sep 17 00:00:00 2001
From: Martin Heistermann <git@mheistermann.de>
Date: Mon, 6 Apr 2020 19:02:07 +0200
Subject: [PATCH 2/2] Implement vector dot/cross unit tests

---
 src/Unittests/unittests_vector_type.cc | 29 +++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/Unittests/unittests_vector_type.cc b/src/Unittests/unittests_vector_type.cc
index 878c3248..98643d9e 100644
--- a/src/Unittests/unittests_vector_type.cc
+++ b/src/Unittests/unittests_vector_type.cc
@@ -263,6 +263,23 @@ TEST_F(OpenMeshVectorTest, BasicArithmeticImmutable) {
     EXPECT_NEAR(-2, v2neg[1], epsilon);
     EXPECT_NEAR(-3, v2neg[2], epsilon);
 }
+template <typename V1, typename V2, typename S>
+void test_dot(const V1 &v1, const V2 &v2, const S&s) {
+    EXPECT_NEAR(s, v1 | v2, 1e-6);
+    EXPECT_NEAR(s, v1.dot(v2), 1e-6);
+    EXPECT_NEAR(-s, (-v1) | v2, 1e-6);
+    EXPECT_NEAR(-s, (-v1).dot(v2), 1e-6);
+    EXPECT_NEAR(s, v2 | v1, 1e-6);
+    EXPECT_NEAR(s, v2.dot(v1), 1e-6);
+}
+
+template <typename V1, typename V2, typename V3>
+void test_cross(const V1 &v1, const V2 &v2, const V3 &res) {
+    EXPECT_NEAR(0, (v1.cross(v2) - res).norm(), 1e-6);
+    EXPECT_NEAR(0, (v1 % v2 - res).norm(), 1e-6);
+    EXPECT_NEAR(0, (v2.cross(v1) + res).norm(), 1e-6);
+    EXPECT_NEAR(0, (v2 % v1 + res).norm(), 1e-6);
+}
 
 TEST_F(OpenMeshVectorTest, BasicLinearAlgebra) {
     OpenMesh::Vec3d v(1, 2, 3);
@@ -285,9 +302,15 @@ TEST_F(OpenMeshVectorTest, BasicLinearAlgebra) {
     EXPECT_EQ(1, OpenMesh::Vec3d(1, 3, -4).min_abs());
     EXPECT_EQ(2, OpenMesh::Vec3d(-4, 2, 3).min_abs());
 
-    EXPECT_NEAR(14, OpenMesh::Vec3d(1, 2, 3) | OpenMesh::Vec3d(1, 2, 3), 1e-6);
-    EXPECT_NEAR(-14, OpenMesh::Vec3d(1, 2, 3) | OpenMesh::Vec3d(-1, -2, -3), 1e-6);
-    EXPECT_NEAR(14, OpenMesh::Vec3d(-1, -2, -3) | OpenMesh::Vec3d(-1, -2, -3), 1e-6);
+
+    test_dot(OpenMesh::Vec3d(1, 2, 3), OpenMesh::Vec3d(1, 2, 3), 14.);
+    test_dot(OpenMesh::Vec3d(1, 2, 3), OpenMesh::Vec3d(-1, -2, -3), -14.);
+    test_dot(OpenMesh::Vec3d(1, 2, 3), OpenMesh::Vec3i(1, 2, 3), 14);
+    test_dot(OpenMesh::Vec3i(1, 2, 3), OpenMesh::Vec3i(1, 2, 3), 14);
+
+    test_cross(OpenMesh::Vec3i(2, 0, 0), OpenMesh::Vec3i(0, 3, 0), OpenMesh::Vec3i(0, 0, 6));
+    test_cross(OpenMesh::Vec3d(2, 0, 0), OpenMesh::Vec3d(0, 3, 0), OpenMesh::Vec3d(0, 0, 6));
+    test_cross(OpenMesh::Vec3d(2, 0, 0), OpenMesh::Vec3i(0, 3, 0), OpenMesh::Vec3d(0, 0, 6));
 }
 
 TEST_F(OpenMeshVectorTest, array_init) {