Method getStepColors

src/common/overlay/levelRenderer/Color.js:339–370

* @function LevelRenderer.Tool.Color.prototype.getStepColors * @description 获取两种颜色之间渐变颜色数组。 * @param {Object} start - 起始颜色对象。 * @param {Object} end - 结束颜色对象。 * @param {number} step - 渐变级数。 * @returns {Array} 颜色数组。

(start, end, step)

     * @returns {Array} 颜色数组。
     */
    getStepColors(start, end, step) {
        start = this.toRGBA(start);
        end = this.toRGBA(end);
        start = this.getData(start);
        end = this.getData(end);

        var colors = [];
        var stepR = (end[0] - start[0]) / step;
        var stepG = (end[1] - start[1]) / step;
        var stepB = (end[2] - start[2]) / step;
        var stepA = (end[3] - start[3]) / step;
        // 生成颜色集合
        // fix by linfeng 颜色堆积
        for (var i = 0, r = start[0], g = start[1], b = start[2], a = start[3]; i < step; i++) {
            colors[i] = this.toColor([
                this.adjust(Math.floor(r), [0, 255]),
                this.adjust(Math.floor(g), [0, 255]),
                this.adjust(Math.floor(b), [0, 255]),
                a.toFixed(4) - 0
            ], 'rgba');
            r += stepR;
            g += stepG;
            b += stepB;
            a += stepA;
        }
        r = end[0];
        g = end[1];
        b = end[2];
        a = end[3];
        colors[i] = this.toColor([r, g, b, a], 'rgba');
        return colors;
    }

    /**
     * @function LevelRenderer.Tool.Color.prototype.getGradientColors