Current File : /www/varak.net/wiki.varak.net/includes/media/XCF.php
<?php
/**
* Handler for the Gimp's native file format (XCF)
*
* Overview:
* https://en.wikipedia.org/wiki/XCF_(file_format)
* Specification in Gnome repository:
* http://svn.gnome.org/viewvc/gimp/trunk/devel-docs/xcf.txt?view=markup
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
* http://www.gnu.org/copyleft/gpl.html
*
* @file
* @ingroup Media
*/
/**
* Handler for the Gimp's native file format; getimagesize() doesn't
* support these files
*
* @ingroup Media
*/
class XCFHandler extends BitmapHandler {
/**
* @param File $file
* @return bool
*/
public function mustRender( $file ) {
return true;
}
/**
* Render files as PNG
*
* @param string $ext
* @param string $mime
* @param array|null $params
* @return array
*/
function getThumbType( $ext, $mime, $params = null ) {
return [ 'png', 'image/png' ];
}
/**
* Get width and height from the XCF header.
*
* @param File|FSFile $image
* @param string $filename
* @return array
*/
function getImageSize( $image, $filename ) {
$header = self::getXCFMetaData( $filename );
if ( !$header ) {
return false;
}
# Forge a return array containing metadata information just like getimagesize()
# See PHP documentation at: https://secure.php.net/getimagesize
return [
0 => $header['width'],
1 => $header['height'],
2 => null, # IMAGETYPE constant, none exist for XCF.
3 => "height=\"{$header['height']}\" width=\"{$header['width']}\"",
'mime' => 'image/x-xcf',
'channels' => null,
'bits' => 8, # Always 8-bits per color
];
}
/**
* Metadata for a given XCF file
*
* Will return false if file magic signature is not recognized
* @author Hexmode
* @author Hashar
*
* @param string $filename Full path to a XCF file
* @return bool|array Metadata Array just like PHP getimagesize()
*/
static function getXCFMetaData( $filename ) {
# Decode master structure
$f = fopen( $filename, 'rb' );
if ( !$f ) {
return false;
}
# The image structure always starts at offset 0 in the XCF file.
# So we just read it :-)
$binaryHeader = fread( $f, 26 );
fclose( $f );
/**
* Master image structure:
*
* byte[9] "gimp xcf " File type magic
* byte[4] version XCF version
* "file" - version 0
* "v001" - version 1
* "v002" - version 2
* byte 0 Zero-terminator for version tag
* uint32 width With of canvas
* uint32 height Height of canvas
* uint32 base_type Color mode of the image; one of
* 0: RGB color
* 1: Grayscale
* 2: Indexed color
* (enum GimpImageBaseType in libgimpbase/gimpbaseenums.h)
*/
try {
$header = wfUnpack(
"A9magic" . # A: space padded
"/a5version" . # a: zero padded
"/Nwidth" . # \
"/Nheight" . # N: unsigned long 32bit big endian
"/Nbase_type", # /
$binaryHeader
);
} catch ( Exception $mwe ) {
return false;
}
# Check values
if ( $header['magic'] !== 'gimp xcf' ) {
wfDebug( __METHOD__ . " '$filename' has invalid magic signature.\n" );
return false;
}
# TODO: we might want to check for sane values of width and height
wfDebug( __METHOD__ .
": canvas size of '$filename' is {$header['width']} x {$header['height']} px\n" );
return $header;
}
/**
* Store the channel type
*
* Greyscale files need different command line options.
*
* @param File|FSFile $file The image object, or false if there isn't one.
* Warning, FSFile::getPropsFromPath might pass an (object)array() instead (!)
* @param string $filename
* @return string
*/
public function getMetadata( $file, $filename ) {
$header = self::getXCFMetaData( $filename );
$metadata = [];
if ( $header ) {
// Try to be consistent with the names used by PNG files.
// Unclear from base media type if it has an alpha layer,
// so just assume that it does since it "potentially" could.
switch ( $header['base_type'] ) {
case 0:
$metadata['colorType'] = 'truecolour-alpha';
break;
case 1:
$metadata['colorType'] = 'greyscale-alpha';
break;
case 2:
$metadata['colorType'] = 'index-coloured';
break;
default:
$metadata['colorType'] = 'unknown';
}
} else {
// Marker to prevent repeated attempted extraction
$metadata['error'] = true;
}
return serialize( $metadata );
}
/**
* Should we refresh the metadata
*
* @param File $file The file object for the file in question
* @param string $metadata Serialized metadata
* @return bool One of the self::METADATA_(BAD|GOOD|COMPATIBLE) constants
*/
public function isMetadataValid( $file, $metadata ) {
if ( !$metadata ) {
// Old metadata when we just put an empty string in there
return self::METADATA_BAD;
} else {
return self::METADATA_GOOD;
}
}
/**
* Must use "im" for XCF
*
* @param string $dstPath
* @param bool $checkDstPath
* @return string
*/
protected function getScalerType( $dstPath, $checkDstPath = true ) {
return "im";
}
/**
* Can we render this file?
*
* Image magick doesn't support indexed xcf files as of current
* writing (as of 6.8.9-3)
* @param File $file
* @return bool
*/
public function canRender( $file ) {
Wikimedia\suppressWarnings();
$xcfMeta = unserialize( $file->getMetadata() );
Wikimedia\restoreWarnings();
if ( isset( $xcfMeta['colorType'] ) && $xcfMeta['colorType'] === 'index-coloured' ) {
return false;
}
return parent::canRender( $file );
}
}
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