added AABB_indexed_triangle_primitive_2

AABB_tree/doc/AABB_tree/PackageDescription.txt

@@ -39,6 +39,7 @@
 
 \cgalCRPSection{Primitives}
 - `CGAL::AABB_triangle_primitive_2<GeomTraits, Iterator, CacheDatum>`
+- `CGAL::AABB_indexed_triangle_primitive_2<GeomTraits, IndexIterator, PointRange, CacheDatum>`
 - `CGAL::AABB_segment_primitive_2<GeomTraits, Iterator, CacheDatum>`
 - `CGAL::AABB_polyline_segment_primitive_2<GeomTraits, Iterator, PointRange, CacheDatum>`
 - `CGAL::AABB_triangle_primitive_3<GeomTraits, Iterator, CacheDatum>`

AABB_tree/doc/AABB_tree/examples.txt

@@ -10,6 +10,7 @@
 \example AABB_tree/AABB_polyline_segment_2_example.cpp
 \example AABB_tree/AABB_segment_3_example.cpp
 \example AABB_tree/AABB_ray_shooting_example.cpp
+\example AABB_tree/AABB_indexed_triangle_2_example.cpp
 \example AABB_tree/AABB_triangle_3_example.cpp
 \example AABB_tree/AABB_halfedge_graph_edge_example.cpp
 \example AABB_tree/AABB_face_graph_triangle_example.cpp

AABB_tree/examples/AABB_tree/AABB_indexed_triangle_2_example.cpp

@@ -0,0 +1,55 @@
+// Author(s) : Camille Wormser, Pierre Alliez
+
+#include <iostream>
+#include <list>
+
+#include <CGAL/Simple_cartesian.h>
+#include <CGAL/AABB_tree.h>
+#include <CGAL/AABB_traits_2.h>
+#include <CGAL/AABB_indexed_triangle_primitive_2.h>
+
+typedef CGAL::Simple_cartesian<double> K;
+
+typedef K::FT FT;
+typedef K::Point_2 Point;
+
+typedef std::vector<std::array<uint8_t, 3> >::iterator IndexIterator;
+typedef std::vector<Point> PointRange;
+typedef CGAL::AABB_indexed_triangle_primitive_2<K, IndexIterator, PointRange> Primitive;
+typedef CGAL::AABB_traits_2<K, Primitive> AABB_triangle_traits;
+typedef CGAL::AABB_tree<AABB_triangle_traits> Tree;
+typedef Tree::Point_and_primitive_id Point_and_primitive_id;
+
+int main()
+{
+  Point a(0.0, 0.0);
+  Point b(0.0, 1.0);
+  Point c(1.0, 0.0);
+  Point d(1.0, 1.0);
+  Point e(2.0, 0.0);
+  Point f(2.0, 1.0);
+
+  std::vector<Point> points = { a, b, c, d, e, f };
+
+  std::vector<std::array<uint8_t, 3> > triangles;
+  triangles.push_back({ 0, 2, 1 });
+  triangles.push_back({ 1, 2, 3 });
+  triangles.push_back({ 3, 2, 4 });
+  triangles.push_back({ 3, 4, 5 });
+
+  // constructs AABB tree
+  Tree tree(triangles.begin(), triangles.end(), points);
+
+  // point sampling
+  Point_and_primitive_id id;
+  id = tree.closest_point_and_primitive(Point(0.5, 0.4));
+  std::cout << std::distance(triangles.begin(), id.second) << ". triangle" << std::endl;
+  id = tree.closest_point_and_primitive(Point(0.5, 0.6));
+  std::cout << std::distance(triangles.begin(), id.second) << ". triangle" << std::endl;
+  id = tree.closest_point_and_primitive(Point(1.5, 0.5));
+  std::cout << std::distance(triangles.begin(), id.second) << ". triangle" << std::endl;
+  id = tree.closest_point_and_primitive(Point(1.5, 0.6));
+  std::cout << std::distance(triangles.begin(), id.second) << ". triangle" << std::endl;
+
+  return EXIT_SUCCESS;
+}

