| <?php | |
| /* | |
| * GeoPo Encode in PHP | |
| * @author : Shintaro Inagaki | |
| * @param $location (Array) | |
| * @return $geopo (String) | |
| */ | |
| function geopoEncode($lat, $lng) | |
| { | |
| // 64characters (number + big and small letter + hyphen + underscore) | |
| $chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_"; | |
| $geopo = ""; | |
| $scale = 7; | |
| // Change a degree measure to a decimal number | |
| $lat = ($lat + 90) / 180 * pow(8, 10); | |
| $lng = ($lng + 180) / 360 * pow(8, 10); | |
| // Compute a GeoPo code from head and concatenate | |
| for ($i = 0; $i < $scale; $i++) { | |
| $geopo .= substr($chars, floor($lat / pow(8, 9 - $i) % 8) + floor($lng / pow(8, 9 - $i) % 8) * 8, 1); | |
| } | |
| return $geopo; | |
| } | |
| /* | |
| * GeoPo Decode in PHP | |
| * @author : Shintaro Inagaki | |
| * @param $geopo (String) | |
| * @return $location (Array) | |
| */ | |
| function geopoDecode($geopo) | |
| { | |
| // 64characters (number + big and small letter + hyphen + underscore) | |
| $chars = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-_"; | |
| // Array for geolocation | |
| $location = array(); | |
| for ($i = 0; $i < strlen($geopo); $i++) { | |
| // What number of character that equal to a GeoPo code (0-63) | |
| $order = strpos($chars, substr($geopo, $i, 1)); | |
| // Lat/Lng plus geolocation value of scale | |
| $location['lat'] = $location['lat'] + floor($order % 8) * pow(8, 9 - $i); | |
| $location['lng'] = |