src/applications/macro/engine/PhabricatorMemeEngine.php

   1 <?php
   2
   3 final class PhabricatorMemeEngine extends Phobject {
   4
   5   private $viewer;
   6   private $template;
   7   private $aboveText;
   8   private $belowText;
   9
  10   private $templateFile;
  11   private $metrics;
  12
  13   public function setViewer(PhabricatorUser $viewer) {
  14     $this->viewer = $viewer;
  15     return $this;
  16   }
  17
  18   public function getViewer() {
  19     return $this->viewer;
  20   }
  21
  22   public function setTemplate($template) {
  23     $this->template = $template;
  24     return $this;
  25   }
  26
  27   public function getTemplate() {
  28     return $this->template;
  29   }
  30
  31   public function setAboveText($above_text) {
  32     $this->aboveText = $above_text;
  33     return $this;
  34   }
  35
  36   public function getAboveText() {
  37     return $this->aboveText;
  38   }
  39
  40   public function setBelowText($below_text) {
  41     $this->belowText = $below_text;
  42     return $this;
  43   }
  44
  45   public function getBelowText() {
  46     return $this->belowText;
  47   }
  48
  49   public function getGenerateURI() {
  50     $params = array(
  51       'macro' => $this->getTemplate(),
  52       'above' => $this->getAboveText(),
  53       'below' => $this->getBelowText(),
  54     );
  55
  56     return new PhutilURI('/macro/meme/', $params);
  57   }
  58
  59   public function newAsset() {
  60     $cache = $this->loadCachedFile();
  61     if ($cache) {
  62       return $cache;
  63     }
  64
  65     $template = $this->loadTemplateFile();
  66     if (!$template) {
  67       throw new Exception(
  68         pht(
  69           'Template "%s" is not a valid template.',
  70           $template));
  71     }
  72
  73     $hash = $this->newTransformHash();
  74
  75     $asset = $this->newAssetFile($template);
  76
  77     $xfile = id(new PhabricatorTransformedFile())
  78       ->setOriginalPHID($template->getPHID())
  79       ->setTransformedPHID($asset->getPHID())
  80       ->setTransform($hash);
  81
  82     try {
  83       $caught = null;
  84
  85       $unguarded = AphrontWriteGuard::beginScopedUnguardedWrites();
  86       try {
  87         $xfile->save();
  88       } catch (Exception $ex) {
  89         $caught = $ex;
  90       }
  91       unset($unguarded);
  92
  93       if ($caught) {
  94         throw $caught;
  95       }
  96
  97       return $asset;
  98     } catch (AphrontDuplicateKeyQueryException $ex) {
  99       $xfile = $this->loadCachedFile();
 100       if (!$xfile) {
 101         throw $ex;
 102       }
 103       return $xfile;
 104     }
 105   }
 106
 107   private function newTransformHash() {
 108     $properties = array(
 109       'kind' => 'meme',
 110       'above' => $this->getAboveText(),
 111       'below' => $this->getBelowText(),
 112     );
 113
 114     $properties = phutil_json_encode($properties);
 115
 116     return PhabricatorHash::digestForIndex($properties);
 117   }
 118
 119   public function loadCachedFile() {
 120     $viewer = $this->getViewer();
 121
 122     $template_file = $this->loadTemplateFile();
 123     if (!$template_file) {
 124       return null;
 125     }
 126
 127     $hash = $this->newTransformHash();
 128
 129     $xform = id(new PhabricatorTransformedFile())->loadOneWhere(
 130       'originalPHID = %s AND transform = %s',
 131       $template_file->getPHID(),
 132       $hash);
 133     if (!$xform) {
 134       return null;
 135     }
 136
 137     return id(new PhabricatorFileQuery())
 138       ->setViewer($viewer)
 139       ->withPHIDs(array($xform->getTransformedPHID()))
 140       ->executeOne();
 141   }
 142
 143   private function loadTemplateFile() {
 144     if ($this->templateFile === null) {
 145       $viewer = $this->getViewer();
 146       $template = $this->getTemplate();
 147
 148       $macro = id(new PhabricatorMacroQuery())
 149         ->setViewer($viewer)
 150         ->withNames(array($template))
 151         ->needFiles(true)
 152         ->executeOne();
 153       if (!$macro) {
 154         return null;
 155       }
 156
 157       $this->templateFile = $macro->getFile();
 158     }
 159
 160     return $this->templateFile;
 161   }
 162
 163   private function newAssetFile(PhabricatorFile $template) {
 164     $data = $this->newAssetData($template);
 165     return PhabricatorFile::newFromFileData(
 166       $data,
 167       array(
 168         'name' => 'meme-'.$template->getName(),
 169         'canCDN' => true,
 170
 171         // In modern code these can end up linked directly in email, so let
 172         // them stick around for a while.
