make a large png from map tiles

recolle.php

<?php

# stitch tile images together to form a large image
# see also https://github.com/ericfischer/tile-stitch

function usage($err= null) {

	echo "php recolle.php 'http://TILES_SERVER/%z/%x/%y.png' z x1 y1 [+nx] [+ny]\n";

	if ($err)
		echo "$err\n";

	exit;
}

list(,$pattern, $z, $x1, $y1, $nx, $ny) = $argv;

$z = intval($z);
$x1 = intval($x1);
$y1 = intval($y1);

// by defaut 16x16
if (is_null($nx)) $nx = 16;
if (is_null($ny)) $ny = 16;

$nx = intval($nx);
$ny = intval($ny);

if ($z<0 OR $z > 17) usage ('0 <= z <= 17');

if ($nx * $ny > 1000000) usage ('1 million de tuiles max');

$map = array();
for ($i = 0; $i<=$nx; $i++) {
	$map[$i] = array();
	for ($j = 0; $j<=$ny; $j++) {
		$map[$i][$j] = get_tile($pattern, $z, $x1+$i, $y1+$j);
		var_dump($map[$i][$j]);
	}
}


if ($a = glob('tmp/*.png')) array_map('unlink', $a);

$c = '';
for ($i = 0; $i<=$nx; $i++) {
	$x = $x1+$i;
	$b = join(' ', array_map('escapeshellarg', $map[$i]));
	$b = "montage -background none -alpha on -geometry 256x256:+0+0 ".$b." -tile 1x tmp/$x.png";
	echo "montage bande $x...\n$b\n";
	`$b`;
	$c .= " tmp/$x.png";
}

echo "montage des bandes...\n";

$b = "montage -background none -alpha on -mode Concatenate -tile x1$c tmp/full.png";
`$b`;
`open tmp/full.png`;


function get_tile($pattern, $z, $x, $y) {

	$url = str_replace(array('%z', '%x', '%y'), array($z, $x, $y), $pattern);

	$tile = "tmp/$z/$x/$y";
	if ($a = glob($tile.'.{png,jpg,tmp}', GLOB_BRACE))
		return preg_match(',(png|jpg)$,', $a[0]) ? $a[0] : 'vide.png';

	@mkdir (dirname($tile), 0755, true);

	$_url = escapeshellarg($url);
	$_tile = escapeshellarg($tile.'.tmp');

	`wget $_url -O $_tile`;
	$check = `identify -quiet $_tile`;

	if (preg_match(', (PNG|JPEG),', $check, $r)) {
		rename ($tile.'.tmp', $dest = $tile.'.'.strtolower($r[1]));
		return $dest;
	}

	return 'vide.png'; # null: pour imagemagick/ montage
	# http://www.imagemagick.org/Usage/montage/#zero_geometry

}