From 1df54e3ac23780cd67c91c50f27052199902f81f Mon Sep 17 00:00:00 2001
From: Benoit Jacob <jacob.benoit.1@gmail.com>
Date: Sat, 19 Sep 2009 19:59:49 -0400
Subject: [PATCH] fix bug #42, add missing Transform::Identity()

---
 Eigen/src/Geometry/Transform.h | 4 ++++
 test/geo_transformations.cpp   | 7 +++++++
 2 files changed, 11 insertions(+)

diff --git a/Eigen/src/Geometry/Transform.h b/Eigen/src/Geometry/Transform.h
index dcb41435b..e89581e21 100644
--- a/Eigen/src/Geometry/Transform.h
+++ b/Eigen/src/Geometry/Transform.h
@@ -345,6 +345,10 @@ public:
 
   /** \sa MatrixBase::setIdentity() */
   void setIdentity() { m_matrix.setIdentity(); }
+  static const typename MatrixType::IdentityReturnType Identity()
+  {
+    return MatrixType::Identity();
+  }
 
   template<typename OtherDerived>
   inline Transform& scale(const MatrixBase<OtherDerived> &other);
diff --git a/test/geo_transformations.cpp b/test/geo_transformations.cpp
index 2b05f2457..23b297314 100644
--- a/test/geo_transformations.cpp
+++ b/test/geo_transformations.cpp
@@ -102,7 +102,14 @@ template<typename Scalar, int Mode> void transformations(void)
     a = ei_random<Scalar>(-Scalar(0.4)*Scalar(M_PI), Scalar(0.4)*Scalar(M_PI));
   q1 = AngleAxisx(a, v0.normalized());
   Transform3 t0, t1, t2;
+
+  // first test setIdentity() and Identity()
   t0.setIdentity();
+  VERIFY_IS_APPROX(t0.matrix(), Transform3::MatrixType::Identity());
+  t0.matrix().setZero();
+  t0 = Transform3::Identity();
+  VERIFY_IS_APPROX(t0.matrix(), Transform3::MatrixType::Identity());
+  
   t0.linear() = q1.toRotationMatrix();
   t1.setIdentity();
   t1.linear() = q1.toRotationMatrix();