Instructions for patching firmware 4.30.18838

[geek1011]

I was in a rush last night, so the main thing I tested before merging was that the EPUB font size was at least as good as it was before the 18220 DPI change and that it looked similar to my KEPUB font size. I didn't bother checking font settings other the the minimum, maximum, and my usual, and I didn't go through all of my test books.

[Semwize]

Originally Posted by sherman

Feel free to play with the scale factor and multiplier if you like. For example instead of 1.0 and 6.5, you could try 2.0 and 12.5 for a similar result.

I tried option:

Spoiler:

      FindH:    F3 EE 09 0A # vmov.f32 s1, #25.0
      ReplaceH: F0 EE 00 0A # vmov.f32 s1, #2.0
  # Replace QScreen::logicalDotsPerInchX() with our own multiplier
  - ReplaceBytes:
      Offset:      26
      FindInstBLX: {SymPLT: "QScreen::logicalDotsPerInchX() const"}
      ReplaceH:    B2 EE 09 0B # vmov.f64 d0, #12.5

And all the same I get a different number of lines in epub and kepub. Most likely, it's about other patches me used...

[sherman]

Yeah, I didn't quite get it exact, I was getting very tired of rebooting my Kobo after making every change.

Also, the limited range of values available makes it difficult to get an exact match, so "close enough" will probably have to do.

[Semwize]

In any case, this is much better than the values we get without this patch.

[sherman]

Originally Posted by Semwize

In any case, this is much better than the values we get without this patch.

But I might be able to do even better.

I busted out the spreadsheet, and I noticed that the results obtained from

( font_size / 1.0 ) * 6.5

were actually very close to the results from the following formula

( font_size / 15.0 ) * 96

Which made me think, that might be the actual kepub formula, since the kepub scale_factor is 15.0, and 96 would make sense as a 'default' dpi.

So, I found the equivalent formula that can be achieved using the patch

( font_size / 2.5 ) * 16.0

Here's the patch with the updated numbers:

Unify font sizes:
  - Enabled: no
  - Description: |
      Attempt to unify the font sizes between epub and kepub. Without this patch
      epub font sizes can be much larger than kepub at the same size setting.
    # From my current understanding, the final font size for epubs is calculated
    # as follows: ( font_size / scale_factor ) * DPI, where 'scale_factor' =
    # 25.0. It seems RMSDK must be handling DPI elsewhere however, because the
    # DPI multiplication here seems to have a detrimental effect, and behaves
    # differently on different devices. This patch changes the 'scale_factor' to
    # 2.5, and replaces the call to get DPI with a constant multiplier (16).
    # The results of using these values are equivalent to ( font_size / 15.0 ) * 96 
    # which is what I suspect the kepub equation ends up being.
    # Note, that the replacement values are limited to 0.25 - 31.0 in 0.25
    # increments.
    #
    # Refer to https://github.com/pgaskin/kobopatch-patches/issues/96 for more
    # information.
  # EPUB settings:
  - BaseAddress:
      Sym: "AdobeStyling::update(QString const&)"
      Rel: 5800 # at ReadingSettings::getReadingFontSizeScaleFactor(float, float)
  # Set the scale factor to 2.5
  - ReplaceBytes:
      Offset:   -20
      FindH:    F3 EE 09 0A # vmov.f32 s1, #25.0
      ReplaceH: F0 EE 04 0A # vmov.f32 s1, #2.5
  # Replace QScreen::logicalDotsPerInchX() with our own multiplier
  - ReplaceBytes:
      Offset:      26
      FindInstBLX: {SymPLT: "QScreen::logicalDotsPerInchX() const"}
      ReplaceH:    B3 EE 00 0B # vmov.f64 d0, #16.0

Eyeballing it, it seems very very close on my Glo.

[Semwize]

@sherman

Excellent.
I have no problems with this multiplier.

[sherman]

Originally Posted by Semwize

@sherman

Excellent.
I have no problems with this multiplier.

Yay! That's two devices now...

Unfortunately, I can't (easily) use 15 and 96, but the numbers I've used are the next best thing, and they seem to match up, so it doesn't really matter does it?

[jackie_w]

@sherman,

Your post #20 patch works fine for me on KA1, Forma, ClaraHD, H2Ov1.

Thanks very much for all the time you spent on this.

[DNSB]

@sherman Add a Sage to the list of devices where your Unify Font Sizes patch does a great job of making epub and kepub font sizes match. The results may not be perfect but close enough to save changing font size every second book.

[sherman]

Thanks for the feedback everyone. I've opened a PR to update the patch with the new values.

[marshap]

On my Libra 2 I enabled the custom header/footer captions patch and entered "29px" as follows:
# Part 2. Change font-size
# #caption
# AuraHD/AuraH2O/AuraH202/ClaraHD/Elipsa/Libra2
- Find: "[qApp_deviceIsDragon=true] {\n font-size: 25px;\n}"
Replace: "[qApp_deviceIsDragon=true] {\n font-size: 29px;\n}"

But the header/footer fonts do not change size in epubs.

[the_Pan]

Originally Posted by Anghirrim

Hi, thanks for the super fast update!

Unfortunately, InvertScreen still does not work.

I updated my Kobo Forma to 4.30, then downloaded and updated my favorite patches, applied the KoboRoot.gz file and rebooted.

All of the applied patches are working just fine, except from the InvertScreen.

Same as on 4.28, in flashes once, then get back to white background, black text (even after reboot as suggested in the .yalm file, reload of the reader app, etc...).

Any idea, replacing InvertScreen by DarkMode? For now, back to 4.26.16704.

Thanks,

Thank you for testing!
I also still read on the forma and hope for an fix of the "old" invert screen patch.
The new darkmode seems to be not that good in my opinion.

@geek1011 are there chances to get invert screen working again?

[Semwize]

Originally Posted by Anghirrim

Same as on 4.28, in flashes once, then get back to white background, black text (even after reboot as suggested in the .yalm file, reload of the reader app, etc...).

uh... And when enabled in the developer options, everything works (after a reboot).

[geek1011]

Originally Posted by the_Pan

Thank you for testing!
I also still read on the forma and hope for an fix of the "old" invert screen patch.
The new darkmode seems to be not that good in my opinion.

@geek1011 are there chances to get invert screen working again?

Yes, and it'll probably come in the form of a NickelHook mod and/or a NickelMenu update. I just haven't had enough time to work on it yet.

[the_Pan]

Originally Posted by geek1011

Yes, and it'll probably come in the form of a NickelHook mod and/or a NickelMenu update. I just haven't had enough time to work on it yet.

That's great to hear, thank you!
And take your time, the real life comes first of course.