php - Steins;Gate Divergenzmeter

<?php
/* INFO **********************************************************************
 *
 *                ~ Divergenzmeter generator from Steins;Gate ~
 *
 *  Requires GD for graphic operations
 *  Every access and the generated number is logged,
 *  there is also a counter that's being increased.
 *
 *  Copyright (c) by FichteFoll, 2011-09-06
 *
 *****************************************************************************/

/* PARAMETERS [$_REQUEST] ****************************************************
 *
 *  @int    width                           Used as maximum width
 *  @int    height                          Used as maximum height
 *  @float  num                             Number to show, generated otherwise
 *  @int    precision    = $precision       Amount of digits after the point
 *  @bool   small  [0|1] = $default_small   _small images ar half-sized
 *  @bool   unprop [0|1] = 0                Allows unproportinal resizing (no upscales though)
 *
 *****************************************************************************/

/* LICENCE *******************************************************************
 *
 *  Acutally, no licence required here. You may use this as you please.
 *  It's also not required to name me when you use it or modify,
 *  though you're still allowed to.
 *
 *****************************************************************************/

 /* CHANGELOG *****************************************************************
 *
 *      2011-09-06
 *          + Added: "num" parameter
 *          + Added: Decent algorhythm to generate a digit that exceeds 1
 *          * Fixed: unprop and resizing did not work as expected when ?height=100&unprop=1
 *
 *      2011-08-25
 *          ~ Releasable state
 *
 *****************************************************************************/


/* Some Notes:
 *
 *  I don't use much error handling in this. Logging may be turned off
 *
 */

    $appname = 'divmet';

    // some variables you might want to change
    $source = 'source/';
    $precision = 6;
    $default_small = 0;
    $log = "$appname.log";
    $log_enable = true;
    $counter = "$appname.counter.txt";

    // Parse input from $_REQUEST
    $small = !!$_REQUEST['small'] or $default_small;
    $precision = is_numeric($_REQUEST['precision']) ? $_REQUEST['precision'] : $precision;
    $num = is_numeric($_REQUEST['num']) ? (float) $_REQUEST['num'] : -1;
    $maxwidth = is_numeric($_REQUEST['width']) ? $_REQUEST['width'] : 0;
    $maxheight = is_numeric($_REQUEST['height']) ? $_REQUEST['height'] : 0;
    $prop = !$_REQUEST['unprop'];
    $suffix = $small ? '_small' : '';

    // logging
    $IP = $_SERVER['REMOTE_ADDR'] or '';

    function writeLog($type, $message = null)
    {
        global $log, $IP, $log_enable;
        if (!$log_enable) return ;
        if ($message == null or strlen($type) != 1)
        {
            $message = $type;
            $type = " ";
        }
        $timestamp = date("Y-m-d H:i:s");
        $logstr = $type.' '.$timestamp.' '.$IP.' '.trim($message)."\n";
        return file_put_contents($log, $logstr, FILE_APPEND);
    }

    function incCounter()
    {
        global $counter;
        if (!$f_counter = fopen($counter, (file_exists($counter) ? 'r+' : 'w+')))
            return "";
        $count = (int) fgets($f_counter);
        if ($count == "")
            $count = 0;
        rewind($f_counter);
        fwrite($f_counter, ++$count);
        fclose($f_counter);
    }

// action starts here /////////////////////////////////////////////////////////

    // calculate acutal number if not -1
    if ($num == -1)
    {
        $num = fmt_rand(0, 1.1);
        if ($num > 1)
            $num = 1 +  fmt_rand(0, 0.8);
    }
    $numstr = sprintf("%.{$precision}f", $num = round($num, $precision));

    // create array for keeping opend handles
    $img_array = array();

    // retrieve size of point to calculate size since it's used anyway
    $img_array['.'] = imagecreatefrompng("{$source}Point{$suffix}.png")
                      or die("Failed to determine dimensions");
    $sw = imagesx($img_array['.']);
    $sh = imagesy($img_array['.']);
    $height = $sh;
    $width  = $sw * strlen($numstr);


    // create output image
    $img = imagecreatetruecolor($width, $height)
           or die("Failed to create image");
    // no transparency needed as these images are not transparent, too
    //~ $trans_colour = imagecolorallocatealpha($img, 0, 0, 0, 127);
    //~ imagefill($img, 0, 0, $trans_colour);

    // fill output image
    for ($i = 0; $i < strlen($numstr); ++$i)
    {
        $sub = substr($numstr, $i, 1);
        if (!$img_array[$sub] and !($img_array[$sub] = imagecreatefrompng("{$source}{$sub}{$suffix}.png")))
            die("failed to load image for '$sub'");
        imagecopy($img, $img_array[$sub], $i * $sw, 0, 0, 0, $sw, $sh);
    }

    // resize (no upscale)
    if ($maxwidth or $maxheight)
    {
        if ($newimg = imageresample($img, $maxwidth, $maxheight, $width, $height, $prop))
        {
            imagedestroy($img);
            $img =& $newimg;
        }
    }

    // do logging
    writeLog("$numstr | " . ($newimg ? "Resized to: {$maxwidth}x{$maxheight}" : "{$width}x{$height}"));
    incCounter();


    // output
    header("Content-type: image/png");
    imagepng($img);
    imagedestroy($img);
    foreach ($img_array as $t_img)
        imagedestroy($t_img);


// functions //////////////////////////////////////////////////////////////////
    function fmt_rand($min = 0, $max = 1) // "f" for "float"
    {
        return $min + ($max-$min) * mt_rand()/mt_getrandmax();
    }

    function imageresample($image, &$width, &$height, $width_orig = 0, $height_orig = 0, $prop = true)
    {
        def($width_orig, imagesx($image));
        def($height_orig, imagesy($image));
        if (!$prop)
        {
            def($width, $width_orig);
            def($heigth, $heigth_orig);
        }
        else
        {
            // calculate dimensions
            $ratio = min($width ? $width/$width_orig : 1, $height ? $height/$height_orig : 1);
            $height = (int) ($height_orig * $ratio);
            $width = (int) ($width_orig * $ratio);
        }
        // no upscale
        if ($width > $width_orig or $height > $height_orig) return null;

        // create and copy image
        if (!$image_out = imagecreatetruecolor($width, $height))
            return null;
        return imagecopyresampled($image_out, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig)
                ? $image_out : null;
    }

    function  def(&$ref, $alt)
    {
        $ref = ($ref == 0) ? $alt : $ref or $alt;
    }
?>