What I'm trying to do is simple: scale some SVG dots from scale(0) to scale(1) when a sibling element is hovered using vanilla js. They are the red ones in the demo

Here's the basic SVG setup

<?xml version=1.0 encoding=utf-8 ?>

<!DOCTYPE svg PUBLIC -//W3C//DTD SVG 1.1//EN http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd>

<svg version=1.1 xmlns=http://www.w3.org/2000/svg xmlns:xlink=http://www.w3.org/1999/xlink 

      x=0px y=0px viewBox=0 0 720 576 style=enable-background:new 0 0 720 576; xml:space=preserve>

    <style type=text/css>

        .st3 {

            fill:red;

        }

        * {

            -webkit-transition:.3s;

            transition:.3s;

        }

    </style>

    <g id=Layer_4>

        <!-- Shield -->

        <path class=st8 d=M601,304.7c-32.4-15.4-68.6-24-106.8-24c-40.4,0-78.5,9.6-112.3,26.6c4.9,79.7,41.9,146.7,109.5,187.6

            C559.8,454.1,597,385.6,601,304.7z />

        <path class=st9 d=M420.1,328.7c2.1-4.7,32.5-23.9,72.5-23.9c39.9,0,73.1,20,75.5,24.3c2.4,4.3,5.7,40-12.7,74.6

                c-19.7,36.9-53.5,50.1-61.8,50.4c-6.4,0.2-41.8-14.3-62.5-51.6C411.5,367.4,418,333.4,420.1,328.7z />

        <circle class=st10 cx=494.9 cy=373.3 r=35.5 />

    </g>

    <g id=Layer_8>

        <!-- Dots on shield -->

        <circle class=st3 cx=578.8 cy=316.2 r=4.6 />

        <circle class=st3 cx=543.4 cy=346.2 r=4.6 />

        <circle class=st3 cx=505 cy=375.5 r=4.6 />

    </g>

</svg>

The issue is that SVG scales based on the origin location, not the current location, thus when a transform is applied it moves the element in addition to scaling it. I am attempting to fix this situation by translating by the BBox() offset, scaling, then translating back but that only seemed to help and not entirely fix the issue.

var shield = document.getElementById(Layer_4),

    dots = document.querySelectorAll(#Layer_8 .st3);



toggleTransform(false);



shield.onmouseover = function () { toggleTransform(true); }

shield.onmouseout = function () { toggleTransform(false); }



function toggleTransform(bool) {

    if (!bool) {

        for (var i = 0; i < dots.length; i++) {

            var box = dots[i].getBBox(),

                cx = box.x + box.width / 10,

                cy = box.y + box.height / 10;

            //dots[i].setAttribute(transform, translate( + cx +   + cy + ) scale(0) translate( + cx +   + cy + ));

            dots[i].style.WebkitTransform = translate( + cx + px,  + cy + px) scale(0) translate( + -cx + px,  + -cy + px);

        }

    } else {

        for (var i = 0; i < dots.length; i++) {

            var box = dots[i].getBBox(),

                cx = box.x + box.width / 2,

                cy = box.y + box.height / 2;

            //dots[i].setAttribute(transform, translate(0 0) scale(1) translate(0 0));

            dots[i].style.WebkitTransform = translate(0, 0) scale(1) translate(0, 0);

        }

    }

}

I tried using both setAttribute and CSS's transform (I couldn't get setAttribute to transition, presumably because it's not animatable by CSS) but couldn't get it with either. I've only been testing in Chrome

Anyone have an idea how I can scale, while not moving, red dots?

Here's the demo again if you missed it

Edit

I made a function based on RashFlash's answer to make it quite simple to use and also takes into account offsets and different transform origins

function scaleMe(elem, scaleX, scaleY, newOffsetX, newOffsetY, originX, originY) {

    newOffsetX = null ? 0 : newOffsetX;

    newOffsetY = null ? 0 : newOffsetY;

    originX = null ? center : originX;

    originY = null ? center : originY;



    var bbox = elem.getBBox(),

        cx = bbox.x + (bbox.width / 2),

        cy = bbox.y + (bbox.height / 2),        

        tx = -cx * (scaleX - 1) + newOffsetX,

        ty = -cy * (scaleY - 1) + newOffsetY;        



    if(originX === left || originX === right) {

        tx = newOffsetX;

    }

    if(originY === top || originY === bottom) {

        ty = newOffsetY;

    }



    var scalestr = scaleX + ',' + scaleY,

        translatestr = tx + 'px,' + ty + 'px';



    elem.style.WebkitTransformOrigin = originX +   + originY;

    elem.style.MozTransformOrigin = originX +   + originY;

    elem.style.msTransformOrigin = originX +   + originY;

    elem.style.transformOrigin = originX +   + originY;



    elem.style.WebkitTransform = translate( + translatestr + ) scale( + scalestr + );

    elem.style.MozTransform = translate( + translatestr + ) scale( + scalestr + );

    elem.style.msTransform = translate( + translatestr + ) scale( + scalestr + );

    elem.style.transform = translate( + translatestr + ) scale( + scalestr + );

}