Function zoomNonClipped

src/plots/geo/zoom.js:111–197

(geo, projection)

// zoom for non-clipped projections
function zoomNonClipped(geo, projection) {
    var zoom = initZoom(geo, projection);

    var INSIDETOLORANCEPXS = 2;

    var mouse0, rotate0, translate0, lastRotate, zoomPoint,
        mouse1, rotate1, point1, didZoom;

    function position(x) { return projection.invert(x); }

    function outside(x) {
        var pos = position(x);
        if(!pos) return true;

        var pt = projection(pos);
        return (
            Math.abs(pt[0] - x[0]) > INSIDETOLORANCEPXS ||
            Math.abs(pt[1] - x[1]) > INSIDETOLORANCEPXS
        );
    }

    function handleZoomstart() {
        d3.select(this).style(zoomstartStyle);

        mouse0 = d3.mouse(this);
        rotate0 = projection.rotate();
        translate0 = projection.translate();
        lastRotate = rotate0;
        zoomPoint = position(mouse0);
    }

    function handleZoom() {
        mouse1 = d3.mouse(this);

        if(outside(mouse0)) {
            zoom.scale(projection.scale());
            zoom.translate(projection.translate());
            return;
        }

        projection.scale(d3.event.scale);
        projection.translate([translate0[0], d3.event.translate[1]]);

        if(!zoomPoint) {
            mouse0 = mouse1;
            zoomPoint = position(mouse0);
        } else if(position(mouse1)) {
            point1 = position(mouse1);
            rotate1 = [lastRotate[0] + (point1[0] - zoomPoint[0]), rotate0[1], rotate0[2]];
            projection.rotate(rotate1);
            lastRotate = rotate1;
        }

        didZoom = true;
        geo.render(true);

        var rotate = projection.rotate();
        var center = projection.invert(geo.midPt);