https://util.fiveyellowmice.com/contaminative-moons/

contaminative-moons.php

<?php

define('PREPARED_MOONS', [
  'apple_new_moon_with_face',
  'apple_full_moon_with_face',
  'apple_ios10_new_moon_with_face',
  'apple_ios10_full_moon_with_face',
  'noto_new_moon_with_face',
  'noto_full_moon_with_face',
  'segoe_new_moon_with_face',
  'segoe_full_moon_with_face',
  'apple_new_moon',
  'apple_full_moon',
  'apple_ios10_new_moon',
  'apple_ios10_full_moon',
  'noto_new_moon',
  'noto_full_moon',
  'segoe_new_moon',
  'segoe_full_moon',
]);

class InvalidParameterException extends Exception {}

function expect_param($name) {
  if (!array_key_exists($name, $_GET) || in_array($_GET[$name], [null, ''])) {
    throw new InvalidParameterException("Parameter $name is required but not specified.");
  }
  return $_GET[$name];
}

function rand_float($min, $max) {
  return lcg_value() * ($max - $min) + $min;
}


if (!in_array($_SERVER['REQUEST_METHOD'], ['GET', 'HEAD'])) {
  http_response_code(405);
  header('Cache-Control: no-cache');
  header('Content-Type: text/plain');
  header('Content-Length: 20');
  echo "Method not allowed.\n";
  die();
}

try {
  $canvas_width = intval(expect_param('width'));
  if ($canvas_width <= 0 || $canvas_width > 3840) {
    throw new InvalidParameterException("Width must be a number between 0 and 3840.");
  }

  $canvas_height = intval(expect_param('height'));
  if ($canvas_height <= 0 || $canvas_height > 2160) {
    throw new InvalidParameterException("Height must be a number between 0 and 2160.");
  }

  $moon_count = intval(expect_param('count'));
  if ($moon_count <= 0 || $moon_count > 512) {
    throw new InvalidParameterException("Count must be a number between 0 and 512.");
  }

  $background = expect_param('background');
  if (!in_array($background, ['black', 'white', 'transparent'])) {
    throw new InvalidParameterException("Background must be \"black\", \"white\" or \"transparent\".");
  }

  $output_format = expect_param('format');
  if (!in_array($output_format, ['jpeg', 'png', 'webp'])) {
    throw new InvalidParameterException("Format must be \"jpeg\", \"png\" or \"webp\".");
  }

  $moon_settings = array_map(function($w) {
    $q = explode(',', $w);
    if (sizeof($q) !== 3) {
      throw new InvalidParameterException('Each moons must have 3 parameters.');
    }
    if (!in_array($q[0], PREPARED_MOONS)) {
      throw new InvalidParameterException("$q[0] is not a valid moon name.");
    }
    $q[1] = (float) $q[1];
    if ($q[1] <= 0 || $q[1] > 128) {
      throw new InvalidParameterException("Moon minimum scale size must be a number between 0 and 128.");
    }
    $q[2] = (float) $q[2];
    if ($q[2] <= 0 || $q[2] > 128) {
      throw new InvalidParameterException("Moon maximum scale size must be a number between 0 and 128.");
    }
    return [
      'image_path' => 'prepared-moons/'.$q[0].'.png',
      'min_scale' => $q[1],
      'max_scale' => $q[2],
    ];
  }, explode(';', expect_param('moons')));
  if (sizeof($moon_settings) > 16) {
    throw new InvalidParameterException("Too many moons.");
  }

} catch (InvalidParameterException $e) {
  http_response_code(400);
  header('Cache-Control: no-cache');
  header('Content-Type: text/plain');
  header('Content-Length: '.(strlen($e->getMessage()) + 1));
  header('X-Error: '.$e->getMessage());
  echo $e->getMessage()."\n";
  die();
}


$black = new ImagickPixel('black');
$white = new ImagickPixel('white');
$transparent = new ImagickPixel('transparent');

$moons = array_map(function($moon) {
  $moon['image'] = new Imagick($moon['image_path']);
  return $moon;
}, $moon_settings);

$canvas = new Imagick();
$canvas->newImage($canvas_width, $canvas_height, [
  'black' => $black,
  'white' => $white,
  'transparent' => $transparent,
][$background]);

for ($i = 0; $i < $moon_count; $i++) {
  $moon = $moons[array_rand($moons)];

  $changed_moon = clone $moon['image'];

  $scale = rand_float($moon['min_scale'], $moon['max_scale']);
  $moon_width = round($changed_moon->getImageWidth() * $scale);
  $moon_height = round($changed_moon->getImageHeight() * $scale);
  $moon_size = min($moon_width, $moon_height);
  $changed_moon->scaleImage($moon_width, $moon_height);

  $changed_moon->rotateImage($transparent, rand_float(0, 360));

  $canvas->compositeImage(
    $changed_moon,
    imagick::COMPOSITE_OVER,
    ($moon_size - $changed_moon->getImageWidth()) / 2 + rand(0, $canvas_width - $moon_size),
    ($moon_size - $changed_moon->getImageHeight()) / 2 + rand(0, $canvas_height - $moon_size)
  );

  $changed_moon->clear();
}

foreach ($moons as $moon) {
  $moon['image']->clear();
}

$canvas->setImageFormat($output_format);
$canvas->setImageCompressionQuality(90);

header('Content-Type: image/'.$output_format);
header('Cache-Control: no-cache');
header('Content-Length: '.strlen($canvas));
echo $canvas;

$canvas->clear();
$black->clear();
$white->clear();
$transparent->clear();