Method colorize

src/openlayers/overlay/HeatMap.js:260–269

* @function HeatMap.prototype.colorize * @description 根据渐变色重置热点图 rgb 值。 * @param {Object} pixels - 像素 rgba 值。 * @param {Array} gradient - 渐变 canvas.getImageData.data。 * @private

(pixels, gradient)

     * @private
     */
    colorize(pixels, gradient) {
        for (var i = 0, j; i < pixels.length; i += 4) {
            j = pixels[i + 3] * 4;
            if (j) {
                pixels[i] = gradient[j];
                pixels[i + 1] = gradient[j + 1];
                pixels[i + 2] = gradient[j + 2];
            }
        }
    }

    /**
     * @function HeatMap.drawCircle