Function makeUpdateTextInterpolator

src/traces/sunburst/plot.js:409–498

(pt)

    }

    function makeUpdateTextInterpolator(pt) {
        var prev0 = prevLookup[helpers.getPtId(pt)];
        var prev;
        var transform = pt.transform;

        if (prev0) {
            prev = prev0;
        } else {
            prev = {
                rpx1: pt.rpx1,
                transform: {
                    textPosAngle: transform.textPosAngle,
                    scale: 0,
                    rotate: transform.rotate,
                    rCenter: transform.rCenter,
                    x: transform.x,
                    y: transform.y
                }
            };

            // for new pts:
            if (prevEntry) {
                // if trace was visible before
                if (pt.parent) {
                    if (nextX1ofPrevEntry) {
                        // if new branch, twist it in clockwise or
                        // counterclockwise which ever is shorter to
                        // its final angle
                        var a = pt.x1 > nextX1ofPrevEntry ? 2 * Math.PI : 0;
                        prev.x0 = prev.x1 = a;
                    } else {
                        // if leaf
                        Lib.extendFlat(prev, interpX0X1FromParent(pt));
                    }
                } else {
                    // if new root-node
                    prev.x0 = prev.x1 = baseX;
                }
            } else {
                // on new traces
                prev.x0 = prev.x1 = baseX;
            }
        }

        var textPosAngleFn = interpolate(prev.transform.textPosAngle, pt.transform.textPosAngle);
        var rpx1Fn = interpolate(prev.rpx1, pt.rpx1);
        var x0Fn = interpolate(prev.x0, pt.x0);
        var x1Fn = interpolate(prev.x1, pt.x1);
        var scaleFn = interpolate(prev.transform.scale, transform.scale);
        var rotateFn = interpolate(prev.transform.rotate, transform.rotate);

        // smooth out start/end from entry, to try to keep text inside sector
        // while keeping transition smooth
        var pow = transform.rCenter === 0 ? 3 : prev.transform.rCenter === 0 ? 1 / 3 : 1;
        var _rCenterFn = interpolate(prev.transform.rCenter, transform.rCenter);
        var rCenterFn = function (t) {
            return _rCenterFn(Math.pow(t, pow));
        };