wiki.techinc.nl/includes/ImageFunctions.php

150 lines
4.1 KiB
PHP

<?php
/**
* Return a rounded pixel equivalent for a labeled CSS/SVG length.
* http://www.w3.org/TR/SVG11/coords.html#UnitIdentifiers
*
* @param $length String: CSS/SVG length.
* @return Integer: length in pixels
*/
function wfScaleSVGUnit( $length ) {
static $unitLength = array(
'px' => 1.0,
'pt' => 1.25,
'pc' => 15.0,
'mm' => 3.543307,
'cm' => 35.43307,
'in' => 90.0,
'' => 1.0, // "User units" pixels by default
'%' => 2.0, // Fake it!
);
$matches = array();
if( preg_match( '/^(\d+(?:\.\d+)?)(em|ex|px|pt|pc|cm|mm|in|%|)$/', $length, $matches ) ) {
$length = floatval( $matches[1] );
$unit = $matches[2];
return round( $length * $unitLength[$unit] );
} else {
// Assume pixels
return round( floatval( $length ) );
}
}
/**
* Compatible with PHP getimagesize()
* @todo support gzipped SVGZ
* @todo check XML more carefully
* @todo sensible defaults
*
* @param $filename String: full name of the file (passed to php fopen()).
* @return array
*/
function wfGetSVGsize( $filename ) {
$width = 256;
$height = 256;
// Read a chunk of the file
$f = fopen( $filename, "rt" );
if( !$f ) return false;
$chunk = fread( $f, 4096 );
fclose( $f );
// Uber-crappy hack! Run through a real XML parser.
$matches = array();
if( !preg_match( '/<svg\s*([^>]*)\s*>/s', $chunk, $matches ) ) {
return false;
}
$tag = $matches[1];
if( preg_match( '/\bwidth\s*=\s*("[^"]+"|\'[^\']+\')/s', $tag, $matches ) ) {
$width = wfScaleSVGUnit( trim( substr( $matches[1], 1, -1 ) ) );
}
if( preg_match( '/\bheight\s*=\s*("[^"]+"|\'[^\']+\')/s', $tag, $matches ) ) {
$height = wfScaleSVGUnit( trim( substr( $matches[1], 1, -1 ) ) );
}
return array( $width, $height, 'SVG',
"width=\"$width\" height=\"$height\"" );
}
/**
* Determine if an image exists on the 'bad image list'.
*
* The format of MediaWiki:Bad_image_list is as follows:
* * Only list items (lines starting with "*") are considered
* * The first link on a line must be a link to a bad image
* * Any subsequent links on the same line are considered to be exceptions,
* i.e. articles where the image may occur inline.
*
* @param string $name the image name to check
* @param Title $contextTitle The page on which the image occurs, if known
* @return bool
*/
function wfIsBadImage( $name, $contextTitle = false ) {
static $badImages = false;
wfProfileIn( __METHOD__ );
# Run the extension hook
$bad = false;
if( !wfRunHooks( 'BadImage', array( $name, &$bad ) ) ) {
wfProfileOut( __METHOD__ );
return $bad;
}
if( !$badImages ) {
# Build the list now
$badImages = array();
$lines = explode( "\n", wfMsgForContentNoTrans( 'bad_image_list' ) );
foreach( $lines as $line ) {
# List items only
if ( substr( $line, 0, 1 ) !== '*' ) {
continue;
}
# Find all links
$m = array();
if ( !preg_match_all( '/\[\[:?(.*?)\]\]/', $line, $m ) ) {
continue;
}
$exceptions = array();
$imageDBkey = false;
foreach ( $m[1] as $i => $titleText ) {
$title = Title::newFromText( $titleText );
if ( !is_null( $title ) ) {
if ( $i == 0 ) {
$imageDBkey = $title->getDBkey();
} else {
$exceptions[$title->getPrefixedDBkey()] = true;
}
}
}
if ( $imageDBkey !== false ) {
$badImages[$imageDBkey] = $exceptions;
}
}
}
$contextKey = $contextTitle ? $contextTitle->getPrefixedDBkey() : false;
$bad = isset( $badImages[$name] ) && !isset( $badImages[$name][$contextKey] );
wfProfileOut( __METHOD__ );
return $bad;
}
/**
* Calculate the largest thumbnail width for a given original file size
* such that the thumbnail's height is at most $maxHeight.
* @param $boxWidth Integer Width of the thumbnail box.
* @param $boxHeight Integer Height of the thumbnail box.
* @param $maxHeight Integer Maximum height expected for the thumbnail.
* @return Integer.
*/
function wfFitBoxWidth( $boxWidth, $boxHeight, $maxHeight ) {
$idealWidth = $boxWidth * $maxHeight / $boxHeight;
$roundedUp = ceil( $idealWidth );
if( round( $roundedUp * $boxHeight / $boxWidth ) > $maxHeight )
return floor( $idealWidth );
else
return $roundedUp;
}