Method _makeColorGradient

src/component/visualMap/ContinuousView.ts:531–567

(
        dataInterval: number[],
        opts: {
            forceState?: ContinuousModel['stateList'][number]
            convertOpacityToAlpha?: boolean
        }
    )

    }

    private _makeColorGradient(
        dataInterval: number[],
        opts: {
            forceState?: ContinuousModel['stateList'][number]
            convertOpacityToAlpha?: boolean
        }
    ) {
        // Considering colorHue, which is not linear, so we have to sample
        // to calculate gradient color stops, but not only calculate head
        // and tail.
        const sampleNumber = 100; // Arbitrary value.
        const colorStops: LinearGradientObject['colorStops'] = [];
        const step = (dataInterval[1] - dataInterval[0]) / sampleNumber;

        colorStops.push({
            color: this.getControllerVisual(dataInterval[0], 'color', opts) as ColorString,
            offset: 0
        });

        for (let i = 1; i < sampleNumber; i++) {
            const currValue = dataInterval[0] + step * i;
            if (currValue > dataInterval[1]) {
                break;
            }
            colorStops.push({
                color: this.getControllerVisual(currValue, 'color', opts) as ColorString,
                offset: i / sampleNumber
            });
        }

        colorStops.push({
            color: this.getControllerVisual(dataInterval[1], 'color', opts) as ColorString,
            offset: 1
        });

        return colorStops;
    }

    private _createBarPoints(handleEnds: number[], symbolSizes: number[]) {
        const itemSize = this.visualMapModel.itemSize;