Formula or API for calulating desktop icon spacing on Windows XP.

Question

I've built a simple application that applies grid-lines to an image or just simple colors for use as desktop wallpaper. The idea is that the desktop icons can be arranged within the grid. The problem is that depending on more things than I understand the actual spacing in pixels seems to be different from system to system. I've learned that at least these things play a factor:

• Resolution (duh)
• Taskbar size and placement
• Fonts

There has to be more than this. Maybe there's some api call that I don't know about?

Answer 1

They might also be a size problem due to scaling algorithm if the requested size of the icon is not available.
(since an icon file is actually a collection of icons, as explained in this thread about Icons and cursors know where they came from, from the The Old New Thing)