Notepad3: Font scaling on High-DPI displays

[craigo-]

Notepad3 (64-bit) TinyExpr v4.18.816.1059

Please refer previous issues: #563 (Toolbar icons and DPI scaling), #451 (Status Bar: overhaul) (particularly comment).

I've finally laid hands on a laptop with a high(ish)-DPI display (1920 x 1080, 14", approximately 157 dpi). The Windows-recommended scaling factor for this display is 150%. When using this display, the text in Notepad3 looks like this:

i.e. the same font in Notepad3 is larger than in Word 2016. (I'll hazard a guess and say it's 50% larger :smile:)

When using an external display (1920 x 1080, 24" approximately 92dpi) and the Windows-recommended scaling factor of 100%, Notepad3 looks like this:

i.e. the same font in Notepad3 renders the same size as in Word 2016.

The font in both cases is Cousine Regular 10. The same phenomenon occurs with Notepad3's default font, Consolas Regular 10.

(I will test older versions of Notepad3 and see if any of them avoid this issue; will report back.)

Additionally, in both cases I am using fixed widths for the following Notepad3 status bar elements:

• Line Endings (-44)
• INS / OVR (-32)
• STD / 2ND (-32)

When scaled at 100% on the external display (the bottom image), these elements render how I want them: just large enough to accommodate the element's longest possible string.

When scaled at 150% on the built-in display (the top image), these elements render larger and no longer fit their allocated horizontal space.

I'm wondering if there is some way to make fixed-width status bar elements OS-scaling-aware. Is it as simple as scaling the status bar value by the Windows scaling factor, as I alluded to in my comment?

[RaiKoHoff]

🤔 - I have to dig deeper into that DPI scaling thing ... 🤔

[zufuliu]

@craigo- Is https://github.com/zufuliu/notepad2/ has same problem? You can download from https://github.com/zufuliu/notepad2/releases or build from latest master code.

Those DPI scaling thing is written on a monitor with 100%, 125%, 150% and 175% scaling. Screenshot with 150%, looks not that bad.

[craigo-]

1920 x 1080, 14", 157ppi, 150% scaling; from left to right:

• Word 2016
• Wordpad
• Notepad3 (64-bit) TinyExpr v4.18.816.1059
• Zufuliu Notepad2 (64-bit) 4.2.25 r1172 (8d804e5)

Wordpad included in case the problem was with Word.

Looks like the Notepads are the same, both larger than rendered in Word and Wordpad.

Zufuliu Notepad2 using out-of-box settings except Default Font (Cousine Regular 10). The same can be seen when using Consolas Regular 10 in all applications.

[zufuliu]

@craigo- Thank you, seems font in Notepad2 is even bigger.

[zufuliu]

@craigo- Can you build the source code (either Notepad3 or Notepad2)?

What value for dpi for following code (in Helpers.c UINT GetCurrentDPI(HWND hwnd)):

    /*if (dpi == 0)*/ {
        // FIXME: seems always get 96
        HDC hDC = GetDC(hwnd);
        dpi = GetDeviceCaps(hDC, LOGPIXELSX);
        ReleaseDC(hwnd, hDC);

                // code used by SciTE
        hDC = CreateCompatibleDC(NULL);
        dpi = GetDeviceCaps(hDC, LOGPIXELSX);
        DeleteDC(hDC);
    }

[zufuliu]

@craigo- Sorry for ask you to debug the code. This bug is fixed by https://github.com/zufuliu/notepad2/commit/3b835c72df8645636806c91b029e4c6adbb85329.

It was my fail: changed the scaling but not logout/reboot and not observed the bug.

@RaiKoHoff Can you build new beta test with changes in https://github.com/zufuliu/notepad2/commit/3b835c72df8645636806c91b029e4c6adbb85329.

[RaiKoHoff]

Please test development beta _TinyExpr_4.18.820.1062.
@zufuliu : thank you for the analysis and the DPI Awareness changes you provide.

[zufuliu]

@craigo- What's the result of moving open Notepad3 (above beta _TinyExpr_4.18.820.1062) window between the built-in High DPI screen and the external normal screen.

• Moving to the High DPI screen, open the test file, moving Notepad3 to the normal screen, is the font size scale down?
• Moving to the normal screen, open the test file, moving Notepad3 to the High DPI screen, is the font size scale up?

In both case, after moving to the new screen, changing rendering technology from GDI to D2D (and vice versa) has some effects?

[craigo-]

@zufuliu - have had to blow away that computer (for reasons not related to its displays); am busy rebuilding it now. Will test when I'm next able (probably within the next 24 hours).
@RaiKoHoff - thanks, will test when I can (1062-64, or whatever build you're up to!)

[RaiKoHoff]

@zufuliu : is it OK for you to be mentioned (your GitHub reference) in Notepad3's "Acknowledgments" (About Box)?

[zufuliu]

@RaiKoHoff No problem, thank you.

[RaiKoHoff]

@craigo- : on DPI scaling tests, please check behavior of HighDPI toolbar described in #563 too 😃

[zufuliu]

@RaiKoHoff This is bug is not fixed yet.

One is the margin width bug, fixed by https://github.com/zufuliu/notepad2/commit/96811f5dd7b97bf3e239c33ad7a4498789f13f69. There are other Scintilla APIs which using pixel as unit, but I don't find their effects on changing DPI.

Another bug is Encoding and Scheme selection dialog, they only looks well on main display but not on second display.

[zufuliu]

Other dialogs have same problem: Favorites, Recent Files.

[RaiKoHoff]

@zufuliu : thank you for the hint, I will check this ...

[hpwamr]

As far as I am concerned, this issue may be closed....