openstreetmap-website/db/functions/maptile.c
2008-11-08 19:21:03 +00:00

93 lines
2.1 KiB
C

#ifndef USE_MYSQL
#ifndef USE_PGSQL
#error One of USE_MYSQL or USE_PGSQL must be defined
#endif
#endif
#include <math.h>
/* The real maptile-for-point functionality is here */
static long long internal_maptile_for_point(double lat, double lon, long long zoom)
{
double scale = pow(2, zoom);
double r_per_d = M_PI / 180;
unsigned int x;
unsigned int y;
x = floor((lon + 180.0) * scale / 360.0);
y = floor((1 - log(tan(lat * r_per_d) + 1.0 / cos(lat * r_per_d)) / M_PI) * scale / 2.0);
return (x << zoom) | y;
}
#ifdef USE_MYSQL
#ifdef USE_PGSQL
#error ONLY one of USE_MYSQL and USE_PGSQL should be defined
#endif
#include <my_global.h>
#include <my_sys.h>
#include <m_string.h>
#include <mysql.h>
my_bool maptile_for_point_init(UDF_INIT *initid, UDF_ARGS *args, char *message)
{
if ( args->arg_count != 3 ||
args->arg_type[0] != INT_RESULT ||
args->arg_type[1] != INT_RESULT ||
args->arg_type[2] != INT_RESULT )
{
strcpy( message, "Your maptile_for_point arguments are bogus!" );
return 1;
}
return 0;
}
void maptile_for_point_deinit(UDF_INIT *initid)
{
return;
}
long long maptile_for_point(UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error)
{
double lat = *(long long *)args->args[0] / 10000000.0;
double lon = *(long long *)args->args[1] / 10000000.0;
long long zoom = *(long long *)args->args[2];
return internal_maptile_for_point(lat, lon, zoom);
}
#endif
#ifdef USE_PGSQL
#include <postgres.h>
#include <fmgr.h>
Datum
maptile_for_point(PG_FUNCTION_ARGS)
{
double lat = PG_GETARG_INT64(0) / 10000000.0;
double lon = PG_GETARG_INT64(1) / 10000000.0;
int zoom = PG_GETARG_INT32(2);
PG_RETURN_INT32(internal_maptile_for_point(lat, lon, zoom));
}
PG_FUNCTION_INFO_V1(maptile_for_point);
/*
* To bind this into PGSQL, try something like:
*
* CREATE FUNCTION maptile_for_point(int8, int8, int4) RETURNS int4
* AS '/path/to/rails-port/db/functions/libpgosm', 'maptile_for_point'
* LANGUAGE C STRICT;
*
* (without all the *s)
*/
#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif
#endif