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3ada0d2 May 23, 2018
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/*
* Copyright 2017 Uber Technologies, Inc.
*
* 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.
*/
/**
* Example program that converts coordinates to an H3 index (hexagon),
* and then finds the vertices and center coordinates of the index.
*/
#include <h3/h3api.h>
#include <inttypes.h>
#include <stdio.h>
int main(int argc, char *argv[]) {
// Get the H3 index of some location and print it.
GeoCoord location;
location.lat = degsToRads(40.689167);
location.lon = degsToRads(-74.044444);
int resolution = 10;
H3Index indexed = geoToH3(&location, resolution);
printf("The index is: %" PRIx64 "\n", indexed);
// Get the vertices of the H3 index.
GeoBoundary boundary;
h3ToGeoBoundary(indexed, &boundary);
// Indexes can have different number of vertices under some cases,
// which is why boundary.numVerts is needed.
for (int v = 0; v < boundary.numVerts; v++) {
printf("Boundary vertex #%d: %lf, %lf\n", v,
radsToDegs(boundary.verts[v].lat),
radsToDegs(boundary.verts[v].lon));
}
// Get the center coordinates.
GeoCoord center;
h3ToGeo(indexed, &center);
printf("Center coordinates: %lf, %lf\n", radsToDegs(center.lat),
radsToDegs(center.lon));
}