* (bug 3691) Aspect ratio from viewBox attribute is now preserved for SVG

  images which do not specify width and height attributes.

Examples from bugs:
http://commons.wikimedia.org/wiki/Image:Gcj.svg
http://commons.wikimedia.org/wiki/File:Providence_Metro_Area.svg

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 467ab57..674f7c6 100644 (file)
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -422,6 +422,8 @@ The following extensions are migrated into MediaWiki 1.14:
   Arabic script (Persian, Urdu, Sindhi, Punjabi)
 * (bug 16656) cleanupTitles and friends should now work in load-balanced
   DB environments when $wgDBserver isn't set.
+* (bug 3691) Aspect ratio from viewBox attribute is now preserved for SVG
+  images which do not specify width and height attributes.
 
 === API changes in 1.14 ===
 

diff --git a/includes/ImageFunctions.php b/includes/ImageFunctions.php
index 8f40c81..219b5b0 100644 (file)
--- a/includes/ImageFunctions.php
+++ b/includes/ImageFunctions.php
@@ -4,9 +4,10 @@
  * http://www.w3.org/TR/SVG11/coords.html#UnitIdentifiers
  *
  * @param $length String: CSS/SVG length.
+ * @param $viewpoerSize: Float optional scale for percentage units...
  * @return Integer: length in pixels
  */
-function wfScaleSVGUnit( $length ) {
+function wfScaleSVGUnit( $length, $viewportSize=512 ) {
        static $unitLength = array(
                'px' => 1.0,
                'pt' => 1.25,
@@ -14,14 +15,19 @@ function wfScaleSVGUnit( $length ) {
                'mm' => 3.543307,
                'cm' => 35.43307,
                'in' => 90.0,
+               'em' => 16.0, // fake it?
+               'ex' => 12.0, // fake it?
                ''   => 1.0, // "User units" pixels by default
-               '%'  => 2.0, // Fake it!
                );
        $matches = array();
        if( preg_match( '/^\s*(\d+(?:\.\d+)?)(em|ex|px|pt|pc|cm|mm|in|%|)\s*$/', $length, $matches ) ) {
                $length = floatval( $matches[1] );
                $unit = $matches[2];
-               return round( $length * $unitLength[$unit] );
+               if( $unit == '%' ) {
+                       return round( $length * 0.01 * $viewportSize );
+               } else {
+                       return round( $length * $unitLength[$unit] );
+               }
        } else {
                // Assume pixels
                return round( floatval( $length ) );
@@ -29,17 +35,49 @@ function wfScaleSVGUnit( $length ) {
 }
 
 class XmlSizeFilter {
+       const DEFAULT_WIDTH = 512;
+       const DEFAULT_HEIGHT = 512;
        var $first = true;
-       var $width = 256;
-       var $height = 256;
+       var $width = self::DEFAULT_WIDTH;
+       var $height = self::DEFAULT_HEIGHT;
        function filter( $name, $attribs ) {
                if( $this->first ) {
+                       $defaultWidth = self::DEFAULT_WIDTH;
+                       $defaultHeight = self::DEFAULT_HEIGHT;
+                       $aspect = 1.0;
+                       $width = null;
+                       $height = null;
+                       
+                       if( isset( $attribs['viewBox'] ) ) {
+                               // min-x min-y width height
+                               $viewBox = preg_split( '/\s+/', trim( $attribs['viewBox'] ) );
+                               if( count( $viewBox ) == 4 ) {
+                                       $viewWidth = wfScaleSVGUnit( $viewBox[2] );
+                                       $viewHeight = wfScaleSVGUnit( $viewBox[3] );
+                                       if( $viewWidth > 0 && $viewHeight > 0 ) {
+                                               $aspect = $viewWidth / $viewHeight;
+                                               $defaultHeight = $defaultWidth / $aspect;
+                                       }
+                               }
+                       }
                        if( isset( $attribs['width'] ) ) {
-                               $this->width = wfScaleSVGUnit( $attribs['width'] );
+                               $width = wfScaleSVGUnit( $attribs['width'], $defaultWidth );
                        }
                        if( isset( $attribs['height'] ) ) {
-                               $this->height = wfScaleSVGUnit( $attribs['height'] );
+                               $height = wfScaleSVGUnit( $attribs['height'], $defaultHeight );
+                       }
+                       
+                       if( !isset( $width ) && !isset( $height ) ) {
+                               $width = $defaultWidth;
+                               $height = $width / $aspect;
+                       } elseif( isset( $width ) && !isset( $height ) ) {
+                               $height = $width / $aspect;
+                       } elseif( isset( $height ) && !isset( $width ) ) {
+                               $width = $height * $aspect;
                        }
+                       
+                       $this->width = $width;
+                       $this->height = $height;
                        $this->first = false;
                }
        }