/inc/lib/a2s/a2s52.php

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<?php # DO NOT EDIT: generated from ASCIIToSVG.php by mk52.pl
/*
 * A2S_ASCIIToSVG.php: ASCII diagram -> SVG art generator.
 * Copyright Š 2012 Devon H. O'Dell <devon.odell@gmail.com>
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  o Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *  o Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

#namespace org\dh0\a2s;

include 'svg-path.lex.php';
include 'colors.php';

/*
 * A2S_Scale is a singleton class that is instantiated to apply scale
 * transformations on the text -> canvas grid geometry. We could probably use
 * SVG's native scaling for this, but I'm not sure how yet.
 */
class A2S_Scale {
  private static $instance = null;

  public $xScale;
  public $yScale;

  private function __construct() {}
  private function __clone() {}

  public static function getInstance() {
    if (self::$instance == null) {
      self::$instance = new A2S_Scale();
    }

    return self::$instance;
  }

  public function setScale($x, $y) {
    $o = self::getInstance();
    $o->xScale = $x;
    $o->yScale = $y;
  }
}

/*
 * A2S_CustomObjects allows users to create their own custom SVG paths and use
 * them as box types with a2s:type references.
 *
 * Paths must have width and height set, and must not span multiple lines.
 * Multiple paths can be specified, one path per line. All objects must
 * reside in the same directory.
 *
 * File operations are horribly slow, so we make a best effort to avoid
 * as many as possible:
 *
 *  * If the directory mtime hasn't changed, we attempt to load our
 *    objects from a cache file.
 *
 *  * If this file doesn't exist, can't be read, or the mtime has
 *    changed, we scan the directory and update files that have changed
 *    based on their mtime.
 *
 *  * We attempt to save our cache in a temporary directory. It's volatile
 *    but also requires no configuration.
 *
 * We could do a bit better by utilizing APC's shared memory storage, which
 * would help greatly when running on a server.
 *
 * Note that the path parser isn't foolproof, mostly because PHP isn't the
 * greatest language ever for implementing a parser.
 */
class A2S_CustomObjects {
  public static $objects = array();

  /*
   * Closures / callable function names / whatever for integrating non-default
   * loading and storage functionality.
   */
  public static $loadCacheFn = null;
  public static $storCacheFn = null;
  public static $loadObjsFn = null;


  public static function loadObjects() {
    $cacheFile = sys_get_temp_dir() . "/.a2s.objcache";
    $dir = './objects';

    if (is_callable(self::$loadCacheFn)) {
      /*
       * Should return exactly what was given to the $storCacheFn when it was
       * last called, or null if nothing can be loaded.
       */
      $fn = self::$loadCacheFn;
      self::$objects = $fn();
      return;
    } else {
      if (is_readable($cacheFile)) {
        $cacheTime = filemtime($cacheFile);

        if (filemtime($dir) <= filemtime($cacheFile)) {
          self::$objects = unserialize(file_get_contents($cacheFile));
          return;
        }
      } else {
        $cacheTime = 0;
      }
    }

    if (is_callable(self::$loadObjsFn)) {
      /*
       * Returns an array of arrays of path information. The innermost arrays
       * (containing the path information) contain the path name, the width of
       * the bounding box, the height of the bounding box, and the path
       * command. This interface does *not* want the path's XML tag. An array
       * returned from here containing two objects that each have 1 line would
       * look like:
       *
       * array (
       *   array (
       *     name => 'pathA',
       *     paths => array (
       *       array ('width' => 10, 'height' => 10, 'path' => 'M 0 0 L 10 10'),
       *       array ('width' => 10, 'height' => 10, 'path' => 'M 0 10 L 10 0'),
       *     ),
       *   ),
       *   array (
       *     name => 'pathB',
       *     paths => array (
       *       array ('width' => 10, 'height' => 10, 'path' => 'M 0 5 L 5 10'),
       *       array ('width' => 10, 'height' => 10, 'path' => 'M 5 10 L 10 5'),
       *     ),
       *   ),
       * );
       */
      $fn = self::$loadObjsFn;
      $objs = $fn();

      $i = 0;
      foreach ($objs as $obj) {
        foreach ($obj['paths'] as $path) {
          self::$objects[$obj['name']][$i]['width'] = $path['width'];
          self::$objects[$obj['name']][$i]['height'] = $path['height'];
          self::$objects[$obj['name']][$i++]['path'] =
            self::parsePath($path['path']);
        }
      }
    } else {
      $ents = scandir($dir);
      foreach ($ents as $ent) {
        $file = "{$dir}/{$ent}";
        $base = substr($ent, 0, -5);
        if (substr($ent, -5) == '.path' && is_readable($file)) {
          if (isset(self::$objects[$base]) &&
              filemtime($file) <= self::$cacheTime) {
            continue;
          }

          $lines = file($file);

          $i = 0;
          foreach ($lines as $line) {
            preg_match('/width="(\d+)/', $line, $m);
            $width = $m[1];
            preg_match('/height="(\d+)/', $line, $m);
            $height = $m[1];
            preg_match('/d="([^"]+)"/', $line, $m);
            $path = $m[1];

            self::$objects[$base][$i]['width'] = $width;
            self::$objects[$base][$i]['height'] = $height;
            self::$objects[$base][$i++]['path'] = self::parsePath($path);
          }
        }
      }
    }

    if (is_callable(self::$storCacheFn)) {
      $fn = self::$storCacheFn;
      $fn(self::$objects);
    } else {
      file_put_contents($cacheFile, serialize(self::$objects));
    }
  }

  private static function parsePath($path) {
    $stream = fopen("data://text/plain,{$path}", 'r');

    $P = new A2S_SVGPathParser();
    $S = new A2S_Yylex($stream);

    while ($t = $S->nextToken()) {
      $P->A2S_SVGPath($t->type, $t);
    }
    /* Force shift/reduce of last token. */
    $P->A2S_SVGPath(0);

    fclose($stream);

