- function geocodeReverse($fLat, $fLon, $iZoom=18)
- {
- $oDB =& getDB();
-
- $sPointSQL = "ST_SetSRID(ST_Point($fLon,$fLat),4326)";
-
- // Zoom to rank, this could probably be calculated but a lookup gives fine control
- $aZoomRank = array(
- 0 => 2, // Continent / Sea
- 1 => 2,
- 2 => 2,
- 3 => 4, // Country
- 4 => 4,
- 5 => 8, // State
- 6 => 10, // Region
- 7 => 10,
- 8 => 12, // County
- 9 => 12,
- 10 => 17, // City
- 11 => 17,
- 12 => 18, // Town / Village
- 13 => 18,
- 14 => 22, // Suburb
- 15 => 22,
- 16 => 26, // Street, TODO: major street?
- 17 => 26,
- 18 => 30, // or >, Building
- 19 => 30, // or >, Building
- );
- $iMaxRank = isset($aZoomRank[$iZoom])?$aZoomRank[$iZoom]:28;
-
- // Find the nearest point
- $fSearchDiam = 0.0001;
- $iPlaceID = null;
- $aArea = false;
- $fMaxAreaDistance = 1;
- while(!$iPlaceID && $fSearchDiam < $fMaxAreaDistance)
- {
- $fSearchDiam = $fSearchDiam * 2;
-
- // If we have to expand the search area by a large amount then we need a larger feature
- // then there is a limit to how small the feature should be
- if ($fSearchDiam > 2 && $iMaxRank > 4) $iMaxRank = 4;
- if ($fSearchDiam > 1 && $iMaxRank > 9) $iMaxRank = 8;
- if ($fSearchDiam > 0.8 && $iMaxRank > 10) $iMaxRank = 10;
- if ($fSearchDiam > 0.6 && $iMaxRank > 12) $iMaxRank = 12;
- if ($fSearchDiam > 0.2 && $iMaxRank > 17) $iMaxRank = 17;
- if ($fSearchDiam > 0.1 && $iMaxRank > 18) $iMaxRank = 18;
- if ($fSearchDiam > 0.008 && $iMaxRank > 22) $iMaxRank = 22;
- if ($fSearchDiam > 0.001 && $iMaxRank > 26) $iMaxRank = 26;
-
- $sSQL = 'select place_id,parent_place_id from placex';
- $sSQL .= ' WHERE ST_DWithin('.$sPointSQL.', geometry, '.$fSearchDiam.')';
- $sSQL .= ' and rank_search != 28 and rank_search >= '.$iMaxRank;
- $sSQL .= ' and (name is not null or housenumber is not null)';
- $sSQL .= ' and class not in (\'waterway\')';
- $sSQL .= ' and (ST_GeometryType(geometry) not in (\'ST_Polygon\',\'ST_MultiPolygon\') ';
- $sSQL .= ' OR ST_DWithin('.$sPointSQL.', ST_Centroid(geometry), '.$fSearchDiam.'))';
- $sSQL .= ' ORDER BY ST_distance('.$sPointSQL.', geometry) ASC limit 1';
- //var_dump($sSQL);
- $aPlace = chksql($oDB->getRow($sSQL));
- $iPlaceID = $aPlace['place_id'];
- }
-
- // The point we found might be too small - use the address to find what it is a child of
- if ($iPlaceID)
- {
- $sSQL = "select address_place_id from place_addressline where cached_rank_address <= $iMaxRank and place_id = $iPlaceID order by cached_rank_address desc,isaddress desc,distance desc limit 1";
- $iPlaceID = chksql($oDB->getOne($sSQL));
-
- if ($iPlaceID && $aPlace['place_id'] && $iMaxRank < 28)
- {
- $sSQL = "select address_place_id from place_addressline where cached_rank_address <= $iMaxRank and place_id = ".$aPlace['place_id']." order by cached_rank_address desc,isaddress desc,distance desc";
- $iPlaceID = chksql($oDB->getOne($sSQL));
- }
- if (!$iPlaceID)
- {
- $iPlaceID = $aPlace['place_id'];
- }
- }
-
- return $iPlaceID;
- }
-