From f4c207b85653efc53e41dcf329e0e3efe9c68bf3 Mon Sep 17 00:00:00 2001
From: Regina Obe <lr@pcorp.us>
Date: Fri, 3 May 2013 04:12:36 +0000
Subject: [PATCH] #1818: geohash one more file forgot to commit.

git-svn-id: http://svn.osgeo.org/postgis/trunk@11343 b70326c6-7e19-0410-871a-916f4a2858ee
---
 postgis/lwgeom_in_geohash.c | 121 ++++++++++++++++++++++++++++++++++++
 1 file changed, 121 insertions(+)
 create mode 100644 postgis/lwgeom_in_geohash.c

diff --git a/postgis/lwgeom_in_geohash.c b/postgis/lwgeom_in_geohash.c
new file mode 100644
index 000000000..c1163a8cc
--- /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);
+}
-- 
2.40.0