[REQUEST] Invert pages toggle

[Reinachan]

Description Add a toggle to invert any non-colour pages to make it easier on the eyes when reading in the dark.

How would it improve the App? More options for easier reading in dark environments or in general for people who struggle with light sensitivity. The current method of darkening the white (with an overlay) reduces the contrast which makes text much harder to read. Inverting the pages retains the contrast but will in most cases make the manga darker and also easier on the eye.

I suggest this more as an accessibility function than anything else as I understand most people will not want to "hamper with the artistic vision". For some of us, however, it's difficult to read that way and it ruins our enjoyment, so a filter like this is preferable. It would also benefit anyone who just prefers reading this way.

Additional context As Paper mentioned on the Discord, this requires more power usage, so this might need a warning when toggling on for the first time and should probably not be enabled by default, even when dark mode is enabled.

While I suggest that it doesn't invert pages with colours (which would require an additional check for colours in the image, or a more complex filter), even a simple implementation that inverts everything is better than nothing. Not all manga will look good with a filter like this on, so it should have a toggle in the reader options to easily turn on/off.

When adding this, you could also additionally consider implementing the same but for a sepia look.

Resource on how to implement And a more direct source from Apple Same as above but for a Sepia effect

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[ConradWeiser]

Doesn't iOS naturally have an invert-colors feature? I could have sworn in the accessibility settings, there's a toggle to do what you're suggesting. I remember many years back, triple-tapping the home button did this.

[Reinachan]

I somehow forgot the whole paragraph on why it's much better to do this in-app than system-wide!

Either way, the issue with system-wide is that it also inverts literally everything else. That means it will invert the UI and night shift/true tone making the whole screen quite blue and weird. It will also invert every other app which means you get blinded when going to other apps that you have set to dark-mode because inverting everything isn't really a great way to do things.

Inverting the images themselves will mean you don't have to constantly go back and forth turning system-wide inversion on and off. It also means you could technically combine it with other filters like sepia if you wanted. Having it system-wide is not really a solution, moreso a hack method.

[ConradWeiser]

You've made a reasonable point. We'll have to see what @FaizanDurrani thinks about this.