$y = isset($_GET['y']) ? intval($_GET['y']) : round($mosaic->image_h / $mosaic->mosaic_factor / 2);
//get the image index
$i = intval($_GET['i']);
$j = intval($_GET['j']);
//handle the zoom
$mosaic->zoomIn($i, $j, $x, $y);
}
if (isset($_GET['center'])) {
//extract x and y click coordinate from imagemap
$x = isset($_GET['x']) ? intval($_GET['x']) : round($overview->image_w / $mosaic->mosaic_factor / 2);
$y = isset($_GET['y']) ? intval($_GET['y']) : round($overview->image_h / $mosaic->mosaic_factor / 2);
//get the image index
$i = intval($_GET['i']);
$j = intval($_GET['j']);
//get click coordinate on overview, use it to centre the main map
list($intx, $inty) = $overview->getClickCoordinates($i, $j, $x, $y);
$zoomindex = array_search($overview->pixels_per_km, $overview->scales);
$scale = $overview->scales[$zoomindex + 1];
$mosaic->setScale($scale);
$mosaic->setMosaicFactor(2);
$mosaic->setCentre($intx, $inty);
}
if (isset($_GET['recenter'])) {
//extract x and y click coordinate from imagemap
$x = isset($_GET['x']) ? intval($_GET['x']) : round($overview->image_w / $mosaic->mosaic_factor / 2);
$y = isset($_GET['y']) ? intval($_GET['y']) : round($overview->image_h / $mosaic->mosaic_factor / 2);
//get the image index
$i = intval($_GET['i']);
$j = intval($_GET['j']);
//get click coordinate on overview, use it to centre the main map
list($intx, $inty) = $overview->getClickCoordinates($i, $j, $x, $y);