    $cmdArr = array();
    $i = 0;
    foreach ($P->commands as $cmd) {
      foreach ($cmd as $arg) {
        $arg = (array)$arg;
        $cmdArr[$i][] = $arg['value'];
      }
      $i++;
    }

    return $cmdArr;
  }
}

/*
 * All lines and polygons are represented as a series of point coordinates
 * along a path. Points can have different properties; markers appear on
 * edges of lines and control points denote that a bezier curve should be
 * calculated for the corner represented by this point.
 */
class A2S_Point {
  public $gridX;
  public $gridY;

  public $x;
  public $y;

  public $flags;

  const POINT    = 0x1;
  const CONTROL  = 0x2;
  const SMARKER  = 0x4;
  const IMARKER  = 0x8;

  public function __construct($x, $y) {
    $this->flags = 0;

    $s = A2S_Scale::getInstance();
    $this->x = ($x * $s->xScale) + ($s->xScale / 2);
    $this->y = ($y * $s->yScale) + ($s->yScale / 2);

    $this->gridX = $x;
    $this->gridY = $y;
  }
}

/*
 * Groups objects together and sets common properties for the objects in the
 * group.
 */
class A2S_SVGGroup {
  private $groups;
  private $curGroup;
  private $groupStack;
  private $options;

  public function __construct() {
    $this->groups = array();
    $this->groupStack = array();
    $this->options = array();
  }

  public function getGroup($groupName) {
    return $this->groups[$groupName];
  }

  public function pushGroup($groupName) {
    if (!isset($this->groups[$groupName])) {
      $this->groups[$groupName] = array();
      $this->options[$groupName] = array();
    }

    $this->groupStack[] = $groupName;
    $this->curGroup = $groupName;
  }

  public function popGroup() {
    /*
     * Remove the last group and fetch the current one. array_pop will return
     * NULL for an empty array, so this is safe to do when only one element
     * is left.
     */
    array_pop($this->groupStack);
    $this->curGroup = array_pop($this->groupStack);
  }

  public function addObject($o) {
    $this->groups[$this->curGroup][] = $o;
  }

  public function setOption($opt, $val) {
    $this->options[$this->curGroup][$opt] = $val;
  }

  public function render() {
    $out = '';

    foreach($this->groups as $groupName => $objects) {
      $out .= "<g id=\"{$groupName}\" ";
      foreach ($this->options[$groupName] as $opt => $val) {
        if (strpos($opt, 'a2s:', 0) === 0) {
          continue;
        }
        $out .= "$opt=\"$val\" ";
      }
      $out .= ">\n";

      foreach($objects as $obj) {
        $out .= $obj->render();
      }

      $out .= "</g>\n";
    }

    return $out;
  }
}

/*
 * The Path class represents lines and polygons.
 */
class A2S_SVGPath {
  private $options;
  private $points;
  private $flags;
  private $text;
  private $name;

  private static $id = 0;

  const CLOSED = 0x1;

  public function __construct() {
    $this->options = array();
    $this->points = array();
    $this->text = array();
    $this->flags = 0;
    $this->name = self::$id++;
  }

  /*
   * Making sure that we always started at the top left coordinate 
   * makes so many things so much easier. First, find the lowest Y
   * position. Then, of all matching Y positions, find the lowest X
   * position. This is the top left.
   *
   * As far as the points are considered, they're definitely on the
   * top somewhere, but not necessarily the most left. This could
   * happen if there was a corner connector in the top edge (perhaps
   * for a line to connect to). Since we couldn't turn right there,
   * we have to try now.
   *
   * This should only be called when we close a polygon.
   */
  public function orderPoints() {
    $pPoints = count($this->points);

    $minY = $this->points[0]->y;
    $minX = $this->points[0]->x;
    $minIdx = 0;
    for ($i = 1; $i < $pPoints; $i++) {
      if ($this->points[$i]->y <= $minY) {
        $minY = $this->points[$i]->y;

        if ($this->points[$i]->x < $minX) {
          $minX = $this->points[$i]->x;
          $minIdx = $i;
        }
      }
    }

    /*
     * If our top left isn't at the 0th index, it is at the end. If
     * there are bits after it, we need to cut those and put them at
     * the front.
     */
    if ($minIdx != 0) {
      $startPoints = array_splice($this->points, $minIdx);
      $this->points = array_merge($startPoints, $this->points);
    }
  }

  /*
   * Useful for recursive walkers when speculatively trying a direction.
   */
  public function popPoint() {
    array_pop($this->points);
  }

  public function addPoint($x, $y, $flags = A2S_Point::POINT) {
    $p = new A2S_Point($x, $y);

    /*
     * If we attempt to add our original point back to the path, the polygon
     * must be closed.
     */
    if (count($this->points) > 0) {
      if ($this->points[0]->x == $p->x && $this->points[0]->y == $p->y) {
        $this->flags |= self::CLOSED;
        return true;
      }

      /*
      * For the purposes of this library, paths should never intersect each
      * other. Even in the case of closing the polygon, we do not store the
      * final coordinate twice.
      */
      foreach ($this->points as $point) {
        if ($point->x == $p->x && $point->y == $p->y) {
          return true;
        }
      }
    }

    $p->flags |= $flags;
    $this->points[] = $p;

    return false;
  }

  /*
   * It's useful to be able to know the points in a shape.
   */
  public function getPoints() {
    return $this->points;
  }

  /*
   * Add a marker to a line. The third argument specifies which marker to use,
   * and this depends on the orientation of the line. Due to the way the line
   * parser works, we may have to use an inverted representation.
   */
  public function addMarker($x, $y, $t) {
    $p = new A2S_Point($x, $y);
    $p->flags |= $t;
    $this->points[] = $p;
  }

