等比例縮放尺寸怎么算？

等比列計算公式:

百分比縮放

const imgPect = (picture_width, picture_height, default_width, default_height) => {

var widthRatio = default_width / picture_width

var heightRatio = default_height / picture_height

var ratio

widthRatio < heightRatio ? ratio = widthRatio : ratio = heightRatio

var currentImg = { picture_width: parseInt(picture_width * ratio), picture_height: parseInt(picture_height * ratio)}

return currentImg