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/*
* Copyright (c) 2013-2014, yinqiwen <yinqiwen@gmail.com>
* Copyright (c) 2014, Matt Stancliff <matt@genges.com>.
* Copyright (c) 2015, Salvatore Sanfilippo <antirez@gmail.com>.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef GEOHASH_H_
#define GEOHASH_H_
#include <stddef.h>
#include <stdint.h>
#include <stdint.h>
#if defined(__cplusplus)
extern "C" {
#endif
#define HASHISZERO(r) (!(r).bits && !(r).step)
#define RANGEISZERO(r) (!(r).max && !(r).min)
#define RANGEPISZERO(r) (r == NULL || RANGEISZERO(*r))
#define GEO_STEP_MAX 26 /* 26*2 = 52 bits. */
/* Limits from EPSG:900913 / EPSG:3785 / OSGEO:41001 */
#define GEO_LAT_MIN -85.05112878
#define GEO_LAT_MAX 85.05112878
#define GEO_LONG_MIN -180
#define GEO_LONG_MAX 180
typedef enum {
GEOHASH_NORTH = 0,
GEOHASH_EAST,
GEOHASH_WEST,
GEOHASH_SOUTH,
GEOHASH_SOUTH_WEST,
GEOHASH_SOUTH_EAST,
GEOHASH_NORT_WEST,
GEOHASH_NORT_EAST
} GeoDirection;
typedef struct {
uint64_t bits;
uint8_t step;
} GeoHashBits;
typedef struct {
double min;
double max;
} GeoHashRange;
typedef struct {
GeoHashBits hash;
GeoHashRange longitude;
GeoHashRange latitude;
} GeoHashArea;
typedef struct {
GeoHashBits north;
GeoHashBits east;
GeoHashBits west;
GeoHashBits south;
GeoHashBits north_east;
GeoHashBits south_east;
GeoHashBits north_west;
GeoHashBits south_west;
} GeoHashNeighbors;
/*
* 0:success
* -1:failed
*/
void geohashGetCoordRange(GeoHashRange *long_range, GeoHashRange *lat_range);
int geohashEncode(GeoHashRange *long_range, GeoHashRange *lat_range,
double longitude, double latitude, uint8_t step,
GeoHashBits *hash);
int geohashEncodeType(double longitude, double latitude,
uint8_t step, GeoHashBits *hash);
int geohashEncodeWGS84(double longitude, double latitude, uint8_t step,
GeoHashBits *hash);
int geohashDecode(const GeoHashRange long_range, const GeoHashRange lat_range,
const GeoHashBits hash, GeoHashArea *area);
int geohashDecodeType(const GeoHashBits hash, GeoHashArea *area);
int geohashDecodeWGS84(const GeoHashBits hash, GeoHashArea *area);
int geohashDecodeAreaToLongLat(const GeoHashArea *area, double *xy);
int geohashDecodeToLongLatType(const GeoHashBits hash, double *xy);
int geohashDecodeToLongLatWGS84(const GeoHashBits hash, double *xy);
int geohashDecodeToLongLatMercator(const GeoHashBits hash, double *xy);
void geohashNeighbors(const GeoHashBits *hash, GeoHashNeighbors *neighbors);
#if defined(__cplusplus)
}
#endif
#endif /* GEOHASH_H_ */
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