  /*
   * Is this path closed?
   */
  public function isClosed() {
    return ($this->flags & self::CLOSED);
  }

  public function addText($t) {
    $this->text[] = $t;
  }

  public function getText() {
    return $this->text;
  }

  public function setID($id) {
    $this->name = str_replace(' ', '_', str_replace('"', '_', $id));
  }

  public function getID() {
    return $this->name;
  }

  /*
   * Set options as a JSON string. Specified as a merge operation so that it
   * can be called after an individual setOption call.
   */
  public function setOptions($opt) {
    $this->options = array_merge($this->options, $opt);
  }

  public function setOption($opt, $val) {
    $this->options[$opt] = $val;
  }

  public function getOption($opt) {
    if (isset($this->options[$opt])) {
      return $this->options[$opt];
    }

    return null;
  }

  /*
   * Does the given point exist within this polygon? Since we can
   * theoretically have some complex concave and convex polygon edges in the
   * same shape, we need to do a full point-in-polygon test. This algorithm
   * seems like the standard one. See: http://alienryderflex.com/polygon/
   */
  public function hasPoint($x, $y) {
    if ($this->isClosed() == false) {
      return false;
    }

    $oddNodes = false;

    $bound = count($this->points);
    for ($i = 0, $j = count($this->points) - 1; $i < $bound; $i++) {
      if (($this->points[$i]->gridY < $y && $this->points[$j]->gridY >= $y ||
           $this->points[$j]->gridY < $y && $this->points[$i]->gridY >= $y) &&
          ($this->points[$i]->gridX <= $x || $this->points[$j]->gridX <= $x)) {
        if ($this->points[$i]->gridX + ($y - $this->points[$i]->gridY) /
            ($this->points[$j]->gridY - $this->points[$i]->gridY) *
            ($this->points[$j]->gridX - $this->points[$i]->gridX) < $x) {
          $oddNodes = !$oddNodes;
        }
      }

      $j = $i;
    }

    return $oddNodes;
  }

  /* 
   * Apply a matrix transformation to the coordinates ($x, $y). The
   * multiplication is implemented on the matrices:
   *
   * | a b c |   | x |
   * | d e f | * | y |
   * | 0 0 1 |   | 1 |
   *
   * Additional information on the transformations and what each R,C in the
   * transformation matrix represents, see:
   *
   * http://www.w3.org/TR/SVG/coords.html#TransformMatrixDefined
   */
  private function matrixTransform($matrix, $x, $y) {
    $xyMat = array(array($x), array($y), array(1));
    $newXY = array(array());

    for ($i = 0; $i < 3; $i++) {
      for ($j = 0; $j < 1; $j++) {
        $sum = 0;

        for ($k = 0; $k < 3; $k++) {
          $sum += $matrix[$i][$k] * $xyMat[$k][$j];
        }

        $newXY[$i][$j] = $sum;
      }
    }

    /* Return the coordinates as a vector */
    return array($newXY[0][0], $newXY[1][0], $newXY[2][0]);
  }

  /*
   * Translate the X and Y coordinates. tX and tY specify the distance to
   * transform.
   */
  private function translateTransform($tX, $tY, $x, $y) {
    $matrix = array(array(1, 0, $tX), array(0, 1, $tY), array(0, 0, 1));
    return $this->matrixTransform($matrix, $x, $y);
  }

  /*
   * A2S_Scale transformations are implemented by applying the scale to the X and
   * Y coordinates. One unit in the new coordinate system equals $s[XY] units
   * in the old system. Thus, if you want to double the size of an object on
   * both axes, you sould call scaleTransform(0.5, 0.5, $x, $y)
   */
  private function scaleTransform($sX, $sY, $x, $y) {
    $matrix = array(array($sX, 0, 0), array(0, $sY, 0), array(0, 0, 1));
    return $this->matrixTransform($matrix, $x, $y);
  }

  /*
   * Rotate the coordinates around the center point cX and cY. If these
   * are not specified, the coordinate is rotated around 0,0. The angle
   * is specified in degrees.
   */
  private function rotateTransform($angle, $x, $y, $cX = 0, $cY = 0) {
    $angle = $angle * (pi() / 180);
    if ($cX != 0 || $cY != 0) {
      list ($x, $y) = $this->translateTransform($cX, $cY, $x, $y);
    }

    $matrix = array(array(cos($angle), -sin($angle), 0),
                    array(sin($angle), cos($angle), 0),
                    array(0, 0, 1));
    $ret = $this->matrixTransform($matrix, $x, $y);

    if ($cX != 0 || $cY != 0) {
      list ($x, $y) = $this->translateTransform(-$cX, -$cY, $ret[0], $ret[1]);
      $ret[0] = $x;
      $ret[1] = $y;
    }

    return $ret;
  }

  /*
   * Skews along the X axis at specified angle. The angle is specified in
   * degrees.
   */
  private function skewXTransform($angle, $x, $y) {
    $angle = $angle * (pi() / 180);
    $matrix = array(array(1, tan($angle), 0), array(0, 1, 0), array(0, 0, 1));
    return $this->matrixTransform($matrix, $x, $y);
  }

  /*
   * Skews along the Y axis at specified angle. The angle is specified in
   * degrees.
   */
  private function skewYTransform($angle, $x, $y) {
    $angle = $angle * (pi() / 180);
    $matrix = array(array(1, 0, 0), array(tan($angle), 1, 0), array(0, 0, 1));
    return $this->matrixTransform($matrix, $x, $y);
  }

  /*
   * Apply a transformation to a point $p.
   */
  private function applyTransformToPoint($txf, $p, $args) {
    switch ($txf) {
    case 'translate':
      return $this->translateTransform($args[0], $args[1], $p->x, $p->y);

    case 'scale':
      return $this->scaleTransform($args[0], $args[1], $p->x, $p->y);

    case 'rotate':
      if (count($args) > 1) {
        return  $this->rotateTransform($args[0], $p->x, $p->y, $args[1], $args[2]);
      } else {
        return  $this->rotateTransform($args[0], $p->x, $p->y);
      }

    case 'skewX':
      return $this->skewXTransform($args[0], $p->x, $p->y);

    case 'skewY':
      return $this->skewYTransform($args[0], $p->x, $p->y);
    }
  }

  /*
   * Apply the transformation function $txf to all coordinates on path $p
   * providing $args as arguments to the transformation function.
   */
  private function applyTransformToPath($txf, &$p, $args) {
    $pathCmds = count($p['path']);
    $curPoint = new A2S_Point(0, 0);
    $prevType = null;
    $curType = null;

    for ($i = 0; $i < $pathCmds; $i++) {
      $cmd = &$p['path'][$i];

      $prevType = $curType;
      $curType = $cmd[0];

      switch ($curType) {
      case 'z':
      case 'Z':
        /* Can't transform this */
        break;

      case 'm':
        if ($prevType != null) {
          $curPoint->x += $cmd[1];
          $curPoint->y += $cmd[2];

          list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
          $curPoint->x = $x;
          $curPoint->y = $y;

          $cmd[1] = $x;
          $cmd[2] = $y;
        } else {
          $curPoint->x = $cmd[1];
          $curPoint->y = $cmd[2];

          list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
          $curPoint->x = $x;
          $curPoint->y = $y;

          $cmd[1] = $x;
          $cmd[2] = $y;
          $curType = 'l';
        }

        break;

      case 'M':
        $curPoint->x = $cmd[1];
        $curPoint->y = $cmd[2];

        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
        $curPoint->x = $x;
        $curPoint->y = $y;

        $cmd[1] = $x;
        $cmd[2] = $y;

        if ($prevType == null) {
          $curType = 'L';
        }
        break;

      case 'l':
        $curPoint->x += $cmd[1];
        $curPoint->y += $cmd[2];

        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
        $curPoint->x = $x;
        $curPoint->y = $y;

        $cmd[1] = $x;
        $cmd[2] = $y;

        break;

      case 'L':
        $curPoint->x = $cmd[1];
        $curPoint->y = $cmd[2];

        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
        $curPoint->x = $x;
        $curPoint->y = $y;

        $cmd[1] = $x;
        $cmd[2] = $y;

        break;

      case 'v':
        $curPoint->y += $cmd[1];
        $curPoint->x += 0;

        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
        $curPoint->x = $x;
        $curPoint->y = $y;

        $cmd[1] = $y;

        break;

      case 'V':
        $curPoint->y = $cmd[1];

        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
        $curPoint->x = $x;
        $curPoint->y = $y;

        $cmd[1] = $y;

        break;

      case 'h':
        $curPoint->x += $cmd[1];

        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
        $curPoint->x = $x;
        $curPoint->y = $y;

        $cmd[1] = $x;

        break;

      case 'H':
        $curPoint->x = $cmd[1];

        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
        $curPoint->x = $x;
        $curPoint->y = $y;

        $cmd[1] = $x;

        break;

      case 'c':
        $tP = new A2S_Point(0, 0);
        $tP->x = $curPoint->x + $cmd[1]; $tP->y = $curPoint->y + $cmd[2];
        list ($x, $y) = $this->applyTransformToPoint($txf, $tP, $args);
        $cmd[1] = $x;
        $cmd[2] = $y;

        $tP->x = $curPoint->x + $cmd[3]; $tP->y = $curPoint->y + $cmd[4];
        list ($x, $y) = $this->applyTransformToPoint($txf, $tP, $args);
        $cmd[3] = $x;
        $cmd[4] = $y;

        $curPoint->x += $cmd[5];
        $curPoint->y += $cmd[6];
        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);

        $curPoint->x = $x;
        $curPoint->y = $y;
        $cmd[5] = $x;
        $cmd[6] = $y;

        break;
      case 'C':
        $curPoint->x = $cmd[1];
        $curPoint->y = $cmd[2];
        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
        $cmd[1] = $x;
        $cmd[2] = $y;

        $curPoint->x = $cmd[3];
        $curPoint->y = $cmd[4];
        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
        $cmd[3] = $x;
        $cmd[4] = $y;

        $curPoint->x = $cmd[5];
        $curPoint->y = $cmd[6];
        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);

        $curPoint->x = $x;
        $curPoint->y = $y;
        $cmd[5] = $x;
        $cmd[6] = $y;

        break;

      case 's':
      case 'S':

      case 'q':
      case 'Q':
        
      case 't':
      case 'T':

      case 'a':
        break;

      case 'A':
        /*
         * This radius is relative to the start and end points, so it makes
         * sense to scale, rotate, or skew it, but not translate it.
         */
        if ($txf != 'translate') {
          $curPoint->x = $cmd[1];
          $curPoint->y = $cmd[2];
          list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
          $cmd[1] = $x;
          $cmd[2] = $y;
        }

        $curPoint->x = $cmd[6];
        $curPoint->y = $cmd[7];
        list ($x, $y) = $this->applyTransformToPoint($txf, $curPoint, $args);
        $curPoint->x = $x;
        $curPoint->y = $y;
        $cmd[6] = $x;
        $cmd[7] = $y;

        break;
      }
    }
  }

  public function render() {
    $startPoint = array_shift($this->points);
    $endPoint = $this->points[count($this->points) - 1];

    $out = "<g id=\"group{$this->name}\">\n";

    /*
     * If someone has specified one of our special object types, we are going
     * to want to completely override any of the pathing that we would have
     * done otherwise, but we defer until here to do anything about it because
     * we need information about the object we're replacing.
     */
    if (isset($this->options['a2s:type']) &&
        isset(A2S_CustomObjects::$objects[$this->options['a2s:type']])) {
      $object = A2S_CustomObjects::$objects[$this->options['a2s:type']];

      /* Again, if no fill was specified, specify one. */
      if (!isset($this->options['fill'])) {
        $this->options['fill'] = '#fff';
      }

      /*
       * We don't care so much about the area, but we do care about the width
       * and height of the object. All of our "custom" objects are implemented
       * in 100x100 space, which makes the transformation marginally easier.
       */
      $minX = $startPoint->x; $maxX = $minX;
      $minY = $startPoint->y; $maxY = $minY;
      foreach ($this->points as $p) {
        if ($p->x < $minX) {
          $minX = $p->x;
        } elseif ($p->x > $maxX) {
          $maxX = $p->x;
        }
        if ($p->y < $minY) {
          $minY = $p->y;
        } elseif ($p->y > $maxY) {
          $maxY = $p->y;
        }
      }

      $objW = $maxX - $minX;
      $objH = $maxY - $minY;

      $i = 0;
      foreach ($object as $o) {
        $id = self::$id++;
        $out .= "\t<path id=\"path{$this->name}\" d=\"";

        $oW = $o['width'];
        $oH = $o['height'];

        $this->applyTransformToPath('scale', $o, array($objW/$oW, $objH/$oH));
        $this->applyTransformToPath('translate', $o, array($minX, $minY));

        foreach ($o['path'] as $cmd) {
          $out .= join(' ', $cmd) . ' ';
        }
        $out .= '" ';

        /* Don't add options to sub-paths */
        if ($i++ < 1) {
          foreach ($this->options as $opt => $val) {
            if (strpos($opt, 'a2s:', 0) === 0) {
              continue;
            }
            $out .= "$opt=\"$val\" ";
          }
        }

        $out .= " />\n";
      }

      if (count($this->text) > 0) {
        foreach ($this->text as $text) {
          $out .= "\t" . $text->render() . "\n";
        }
      }
      $out .= "</g>\n";

      /* Bazinga. */
      return $out;
    }

    /*
     * Nothing fancy here -- this is just rendering for our standard
     * polygons.
     *
     * Our start point is represented by a single moveto command (unless the
     * start point is curved) as the shape will be closed with the Z command
     * automatically if it is a closed shape. If we have a control point, we
     * have to go ahead and draw the curve.
     */
    if (($startPoint->flags & A2S_Point::CONTROL)) {
      $cX = $startPoint->x;
      $cY = $startPoint->y;
      $sX = $startPoint->x;
      $sY = $startPoint->y + 10;
      $eX = $startPoint->x + 10;
      $eY = $startPoint->y;

      $path = "M {$sX} {$sY} Q {$cX} {$cY} {$eX} {$eY} ";
    } else {
      $path = "M {$startPoint->x} {$startPoint->y} ";
    }

    $prevP = $startPoint;
    $bound = count($this->points);
    for ($i = 0; $i < $bound; $i++) {
      $p = $this->points[$i];

      /*
       * Handle quadratic Bezier curves. NOTE: This algorithm for drawing
       * the curves only works if the shapes are drawn in a clockwise
       * manner.
       */
      if (($p->flags & A2S_Point::CONTROL)) {
        /* Our control point is always the original corner */
        $cX = $p->x;
        $cY = $p->y;

        /* Need next point to determine which way to turn */
        if ($i == count($this->points) - 1) {
          $nP = $startPoint;
        } else {
          $nP = $this->points[$i + 1];
        }

        if ($prevP->x == $p->x) {
          /*
           * If we are on the same vertical axis, our starting X coordinate
           * is the same as the control point coordinate.
           */
          $sX = $p->x;
        
          /* Offset start point from control point in the proper direction */
          if ($prevP->y < $p->y) {
            $sY = $p->y - 10;
          } else {
            $sY = $p->y + 10;
          }

          $eY = $p->y;
          /* Offset end point from control point in the proper direction */
          if ($nP->x < $p->x) {
            $eX = $p->x - 10;
          } else {
            $eX = $p->x + 10;
          }
        } elseif ($prevP->y == $p->y) {
          /* Horizontal decisions mirror vertical's above */
          $sY = $p->y;
          if ($prevP->x < $p->x) {
            $sX = $p->x - 10;
          } else {
            $sX = $p->x + 10;
          }

          $eX = $p->x;
          if ($nP->y <= $p->y) {
            $eY = $p->y - 10;
          } else {
            $eY = $p->y + 10;
          }
        }

        $path .= "L {$sX} {$sY} Q {$cX} {$cY} {$eX} {$eY} ";
      } else {
        /* The excruciating difficulty of drawing a straight line */
        $path .= "L {$p->x} {$p->y} ";
      }

      $prevP = $p;
    }

    if ($this->isClosed()) {
      $path .= 'Z';
    } 

    $id = self::$id++;

    /* Add markers if necessary. */
    if ($startPoint->flags & A2S_Point::SMARKER) {
      $this->options["marker-start"] = "url(#Pointer)";
    } elseif ($startPoint->flags & A2S_Point::IMARKER) {
      $this->options["marker-start"] = "url(#iPointer)";
    }

    if ($endPoint->flags & A2S_Point::SMARKER) {
      $this->options["marker-end"] = "url(#Pointer)";
    } elseif ($endPoint->flags & A2S_Point::IMARKER) {
      $this->options["marker-end"] = "url(#iPointer)";
    }

    /*
     * SVG objects without a fill will be transparent, and this looks so
     * terrible with the drop-shadow effect. Any objects that aren't filled
     * automatically get a white fill.
     */
    if ($this->isClosed() && !isset($this->options['fill'])) {
      $this->options['fill'] = '#fff';
    }


    $out .= "\t<path id=\"path{$this->name}\" ";
    foreach ($this->options as $opt => $val) {
      if (strpos($opt, 'a2s:', 0) === 0) {
        continue;
      }
      $out .= "$opt=\"$val\" ";
    }
    $out .= "d=\"{$path}\" />\n";
    
    if (count($this->text) > 0) {
      foreach ($this->text as $text) {
        $text->setID($this->name);
        $out .= "\t" . $text->render() . "\n";
      }
    }

    $out .= "</g>\n";
    return $out;
  }
}

/*
 * Nothing really special here. Container for representing text bits.
 */
class A2S_SVGText {
  private $options;
  private $string;
  private $point;
  private $name;

  private static $id = 0;

  public function __construct($x, $y) {
    $this->point = new A2S_Point($x, $y);
    $this->name = self::$id++;
    $this->options = array();
  }

  public function setOption($opt, $val) {
    $this->options[$opt] = $val;
  }

  public function setID($id) {
    $this->name = str_replace(' ', '_', str_replace('"', '_', $id));
  }

  public function getID() {
    return $this->name;
  }

  public function getPoint() {
    return $this->point;
  }

  public function setString($string) {
    $this->string = $string;
  }

  public function render() {
    $out = "<text x=\"{$this->point->x}\" y=\"{$this->point->y}\" id=\"text{$this->name}\" ";
    foreach ($this->options as $opt => $val) {
      if (strpos($opt, 'a2s:', 0) === 0) {
        continue;
      }
      $out .= "$opt=\"$val\" ";
    }
    $out .= ">";
    $out .= htmlentities($this->string);
    $out .= "</text>\n";
    return $out;
  }
}

/*
 * Main class for parsing ASCII and constructing the SVG output based on the
 * above classes.
 */
class A2S_ASCIIToSVG {
  private $rawData;
  private $grid;

  private $svgObjects;
  private $clearCorners;

  /* Directions for traversing lines in our grid */
  const DIR_UP    = 0x1;
  const DIR_DOWN  = 0x2;
  const DIR_LEFT  = 0x4;
  const DIR_RIGHT = 0x8;
  const DIR_NE    = 0x10;
  const DIR_SE    = 0x20;

  public function __construct($data) {
    /* For debugging purposes */
    $this->rawData = $data;

    A2S_CustomObjects::loadObjects();

    $this->clearCorners = array();

    /*
     * Parse out any command references. These need to be at the bottom of the
     * diagram due to the way they're removed. Format is:
     * [identifier] optional-colon optional-spaces ({json-blob})\n
     *
     * The JSON blob may not contain objects as values or the regex will break.
     */
    $this->commands = array();
    preg_match_all('/^\[([^\]]+)\]:?\s+({[^}]+?})/ims', $data, $matches);
    $bound = count($matches[1]);
    for ($i = 0; $i < $bound; $i++) {
      $this->commands[$matches[1][$i]] = json_decode($matches[2][$i], true);
    }

    $data = preg_replace('/^\[([^\]]+)\](:?)\s+.*/ims', '', $data);

    /*
     * Treat our ASCII field as a grid and store each character as a point in
     * that grid. The (0, 0) coordinate on this grid is top-left, just as it
     * is in images.
     */
    $this->grid = explode("\n", $data);

    foreach ($this->grid as $k => $line) {
      $this->grid[$k] = str_split($line);
    }

    $this->svgObjects = new A2S_SVGGroup();
  }

  /*
   * This is kind of a stupid and hacky way to do this, but this allows setting
   * the default scale of one grid space on the X and Y axes.
   */
  public function setDimensionScale($x, $y) {
    $o = A2S_Scale::getInstance();
    $o->setScale($x, $y);
  }

  public function dump() {
    var_export($this);
  }

  /* Render out what we've done!  */
  public function render() {
    $o = A2S_Scale::getInstance();

    /* Figure out how wide we need to make the canvas */
    $canvasWidth = 0;
    foreach($this->grid as $line) {
      if (count($line) > $canvasWidth) {
        $canvasWidth = count($line);
      }
    }

    /* Add a fudge factor for drop-shadow and gaussian blur */
    $canvasWidth = $canvasWidth * $o->xScale + 30;
    $canvasHeight = count($this->grid) * $o->yScale + 30;

    /*
     * Boilerplate header with definitions that we might be using for markers
     * and drop shadows.
     */
    $out = <<<SVG
<?xml version="1.0" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" 
  "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<!-- Created with A2S_ASCIIToSVG (http://9vx.org/~dho/a2s/) -->
<svg width="{$canvasWidth}px" height="{$canvasHeight}px" version="1.1"
  xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink">
  <defs>
    <filter id="dsFilter" width="150%" height="150%">
      <feOffset result="offOut" in="SourceGraphic" dx="3" dy="3"/>
      <feColorMatrix result="matrixOut" in="offOut" type="matrix" values="0.2 0 0 0 0 0 0.2 0 0 0 0 0 0.2 0 0 0 0 0 1 0"/>
      <feGaussianBlur result="blurOut" in="matrixOut" stdDeviation="3"/>
      <feBlend in="SourceGraphic" in2="blurOut" mode="normal"/>
    </filter>
    <marker id="iPointer"
      viewBox="0 0 10 10" refX="5" refY="5" 
      markerUnits="strokeWidth"
      markerWidth="8" markerHeight="7"
      orient="auto">
      <path d="M 10 0 L 10 10 L 0 5 z" />
    </marker>
    <marker id="Pointer"
      viewBox="0 0 10 10" refX="5" refY="5" 
      markerUnits="strokeWidth"
      markerWidth="8" markerHeight="7"
      orient="auto">
      <path d="M 0 0 L 10 5 L 0 10 z" />
    </marker>
  </defs>
SVG;

    /* Render the group, everything lives in there */
    $out .= $this->svgObjects->render();

    $out .= "</svg>\n";

    return $out;
  }

  /*
   * Parsing the grid is a multi-step process. We parse out boxes first, as
   * this makes it easier to then parse lines. By parse out, I do mean we
   * parse them and then remove them. This does mean that a complete line
   * will not travel along the edge of a box, but you probably won't notice
   * unless the box is curved anyway. While edges are removed, points are
   * not. This means that you can cleanly allow lines to intersect boxes
   * (as long as they do not bisect!
   *
   * After parsing boxes and lines, we remove the corners from the grid. At
   * this point, all we have left should be text, which we can pick up and
   * place.
   */
  public function parseGrid() {
    $this->parseBoxes();
    $this->parseLines();

    foreach ($this->clearCorners as $corner) {
      $this->grid[$corner[0]][$corner[1]] = ' ';
    }

    $this->parseText();

    $this->injectCommands();
  }

  /*
   * Ahh, good ol' box parsing. We do this by scanning each row for points and
   * attempting to close the shape. Since the approach is first horizontal,
   * then vertical, we complete the shape in a clockwise order (which is
   * important for the Bezier curve generation.
   */
  private function parseBoxes() {
    /* Set up our box group  */
    $this->svgObjects->pushGroup('boxes');
    $this->svgObjects->setOption('stroke', 'black');
    $this->svgObjects->setOption('stroke-width', '2');
    $this->svgObjects->setOption('fill', 'none');

    /* Scan the grid for corners */
    foreach ($this->grid as $row => $line) {
      foreach ($line as $col => $char) {
        if ($this->isCorner($char)) {
          $path = new A2S_SVGPath();

          if ($char == '.' || $char == "'") {
            $path->addPoint($col, $row, A2S_Point::CONTROL);
          } else {
            $path->addPoint($col, $row);
          }

          /*
           * The wall follower is a left-turning, marking follower. See that
           * function for more information on how it works.
           */
          $this->wallFollow($path, $row, $col+1, self::DIR_RIGHT);
        
          /* We only care about closed polygons */
          if ($path->isClosed()) {
            $path->orderPoints();

            $skip = false;
            /*
             * The walking code can find the same box from a different edge:
             *
             * +---+   +---+
             * |   |   |   |
             * |   +---+   |
             * +-----------+
             *
             * so ignore adding a box that we've already added.
             */
            foreach($this->svgObjects->getGroup('boxes') as $box) {
              $bP = $box->getPoints();
              $pP = $path->getPoints();
              $pPoints = count($pP);
              $shared = 0;

              /*
               * If the boxes don't have the same number of edges, they 
               * obviously cannot be the same box.
               */
              if (count($bP) != $pPoints) {
                continue;
              }

              /* Traverse the vertices of this new box... */
              for ($i = 0; $i < $pPoints; $i++) {
                /* ...and find them in this existing box. */
                for ($j = 0; $j < $pPoints; $j++) {
                  if ($pP[$i]->x == $bP[$j]->x && $pP[$i]->y == $bP[$j]->y) {
                    $shared++;
                  }
                }
              }

              /* If all the edges are in common, it's the same shape. */
              if ($shared == count($bP)) {
                $skip = true;
                break;
              }
            }

            if ($skip == false) {
              /* Search for any references for styling this polygon; add it */
              $path->setOption('filter', 'url(#dsFilter)');
              $name = $this->findCommands($path);

              if ($name != '') {
                $path->setID($name);
              }

              $this->svgObjects->addObject($path);
            }
          }
        }
      }
    }

    /*
     * Once we've found all the boxes, we want to remove them from the grid so
     * that they don't confuse the line parser. However, we don't remove any
     * corner characters because these might be shared by lines.
     */
    foreach ($this->svgObjects->getGroup('boxes') as $box) {
      $this->clearObject($box);
    }

    /* Anything after this is not a subgroup */
    $this->svgObjects->popGroup();
  }

  /*
   * Our line parser operates differently than the polygon parser. This is 
   * because lines are not intrinsically marked with starting points (markers
   * are optional) -- they just sort of begin. Additionally, so that markers
   * will work, we can't just construct a line from some random point: we need
   * to start at the correct edge.
   *
   * Thus, the line parser traverses vertically first, then horizontally. Once
   * a line is found, it is cleared immediately (but leaving any control points
   * in case there were any intersections.
   */
  private function parseLines() {
    /* Set standard line options */
    $this->svgObjects->pushGroup('lines');
    $this->svgObjects->setOption('stroke', 'black');
    $this->svgObjects->setOption('stroke-width', '2');
    $this->svgObjects->setOption('fill', 'none');

    /* The grid is not uniform, so we need to determine the longest row. */
    $maxCols = 0;
    $bound = count($this->grid);
    for ($r = 0; $r < $bound; $r++) {
      $maxCols = max($maxCols, count($this->grid[$r]));
    }

    for ($c = 0; $c < $maxCols; $c++) {
      for ($r = 0; $r < $bound; $r++) {
        /* This gets set if we find a line-start here. */
        $dir = false;

        $line = new A2S_SVGPath();

        /*
         * Since the column count isn't uniform, don't attempt to handle any
         * rows that don't extend out this far.
         */
        if (!isset($this->grid[$r][$c])) {
          continue;
        }

        $char = $this->getChar($r, $c);
        switch ($char) {
        /*
         * Do marker characters first. These are the easiest because they are
         * basically guaranteed to represent the start of the line.
         */
        case '<':
          $e = $this->getChar($r, $c + 1);
          if ($this->isEdge($e, self::DIR_RIGHT) || $this->isCorner($e)) {
            $line->addMarker($c, $r, A2S_Point::IMARKER);
            $dir = self::DIR_RIGHT;
          } else {
            $se = $this->getChar($r + 1, $c + 1);
            $ne = $this->getChar($r - 1, $c + 1);
            if ($se == "\\") {
              $line->addMarker($c, $r, A2S_Point::IMARKER);
              $dir = self::DIR_SE;
            } elseif ($ne == '/') {
              $line->addMarker($c, $r, A2S_Point::IMARKER);
              $dir = self::DIR_NE;
            }
          }
          break;
        case '^':
          $s = $this->getChar($r + 1, $c);
          if ($this->isEdge($s, self::DIR_DOWN) || $this->isCorner($s)) { 
            $line->addMarker($c, $r, A2S_Point::IMARKER);
            $dir = self::DIR_DOWN;
          } elseif ($this->getChar($r + 1, $c + 1) == "\\") {
            /* Don't need to check west for diagonals. */
            $line->addMarker($c, $r, A2S_Point::IMARKER);
            $dir = self::DIR_SE;
          }
          break;
        case '>':
          $w = $this->getChar($r, $c - 1);
          if ($this->isEdge($w, self::DIR_LEFT) || $this->isCorner($w)) {
            $line->addMarker($c, $r, A2S_Point::IMARKER);
            $dir = self::DIR_LEFT;
          }
          /* All diagonals come from west, so we don't need to check */
          break;
        case 'v':
          $n = $this->getChar($r - 1, $c);
          if ($this->isEdge($n, self::DIR_UP) || $this->isCorner($n)) {
            $line->addMarker($c, $r, A2S_Point::IMARKER);
            $dir = self::DIR_UP;
          } elseif ($this->getChar($r - 1, $c + 1) == '/') {
            $line->addMarker($c, $r, A2S_Point::IMARKER);
            $dir = self::DIR_NE;
          }
          break;

        /*
         * Edges are handled specially. We have to look at the context of the
         * edge to determine whether it's the start of a line. A vertical edge
         * can appear as the start of a line in the following circumstances:
         *
         * +-------------      +--------------     +----    | (s)
         * |                   |                   |        |
         * |      | (s)        +-------+           |(s)     |
         * +------+                    | (s)
         *
         * From this we can extrapolate that we are a starting edge if our
         * southern neighbor is a vertical edge or corner, but we have no line
         * material to our north (and vice versa). This logic does allow for
         * the southern / northern neighbor to be part of a separate
         * horizontal line.
         */
        case ':':
          $line->setOption('stroke-dasharray', '5 5');
          /* FALLTHROUGH */
        case '|':
          $n = $this->getChar($r-1, $c);
          $s = $this->getChar($r+1, $c);
          if (($s == '|' || $s == ':' || $this->isCorner($s)) &&
              $n != '|' && $n != ':' && !$this->isCorner($n) &&
              $n != '^') {
            $dir = self::DIR_DOWN;
          } elseif (($n == '|' || $n == ':' || $this->isCorner($n)) &&
                    $s != '|' && $s != ':' && !$this->isCorner($s) &&
                    $s != 'v') {
            $dir = self::DIR_UP;
          }
          break;

        /*
         * Horizontal edges have the same properties for search as vertical
         * edges, except we need to look east / west. The diagrams for the
         * vertical case are still accurate to visualize this case; just
         * mentally turn them 90 degrees clockwise.
         */
        case '=':
          $line->setOption('stroke-dasharray', '5 5');
          /* FALLTHROUGH */
        case '-':
          $w = $this->getChar($r, $c-1);
          $e = $this->getChar($r, $c+1);
          if (($w == '-' || $w == '=' || $this->isCorner($w)) &&
              $e != '=' && $e != '-' && !$this->isCorner($e) &&
              $e != '>') {
            $dir = self::DIR_LEFT;
          } elseif (($e == '-' || $e == '=' || $this->isCorner($e)) &&
                    $w != '=' && $w != '-' && !$this->isCorner($w) &&
                    $w != '<') {
            $dir = self::DIR_RIGHT;
          }
          break;

        /*
         * We can only find diagonals going north or south and east. This is
         * simplified due to the fact that they have no corners. We are
         * guaranteed to run into their westernmost point or their relevant
         * marker.
         */
        case '/':
          $ne = $this->getChar($r-1, $c+1);
          if ($ne == '/' || $ne == '^' || $ne == '>') {
            $dir = self::DIR_NE;
          }
          break;

        case "\\":
          $se =  $this->getChar($r+1, $c+1);
          if ($se == "\\" || $se == "v" || $se == '>') {
            $dir = self::DIR_SE;
          }
          break;

        /*
         * The corner case must consider all four directions. Though a
         * reasonable person wouldn't use slant corners for this, they are
         * considered corners, so it kind of makes sense to handle them the
         * same way. For this case, envision the starting point being a corner
         * character in both the horizontal and vertical case. And then
         * mentally overlay them and consider that :).
         */
        case '+':
        case '#':
          $ne = $this->getChar($r-1, $c+1);
          $se =  $this->getChar($r+1, $c+1);
          if ($ne == '/' || $ne == '^' || $ne == '>') {
            $dir = self::DIR_NE;
          } elseif ($se == "\\" || $se == "v" || $se == '>') {
            $dir = self::DIR_SE;
          }
          /* FALLTHROUGH */

        case '.':
        case "'":
          $n = $this->getChar($r-1, $c);
          $w = $this->getChar($r, $c-1);
          $s = $this->getChar($r+1, $c);
          $e = $this->getChar($r, $c+1);
          if (($w == '=' || $w == '-') && $n != '|' && $n != ':' && $w != '-' &&
              $e != '=' && $e != '|' && $s != ':') {
            $dir = self::DIR_LEFT;
          } elseif (($e == '=' || $e == '-') && $n != '|' && $n != ':' && 
              $w != '-' && $w != '=' && $s != '|' && $s != ':') {
            $dir = self::DIR_RIGHT;
          } elseif (($s == '|' || $s == ':') && $n != '|' && $n != ':' &&
                    $w != '-' && $w != '=' && $e != '-' && $e != '=' &&
                    (($char != '.' && $char != "'") || 
                     ($char == '.' && $s != '.') || 
                     ($char == "'" && $s != "'"))) {
            $dir = self::DIR_DOWN;
          } elseif (($n == '|' || $n == ':') && $s != '|' && $s != ':' &&
                    $w != '-' && $w != '=' && $e != '-' && $e != '=' &&
                    (($char != '.' && $char != "'") || 
                     ($char == '.' && $s != '.') || 
                     ($char == "'" && $s != "'"))) {
            $dir = self::DIR_UP;
          }
          break;
        }

        /* It does actually save lines! */
        if ($dir !== false) {
          $rInc = 0; $cInc = 0;
          if (!$this->isMarker($char)) {
            $line->addPoint($c, $r);
          }

          /*
           * The walk routine may attempt to add the point again, so skip it.
           * If we don't, we can miss the line or end up with just a point.
           */
          if ($dir == self::DIR_UP) {
            $rInc = -1; $cInc = 0;
          } elseif ($dir == self::DIR_DOWN) {
            $rInc = 1; $cInc = 0;
          } elseif ($dir == self::DIR_RIGHT) {
            $rInc = 0; $cInc = 1;
          } elseif ($dir == self::DIR_LEFT) {
            $rInc = 0; $cInc = -1;
          } elseif ($dir == self::DIR_NE) {
            $rInc = -1; $cInc = 1;
          } elseif ($dir == self::DIR_SE) {
            $rInc = 1; $cInc = 1;
          }

          /*
           * Walk the points of this line. Note we don't use wallFollow; we are
           * operating under the assumption that lines do not meander. (And, in
           * any event, that algorithm is intended to find a closed object.)
           */
          $this->walk($line, $r+$rInc, $c+$cInc, $dir);

          /*
           * Remove it so that we don't confuse any other lines. This leaves
           * corners in tact, still.
           */
          $this->clearObject($line);
          $this->svgObjects->addObject($line);
        }
      }
    }
…