I'm writing a desktop entry file for a program that doesn't come with one. The icon the program has on Windows is a circle, but the one I found on the web has an annoying white square background. I'm trying to make a circle icon, but to do so I need a transparent background. I've tried using the .gif and .png file types, but they don't show up in the dock or Slingshot. Is there a filetype that will keep the transparent background but still show up in the dock/Slingshot?