 173         'ttl.relative' => phutil_units('30 days in seconds'),
 174       ));
 175   }
 176
 177   private function newAssetData(PhabricatorFile $template) {
 178     $template_data = $template->loadFileData();
 179
 180     // When we aren't adding text, just return the data unmodified. This saves
 181     // us from doing expensive stitching when we aren't actually making any
 182     // changes to the image.
 183     $above_text = $this->getAboveText();
 184     $below_text = $this->getBelowText();
 185     if (!strlen(trim($above_text)) && !strlen(trim($below_text))) {
 186       return $template_data;
 187     }
 188
 189     $result = $this->newImagemagickAsset($template, $template_data);
 190     if ($result) {
 191       return $result;
 192     }
 193
 194     return $this->newGDAsset($template, $template_data);
 195   }
 196
 197   private function newImagemagickAsset(
 198     PhabricatorFile $template,
 199     $template_data) {
 200
 201     // We're only going to use Imagemagick on GIFs.
 202     $mime_type = $template->getMimeType();
 203     if ($mime_type != 'image/gif') {
 204       return null;
 205     }
 206
 207     // We're only going to use Imagemagick if it is actually available.
 208     $available = PhabricatorEnv::getEnvConfig('files.enable-imagemagick');
 209     if (!$available) {
 210       return null;
 211     }
 212
 213     // Test of the GIF is an animated GIF. If it's a flat GIF, we'll fall
 214     // back to GD.
 215     $input = new TempFile();
 216     Filesystem::writeFile($input, $template_data);
 217     list($err, $out) = exec_manual('convert %s info:', $input);
 218     if ($err) {
 219       return null;
 220     }
 221
 222     $split = phutil_split_lines($out);
 223     $frames = count($split);
 224     if ($frames <= 1) {
 225       return null;
 226     }
 227
 228     // Split the frames apart, transform each frame, then merge them back
 229     // together.
 230     $output = new TempFile();
 231
 232     $future = new ExecFuture(
 233       'convert %s -coalesce +adjoin %s_%s',
 234       $input,
 235       $input,
 236       '%09d');
 237     $future->setTimeout(10)->resolvex();
 238
 239     $output_files = array();
 240     for ($ii = 0; $ii < $frames; $ii++) {
 241       $frame_name = sprintf('%s_%09d', $input, $ii);
 242       $output_name = sprintf('%s_%09d', $output, $ii);
 243
 244       $output_files[] = $output_name;
 245
 246       $frame_data = Filesystem::readFile($frame_name);
 247       $memed_frame_data = $this->newGDAsset($template, $frame_data);
 248       Filesystem::writeFile($output_name, $memed_frame_data);
 249     }
 250
 251     $future = new ExecFuture(
 252       'convert -dispose background -loop 0 %Ls %s',
 253       $output_files,
 254       $output);
 255     $future->setTimeout(10)->resolvex();
 256
 257     return Filesystem::readFile($output);
 258   }
 259
 260   private function newGDAsset(PhabricatorFile $template, $data) {
 261     $img = imagecreatefromstring($data);
 262     if (!$img) {
 263       throw new Exception(
 264         pht('Failed to imagecreatefromstring() image template data.'));
 265     }
 266
 267     $dx = imagesx($img);
 268     $dy = imagesy($img);
 269
 270     $metrics = $this->getMetrics($dx, $dy);
 271     $font = $this->getFont();
 272     $size = $metrics['size'];
 273
 274     $above = $this->getAboveText();
 275     if (strlen($above)) {
 276       $x = (int)floor(($dx - $metrics['text']['above']['width']) / 2);
 277       $y = $metrics['text']['above']['height'] + 12;
 278
 279       $this->drawText($img, $font, $metrics['size'], $x, $y, $above);
 280     }
 281
