Random Avatar

<?php
define('APPROOT', dirname(basename(__FILE__)));
define('IMAGEROOT', APPROOT . '/images/');
define('SIZE_X', 200);
define('SIZE_Y', 200);
define('CHANGE_TIME', 3600);

/**
* Resize image, keeping aspect ratio. Image will be within the max sizes specified
* return an array containing resized image resource, neww, newh
*
* @param resource $image
* @param int $iw (current width)
* @param int $ih (current height)
* @param int $maxw (max permitted width)
* @param int $maxh (max permitted height)
* @return array(resource $newImg, int $neww, int $newh)
*/
function resizeImage($image, $iw, $ih, $maxw, $maxh)
{
    if ($iw > $maxw || $ih > $maxh){

        if ($iw>$maxw && $ih<=$maxh){//too wide, height is OK
            $proportion=($maxw*100)/$iw;
            $neww=$maxw;
            $newh=ceil(($ih*$proportion)/100);
        }

        else if ($iw<=$maxw && $ih>$maxh){//too high, width is OK
            $proportion=($maxh*100)/$ih;
            $newh=$maxh;
            $neww=ceil(($iw*$proportion)/100);
        }

        else {//too high and too wide

            if ($iw/$maxw > $ih/$maxh){//width is the bigger problem
                $proportion=($maxw*100)/$iw;
                $neww=$maxw;
                $newh=ceil(($ih*$proportion)/100);
            }

            else {//height is the bigger problem
                $proportion=($maxh*100)/$ih;
                $newh=$maxh;
                $neww=ceil(($iw*$proportion)/100);
            }
        }
    }

    else {//copy image even if not resizing
        $neww=$iw;
        $newh=$ih;
    }

    if (function_exists("imagecreatetruecolor")){//GD 2.0=good!
        $newImage=imagecreatetruecolor($neww, $newh);
        imagecopyresampled($newImage, $image, 0,0,0,0, $neww, $newh, $iw, $ih);
    } else {//GD 1.8=only 256 colours
        $newImage=imagecreate($neww, $newh);
        imagecopyresized($newImage, $image, 0,0,0,0, $neww, $newh, $iw, $ih);
    }

    return Array($newImage, $neww, $newh);
}

$lasttime = null;
if (file_exists(APPROOT . '/lasttime')) {
    $lasttime = file_get_contents(APPROOT . '/lasttime');
}

header('Content-Type: image/png');

if ($lasttime + CHANGE_TIME >= time() && file_exists(APPROOT . '/curavatar.png')) {
    $image = @imagecreatefrompng(APPROOT . '/curavatar.png');
    @imagepng($image);
    @imagedestroy($image);
    exit;
}

$images = scandir(IMAGEROOT);
while (true) {
    $selectedFile = IMAGEROOT . '/' . $images[array_rand($images)];
    if (file_exists($selectedFile) && !is_dir($selectedFile) && is_readable($selectedFile)) {
        $image = @imagecreatefromstring(file_get_contents($selectedFile));
        $size = @getimagesize($selectedFile);

        $ret = @resizeImage($image, $size[0], $size[1], SIZE_X, SIZE_Y);
        $image = $ret[0];
        @imagepng($image, APPROOT . '/curavatar.png');
        @imagepng($image);
        @imagedestroy($image);
        break;
    }
}

file_put_contents(APPROOT . '/lasttime', time());