1 /*
2  * Copyright (c) 2013-2014, yinqiwen <[email protected]>
3  * Copyright (c) 2014, Matt Stancliff <[email protected]>.
4  * Copyright (c) 2015, Salvatore Sanfilippo <[email protected]>.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions are met:
9  *
10  *  * Redistributions of source code must retain the above copyright notice,
11  *    this list of conditions and the following disclaimer.
12  *  * Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *  * Neither the name of Redis nor the names of its contributors may be used
16  *    to endorse or promote products derived from this software without
17  *    specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
29  * THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #ifndef GEOHASH_HELPER_HPP_
33 #define GEOHASH_HELPER_HPP_
34 
35 #include <math.h>
36 #include "geohash.h"
37 
38 #define GZERO(s) s.bits = s.step = 0;
39 #define GISZERO(s) (!s.bits && !s.step)
40 #define GISNOTZERO(s) (s.bits || s.step)
41 
42 typedef uint64_t GeoHashFix52Bits;
43 typedef uint64_t GeoHashVarBits;
44 
45 typedef struct {
46     GeoHashBits hash;
47     GeoHashArea area;
48     GeoHashNeighbors neighbors;
49 } GeoHashRadius;
50 
51 int GeoHashBitsComparator(const GeoHashBits *a, const GeoHashBits *b);
52 uint8_t geohashEstimateStepsByRadius(double range_meters, double lat);
53 int geohashBoundingBox(double longitude, double latitude, double radius_meters,
54                         double *bounds);
55 GeoHashRadius geohashGetAreasByRadius(double longitude,
56                                       double latitude, double radius_meters);
57 GeoHashRadius geohashGetAreasByRadiusWGS84(double longitude, double latitude,
58                                            double radius_meters);
59 GeoHashRadius geohashGetAreasByRadiusMercator(double longitude, double latitude,
60                                               double radius_meters);
61 GeoHashFix52Bits geohashAlign52Bits(const GeoHashBits hash);
62 double geohashGetDistance(double lon1d, double lat1d,
63                           double lon2d, double lat2d);
64 int geohashGetDistanceIfInRadius(double x1, double y1,
65                                  double x2, double y2, double radius,
66                                  double *distance);
67 int geohashGetDistanceIfInRadiusWGS84(double x1, double y1, double x2,
68                                       double y2, double radius,
69                                       double *distance);
70 
71 #endif /* GEOHASH_HELPER_HPP_ */
72