From 1948883fd1c3d1d1032fc1964ddb092d05dbdc25 Mon Sep 17 00:00:00 2001
From: Max Lyon <lyon@cs.rwth-aachen.de>
Date: Mon, 7 Oct 2019 13:06:15 +0200
Subject: [PATCH] update min and max functions on ranges and add minmax
 function

---
 src/OpenMesh/Core/Mesh/SmartRange.hh    | 40 +++++++++++++------------
 src/Unittests/unittests_smart_ranges.cc | 26 +++++++++-------
 2 files changed, 37 insertions(+), 29 deletions(-)

diff --git a/src/OpenMesh/Core/Mesh/SmartRange.hh b/src/OpenMesh/Core/Mesh/SmartRange.hh
index 43ab02cd..9ccc3a36 100644
--- a/src/OpenMesh/Core/Mesh/SmartRange.hh
+++ b/src/OpenMesh/Core/Mesh/SmartRange.hh
@@ -71,7 +71,6 @@ struct SmartRangeT
   // TODO: Someone with better c++ knowledge may improve the code below.
 
 
-
   template <typename Functor>
   auto sum(Functor&& f) -> decltype (f(std::declval<HandleT>())+f(std::declval<HandleT>()))
   {
@@ -130,46 +129,49 @@ struct SmartRangeT
   }
 
 
-  template <int n, typename Functor>
-  auto elem_wise_min(Functor&& f) -> typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type
+  template <typename Functor>
+  auto min(Functor&& f) -> typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type
   {
+    using std::min;
+
     auto range = static_cast<const RangeT*>(this);
     auto it    = range->begin();
     auto end   = range->end();
     assert(it != end);
 
-    typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type min = f(*it);
+    typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type res = f(*it);
     ++it;
 
     for (; it != end; ++it)
-    {
-      const auto& tmp = f(*it);
-      for (int i = 0; i < n; ++i)
-        min[i] = std::min(min[i], tmp[i]);
-    }
+      res = min(res, f(*it));
 
-    return min;
+    return res;
   }
 
-  template <int n, typename Functor>
-  auto elem_wise_max(Functor&& f) -> typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type
+  template <typename Functor>
+  auto max(Functor&& f) -> typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type
   {
+    using std::max;
+
     auto range = static_cast<const RangeT*>(this);
     auto it    = range->begin();
     auto end   = range->end();
     assert(it != end);
 
-    typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type max = f(*it);
+    typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type res = f(*it);
     ++it;
 
     for (; it != end; ++it)
-    {
-      const auto& tmp = f(*it);
-      for (int i = 0; i < n; ++i)
-        max[i] = std::max(max[i], tmp[i]);
-    }
+      res = max(res, f(*it));
 
-    return max;
+    return res;
+  }
+
+  template <typename Functor>
+  auto minmax(Functor&& f) -> std::pair<typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type,
+                                        typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type>
+  {
+    return std::make_pair(this->min(f), this->max(f));
   }
 
 
diff --git a/src/Unittests/unittests_smart_ranges.cc b/src/Unittests/unittests_smart_ranges.cc
index fe613952..be5a3dc0 100644
--- a/src/Unittests/unittests_smart_ranges.cc
+++ b/src/Unittests/unittests_smart_ranges.cc
@@ -249,28 +249,34 @@ TEST_F(OpenMeshSmartRanges, ToArray)
   }
 }
 
+
 /* Test bounding box
  */
 TEST_F(OpenMeshSmartRanges, BoundingBox)
 {
-  auto myPos = OpenMesh::makeTemporaryProperty<OpenMesh::VertexHandle, Mesh::Point>(mesh_);
+  // The custom vecs OpenMesh are tested with here do not implement a min or max function.
+  // Thus we convert here.
+  auto myPos = OpenMesh::makeTemporaryProperty<OpenMesh::VertexHandle, OpenMesh::Vec3f>(mesh_);
   for (auto vh : mesh_.vertices())
-    myPos(vh) = mesh_.point(vh);
+    for (size_t i = 0; i < 3; ++i)
+      myPos(vh)[i] = mesh_.point(vh)[i];
+
+  auto bb_min = mesh_.vertices().min(myPos);
+  auto bb_max = mesh_.vertices().max(myPos);
+  auto bb     = mesh_.vertices().minmax(myPos);
+
+  EXPECT_LT(norm(bb_min - OpenMesh::Vec3f(-1,-1,-1)), 0.000001) << "Bounding box minimum seems off";
+  EXPECT_LT(norm(bb_max - OpenMesh::Vec3f( 1, 1, 1)), 0.000001) << "Bounding box maximum seems off";
+
 
   auto uvs = OpenMesh::makeTemporaryProperty<OpenMesh::HalfedgeHandle, OpenMesh::Vec2d>(mesh_);
   for (auto heh : mesh_.halfedges())
     uvs(heh) = OpenMesh::Vec2d(heh.idx(), (heh.idx() * 13)%7);
 
-  auto bb_min = mesh_.vertices().elem_wise_min<3>(myPos);
-  auto bb_max = mesh_.vertices().elem_wise_max<3>(myPos);
-
-  EXPECT_LT(norm(bb_min - Mesh::Point(-1,-1,-1)), 0.000001) << "Bounding box minimum seems off";
-  EXPECT_LT(norm(bb_max - Mesh::Point( 1, 1, 1)), 0.000001) << "Bounding box maximum seems off";
-
   for (auto fh : mesh_.faces())
   {
-    auto uv_bb_min = fh.halfedges().elem_wise_min<2>(uvs);
-    auto uv_bb_max = fh.halfedges().elem_wise_max<2>(uvs);
+    auto uv_bb_min = fh.halfedges().min(uvs);
+    auto uv_bb_max = fh.halfedges().max(uvs);
   }
 }