function crop_ways_to_box(&$input_osm_ways, $min_lat, $min_lon, $max_lat, $max_lon, $verbose)
{
if ($verbose) {
error_log("Starting way cropping");
}
$clipping_planes = get_clipping_planes_for_box($min_lat, $min_lon, $max_lat, $max_lon);
$input_nodes = $input_osm_ways->nodes;
$input_ways = $input_osm_ways->ways;
$result = new OSMWays();
$count = 0;
foreach ($input_ways as $input_way) {
$count += 1;
if ($verbose && $count % 1000 === 0) {
error_log("Processing {$count}/" . count($input_ways));
}
$nds = $input_way['nds'];
if (empty($nds)) {
continue;
}
$output_vertices = array();
foreach ($nds as $nd_ref) {
$current_vertex = $input_nodes[$nd_ref];
$output_vertices[] = $current_vertex;
}
foreach ($clipping_planes as $plane) {
$output_vertices = clip_vertices_against_plane($output_vertices, $plane, $verbose);
}
if (empty($output_vertices)) {
continue;
}
$result->begin_way();
foreach ($input_way['tags'] as $key => $value) {
$result->add_tag($key, $value);
}
foreach ($output_vertices as $vertex) {
$result->add_vertex($vertex['lat'], $vertex['lon']);
}
if ($input_way['is_closed']) {
$result->force_closed();
}
$result->end_way();
}
if ($verbose) {
error_log("Finished way cropping");
}
return $result;
}
