From b5b708a6bad5ddf858e7f0d30fad61978e37bd4f Mon Sep 17 00:00:00 2001
From: Max Lyon <lyon@cs.rwth-aachen.de>
Date: Fri, 27 Sep 2019 16:34:20 +0200
Subject: [PATCH] smart range improvements

---
 src/OpenMesh/Core/Mesh/SmartRange.hh    | 82 +++++++++++++++++++++++++
 src/Unittests/unittests_smart_ranges.cc | 64 ++++++++++++++++++-
 2 files changed, 145 insertions(+), 1 deletion(-)

diff --git a/src/OpenMesh/Core/Mesh/SmartRange.hh b/src/OpenMesh/Core/Mesh/SmartRange.hh
index f6bac807..43ab02cd 100644
--- a/src/OpenMesh/Core/Mesh/SmartRange.hh
+++ b/src/OpenMesh/Core/Mesh/SmartRange.hh
@@ -43,6 +43,8 @@
 #pragma once
 
 #include <utility>
+#include <array>
+#include <vector>
 
 //== NAMESPACES ===============================================================
 
@@ -52,12 +54,24 @@ namespace OpenMesh {
 
 //== CLASS DEFINITION =========================================================
 
+namespace  {
+
+struct Identity
+{
+  template <typename T>
+  T operator()(const T& _t) const { return _t; }
+};
+
+}
+
 /// Base class for all smart range types
 template <typename RangeT, typename HandleT>
 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>()))
   {
@@ -92,6 +106,74 @@ struct SmartRangeT
     return (1.0 / n_elements) * sum;
   }
 
+  template <int n, typename Functor = Identity>
+  auto to_array(Functor&& f = {}) -> std::array<typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type, n>
+  {
+    auto range = static_cast<const RangeT*>(this);
+    std::array<typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type, n> res;
+    auto it = range->begin();
+    auto end = range->end();
+    int i = 0;
+    while (i < n && it != end)
+      res[i++] = f(*(it++));
+    return res;
+  }
+
+  template <typename Functor = Identity>
+  auto to_vector(Functor&& f = {}) -> std::vector<typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type>
+  {
+    auto range = static_cast<const RangeT*>(this);
+    std::vector<typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type> res;
+    for (auto e : *range)
+      res.push_back(f(e));
+    return res;
+  }
+
+
+  template <int n, typename Functor>
+  auto elem_wise_min(Functor&& f) -> typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type
+  {
+    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);
+    ++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]);
+    }
+
+    return min;
+  }
+
+  template <int n, typename Functor>
+  auto elem_wise_max(Functor&& f) -> typename std::remove_reference<decltype (f(std::declval<HandleT>()))>::type
+  {
+    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);
+    ++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]);
+    }
+
+    return max;
+  }
+
+
+
 
 
 };
diff --git a/src/Unittests/unittests_smart_ranges.cc b/src/Unittests/unittests_smart_ranges.cc
index 15b7da3f..892c0c73 100644
--- a/src/Unittests/unittests_smart_ranges.cc
+++ b/src/Unittests/unittests_smart_ranges.cc
@@ -198,7 +198,6 @@ TEST_F(OpenMeshSmartRanges, Sum)
 TEST_F(OpenMeshSmartRanges, PropertyManagerAsFunctor)
 {
   auto myPos = OpenMesh::makeTemporaryProperty<OpenMesh::VertexHandle, Mesh::Point>(mesh_);
-
   for (auto vh : mesh_.vertices())
     myPos(vh) = mesh_.point(vh);
 
@@ -212,6 +211,69 @@ TEST_F(OpenMeshSmartRanges, PropertyManagerAsFunctor)
   EXPECT_LT(norm(cog - cog2), 0.00001) << "Computed center of gravities are significantly different.";
 }
 
+/* Test to vector
+ */
+TEST_F(OpenMeshSmartRanges, ToVector)
+{
+  auto uvs = OpenMesh::makeTemporaryProperty<OpenMesh::HalfedgeHandle, OpenMesh::Vec2d>(mesh_);
+
+  for (auto heh : mesh_.halfedges())
+    uvs(heh) = OpenMesh::Vec2d(heh.idx(), (heh.idx() * 13)%7);
+
+  for (auto fh : mesh_.faces())
+  {
+    auto tri_uvs = fh.halfedges().to_vector(uvs);
+    auto heh_handles = fh.halfedges().to_vector();
+//    for (auto heh : heh_handles)
+//      auto n = heh.next();
+  }
+
+  auto vertex_vec = mesh_.vertices().to_vector();
+  for (auto vh : vertex_vec)
+    auto heh = vh.out();
+}
+
+/* Test to array
+ */
+TEST_F(OpenMeshSmartRanges, ToArray)
+{
+  auto uvs = OpenMesh::makeTemporaryProperty<OpenMesh::HalfedgeHandle, OpenMesh::Vec2d>(mesh_);
+
+  for (auto heh : mesh_.halfedges())
+    uvs(heh) = OpenMesh::Vec2d(heh.idx(), (heh.idx() * 13)%7);
+
+  for (auto fh : mesh_.faces())
+  {
+    auto tri_uvs = fh.halfedges().to_array<3>(uvs);
+    auto heh_handles = fh.halfedges().to_array<3>();
+  }
+}
+
+/* Test bounding box
+ */
+TEST_F(OpenMeshSmartRanges, BoundingBox)
+{
+  auto myPos = OpenMesh::makeTemporaryProperty<OpenMesh::VertexHandle, Mesh::Point>(mesh_);
+  for (auto vh : mesh_.vertices())
+    myPos(vh) = mesh_.point(vh);
+
+  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);
+  }
+}
+
 
 
 }