 282     $below = $this->getBelowText();
 283     if (strlen($below)) {
 284       $x = (int)floor(($dx - $metrics['text']['below']['width']) / 2);
 285       $y = $dy - 12 - $metrics['text']['below']['descend'];
 286
 287       $this->drawText($img, $font, $metrics['size'], $x, $y, $below);
 288     }
 289
 290     return PhabricatorImageTransformer::saveImageDataInAnyFormat(
 291       $img,
 292       $template->getMimeType());
 293   }
 294
 295   private function getFont() {
 296     $phabricator_root = dirname(phutil_get_library_root('phabricator'));
 297
 298     $font_root = $phabricator_root.'/resources/font/';
 299     if (Filesystem::pathExists($font_root.'impact.ttf')) {
 300       $font_path = $font_root.'impact.ttf';
 301     } else {
 302       $font_path = $font_root.'tuffy.ttf';
 303     }
 304
 305     return $font_path;
 306   }
 307
 308   private function getMetrics($dim_x, $dim_y) {
 309     if ($this->metrics === null) {
 310       $font = $this->getFont();
 311
 312       $font_max = 72;
 313       $font_min = 5;
 314
 315       $margin_x = 16;
 316       $margin_y = 16;
 317
 318       $last = null;
 319       $cursor = floor(($font_max + $font_min) / 2);
 320       $min = $font_min;
 321       $max = $font_max;
 322
 323       $texts = array(
 324         'above' => $this->getAboveText(),
 325         'below' => $this->getBelowText(),
 326       );
 327
 328       $metrics = null;
 329       $best = null;
 330       while (true) {
 331         $all_fit = true;
 332         $text_metrics = array();
 333         foreach ($texts as $key => $text) {
 334           $box = imagettfbbox($cursor, 0, $font, $text);
 335           $height = abs($box[3] - $box[5]);
 336           $width = abs($box[0] - $box[2]);
 337
 338           // This is the number of pixels below the baseline that the
 339           // text extends, for example if it has a "y".
 340           $descend = $box[3];
 341
 342           if (($height + $margin_y) > $dim_y) {
 343             $all_fit = false;
 344             break;
 345           }
 346
 347           if (($width + $margin_x) > $dim_x) {
 348             $all_fit = false;
 349             break;
 350           }
 351
 352           $text_metrics[$key]['width'] = $width;
 353           $text_metrics[$key]['height'] = $height;
 354           $text_metrics[$key]['descend'] = $descend;
 355         }
 356
 357         if ($all_fit || $best === null) {
 358           $best = $cursor;
 359           $metrics = $text_metrics;
 360         }
 361
 362         if ($all_fit) {
 363           $min = $cursor;
 364         } else {
 365           $max = $cursor;
 366         }
 367
 368         $last = $cursor;
 369         $cursor = floor(($max + $min) / 2);
 370         if ($cursor === $last) {
 371           break;
 372         }
 373       }
 374
 375       $this->metrics = array(
 376         'size' => $best,
 377         'text' => $metrics,
 378       );
 379     }
 380
 381     return $this->metrics;
 382   }
 383
 384   private function drawText($img, $font, $size, $x, $y, $text) {
 385     $text_color = imagecolorallocate($img, 255, 255, 255);
 386     $border_color = imagecolorallocate($img, 0, 0, 0);
 387
 388     $border = 2;
 389     for ($xx = ($x - $border); $xx <= ($x + $border); $xx += $border) {
 390       for ($yy = ($y - $border); $yy <= ($y + $border); $yy += $border) {
 391         if (($xx === $x) && ($yy === $y)) {
 392           continue;
 393         }
 394         imagettftext($img, $size, 0, $xx, $yy, $border_color, $font, $text);
 395       }
 396     }
 397
 398     imagettftext($img, $size, 0, $x, $y, $text_color, $font, $text);
 399   }
 400
 401
 402 }