is it possible to remove these black rectangle corner of Interface Plugins' window?

[steve3d]

 

there are many ways to render a non-rectangle window using win32 api, is it possible to use that to render a better looking interface plugin window?

 

I played with WS_EX_LAYERED, but no luck, seems it not working...

[frustum]

With WS_EX_LAYERED we should render content into the system bitmap and call BitBlt system function inside the WM_PAINT message. Such rounded windows will work only under "Windows", so we will remove rounding corners from the GUI skin.