#1818: geohash one more file forgot to commit.

git-svn-id: http://svn.osgeo.org/postgis/trunk@11343 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/postgis/lwgeom_in_geohash.c b/postgis/lwgeom_in_geohash.c
new file mode 100644 (file)
index 0000000..c1163a8
--- /dev/null
+++ b/postgis/lwgeom_in_geohash.c
@@ -0,0 +1,121 @@
+/**********************************************************************
+ *
+ * PostGIS - Spatial Types for PostgreSQL
+ * Copyright 2012 J Smith <dark.panda@gmail.com>
+ *
+ * This is free software; you can redistribute and/or modify it under
+ * the terms of the GNU General Public Licence. See the COPYING file.
+ *
+ **********************************************************************/
+
+#include <assert.h>
+
+#include "postgres.h"
+
+#include "../postgis_config.h"
+#include "lwgeom_pg.h"
+#include "liblwgeom.h"
+
+Datum box2d_from_geohash(PG_FUNCTION_ARGS);
+Datum point_from_geohash(PG_FUNCTION_ARGS);
+
+static void geohash_lwerror(char *msg, int error_code)
+{
+       POSTGIS_DEBUGF(3, "ST_Box2dFromGeoHash ERROR %i", error_code);
+       lwerror("%s", msg);
+}
+
+#include "lwgeom_export.h"
+
+GBOX*
+parse_geohash(char *geohash, int precision)
+{
+       GBOX *box = NULL;
+       double lat[2], lon[2];
+
+       POSTGIS_DEBUG(2, "parse_geohash called.");
+
+       if (NULL == geohash)
+       {
+               geohash_lwerror("invalid GeoHash representation", 2);
+       }
+
+       decode_geohash_bbox(geohash, lat, lon, precision);
+
+       POSTGIS_DEBUGF(2, "ST_Box2dFromGeoHash sw: %.20f, %.20f", lon[0], lat[0]);
+       POSTGIS_DEBUGF(2, "ST_Box2dFromGeoHash ne: %.20f, %.20f", lon[1], lat[1]);
+
+       box = gbox_new(gflags(0, 0, 1));
+
+       box->xmin = lon[0];
+       box->ymin = lat[0];
+
+       box->xmax = lon[1];
+       box->ymax = lat[1];
+
+       POSTGIS_DEBUG(2, "parse_geohash finished.");
+       return box;
+}
+
+PG_FUNCTION_INFO_V1(box2d_from_geohash);
+Datum box2d_from_geohash(PG_FUNCTION_ARGS)
+{
+       GBOX *box = NULL;
+       text *geohash_input = NULL;
+       char *geohash = NULL;
+       int precision = -1;
+
+       if (PG_ARGISNULL(0))
+       {
+               PG_RETURN_NULL();
+       }
+
+       if (!PG_ARGISNULL(1))
+       {
+               precision = PG_GETARG_INT32(1);
+       }
+
+       geohash_input = PG_GETARG_TEXT_P(0);
+       geohash = text2cstring(geohash_input);
+
+       box = parse_geohash(geohash, precision);
+
+       PG_RETURN_POINTER(box);
+}
+
+PG_FUNCTION_INFO_V1(point_from_geohash);
+Datum point_from_geohash(PG_FUNCTION_ARGS)
+{
+       GBOX *box = NULL;
+       LWPOINT *point = NULL;
+       GSERIALIZED *result = NULL;
+       text *geohash_input = NULL;
+       char *geohash = NULL;
+       double lon, lat;
+       int precision = -1;
+
+       if (PG_ARGISNULL(0))
+       {
+               PG_RETURN_NULL();
+       }
+
+       if (!PG_ARGISNULL(1))
+       {
+               precision = PG_GETARG_INT32(1);
+       }
+
+       geohash_input = PG_GETARG_TEXT_P(0);
+       geohash = text2cstring(geohash_input);
+
+       box = parse_geohash(geohash, precision);
+
+       lon = box->xmin + (box->xmax - box->xmin) / 2;
+       lat = box->ymin + (box->ymax - box->ymin) / 2;
+
+       point = lwpoint_make2d(SRID_UNKNOWN, lon, lat);
+       result = geometry_serialize((LWGEOM *) point);
+
+       lwfree(box);
+
+       PG_RETURN_POINTER(result);
+}