Creating an irregular shaped window

[RHoare]

I am wondering how to create an irregularly shaped window from C++.
Products exist, such as the Palm Pilot Emulator, which create a window in a non-rectangular shape, without the normal windows border, and bring up the normal task bar box with right-click access to minimise / move etc.
Does anyone know how this is done?

 

[GEAK]

Assuming that you're using MFC, try calling the CWnd::SetWindowRgn function from your main window (you can do it in OnPaint in a generic CWnd). Create a CRgn object defining the coordinates of your window, and pass that into the function (type-cast to HRGN). Only the portions of your window that appear within your region's boundaries will be drawn on screen.