Pressure pen preview doesn’t match final stroke at light pressure

[sametakofficial]

Description:

When I use the pressure-sensitive pen and write very lightly, the line I see while writing doesn’t match how it looks afterwards.

While I’m writing with almost no pressure, the line on the screen looks thicker.

After I change the tool or tap somewhere else and the stroke is rendered again, the same line becomes thinner.

So the live preview and the final result are not the same at low pressure.
If the final stroke is very thin (because I’m writing lightly), I’d expect the live preview while writing to also look that thin.

Right now this feels inconsistent and makes it hard to know how my handwriting will actually look when I write with light pressure.

[Ethran]

Does turning "use onyxTools" in settings fix it?

[sametakofficial]

Yes – turning on "Use Onyx NeoTools" in the settings completely fixes the problem for me. With NeoTools enabled, the live stroke while writing matches the final result, even at very light pressure, and I also get more pen types (like in the Notes app).

So the issue seems to be only in the default Onyx pen path (when NeoTools is off). Because you might drop NeoTools support in the future, I think it makes sense to keep this issue open to solve the pressure-sensitive pen behavior with onyx sdk pen.

I’d also like to contribute if I can. The things I personally care most about are:

• More pen / custom brush options (far more options than Onyx Notes)
• OCR (automatic OCR for all pages, with full-text search across all notes)
• Less full screen refreshes and more partial refresh for better battery usage (for note air 3c there is just regal and fast mode)

Before I start hacking on anything, I’d really like to understand your vision for the project a bit better – especially the long-term plan for the editor architecture, pen/brush system, and how much you want to rely on the Onyx SDK vs. custom code.

If you already have any notes, issues, or documents where you’ve written down your ideas or priorities (even rough ones), I’d be happy if you could point me there. That way I can try to align with your plans and help in places that actually move the project in the direction you want.

[Ethran]

option "Use Onyx NeoTools" make app use the function provided by onyx library. I don't trust them, they caused crashes for me, so I tried to implement them by myself. It work till onyx did release v4.1 when they changed how pens work.

There are two stages of drawing:

1. drawing on screen, with pen, using system functions
2. drawing on canvas already drawn strokes, then the app is handling it.

The less dependence on the onyx library, the better. Onyx does not give good suport for it, see:
onyx-intl/OnyxAndroidDemo#133
onyx-intl/OnyxAndroidDemo#132
Also, their "documentation" isn't that good, I have to guess what refresh modes are doing.

If you want to contribute more strokes styles, it wil require de-compiling system libraries and trying to reverse engineer how the device work. It will be hard. See: timschneeb/OnyxTweaks#11

OCR (automatic OCR for all pages, with full-text search across all notes)

First propose what tool would you like to use for it. I would want to see local recognition, without sending data to external services. I didn't found anything good enough yet. See #44
The recognition I think should be made with stroke data (points/curves parameters), not image data.

Less full screen refreshes and more partial refresh for better battery usage (for note air 3c there is just regal and fast mode)

Again, the library does not provide good tool for partial updates. I really don't see point in calling their function for partial update: it does not work in scribble mode, when changing refresh mode of screen to normal, after animation, autoEInkAnimationOnScroll(...) it will do a full refresh, you can try to force it to update only effected area, but I don't know how.

https://github.com/Ethran/notable/blob/main/app/src/main/java/com/ethran/notable/editor/utils/einkHelper.kt

Before I start hacking on anything, I’d really like to understand your vision for the project a bit better – especially the long-term plan for the editor architecture, pen/brush system, and how much you want to rely on the Onyx SDK vs. custom code.

• The lest dependence on onyx sdk the better.
• If you have more experience with android, I think of changing gesture recognition system. But before I do it, I will want an opinion from experience dev.
• If you like UI work, then the editor UI needs some work: Redesign Editor UI #151 , mostly so that it can be customized.
• It would be also nice to have better pdf support.

If you already have any notes, issues, or documents where you’ve written down your ideas or priorities (even rough ones), I’d be happy if you could point me there. That way I can try to align with your plans and help in places that actually move the project in the direction you want.

https://github.com/Ethran/notable/tree/main/docs

and (not finished):

#157

All of them are written by AI, the one on main ware checked if they are roughly correct.