Header-only quadtree_point_to_nearest_linestring

cpp/benchmarks/points_in_range.cu

@@ -36,7 +36,7 @@
 
 #include <memory>
 
-using namespace cuspatial;
+using cuspatial::vec_2d;
 
 /**
  * @brief Helper to generate random points within a range

cpp/include/cuspatial/detail/utility/validation.hpp

@@ -18,6 +18,51 @@
 
 #include <cuspatial/error.hpp>
 
+/**
+ * @brief Macro for validating the data array sizes for linestrings.
+ *
+ * Raises an exception if any of the following are false:
+ *  - The number of linestring offsets is greater than zero.
+ *  - There are at least two vertices per linestring offset.
+ *
+ * Linestrings follow [GeoArrow data layout][1]. Offsets arrays have one more element than the
+ * number of items in the array. The last offset is always the sum of the previous offset and the
+ * size of that element. For example the last value in the linestring offsets array is the
+ * last linestring offset plus one. See [Arrow Variable-Size Binary layout](2). Note that an
+ * empty list still has one offset: {0}.
+ *
+ * [1]: https://github.com/geoarrow/geoarrow/blob/main/format.md
+ * [2]: https://arrow.apache.org/docs/format/Columnar.html#variable-size-binary-layout
+ */
+#define CUSPATIAL_EXPECTS_VALID_LINESTRING_SIZES(num_linestring_points, num_linestring_offsets) \
+  CUSPATIAL_EXPECTS(num_linestring_offsets > 0,                                                 \
+                    "Polygon offsets must contain at least one (1) value");                     \
+  CUSPATIAL_EXPECTS(num_linestring_points >= 2 * (num_linestring_offsets - 1),                  \
+                    "Each linestring must have at least two vertices");
+
+/**
+ * @brief Macro for validating the data array sizes for multilinestrings.
+ *
+ * Raises an exception if any of the following are false:
+ *  - The number of multilinestring offsets is greater than zero.
+ *  - The number of linestring offsets is greater than zero.
+ *  - There are at least two vertices per linestring offset.
+ *
+ * Multilinestrings follow [GeoArrow data layout][1]. Offsets arrays have one more element than the
+ * number of items in the array. The last offset is always the sum of the previous offset and the
+ * size of that element. For example the last value in the linestring offsets array is the
+ * last linestring offset plus one. See [Arrow Variable-Size Binary layout](2). Note that an
+ * empty list still has one offset: {0}.
+ *
+ * [1]: https://github.com/geoarrow/geoarrow/blob/main/format.md
+ * [2]: https://arrow.apache.org/docs/format/Columnar.html#variable-size-binary-layout
+ */
+#define CUSPATIAL_EXPECTS_VALID_MULTILINESTRING_SIZES(                              \
+  num_linestring_points, num_multilinestring_offsets, num_linestring_offsets)       \
+  CUSPATIAL_EXPECTS(num_multilinestring_offsets > 0,                                \
+                    "Multilinestring offsets must contain at least one (1) value"); \
+  CUSPATIAL_EXPECTS_VALID_LINESTRING_SIZES(num_linestring_points, num_linestring_offsets);
+
 /**
  * @brief Macro for validating the data array sizes for a polygon.
  *

cpp/include/cuspatial/experimental/detail/algorithm/is_point_in_polygon.cuh

@@ -27,7 +27,7 @@ namespace cuspatial {
 namespace detail {
 
 /**
- * @brief Kernel to test if a point is inside a polygon.
+ * @brief Test if a point is inside a polygon.
  *
  * Implemented based on Eric Haines's crossings-multiply algorithm:
  * See "Crossings test" section of http://erich.realtimerendering.com/ptinpoly/

cpp/include/cuspatial/experimental/detail/algorithm/point_linestring_distance.cuh

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2023, NVIDIA CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <cuspatial/experimental/geometry/linestring_ref.cuh>
+#include <cuspatial/experimental/geometry/segment.cuh>
+#include <cuspatial/vec_2d.hpp>
+
+namespace cuspatial {
+namespace detail {
+
+template <typename T>
+__device__ T proj2(segment<T> const& s, vec_2d<T> const& v)
+{
+  return dot(v - s.v1, s.v2 - s.v1);
+}
+
+template <typename T, typename LinestringRef>
+inline __device__ T point_linestring_distance(vec_2d<T> const& point,
+                                              LinestringRef const& linestring)
+{
+  T distance_squared = std::numeric_limits<T>::max();
+
+  for (auto const& s : linestring) {
+    auto v1p         = point - s.v1;
+    auto v2p         = point - s.v2;
+    auto d0          = dot(v1p, v1p);
+    auto d1          = dot(v2p, v2p);
+    auto d2          = s.length2();
+    auto d3          = proj2(s, point);
+    auto const r     = d3 * d3 / d2;
+    auto const d     = (d3 <= 0 || r >= d2) ? min(d0, d1) : d0 - r;
+    distance_squared = min(distance_squared, d);
+  }
+
+  return sqrt(distance_squared);
+}
+
+}  // namespace detail
+}  // namespace cuspatial

cpp/include/cuspatial/experimental/detail/linestring_bounding_boxes.cuh

@@ -43,9 +43,12 @@ BoundingBoxIterator linestring_bounding_boxes(LinestringOffsetIterator linestrin
                                               T expansion_radius,
                                               rmm::cuda_stream_view stream)
 {
+  static_assert(is_same<T, iterator_vec_base_type<VertexIterator>>(),
+                "expansion_radius type must match vertex floating-point type");
+
   static_assert(is_floating_point<T>(), "Only floating point polygon vertices supported");
 
-  static_assert(is_same<vec_2d<T>, iterator_value_type<VertexIterator>>(),
+  static_assert(is_vec_2d<iterator_value_type<VertexIterator>>,
                 "Input vertices must be cuspatial::vec_2d");
 
   static_assert(cuspatial::is_integral<iterator_value_type<LinestringOffsetIterator>>(),

cpp/include/cuspatial/experimental/detail/polygon_bounding_boxes.cuh

@@ -47,9 +47,12 @@ BoundingBoxIterator polygon_bounding_boxes(PolygonOffsetIterator polygon_offsets
                                            T expansion_radius,
                                            rmm::cuda_stream_view stream)
 {
+  static_assert(is_same<T, iterator_vec_base_type<VertexIterator>>(),
+                "expansion_radius type must match vertex floating-point type");
+
   static_assert(is_floating_point<T>(), "Only floating point polygon vertices supported");
 
-  static_assert(is_same<vec_2d<T>, iterator_value_type<VertexIterator>>(),
+  static_assert(is_vec_2d<iterator_value_type<VertexIterator>>,
                 "Input vertices must be cuspatial::vec_2d");
 
   static_assert(cuspatial::is_integral<iterator_value_type<PolygonOffsetIterator>,