Заполняшка

filling.js

$(window).scroll(function() {
    drawLines();
});

//If you have more than one SVG per page this will pick it up
function drawLines(){
    $.each($("path"), function(i, val){
        var line = val;
        drawLine($(this), line);
    });
}

//draw the line
function drawLine(container, line){
    var length = 0;
    var pathLength = line.getTotalLength();
    var distanceFromTop = container.offset().top - $(window).scrollTop();
    var percentDone = 1 - (distanceFromTop / $(window).height());
    length = percentDone * pathLength;
    line.style.strokeDasharray = [length,pathLength].join(' ');
    console.log("strokeDasharray: "+[length,pathLength].join(' '));
}