generate(sha512('hello')); * header('Content-type: image/png'); * echo $data; * exit; */ class Vizhash16x16 { /** * hash values * * @access private * @var array */ private $VALUES; /** * index of current value * * @access private * @var int */ private $VALUES_INDEX; /** * image width * * @access private * @var int */ private $width; /** * image height * * @access private * @var int */ private $height; /** * constructor * * @access public */ public function __construct() { $this->width = 16; $this->height = 16; } /** * Generate a 16x16 png corresponding to $text. * * The given text should to be 128 to 150 characters long * * @access public * @param string $text * @return string PNG data. Or empty string if GD is not available. */ public function generate($text) { if (!function_exists('gd_info')) { return ''; } $textlen = strlen($text); // We convert the hash into an array of integers. $this->VALUES = array(); for ($i = 0; $i < $textlen; $i = $i + 2) { array_push($this->VALUES, hexdec(substr($text, $i, 2))); } $this->VALUES_INDEX = 0; // to walk the array. // Then use these integers to drive the creation of an image. $image = imagecreatetruecolor($this->width, $this->height); $r = $r0 = $this->getInt(); $g = $g0 = $this->getInt(); $b = $b0 = $this->getInt(); // First, create an image with a specific gradient background. $op = 'v'; if (($this->getInt() % 2) == 0) { $op = 'h'; } $image = $this->degrade($image, $op, array($r0, $g0, $b0), array(0, 0, 0)); for ($i = 0; $i < 7; ++$i) { $action = $this->getInt(); $color = imagecolorallocate($image, $r, $g, $b); $r = $r0 = (int) ($r0 + $this->getInt() / 25) % 256; $g = $g0 = (int) ($g0 + $this->getInt() / 25) % 256; $b = $b0 = (int) ($b0 + $this->getInt() / 25) % 256; $this->drawshape($image, $action, $color); } $color = imagecolorallocate($image, $this->getInt(), $this->getInt(), $this->getInt()); $this->drawshape($image, $this->getInt(), $color); ob_start(); imagepng($image); $imagedata = ob_get_contents(); ob_end_clean(); imagedestroy($image); return $imagedata; } /** * Returns a single integer from the $VALUES array (0...255) * * @access private * @return int */ private function getInt() { $v = $this->VALUES[$this->VALUES_INDEX]; ++$this->VALUES_INDEX; $this->VALUES_INDEX %= count($this->VALUES); // Wrap around the array return $v; } /** * Returns a single integer from the array (roughly mapped to image width) * * @access private * @return int */ private function getX() { return (int) ($this->width * $this->getInt() / 256); } /** * Returns a single integer from the array (roughly mapped to image height) * * @access private * @return int */ private function getY() { return (int) ($this->height * $this->getInt() / 256); } /** * Gradient function * * taken from: * @link https://www.supportduweb.com/scripts_tutoriaux-code-source-41-gd-faire-un-degrade-en-php-gd-fonction-degrade-imagerie.html * * @access private * @param resource $img * @param string $direction * @param array $color1 * @param array $color2 * @return resource */ private function degrade($img, $direction, $color1, $color2) { if ($direction == 'h') { $size = imagesx($img); $sizeinv = imagesy($img); } else { $size = imagesy($img); $sizeinv = imagesx($img); } $diffs = array( ($color2[0] - $color1[0]) / $size, ($color2[1] - $color1[1]) / $size, ($color2[2] - $color1[2]) / $size, ); for ($i = 0; $i < $size; ++$i) { $r = $color1[0] + ((int) $diffs[0] * $i); $g = $color1[1] + ((int) $diffs[1] * $i); $b = $color1[2] + ((int) $diffs[2] * $i); if ($direction == 'h') { imageline($img, $i, 0, $i, $sizeinv, imagecolorallocate($img, $r, $g, $b)); } else { imageline($img, 0, $i, $sizeinv, $i, imagecolorallocate($img, $r, $g, $b)); } } return $img; } /** * Draw a shape * * @access private * @param resource $image * @param int $action * @param int $color */ private function drawshape($image, $action, $color) { switch ($action % 7) { case 0: imagefilledrectangle($image, $this->getX(), $this->getY(), $this->getX(), $this->getY(), $color); break; case 1: case 2: imagefilledellipse($image, $this->getX(), $this->getY(), $this->getX(), $this->getY(), $color); break; case 3: $points = array($this->getX(), $this->getY(), $this->getX(), $this->getY(), $this->getX(), $this->getY(), $this->getX(), $this->getY()); version_compare(PHP_VERSION, '8.1', '<') ? imagefilledpolygon($image, $points, 4, $color) : imagefilledpolygon($image, $points, $color); break; default: $start = (int) ($this->getInt() * 360 / 256); $end = (int) ($start + $this->getInt() * 180 / 256); imagefilledarc($image, $this->getX(), $this->getY(), $this->getX(), $this->getY(), $start, $end, $color, IMG_ARC_PIE); } } }