Merge pull request #63 from r-spatial/edzer-cap

add s2_cap and s2_lat_lng_rect functions

Author: edzer

NAMESPACE

@@ -53,6 +53,7 @@ export(s2_as_binary)
 export(s2_as_text)
 export(s2_boundary)
 export(s2_buffer_cells)
+export(s2_cap)
 export(s2_centroid)
 export(s2_centroid_agg)
 export(s2_closest_feature)
@@ -87,6 +88,7 @@ export(s2_intersects_box)
 export(s2_intersects_matrix)
 export(s2_is_collection)
 export(s2_is_empty)
+export(s2_lat_lng_rect)
 export(s2_latlng)
 export(s2_length)
 export(s2_make_line)

R/RcppExports.R

@@ -49,6 +49,14 @@ cpp_s2_max_distance <- function(geog1, geog2) {
     .Call(`_s2_cpp_s2_max_distance`, geog1, geog2)
 }
 
+cpp_s2_cap <- function(geog) {
+    .Call(`_s2_cpp_s2_cap`, geog)
+}
+
+cpp_s2_lat_lng_rect <- function(geog) {
+    .Call(`_s2_cpp_s2_lat_lng_rect`, geog)
+}
+
 cpp_s2_geog_point <- function(x, y) {
     .Call(`_s2_cpp_s2_geog_point`, x, y)
 }

R/s2-cap.R

@@ -0,0 +1,31 @@
+
+
+#' compute S2Cap or S2LatLngRect of each geography
+#' 
+#' @param x object of class s2_geography
+#' @export
+#' @return Both functions return a \code{data.frame} with parameters;
+#' \code{s2_cap} returns for each geography a bounding spherical cap that contains the region. 
+#' For points, polylines and geometry collections the bound may not be tight.
+#' @examples
+#' s2_cap(s2_data_countries("Antarctica"))
+#' s2_cap(s2_data_countries("Netherlands"))
+#' s2_cap(s2_data_countries("Fiji"))
+s2_cap <- function(x) {
+  cpp_s2_cap(as_s2_geography(x))
+}
+
+#' @name s2_cap
+#' @export
+#' @return \code{s2_lat_lng_rect} returns a bounding latitude-longitude 
+#' rectangle that contains the region.  The bound may not be tight for points, 
+#' polylines and geometry collections. The rectangle returned may depend on
+#' the order of points or polylines. \code{lng_lo} values larger than \code{lng_hi} indicate 
+#' regions that span the antimeridian, see the Fiji example.
+#' @examples
+#' s2_lat_lng_rect(s2_data_countries("Antarctica"))
+#' s2_lat_lng_rect(s2_data_countries("Netherlands"))
+#' s2_lat_lng_rect(s2_data_countries("Fiji"))
+s2_lat_lng_rect <- function(x) {
+  cpp_s2_lat_lng_rect(as_s2_geography(x))
+}

man/as_s2_geography.Rd

@@ -6,6 +6,7 @@ CXX_STD = CXX11
 OBJECTS = cpp-compat.o \
      s2-accessors.o \
      s2-constructors-formatters.o \
+     s2-cap.o \
      s2-predicates.o \
      s2-transformers.o \
      init.o \

man/s2_cap.Rd

@@ -5,6 +5,7 @@ CXX_STD = CXX11
 
 OBJECTS = cpp-compat.o \
      s2-accessors.o \
+     s2-cap.o \
      s2-constructors-formatters.o \
      s2-predicates.o \
      s2-transformers.o \

man/s2_geog_point.Rd

@@ -137,6 +137,28 @@ BEGIN_RCPP
     return rcpp_result_gen;
 END_RCPP
 }
+// cpp_s2_cap
+DataFrame cpp_s2_cap(List geog);
+RcppExport SEXP _s2_cpp_s2_cap(SEXP geogSEXP) {
+BEGIN_RCPP
+    Rcpp::RObject rcpp_result_gen;
+    Rcpp::RNGScope rcpp_rngScope_gen;
+    Rcpp::traits::input_parameter< List >::type geog(geogSEXP);
+    rcpp_result_gen = Rcpp::wrap(cpp_s2_cap(geog));
+    return rcpp_result_gen;
+END_RCPP
+}
+// cpp_s2_lat_lng_rect
+DataFrame cpp_s2_lat_lng_rect(List geog);
+RcppExport SEXP _s2_cpp_s2_lat_lng_rect(SEXP geogSEXP) {
+BEGIN_RCPP
+    Rcpp::RObject rcpp_result_gen;
+    Rcpp::RNGScope rcpp_rngScope_gen;
+    Rcpp::traits::input_parameter< List >::type geog(geogSEXP);
+    rcpp_result_gen = Rcpp::wrap(cpp_s2_lat_lng_rect(geog));
+    return rcpp_result_gen;
+END_RCPP
+}
 // cpp_s2_geog_point
 List cpp_s2_geog_point(NumericVector x, NumericVector y);
 RcppExport SEXP _s2_cpp_s2_geog_point(SEXP xSEXP, SEXP ySEXP) {
@@ -781,6 +803,8 @@ static const R_CallMethodDef CallEntries[] = {
     {"_s2_cpp_s2_y", (DL_FUNC) &_s2_cpp_s2_y, 1},
     {"_s2_cpp_s2_distance", (DL_FUNC) &_s2_cpp_s2_distance, 2},
     {"_s2_cpp_s2_max_distance", (DL_FUNC) &_s2_cpp_s2_max_distance, 2},
+    {"_s2_cpp_s2_cap", (DL_FUNC) &_s2_cpp_s2_cap, 1},
+    {"_s2_cpp_s2_lat_lng_rect", (DL_FUNC) &_s2_cpp_s2_lat_lng_rect, 1},
     {"_s2_cpp_s2_geog_point", (DL_FUNC) &_s2_cpp_s2_geog_point, 2},
     {"_s2_cpp_s2_make_line", (DL_FUNC) &_s2_cpp_s2_make_line, 3},
     {"_s2_cpp_s2_make_polygon", (DL_FUNC) &_s2_cpp_s2_make_polygon, 6},

src/Makevars.in

@@ -7,8 +7,10 @@
 #include "s2/s2polyline.h"
 #include "s2/s2polygon.h"
 #include "s2/s2shape_index.h"
+#include "s2/s2shape_index_region.h"
 #include "s2/mutable_s2shape_index.h"
 #include "s2/s2point_vector_shape.h"
+#include "s2/s2cap.h"
 #include "wk/geometry-handler.hpp"
 #include <Rcpp.h>
 
@@ -58,6 +60,19 @@ class Geography {
     return &this->shape_index_;
   }
 
+  virtual S2ShapeIndexRegion<S2ShapeIndex> ShapeIndexRegion() {
+	S2ShapeIndex *ix = this->ShapeIndex();
+	return MakeS2ShapeIndexRegion(ix);
+  }
+
+  virtual S2Cap GetCapBound() {
+	return this->ShapeIndexRegion().GetCapBound();
+  }
+
+  virtual S2LatLngRect GetRectBound() {
+	return this->ShapeIndexRegion().GetRectBound();
+  }
+
 protected:
   MutableS2ShapeIndex shape_index_;
   bool hasIndex;