<?php

  // Textorizer2
  // see: http://lapin-bleu.net/software/textorizer/
  // Copyright Max Froumentin 2007
  // This software is distributed under the 
  // W3C SOFTWARE NOTICE AND LICENSE:
  // http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231

function get_contents($filename, $maxFileSize) 
{
    $ch = curl_init();
    curl_setopt ($ch, CURLOPT_URL, $filename);
    curl_setopt ($ch, CURLOPT_RETURNTRANSFER, 1);
    curl_setopt ($ch, CURLOPT_CONNECTTIMEOUT, 5);
    $contents = curl_exec($ch);
    if (curl_error($ch) !== "") {
      echo "The URL you provided for the image isn't valid. Please go back and retry.";
      exit();
    }
    curl_close($ch);
    return $contents;
}
/*
 *  get parameter
 */
function get_value($name, $min, $max, $default)
{
    $value = $_POST[$name];
    trim($value);

    if (!is_numeric($value)) {
      echo "You have entered '$_POST[$name]' where a number was expected. Please go back and enter a valid value.";
      exit();
    }
    if ($value < $min)
        return $min;
    if ($value > $max) 
        return $max;

    return $value;
}

function rAt($img,$x,$y) { return (imagecolorat($img,$x,$y) >> 16) & 0xFF; }
function gAt($img,$x,$y) { return (imagecolorat($img,$x,$y) >> 8) & 0xFF; }
function bAt($img,$x,$y) { return imagecolorat($img,$x,$y) & 0xFF; }

function pixelAt($img,$x,$y) {
  // returns the average of r,g,b for the given pixel
  return round((rAt($img,$x,$y)+gAt($img,$x,$y)+bAt($img,$x,$y))/3);
}

function pixelAt3($img,$x,$y,$w,$h) {
  // returns the pixelAt value, averaged for the 3x3 pixels around x,y
  $count=0;
  $sum=0;
  if ($x>0  && $y>0)  { $sum+=pixelAt($img, $x-1, $y-1);$count++; }
  if (         $y>0)  { $sum+=pixelAt($img, $x  , $y-1);$count++; }
  if ($x<$w && $y>0)  { $sum+=pixelAt($img, $x+1, $y-1);$count++; }

  if ($x>0          ) { $sum+=pixelAt($img, $x-1, $y  );$count++; }
  if (1             ) { $sum+=pixelAt($img, $x  , $y  );$count++; }
  if ($x<$w         ) { $sum+=pixelAt($img, $x+1, $y  );$count++; }

  if ($x>0  && $y<$h) { $sum+=pixelAt($img, $x-1, $y+1);$count++; }
  if (         $y<$h) { $sum+=pixelAt($img, $x  , $y+1);$count++; }
  if ($x<$w && $y<$h) { $sum+=pixelAt($img, $x+1, $y+1);$count++; }

  return $sum/$count;
}

$gaussian5=array(array(1,  4,  7,  4,  1),
                 array(4, 20, 33, 20,  4),
                 array(7, 33, 55, 33,  7),
                 array(4, 20, 33, 20,  4),
                 array(1,  4,  7,  4,  1));

$sharpen5=array(array(-1, -1, -1, -1, -1),
                array(-1,  2,  2,  2, -1),
                array(-1,  2,  8,  2, -1),
                array(-1,  2,  2,  2, -1),
                array(-1, -1, -1, -1, -1));

function pixelAverageAt($img, $x, $y, $s, $w, $h) {
  // averages the pixels around x,y (by convoluting with a (2s+1)x(2s+1) matrix
  global $sharpen5;
  $count=0; $sum=0.0;
  for ($i=-$s; $i<=$s; $i++) {
    for ($j=-$s; $j<=$s; $j++) {
      $px=$x+$i; $py=$y+$j;
      if ($px >= 0 && $px<$w && $py>=0 && $py<$h) {
        $sum+=pixelAt($img,$px,$py);// * $sharpen5[$i+$s][$j+$s];
      } else {
        $sum+=255;// * $sharpen[$i+$s][$j+$s]; // pixels outside of the picture are white
      }
      $count++;
    }
  }
  return $sum/$count;
}

function S2P($x,$y,$params)
// convert x,y from "sinusoidal space" to picture space
// params[0]: angle of rotation (theta)
// params[1]: scaling factor along X
// params[2]: scaling factor along Y
// params[3]: translation along X
// params[4]: translation along Y
{
  $c=cos($params[0]);$s=sin($params[0]);
  $sx=$params[1]; $sy=$params[2];
  $tx=$params[3]; $ty=$params[4];

  $xp=$x*$sx*$c - $y*$sy*$s + $sx*$c*$tx - $sy*$s*$ty;
  $yp=$x*$sx*$s + $y*$sy*$c + $sx*$s*$tx + $sy*$c*$ty;

  return array($xp,$yp);
}

function P2S($x,$y,$params)
// convert x,y from picture space to  "sinusoidal space"
// params[0]: angle of rotation (theta)
// params[1]: scaling factor along X
// params[2]: scaling factor along Y
// params[3]: translation along X
// params[4]: translation along Y
{
  $c=cos(-$params[0]);$s=sin(-$params[0]);
  $sx=1.0/$params[1]; $sy=1.0/$params[2];
  $tx=-$params[3]; $ty=-$params[4];

  $xp=$x*$sx*$c - $y*$sx*$s + $tx;
  $yp=$x*$sy*$s + $y*$sy*$c + $ty;

  ## FIXME: is this the inverse matrix of S2P

  return array($xp,$yp);

}

?>