Just as you can register custom brushes, custom flood fill patterns can be used by
specifying a pattern image to use via the imagesettile() function and specifying the
IMG_COLOR_TILED as the value of the fill color.
<?php
define("WIDTH", 450);
define("HEIGHT", 450);
define("T_WIDTH", 20);
define("T_HEIGHT",20);
$img = imagecreate(WIDTH, HEIGHT);
$background = $white = imagecolorallocate($img, 0xFF, 0xFF, 0xFF);
$black = imagecolorallocate($img, 0, 0, 0);
$tile = imagecreate(T_WIDTH, T_HEIGHT);
$t_bkgr = $t_white = imagecolorallocate($tile, 0xFF, 0xFF, 0xFF);
$t_black = imagecolorallocate($tile, 0,0,0);
imagefilledrectangle($tile, 0, 0, T_WIDTH/2, T_HEIGHT/2, $t_black);
imagefilledrectangle($tile, T_WIDTH/2, T_HEIGHT/2,
T_WIDTH-1, T_HEIGHT-1, $t_black);
imagerectangle($img, 0, 0, WIDTH-1, HEIGHT-1, $black);
imagesettile($img, $tile);
imagefilledrectangle($img, 1, 1, WIDTH-2, HEIGHT-2, IMG_COLOR_TILED);
header("Content-Type: image/png");
imagepng($img);
?>
