[Qt-interest] How do I know my antialiazing hints are being respected or not

[Frank Mertens]

There is a catch with subpixel-AA. First, Qt follows system
settings. For me that works on OS X and Gnome. But it renders
with graylevel-AA on transparent surfaces. (Alpha composition
would be expensive, if it would need to support subpixels.)

Simply use a non-pure color (grayish, e.g.) and zoom onto the text.
The "subpixels" are clearly visible as color sparkles around the edges.
If it's all gray, then no subpixel-AA is performed.