Drop shadows for non-rectangular windows: CS_DROPSHADOW and SetWindowRgn.
Windows has the ability to add a drop-shadow to windows – you see it on menus and tooltips, and you can easily apply it to your own windows via the CS_DROPSHADOW class style.
It also supports non-rectangular windows, via the Windows API SetWindowRgn.
Today I was pleasantly surprised to see that you can combine these two features and produce irregular windows with drop shadows, like this:
It’s not every day that Windows gives me a pleasant surprise, but today was one of those days. π
(I’m coding with MFC – if you’re wondering how to apply CS_DROPSHADOW to your MFC dialog, the answer is here: CodeGuru Forums: How to change the windows class name.)