Ahh so THAT's how they did that!

It depends. Windows can be set to shapes going back to like Windows 95, iirc.

But alpha, specifically, would be faked at that point. Windows 2000 supported alpha for such things in a basic way, like XP. Vista with Aero and 7 then really expanded the themes and the window compositing.

Back in the day terminals under Linux did that to fake transparency: they just copied a chunk of the root window (where you put some wallpaper) as the terminal background and applied an alpha layer if the user wanted a translucid color.

Fake transparency is still a thing, for desktops without compositor. Not only in terminals, but also in docks.

But docks work in a different way, such as XRender or just a PNG with an alpha layer. Much less expensive than copying a chunk of the backdrop and then "pasted" at your terminal background.

Often docks will be able to show you the underlying windows behind it, even without compositing. But under the terminal with fake transparency you couldn't see another window behind it, just the backdrop part.

I think X11 had some extensions to allow translucency too for software like oneko, xroach or such.

From my experience this is wrong. If you set a transparent background in wxwidgets/gtk it will show you a grey background. And gtk3 even removed the ability to query the x background pixmap. So if there is better support for this at an X level, this is not available above.

See https://github.com/onli/simdock/issues/11, and if there really are good alternative solutions I'd be happy for some help.

Ah, too bad then. So, lots of stuff got deprecated, I didn't notice that until right now.

Still, there was another tech not querying the background pixmaps, but used from old X11 software to do non-rectangular windows. Oclock, maybe.

Why is it less expensive? Sounds like the exact same operation, except the OS is doing it.

No. XRender worked in a different way than ATerm/Eterm.

Maybe some incompetent people did it that way, but 1-bit transparency was very well possible with native Windows APIs in the 90s (see SetWindowRgn). Later on (starting with Windows 2000 IIRC) it was also possible to have semi-transparent (alpha-blended) regions.

It's not stupid if it works...

Please educate yourself before you accuse people of incompetency. Of course it was about (pseudo) alpha blending because "smooth shadows" around everything became very popular in the late 90s.

In a thread about “if it’s not stupid if it works” you accuse people of doing something “incompetent” by doing something ostensibly “stupid but works” but totally miss on what was even possible “non-stupidly.” There feels like some form of irony here.

Yes, obviously there a grain of irony in the reply. ;)

I'm not convinced it works though. A screenshot would break any animations playing underneath

Not exactly. With 2000/XP you can set the entire window opacity. Still no gdi+ native. So regions were still just shapes(1bit mask). Trying to set a pre-multiplied bitmap to a window will just give you a brightened version(the multiplied version).

Though there was some support for cursor shadow at this point, and the improved GDI heap really helped, making faking a window drop shadow actually pretty feasible. Vista and Aero is the first native support for Windows with alpha channels.

I actually liked Vista. It worked just fine and wasn't unnecessarily reorganized. Plus the improvements to the OS threading model were excellent, which is why 7 is so incredibly rock solid, probably peak Windows.