Can someone explain me this codes logic?

i have this piece of code and i cant figure out what it's trying to accomplish with its logic. It's just the cases "-1" and "1".

Some Context:

• This is part of a function, which resizes images for a webpage.
• We have the dimensions of the original image and desired sizes, which are given as arguments.
• It is possible that the desired size is just a width or just a height, in either way the empty value will be replaced with the original width/height.

I am trying to rewrite the code..

If it does matter, this is coldfusion and "arguments", "local" and "variables" are scopes, kind of namespaces, where variables can be stored.

---

arguments.width = isNumeric(arguments.width) ? arguments.width : variables.getOrgWidth();
arguments.height = isNumeric(arguments.height) ? arguments.height : variables.getOrgHeight();


switch (arguments.ratio) {
 case "-1":
      // What does this do?
      if ((variables.getOrgWidth() / arguments.width) LT (variables.getOrgHeight() / arguments.height)) {
           local.targetSize = "#arguments.width#"
      } else {
           local.targetSize = "x#arguments.height#"
      }
      break;

 case "0":
      // Force desired width and heigth, even if its distorts
      local.targetSize = "#arguments.width#x#arguments.height#!"
      break;

 case "1":
      // What does this do??
      if ((variables.getOrgWidth() / arguments.width) GT (variables.getOrgHeight() / arguments.height)) {
           local.targetSize = "#arguments.width#"
      } else {
           local.targetSize = "x#arguments.height#"
      }
      break;

 case "2":
      // transform dimensions based on desired width, the height will be calculated
      local.targetSize = "#arguments.width#"
      break;

 case "3":
      // transform dimensions based on desired height, the width will be calculated
      local.targetSize = "x#arguments.height#"
      break;
}