AABB_tree/include/CGAL/AABB_indexed_triangle_primitive_2.h

@@ -0,0 +1,128 @@
+// Copyright (c) 2024 GeometryFactory (France).
+// All rights reserved.
+//
+// This file is part of CGAL (www.cgal.org).
+//
+// $URL$
+// $Id$
+// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
+//
+//
+// Author(s)     : Sven Oesau
+//
+
+
+#ifndef CGAL_AABB_INDEXED_TRIANGLE_PRIMITIVE_2_H_
+#define CGAL_AABB_INDEXED_TRIANGLE_PRIMITIVE_2_H_
+
+#include <CGAL/license/AABB_tree.h>
+
+#include <CGAL/AABB_primitive.h>
+#include <iterator>
+
+namespace CGAL {
+
+namespace internal {
+  template <class GeomTraits, class Iterator, class PointIterator>
+  struct Triangle_2_from_index_range_iterator_property_map {
+    //classical typedefs
+    typedef Iterator key_type;
+    typedef typename GeomTraits::Triangle_2 value_type;
+    typedef typename GeomTraits::Triangle_2& reference;
+
+    typedef boost::readable_property_map_tag category;
+    typedef Triangle_2_from_index_range_iterator_property_map<GeomTraits, Iterator, PointIterator> Self;
+
+    Triangle_2_from_index_range_iterator_property_map() {}
+    Triangle_2_from_index_range_iterator_property_map(PointIterator b) : begin(b) {}
+
+    inline friend value_type
+      get(Self s, key_type it)
+    {
+      return typename GeomTraits::Construct_triangle_2()(s.begin[(*it)[0]], s.begin[(*it)[1]], s.begin[(*it)[2]]);
+    }
+
+    PointIterator begin;
+  };
+
+  template <class GeomTraits, class Iterator, class PointIterator>
+  struct Point_from_indexed_triangle_2_iterator_property_map {
+    //classical typedefs
+    typedef Iterator key_type;
+    typedef typename PointIterator::value_type value_type;
+    typedef const value_type& reference;
+
+    typedef boost::readable_property_map_tag category;
+    typedef Point_from_indexed_triangle_2_iterator_property_map<GeomTraits, Iterator, PointIterator> Self;
+
+    Point_from_indexed_triangle_2_iterator_property_map() {}
+    Point_from_indexed_triangle_2_iterator_property_map(PointIterator b) : begin(b) {}
+
+    inline friend reference
+    get(Self s, key_type it)
+    {
+      return s.begin[((*it)[0])];
+    }
+
+    PointIterator begin;
+  };
+}//namespace internal
+
+
+/*!
+ * \ingroup PkgAABBTreeRef
+ * Primitive type that uses as identifier an iterator with a range of 3 indices as `value_type`.
+ * The iterator from which the primitive is built should not be invalided
+ * while the AABB tree holding the primitive is in use.
+ *
+ * \cgalModels{AABBPrimitive}
+ *
+ * \tparam GeomTraits is a traits class providing the nested type `Point_2` and `Triangle_2`.
+ *         It also provides the functor `Construct_triangle_2` that has an operator taking 3 `Point_2` as
+ *         parameters and returns a `Triangle_2`
+ * \tparam IndexIterator is a model of `ForwardIterator` with its value type being a `RandomAccessRange` of size 3 with an index type as `value_type`, e.g., `uint8_t`, `uint16_t` or int.
+ * \tparam PointRange is a model of `RandomAccessRange` with its value type being a `Point_2`.
+ * \tparam CacheDatum is either `CGAL::Tag_true` or `CGAL::Tag_false`. In the former case,
+ *           the datum is stored in the primitive, while in the latter it is
+ *           constructed on the fly to reduce the memory footprint.
+ *           The default is `CGAL::Tag_false` (datum is not stored).
+ *
+ * \sa `AABBPrimitive`
+ * \sa `AABB_primitive<Id,ObjectPropertyMap,PointPropertyMapPolyhedron,ExternalPropertyMaps,CacheDatum>`
+ * \sa `AABB_segment_primitive_2<Iterator,CacheDatum>`
+ * \sa `AABB_halfedge_graph_segment_primitive<HalfedgeGraph,OneHalfedgeGraphPerTree,CacheDatum>`
+ * \sa `AABB_face_graph_triangle_primitive<FaceGraph,OneFaceGraphPerTree,CacheDatum>`
+ */
+template < class GeomTraits,
+           class IndexIterator,
+           class PointRange,
+           class CacheDatum=Tag_false>
+class AABB_indexed_triangle_primitive_2
+#ifndef DOXYGEN_RUNNING
+  : public AABB_primitive<  IndexIterator,
+                            internal::Triangle_2_from_index_range_iterator_property_map<GeomTraits, IndexIterator, typename PointRange::iterator>,
+                            internal::Point_from_indexed_triangle_2_iterator_property_map<GeomTraits, IndexIterator, typename PointRange::iterator>,
+                            Tag_true,
+                            CacheDatum >
+#endif
+{
+  typedef AABB_primitive< IndexIterator,
+                          internal::Triangle_2_from_index_range_iterator_property_map<GeomTraits, IndexIterator, typename PointRange::iterator>,
+                          internal::Point_from_indexed_triangle_2_iterator_property_map<GeomTraits, IndexIterator, typename PointRange::iterator>,
+                          Tag_true,
+                          CacheDatum > Base;
+public:
+  ///constructor from an iterator
+  AABB_indexed_triangle_primitive_2(IndexIterator it, PointRange &range) : Base(it) {}
+
+  /// \internal
+  static typename Base::Shared_data construct_shared_data(PointRange &range) {
+    return std::make_pair(
+      internal::Triangle_2_from_index_range_iterator_property_map<GeomTraits, IndexIterator, typename PointRange::iterator>(range.begin()),
+      internal::Point_from_indexed_triangle_2_iterator_property_map<GeomTraits, IndexIterator, typename PointRange::iterator>(range.begin()));
+  }
+};
+
+}  // end namespace CGAL
+
+#endif // CGAL_AABB_INDEXED_TRIANGLE_PRIMITIVE_2_H_