Function labelLayout

docs/app/js/sanddance-app.js:139064–139097

(texts, size, compare, offset, anchor, avoidMarks, avoidBaseMark, lineAnchor, markIndex, padding, method)

    "floodfill": placeAreaLabelFloodFill
};
function labelLayout(texts, size, compare, offset, anchor, avoidMarks, avoidBaseMark, lineAnchor, markIndex, padding, method) {
    // early exit for empty data
    if (!texts.length) return texts;
    const positions = Math.max(offset.length, anchor.length), offsets = getOffsets(offset, positions), anchors = getAnchors(anchor, positions), marktype = markType(texts[0].datum), grouptype = marktype === "group" && texts[0].datum.items[markIndex].marktype, isGroupArea = grouptype === "area", boundary = markBoundary(marktype, grouptype, lineAnchor, markIndex), $ = scaler(size[0], size[1], padding), isNaiveGroupArea = isGroupArea && method === "naive"; // prepare text mark data for placing
    const data = texts.map((d)=>({
            datum: d,
            opacity: 0,
            x: undefined,
            y: undefined,
            align: undefined,
            baseline: undefined,
            boundary: boundary(d)
        }));
    let bitmaps;
    if (!isNaiveGroupArea) {
        // sort labels in priority order, if comparator is provided
        if (compare) data.sort((a, b)=>compare(a.datum, b.datum));
         // flag indicating if label can be placed inside its base mark
        let labelInside = false;
        for(let i8 = 0; i8 < anchors.length && !labelInside; ++i8)// label inside if anchor is at center
        // label inside if offset to be inside the mark bound
        labelInside = anchors[i8] === 0x5 || offsets[i8] < 0;
         // extract data information from base mark when base mark is to be avoided
        // base mark is implicitly avoided if it is a group area
        if (marktype && (avoidBaseMark || isGroupArea)) avoidMarks = [
            texts.map((d)=>d.datum)
        ].concat(avoidMarks);
         // generate bitmaps for layout calculation
        bitmaps = avoidMarks.length ? markBitmaps($, avoidMarks, labelInside, isGroupArea) : baseBitmaps($, avoidBaseMark && data);
    } // generate label placement function
    const place = isGroupArea ? placeAreaLabel[method]($, bitmaps, avoidBaseMark, markIndex) : placeMarkLabel($, bitmaps, anchors, offsets); // place all labels
    data.forEach((d)=>d.opacity = +place(d));
    return data;
}
function getOffsets(_, count) {
    const offsets = new Float64Array(count), n = _.length;
    for(let i10 = 0; i10 < n; ++i10)offsets[i10] = _[i10] || 0;