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opoolaka

It's a hack/trick since it exploits a hardware layout that wasn't meant to be used from the software side.

Like most hacks, it can work for some common use cases but will have a lot of edge cases :

- how to detect the user pixel layout? on web, native applications..

- what about users who switch between landscape/portrait orientations?

- does it make correct gamma rendering more complex? switch to dark mode harder?

Also, I cannot find a simple implementation, focused on subpixel-AA. So people will probably have to start from scratch..

Here is the most interesting link I found: https://www.grc.com/cttech.htm

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Yes, it's more complicated, and parts of it might need hacks, as there are no standard way to get subpixel layout. That's a failure of those display APIs though, not the failure of the concept of subpixel-AA itself.

> does it make correct gamma rendering more complex? switch to dark mode harder?

Most text rendering is gamma-incorrect anyway, AFAIK, subpixel-AA or not. It doesn't make it more complex, just work in a linear colorspace either way.

> - how to detect the user pixel layout? on web, native applications..

99% of the monitors are RGB. BGR monitors are an oddity.

My CRT would like to speak with you.

More seriously, it seems every phone screen invents it's own pixel layout and of course, can be rotated 90° at any time.

The fact that there are many different pixel layouts on phones is kinda irrelevant since they've largely all converged on retina resolutions for their viewing distance, making subpixel entirely pointless.

For this reason, to my knowledge no one has ever bothered designing pentile subpixel rendering or whatever. Like I'm sure there's a cute tech demo but no one has any reason to seriously design and ship such a thing.

Same situation with the vast majority of macs. Apple just disables subpixel at the OS level since most things are retina anyway.

It still has its practical applications when you have the kind of userbase Firefox or Chrome does, but yeah it's increasingly easy to just Not Bother.

As soon as phones, tablets, and hybrid laptops (i.e. surface, etc) enter the picture you can no longer assume RGB because users rotate the device. People now stream PC/console games on their phones, too.

Incidentally 'vertical sync is vertical' is also no longer a correct assumption. In some cases if you rotate a device now the tearing (when vsync is off) is vertical instead of horizontal, which is really disorienting if you're not used to it.

But they do exist, as do other sub-pixel layouts (pentile, RGBG, ...). If you use sub-pixel rendering assuming RGB you are going to look worse on some devices (many Samsung phones, IIRC).

Also, if you use sub-pixel tricks in static resources such as images (or your text renderer is not aware that the sub-pixels may not always be arranged horizontally) you are going to have colour halo effects when a device is rotated. Windows is doing that (optimising for horizontal RGB, when vertical RGB is the reality) right now on the screen I have rotated to portrait aspect. It isn't stark enough that I can see any colour halo at this dot pitch, in fact the effect is very subtle, but seen side-by-side text looks a little blury on that screen compared to the other screen (practically the same dot pitch, but landscape so actually is a horizontal RGB layout). Someone with better eyes (mine are somewhat shite) might find it more irritating that I do. I must get around to telling Windows to just use greyscale text trickery...

I use one monitor in portrait mode, one in landscape.

Something relatively common for devs.

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