c3_chart_internal_fn.getShapeIndices = function (typeFilter) {
    var $$ = this, config = $$.config,
        indices = {}, i = 0, j, k;
    $$.filterTargetsToShow($$.data.targets.filter(typeFilter, $$)).forEach(function (d) {
        for (j = 0; j < config.data_groups.length; j++) {
            if (config.data_groups[j].indexOf(d.id) < 0) { continue; }
            for (k = 0; k < config.data_groups[j].length; k++) {
                if (config.data_groups[j][k] in indices) {
                    indices[d.id] = indices[config.data_groups[j][k]];
                    break;
                }
            }
        }
        if (isUndefined(indices[d.id])) { indices[d.id] = i++; }
    });
    indices.__max__ = i - 1;
    return indices;
};
c3_chart_internal_fn.getShapeX = function (offset, targetsNum, indices, isSub) {
    var $$ = this, scale = isSub ? $$.subX : $$.x;
    return function (d) {
        var index = d.id in indices ? indices[d.id] : 0;
        return d.x || d.x === 0 ? scale(d.x) - offset * (targetsNum / 2 - index) : 0;
    };
};
c3_chart_internal_fn.getShapeY = function (isSub) {
    var $$ = this;
    return function (d) {
        var scale = isSub ? $$.getSubYScale(d.id) : $$.getYScale(d.id);
        return scale(d.value);
    };
};
c3_chart_internal_fn.getShapeOffset = function (typeFilter, indices, isSub) {
    var $$ = this,
        targets = $$.orderTargets($$.filterTargetsToShow($$.data.targets.filter(typeFilter, $$))),
        targetIds = targets.map(function (t) { return t.id; });
    return function (d, i) {
        var scale = isSub ? $$.getSubYScale(d.id) : $$.getYScale(d.id),
            y0 = scale(0), offset = y0;
        targets.forEach(function (t) {
            if (t.id === d.id || indices[t.id] !== indices[d.id]) { return; }
            if (targetIds.indexOf(t.id) < targetIds.indexOf(d.id) && t.values[i].value * d.value >= 0) {
                offset += scale(t.values[i].value) - y0;
            }
        });
        return offset;
    };
};

c3_chart_internal_fn.getInterpolate = function (d) {
    var $$ = this;
    return $$.isSplineType(d) ? "cardinal" : $$.isStepType(d) ? "step-after" : "linear";
};
