(PHP 4, PHP 5, PHP 7, PHP 8)
imagefill — Flood fill
   Performs a flood fill starting at the given coordinate (top left is 0, 0)
   with the given color in the
   image.
  
imageA GdImage object, returned by one of the image creation functions, such as imagecreatetruecolor().
xx-coordinate of start point.
yy-coordinate of start point.
colorThe fill color. A color identifier created with imagecolorallocate().
| Version | Description | 
|---|---|
| 8.0.0 | imageexpects a GdImage
  instance now; previously, a validgdresource was expected. | 
Example #1 imagefill() example
<?php
$im = imagecreatetruecolor(100, 100);
// sets background to red
$red = imagecolorallocate($im, 255, 0, 0);
imagefill($im, 0, 0, $red);
header('Content-type: image/png');
imagepng($im);
imagedestroy($im);
?>The above example will output something similar to:
