NickelDissolve: a mod that give you Kindle-style animated page turns

[MrSilverstrike]

Hello everyone,

I wanted to share another mod that I've been working on and just finalized. I tried out a Kindle for a bit and I found that I really liked the "page animations" as it's a really nice touch that also makes it unambiguously clear which page turn you just did (forward or back?) by just looking at the page turn direction.

I missed it on my Kobo, so I did a deep dive on how screen refreshes and such work, and was able to get animated page turns working on the latest models, meaning: Kobo Libra Colour, Kobo Clara Colour, Kobo Clara BW on the 4.x firmware.

Turns out the animation on Kindle is nothing more than a fancy staggered "sweep" of the screen, a special kind of screen refresh. While it's likely it's baked into the hardware, I was able to replicate it on Kobo in software and I think it turned out pretty nice!

Unlike my other mods, this one actually also gets a toggle in the built-in settings menu. So if you go to Reading settings you can find an easy toggle to turn the animations on or off. Uninstalling is also super easy.

You can find the mod here: https://github.com/nicoverbruggen/NickelDissolve

Note: If you have an older device, your device revision may be supported if you have a Libra 2 or Clara 2E, but some older board revisions unfortunately don't work and use a lower quality screen refresh, which results in aliased/unclear text. I really tried to get more devices supported, but unfortunately it's a little hit and miss.

I hope you all find it cool, and enjoy!

[JSWolf]

Would you be able to show us a video of the page turn animation? Thanks.

[MrSilverstrike]

@JSWolf: Absolutely, I made a video earlier when I got the prototype working, you can see it here where I compare it to a family member's Kindle: https://www.youtube.com/watch?v=Rdy5Xh7YX3g

Since then, the animation has been made just a little bit smoother in the release version.

Also worth nothing: due to the way screen refreshes work, the expected impact on battery life and such is probably negligible (<1%), the frontlight for example uses much more power than the screen itself does.

[JSWolf]

That page turn looks good.

Does this work for ePub and KePub or is it one or the other? Do I need the latest firmware on a Libra 2 to use it?

[MrSilverstrike]

Both should work! I only happen to have kepub files on my test devices so I haven't actually tested it yet.

But if it doesn't work on epubs for some reason (if some other sort of page turn mechanism is used there due to RMSDK), I will fix it so it does work there, too.

[Apollyon202]

I've tried this out.
It looks like it's working flawlessly on my Libra 2 revision "F".
Thanks

Edit: I have to add, I really like it, despite being the kind of person whose first thing to do with a device that has a GUI is to turn off all the animations in the dev options. Anyway, cool stuff!

[rantanplan]

Wow, this is incredible. First I thought it would be distracting but this is great!

[Sirtel]

I'm guessing it doesn't work with a full refresh, only with a partial one?

[MrSilverstrike]

Originally Posted by Sirtel

I'm guessing it doesn't work with a full refresh, only with a partial one?

That's correct. Effectively, the partial refresh that Kobo uses for page transitions is chopped into 10 or 12 delayed transitions, which makes it look like it's animating, when it's really different parts of the screen refreshing sequentially (instead of all at once).

Regular refreshes and colour refreshes are unaffected.

[Apollyon202]

Originally Posted by Apollyon202

I've tried this out.
It looks like it's working flawlessly on my Libra 2 revision "F".

I've found an interesting issue.
Tl;dr: Dark mode makes it unusable.

If I turn Dark mode on, the animated page turning goes really slow, it takes around 6 seconds to turn a page.
It also has a high chance of freezing the screen during the page turning, but not the device. So I just do a screen refresh and it's fine, but there's also a random chance of it rebooting.
Turning Dark Mode off makes it work fine again.

Turning on Inverted mode with Dark mode disabled makes it possible to turn black background pages in animated mode flawlessly. Turning on Dark mode while Inverted mode is still enabled makes the pages white, but page turning becomes really slow, same as when I enable Dark mode in Normal mode. (Normal mode as in Inverted mode is off.)

Also, switching Dark mode on while Inverted mode is enabled and then turning a page or pages freezes the screen as well. If I do the same with page animation turned off, no issue happens.

[MrSilverstrike]

Originally Posted by Apollyon202

I've found an interesting issue.
Tl;dr: Dark mode makes it unusable.

Yes, this is due to the nature of how the screen works. If the screen is mostly black then a full flash is required per page turn and the mod can’t do the animation correctly. How the screen behaves depends on the device. I should make it so when inverted or in dark mode, the mod turns itself off… and document this so people understand.

[Apollyon202]

Originally Posted by MrSilverstrike

Yes, this is due to the nature of how the screen works. If the screen is mostly black then a full flash is required per page turn and the mod can’t do the animation correctly. How the screen behaves depends on the device. I should make it so when inverted or in dark mode, the mod turns itself off… and document this so people understand.

But inverted mode is fine, that's what I'm saying... Only the Dark mode which gives issues both in Normal and in Inverted mode.

[MrSilverstrike]

Originally Posted by Apollyon202

But inverted mode is fine, that's what I'm saying... Only the Dark mode which gives issues both in Normal and in Inverted mode.

Ah, I misread that. But is the screen OK after a couple page refreshes? I suspect it’s an anti-ghosting feature added to dark mode that doesn’t fire when inverted. Normally, dark mode without full refreshes periodically results in terrible ghosting…

EDIT: I've done some debugging. You can find v0.7 on GitHub, and it fixes the issue with dark mode; it should work on Kaleido (Colour) and Carta (BW) devices now without heavy ghosting on Colour devices. Thanks for letting me know, Apollyon202!

[Apollyon202]

Originally Posted by MrSilverstrike

Ah, I misread that. But is the screen OK after a couple page refreshes? I suspect it’s an anti-ghosting feature added to dark mode that doesn’t fire when inverted. Normally, dark mode without full refreshes periodically results in terrible ghosting…

EDIT: I've done some debugging. You can find v0.7 on GitHub, and it fixes the issue with dark mode; it should work on Kaleido (Colour) and Carta (BW) devices now without heavy ghosting on Colour devices. Thanks for letting me know, Apollyon202!

Thanks for checking it, although it doesn't solve the problem on my Libra 2.
Dark mode is still buggy, but it works fine in Inverted mode. Something is really up with Dark mode, because in Inverted mode + Dark mode (where the opened book becomes dark text on white background) it freezes with the animation in some books.

BTW in Inverted mode there's a bit more ghosting by default compared to a normally functioning Dark mode, but it's not that bad. Libra 2 has a Carta 1200 screen, and it handles the ghosting better than my Clara HD.

Speaking of which, I tried out the latter as well. I can confirm that the page turn animation works with Clara HD. This is the model from 2018. I know someone who also has this type of reader and it works for them as well.

One thing though, (surprise) Dark mode doesn't work with page turn animation. Not as buggy as on my Libra 2, it won't freeze, and it turns the pages without animation but with a bit more latency, like half a second. The point is, it's very good without Dark mode. The same goes for Inverted mode, it turns the pages wonderfully on a black background with white text without issue (except for the known extra ghosting effect that comes with Inverted mode by default). Anyway, I think I've covered everything I could. I hope it helped and thanks again.

[MrSilverstrike]

@Apollyon202: Yes, so, older devices lack the hardware to do the proper low-ghosting dark mode refreshes in software, which is why I marked only the latest devices as "officially" supported.

That being said, the regular light mode seems to work well on some of the older devices as you have noticed. Although... not all board revisions work properly. All Libra 2's have that Carta 1200 screen, but the actual board hardware and the supported capabilities vary by revision. There's been like six or more revisions, last I dug into the various firmware variants.

I had an early tester report their Libra 2 had issues with aliased text, which is a signal that their Libra 2 was falling back to a worse, low quality refresh mode.

Dark mode on older devices is generally also a miss. As you have noticed The newer devices (Libra Colour, Clara Colour, Clara BW) work pretty well, in both light and dark mode. I have all of those and I was able to test extensively.

I did make some changes in v0.7 to make dark mode page turns work well with very little ghosting. You basically have to tell the panel: "this is a dark mode refresh, optimize for it", and it compensates for ghosting. If you don't do that, the display controller optimizes for less ghosting in light mode by default.

But you only benefit from that "dark mode refresh" if you have one of these latest devices, as older devices lack the hardware capabilities.

Also a fun fact: the toggling of inverted mode is actually a hardware-driven flag (you tell the panel to invert or not) and the "dark mode" you enable in settings is actually a software thing.

So if you combine both, you get strange results because you're not supposed to "drive" the screen with both at the same time.