Phrogz - 2 months ago 7x
Javascript Question

# Convert SVG Path to Absolute Commands

Given an SVG Path element, how can I convert all path commands into absolute coordinates? For example, convert this path:

``````<path d="M17,42 l100,0 v100 h-100 z"/>
``````

into this equivalent path:

``````<path d="M17,42 L117,42 V142 H17 Z"/>
``````

This question was motivated by this question.

Here's the JavaScript code I came up with:

``````function convertToAbsolute(path){
var x0,y0,x1,y1,x2,y2,segs = path.pathSegList;
for (var x=0,y=0,i=0,len=segs.numberOfItems;i<len;++i){
var seg = segs.getItem(i), c=seg.pathSegTypeAsLetter;
if (/[MLHVCSQTA]/.test(c)){
if ('x' in seg) x=seg.x;
if ('y' in seg) y=seg.y;
}else{
if ('x1' in seg) x1=x+seg.x1;
if ('x2' in seg) x2=x+seg.x2;
if ('y1' in seg) y1=y+seg.y1;
if ('y2' in seg) y2=y+seg.y2;
if ('x'  in seg) x+=seg.x;
if ('y'  in seg) y+=seg.y;
switch(c){
case 'm': segs.replaceItem(path.createSVGPathSegMovetoAbs(x,y),i);                   break;
case 'l': segs.replaceItem(path.createSVGPathSegLinetoAbs(x,y),i);                   break;
case 'h': segs.replaceItem(path.createSVGPathSegLinetoHorizontalAbs(x),i);           break;
case 'v': segs.replaceItem(path.createSVGPathSegLinetoVerticalAbs(y),i);             break;
case 'c': segs.replaceItem(path.createSVGPathSegCurvetoCubicAbs(x,y,x1,y1,x2,y2),i); break;
case 's': segs.replaceItem(path.createSVGPathSegCurvetoCubicSmoothAbs(x,y,x2,y2),i); break;
case 'a': segs.replaceItem(path.createSVGPathSegArcAbs(x,y,seg.r1,seg.r2,seg.angle,seg.largeArcFlag,seg.sweepFlag),i);   break;
case 'z': case 'Z': x=x0; y=y0; break;
}
}
// Record the start of a subpath
if (c=='M' || c=='m') x0=x, y0=y;
}
}
``````

Used like so with the path from the question:

``````var path = document.querySelector('path');
convertToAbsolute(path);
console.log(path.getAttribute('d'));
// M 17 42 L 117 42 V 142 H 17 Z
``````

Edit: Here's a test page with a path that includes every command (absolute and relative) interleaved and shows that the conversion works in the now-current versions of IE, Chrome, FF, and Safari.
http://phrogz.net/svg/convert_path_to_absolute_commands.svg

Source (Stackoverflow)