Method getVisualMeta

src/component/visualMap/PiecewiseModel.ts:353–411

(
        getColorVisual: (value: number, valueState: VisualState) => string
    )

    }

    getVisualMeta(
        getColorVisual: (value: number, valueState: VisualState) => string
    ): VisualMeta {
        // Do not support category. (category axis is ordinal, numerical)
        if (this.isCategory()) {
            return;
        }

        const stops: VisualMeta['stops'] = [];
        const outerColors: VisualMeta['outerColors'] = ['', ''];
        const visualMapModel = this;

        function setStop(interval: [number, number], valueState?: VisualState) {
            const representValue = visualMapModel.getRepresentValue({
                interval: interval
            }) as number;// Not category
            if (!valueState) {
                valueState = visualMapModel.getValueState(representValue);
            }
            const color = getColorVisual(representValue, valueState);
            if (interval[0] === -Infinity) {
                outerColors[0] = color;
            }
            else if (interval[1] === Infinity) {
                outerColors[1] = color;
            }
            else {
                stops.push(
                    {value: interval[0], color: color},
                    {value: interval[1], color: color}
                );
            }
        }

        // Suplement
        const pieceList = this._pieceList.slice();
        if (!pieceList.length) {
            pieceList.push({interval: [-Infinity, Infinity]});
        }
        else {
            let edge = pieceList[0].interval[0];
            edge !== -Infinity && pieceList.unshift({interval: [-Infinity, edge]});
            edge = pieceList[pieceList.length - 1].interval[1];
            edge !== Infinity && pieceList.push({interval: [edge, Infinity]});
        }

        let curr = -Infinity;
        zrUtil.each(pieceList, function (piece) {
            const interval = piece.interval;
            if (interval) {
                // Fulfill gap.
                interval[0] > curr && setStop([curr, interval[0]], 'outOfRange');
                setStop(interval.slice() as [number, number]);
                curr = interval[1];
            }
        }, this);

        return {stops: stops, outerColors: outerColors};