protected function lngLatToPixels($lngLatPoints)
{
GoogleMapUtility::$TILE_SIZE = $this->tileSize;
// points contain simple array of x,y,x,y,...
$pointlist = array();
$pointcount = 0;
foreach ($lngLatPoints as $coords) {
$lng = $coords[0];
$lat = $coords[1];
$relativePixelPoint = GoogleMapUtility::toZoomedPixelCoords($lat, $lng, $this->zoom);
$pointlist[] = $absolutePixelX = $relativePixelPoint->x - $this->tileSize * $this->pixelX + $this->offsetX;
$pointlist[] = $absolutePixelY = $relativePixelPoint->y - $this->tileSize * $this->pixelY + $this->offsetY;
$pointcount++;
}
return $pointlist;
}
public static function toZoomedPixelCoords($lat, $lng, $zoom)
{
$normalised = GoogleMapUtility::toNormalisedMercatorCoords(GoogleMapUtility::toMercatorCoords($lat, $lng));
$scale = (1 << $zoom) * GoogleMapUtility::$TILE_SIZE;
return new GoogleMapPoint((int) ($normalised->x * $scale), (int) ($normalised->y * $scale));
}
/**
* Uses {@link GoogleMapUtility} to convert a bounday box in WGS84 coordinates
* to the tiles covered by this boundary. Stores those tiles as a unique
* reference in the database as new {@link TileRenderQueue} objects who
* can be rendered by the {@link TileRenderQueue_Controller}.
* Note: This method just queues requests, doesn't render tiles itself.
*
* In case you're also generating tiles "on the fly" by browser requests,
* make sure to use the same {@link TileRenderer} instance or conventions
* in the {@link $renderer} parameter. Otherwise you might cache tiles
* at a different location, or with different extensions.
*
* Example class MyShape
* <example>
* class MyShape extends DataObject {
* static $db = array(
* 'MyPolygon' => 'Polygon'
* );
* }
* </example>
* <example>
* function populateQueue() {
* $query = singleton('MyShape')->extendedSQL();
* $query->select = array(
* '`MyShape`.`ID`',
* 'ASTEXT(ENVELOPE(`MyShape`.`MyPolygon`)) AS MyPolygonMBR'
* );
* $shapes = $query->execute();
*
* foreach($shapes as $shape) {
* $poly = DBField::create('GeoPolygon', $shape['MyPolygonMBR']);
*
* // first and second-last coordinates of the ring can be assumed
* // to be the min and max coordinates in this specific geopoly
* $rings = $poly->getRings();
* $mbrArr = $rings[0];
* $lat = $mbrArr[0][1];
* $lng = $mbrArr[0][0];
* $maxLat = $mbrArr[2][1];
* $maxLng = $mbrArr[2][0];
*
* // add all necessary tiles for this network and bounds to the queue
* TileRenderQueue::create_by_boundary($renderer, $lat, $lng, $maxLat, $maxLng);
* unset($poly);
* }
* }
* </example>
*
* @param TileRenderer $renderer Used to determine the URL format and folder structure
* @param float $lat
* @param float $lng
* @param float $maxLat
* @param float $maxLng
* @param int $minZoom
* @param int $maxZoom
* @return array Numeric array of tile urls relative to the cache folder, e.g. array('42/34234-23423-17.gif','42/34234-23424-17.gif');
*/
static function create_by_boundary($renderer, $lat, $lng, $maxLat, $maxLng, $minZoom = null, $maxZoom = null)
{
// Defaults from static variables
if ($minZoom == null) {
$minZoom = self::$min_zoom;
}
if ($maxZoom == null) {
$maxZoom = self::$max_zoom;
}
$urls = array();
// for each zoom level
foreach (range($minZoom, $maxZoom) as $zoom) {
$minPointMeters = GoogleMapUtility::latLonToMeters($lat, $lng);
$minPointTile = GoogleMapUtility::metersToTile($minPointMeters->x, $minPointMeters->y, $zoom);
$maxPointMeters = GoogleMapUtility::latLonToMeters($maxLat, $maxLng);
$maxPointTile = GoogleMapUtility::metersToTile($maxPointMeters->x, $maxPointMeters->y, $zoom);
// for each tile on y direction
foreach (range($minPointTile->y, $maxPointTile->y) as $ty) {
// for each tile in x direction
foreach (range($minPointTile->x, $maxPointTile->x) as $tx) {
$googleTile = GoogleMapTile::create_from_tms_tile($tx, $ty, $zoom);
$tileUrl = $renderer->getRelativeTilePath();
$tileUrl .= $renderer->getFilename($googleTile->x, $googleTile->y, $googleTile->zoom);
$urls[] = $tileUrl;
}
}
}
if ($urls) {
foreach ($urls as $url) {
if (!self::has_pending_tile($url)) {
$item = new TileRenderQueue();
$item->URL = $url;
$item->write();
unset($item);
}
}
}
return $urls;
}
