From 699c80e404ac98a06636d530e5a3f8ddf41dd5bb Mon Sep 17 00:00:00 2001
From: Gael Guennebaud <g.gael@free.fr>
Date: Tue, 13 Jan 2015 10:11:44 +0100
Subject: [PATCH] bug #927: backport some unit tests for Rotation2D

---
 test/geo_transformations.cpp | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/test/geo_transformations.cpp b/test/geo_transformations.cpp
index dc2da0542..547765714 100644
--- a/test/geo_transformations.cpp
+++ b/test/geo_transformations.cpp
@@ -98,7 +98,8 @@ template<typename Scalar, int Mode, int Options> void transformations()
   Matrix3 matrot1, m;
 
   Scalar a = internal::random<Scalar>(-Scalar(M_PI), Scalar(M_PI));
-  Scalar s0 = internal::random<Scalar>();
+  Scalar s0 = internal::random<Scalar>(),
+         s1 = internal::random<Scalar>();
   
   while(v0.norm() < test_precision<Scalar>()) v0 = Vector3::Random();
   while(v1.norm() < test_precision<Scalar>()) v1 = Vector3::Random();
@@ -414,6 +415,20 @@ template<typename Scalar, int Mode, int Options> void transformations()
   t21 = Translation2(v20) * Rotation2D<Scalar>(s0) * Eigen::Scaling(s0);
   VERIFY_IS_APPROX(t20,t21);
   
+  Rotation2D<Scalar> R0(s0), R1(s1);
+  t20 = Translation2(v20) * (R0 * Eigen::Scaling(s0));
+  t21 = Translation2(v20) * R0 * Eigen::Scaling(s0);
+  VERIFY_IS_APPROX(t20,t21);
+  
+  t20 = Translation2(v20) * (R0 * R0.inverse() * Eigen::Scaling(s0));
+  t21 = Translation2(v20) * Eigen::Scaling(s0);
+  VERIFY_IS_APPROX(t20,t21);
+  
+  VERIFY_IS_APPROX(s0, (R0.slerp(0, R1)).angle());
+  VERIFY_IS_APPROX(s1, (R0.slerp(1, R1)).angle());
+  VERIFY_IS_APPROX(s0, (R0.slerp(0.5, R0)).angle());
+  VERIFY_IS_APPROX(Scalar(0), (R0.slerp(0.5, R0.inverse())).angle());
+  
   // check basic features
   {
     Rotation2D<Scalar> r1;           // default ctor