压缩后的长边-不满足线性关系。

[john-gao-github]

if (scale <= 1 && scale > 0.5625) {
  if (longSide < 1664) {
    return 1;
  } else if (longSide < 4990) {
    return 2;
  } else if (longSide > 4990 && longSide < 10240) {
    return 4;
  } else {
    return longSide / 1280 == 0 ? 1 : longSide / 1280;
  }
}

---

scale > 0.5625
原始长边 longSide 满足条件 压缩后长边 800 800 longSide < 1664 800 1662 1662 longSide < 1664 1662 1663 1664 longSide < 4990 832 1664 1664 longSide < 4990 832 3800 3800 longSide < 4990 1900 4980 4980 longSide < 4990 2490 4990 4990 else 1663 4992 4992 "longSide > 4990 && longSide < 10240" 1248