Function addZigzagShapes

src/component/axis/axisBreakHelperImpl.ts:196–317

(
        zigzagRandomList: number[],
        breakGroup: Group,
        startCoord: number,
        endCoord: number,
        isAxisHorizontal: boolean,
        trimmedBreak: ParsedAxisBreak
    )

    removeUnusedCacheVisual(cachedVisualList);

    function addZigzagShapes(
        zigzagRandomList: number[],
        breakGroup: Group,
        startCoord: number,
        endCoord: number,
        isAxisHorizontal: boolean,
        trimmedBreak: ParsedAxisBreak
    ) {
        const polylineStyle = {
            stroke: borderColor,
            lineWidth: borderWidth,
            lineDash: borderType,
            fill: 'none'
        };

        const dimBrk = isAxisHorizontal ? 0 : 1;
        const dimZigzag = 1 - dimBrk;
        const zigzagCoordMax = coordSysRect[XY[dimZigzag]] + coordSysRect[WH[dimZigzag]];

        // Apply `subPixelOptimizeLine` for alignning with break ticks.
        function subPixelOpt(brkCoord: number): number {
            const pBrk: number[] = [];
            const dummyP: number[] = [];
            pBrk[dimBrk] = dummyP[dimBrk] = brkCoord;
            pBrk[dimZigzag] = coordSysRect[XY[dimZigzag]];
            dummyP[dimZigzag] = zigzagCoordMax;
            const dummyShape = {x1: pBrk[0], y1: pBrk[1], x2: dummyP[0], y2: dummyP[1]};
            subPixelOptimizeLine(dummyShape, dummyShape, {lineWidth: 1});
            pBrk[0] = dummyShape.x1;
            pBrk[1] = dummyShape.y1;
            return pBrk[dimBrk];
        }
        startCoord = subPixelOpt(startCoord);
        endCoord = subPixelOpt(endCoord);

        const pointsA = [];
        const pointsB = [];

        let isSwap = true;
        let current = coordSysRect[XY[dimZigzag]];
        for (let idx = 0; ; idx++) {
            // Use `isFirstPoint` `isLastPoint` to ensure the intersections between zigzag
            // and axis are precise, thus it can join its axis tick correctly.
            const isFirstPoint = current === coordSysRect[XY[dimZigzag]];
            const isLastPoint = current >= zigzagCoordMax;
            if (isLastPoint) {
                current = zigzagCoordMax;
            }

            const pA: number[] = [];
            const pB: number[] = [];
            pA[dimBrk] = startCoord;
            pB[dimBrk] = endCoord;
            if (!isFirstPoint && !isLastPoint) {
                pA[dimBrk] += isSwap ? -zigzagAmplitude : zigzagAmplitude;
                pB[dimBrk] -= !isSwap ? -zigzagAmplitude : zigzagAmplitude;
            }
            pA[dimZigzag] = current;