(PHP 4, PHP 5, PHP 7)
imagesetpixel — Set a single pixel
$image
   , int $x
   , int $y
   , int $color
   )imagesetpixel() draws a pixel at the specified coordinate.
imageAn image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
xx-coordinate.
yy-coordinate.
colorA color identifier created with imagecolorallocate().
   Returns TRUE on success or FALSE on failure.
  
Example #1 imagesetpixel() example
A random drawing that ends with a regular picture.
<?php
$x = 200;
$y = 200;
$gd = imagecreatetruecolor($x, $y);
 
$corners[0] = array('x' => 100, 'y' =>  10);
$corners[1] = array('x' =>   0, 'y' => 190);
$corners[2] = array('x' => 200, 'y' => 190);
$red = imagecolorallocate($gd, 255, 0, 0); 
for ($i = 0; $i < 100000; $i++) {
  imagesetpixel($gd, round($x),round($y), $red);
  $a = rand(0, 2);
  $x = ($x + $corners[$a]['x']) / 2;
  $y = ($y + $corners[$a]['y']) / 2;
}
 
header('Content-Type: image/png');
imagepng($gd);
?>
The above example will output something similar to:
