#!/usr/bin/php
<?php /*
argument: filename_ani
exemplo: ./anime try.ani
manual de uso: http://labarc.ufcg.edu.br/loac/index.php?n=OAC.Anime

Dentro do desenho .svg criado no Inkscape,
- opcionalmente faz aparecer um text (dado pelo numero de id dele especificado no arquivo .ani)
- faz o text andar num caminho (dado pela id dele)
- faz o texto desaparecer (opcionalmente)
- opcionalmente faz um path (dado pela id dele) aparecer e desaparecer
- opcionalmente faz uma ellipse (dado pelo numero de id dela) andar num caminho (dado pela id dele)
e gera o desenho SVG animado

Inkscape faz mais frequentemente path relativo (d=m) mas também absoluto (d=M) e até usa L no meio
Só testei path relativo.
*/

$ani = simplexml_load_file($argv[1]);
$svg = simplexml_load_file($ani['svg']); // load Inkscape drawing to be animated

// sometimes Inkscape does not define the namespace xlink
if(array_key_exists('xlink', $svg->getNamespaces(true))==false)
  // create the dummy attribute xlink:_ = ""
  // which creates the namespace xmlns:xlink = "http://www.w3.org/1999/xlink" as side effect
  $svg->addAttribute('xlink:_', '', 'http://www.w3.org/1999/xlink');

function list_replace($list_str, $i, $str) {
   $e = explode(" ",$list_str);
   $e[$i] = $str;
   return implode(" ", $e);;
}

function abs2rel($list_str) { // probably does not work
   $abs = explode(" ",substr($list_str,2));
   $c0 = explode(",",$abs[0]);
   $rel = "m";
   foreach ($abs as $xy) {
      if ($xy == "L")
         $rel = $rel." ".$xy;
      else {
         $c = explode(",",$xy);
         $c[0] = $c[0] - $c0[0];
         $c[1] = $c[1] - $c0[1];
         $rel = $rel." ".$c[0].",".$c[1];
      }
   }
   return $rel;
}

function opacity($opanim, $from, $to, $dur) {
   $opanim->addAttribute('dur', $dur);
   $opanim->addAttribute('attributeType', 'CSS');
   $opanim->addAttribute('attributeName', 'opacity');
   $opanim->addAttribute('from', $from);
   $opanim->addAttribute('to', $to);
   $opanim->addAttribute('fill', 'freeze');
}

function appear($obj, $animate) {
   $appear = $obj->addChild('animate');
   $appear->addAttribute('id', 'appear'.$animate['idnr']);
   if ($animate['begin']) $appear->addAttribute('begin', $animate['begin']);
   if ($animate['appear']=='') $dur = '0.5s';
   else                        $dur = $animate['appear'];
   opacity($appear, '0', '1', $dur);
}

function vanish($obj, $animate) {
   $vanish = $obj->addChild('animate');
   $vanish->addAttribute('id', 'vanish'.$animate['idnr']);
   if ($animate['begin']) $vanish->addAttribute('begin', $animate['begin']);
   if ($animate['vanish']=='') $dur = '0.5s';
   else                        $dur = $animate['vanish'];
   opacity($vanish, '1', '0', $dur);
}

function motion($obj, $animate) {
   global $svg;
   $motion = $obj->addChild('animateMotion');
   $motion->addAttribute('id', 'motion'.$animate['idnr']);
   if ($animate['appear']) $motion->addAttribute('begin', 'appear'.$animate['idnr'].'.end');
   else if ($animate['begin'])$motion->addAttribute('begin', $animate['begin']);
   // mpath_id_dur[0] is id of mpath,
   // mpath_id_dur[1] is dur
   if (strpos($animate['mpath'], ',') == false)  // attribute value string has ',' ?
        $mpath_id_dur = array($animate["mpath"], '3s'); // no, default dur
   else $mpath_id_dur = explode(",",$animate['mpath']); // yes, dur is substring after ','
   $motion->addAttribute('dur', $mpath_id_dur[1]);
   $motion->addAttribute('fill', 'freeze');
   $mpath = $motion->addChild('mpath');
   $mpath->addAttribute('xlink:href', '#'.$mpath_id_dur[0], $svg->getNamespaces(true)['xlink']);
   // search for mpath and make it relative starting with 0,0
   foreach ($svg->g[0]->path as $path)
     if (strcmp($path['id'], $mpath_id_dur[0])==0) // found mpath
        if (substr($path["d"],0,1)=="m")
           // already is relative, resplace start coordinates by 0,0
           $path['d'] = list_replace($path["d"], 1, "0,0");
        else
           // is absolute,convert to relative - this probably does not work
           $path['d'] = abs2rel($path["d"]);
}

function movin($obj, $animate) {
   $movin = $obj->addChild('animate');
   $movin->addAttribute('id', 'movin'.$animate['idnr']);
   $movin->addAttribute('dur', '0.3s');
   $movin->addAttribute('attributeType', 'XML');
   $movin->addAttribute('attributeName', 'x');
   $movin->addAttribute('from', '1');
   if (strpos($animate['movin'], ',') == false) { // attribute value string has ',' ?
      $movin->addAttribute('begin', $animate['movin']); // no, use
      $movin->addAttribute('to', '20');                 // default displacement
   } else {
      $in = explode(",",$animate['movin']);  // yes,
      $movin->addAttribute('begin', $in[0]);
      $movin->addAttribute('to', $in[1]);    // 'to' is substring after ','
   }
   $movin->addAttribute('additive', 'sum');
   $movin->addAttribute('fill', 'freeze');
}

foreach ($ani->animate as $animate) {
   if (strpbrk($animate['idnr'], "-~!@#$%*^&)}]>({[<+~`|,.?/\\\"") != false)
      fwrite(STDERR, "Illegal character in idnr = ".$animate['idnr'].". Edit drawing in Inkscape to correct this.\n");
   switch ($animate["type"]) {
      case "text":
         foreach ($svg->g as $g)  // for each group
          foreach ($g->text as $text)
            if ($text['id'] == $animate['type'].$animate['idnr'] ) {  // found text to be animated
               if ($animate['appear']) {
                  $text['style'] = "opacity:0;".$text['style'];
                  appear($text, $animate);
               }
               if ($animate['mpath']) motion($text, $animate);
               if ($animate['movin']) {
                  $tspan = $text->tspan;  // delete x and y values in tspan
                  if ($tspan['x']) $tspan['x'] = '';
                  if ($tspan['y']) $tspan['y'] = '';
                  movin($text, $animate);
               }
               if ($animate['vanish']) vanish($text, $animate);
            }
         break;
      case "path":
         foreach ($svg->g as $g)
          foreach ($g->path as $path)
            if ($path['id'] == $animate['type'].$animate['idnr'] ) {  // found path to be animated
               if ($animate['appear']) appear($path, $animate);
               if ($animate['vanish']) vanish($path, $animate);
            }
         break;
      case "ellipse":
         foreach ($svg->g as $g)
          foreach ($g->ellipse as $ellipse)
            if ($ellipse['id'] == "path".$animate['idnr'] ) {  // found ellipse to be animated
               if ($animate['mpath']) motion($ellipse, $animate);
            }
         break;
      case "rect":
         foreach ($svg->g as $g)
          foreach ($g->rect as $rect)
            if ($rect['id'] == $animate['type'].$animate['idnr'] ) {  // found rect to be animated
               if ($animate['appear']) appear($rect, $animate);
               if ($animate['vanish']) vanish($rect, $animate);
            }
         break;
   }
}

$svg->asXML($ani['animated']);

?>