Font scaling

["S. Brett Sutton" <bsutton noojee com au>]

So I'm new to the Gnome community, so please be a little gentle :)

I started by reporting a bug under GTK but it was suggested that this list was a better starting place.

So here is the content of my original bug request along with a useful comment from a third party.

I've been running gnome 3.18 and wayland and for the most part its stable and I'm enjoying the experience.

I was however, very disappointed to find out that gnome/wayland was still completely failing to address font scaling issues correctly.

After a fair chunk of research I found that the only options are Font and Window Scaling and HiDpi which, to be blunt, just looks like an hack on top of existing hacks.

Neither of these do the required job for reasons I will explain shortly.

What I'm suggesting is that we need to rethink scaling in gnome, the current methods are hacks and don't work in the real world. Its time we stopped wasting time and got down to solving the real problem which is true font scaling where a 10 point font is displayed as 10 / 72 of an inch regardless of the screen resolution or screen dpi with other screen elements sized relative to the selected system font size.

So here are my use cases and why the above all fail.

I have at least four workstations that I move between, taking my laptop with me as I go.

At each workstation I have a different number of monitors (between 0 and 2) that I attach to my laptop.
The smallest monitor is the laptop which is 15.6" at 1920. The biggest is a 55" running at 4K (board room).

Each time I move between workstations I have to screw around with display settings and scaling. With at a least one of the workstations (28" 4K monitor), I can't use my laptop screen, as by the time I get the scaling large enough for the 4K monitor the laptop fonts are huge.

With the exception of the board room monitor I simply want each piece of text to be display to its correct physical size (e.g. 10 points is 10/72 of an inch). If the font size was consistent across these monitors then I could comfortably read text on any monitor and I wouldn't have to screw around with scaling each time I moved desks.
With the board room monitor I need to be able to scale the board room monitor (as its viewed from a distance) but not scale my laptop monitor.

As I'm getting older I can see in the future that I will want to scale my fonts up to a larger size but this should just be a matter of me changing the system font size to say 16 points rather than actually scaling fonts.

So what do we need.

1) Gnome MUST recognize the correct DPI for each attached monitor. Gnome should allow the DPI to be modified on a per monitor basis and the Gnome community (and everyone else) should do some work into shaming any monitor manufacturer that doesn't report the correct DPI.

2) Gnome MUST display fonts at the correct physical size (10 point is 10/72 of an inch) regardless of dpi or resolution.

3) Gnome should offer Font Scaling on a per monitor basis, but the default is that it scales fonts across all monitors with scaling resulting in the same physically sized font regardless of monitor size or dpi.

4) Window Scaling should be a factor of the font scaling. [Are there scenarios where this isn't the case?]

5) Gnome should offer window scaling. Default to scaling both monitors but provide an option to scale monitors individually

6) Gnome should dump the HiDPI setting as the above should supersede any such requirement.


So my core argument is that we need to do this properly and any other work is wasting time.
The reality is that this work has to be done sooner or later. During the transition to Wayland seems the ideal time.

I do understand that my suggestions are challenging but with a concerted effort I believe its achievable. If we can get a working group together I'm happy to contribute. I was once an excellent 'C' programmer (but rusty know) but have little knowledge of the internal workings of Gnome, but I'm happy to find out.

Brett

Comment 1

Some questions to think about while solving this problem once and for all:

1. What is the correct dpi to report on a projector?

2. How do we detect the default scale factor? Using a 10pt font at 96dpi on a football stadium monitor is probably hard to read from the stands.

3. Does the dpi need to adjust itself when we move further away from/closer to the monitor? Should we detect this via webcam?

4. What dpi should curved monitors report?

5. How do we expect to integrate with web standards that assume 96dpi everywhere?