Bug 500908

Recently I had to purchase a new mouse, because my old cheap one was destroyed, and I tried 6 different models.

Since the new mice were more precise I quickly noticed that the acceleration is completely unpredictable.

All the mice I have tested, including the old 800 dpi one I owned, seemed to benefit from deactivating acceleration and, maybe increase pointer speed.

But here is when the big problem was exposed.

Acceleration was made default with Windows XP, because at the time optical mice were highly imprecise. Between 400 and 800 dpi.

If you set the cursor speed fast, the mouse will be too imprecise to click anywhere. If you set it slow, it would be too inconvenient to move through the screen. Hence acceleration was introduced.

But 25 years later optics are extremely precise. Yet budget mice, without adjustable dpi, assume that mouse acceleration is enabled by default on Windows, and have a dpi that provides adequate speed for that.

Hence if you disable mouse acceleration those budged mice would be too slow to be comfortable. But if you keep it enabled, or artificially increase cursor speed through software, quality mice with adjustable dpi will lose precision.

Because that's the point of having a dpi button, to increase the mouse speed by hardware so the animation is precise.

As result it is obvious to me that there is no good default mouse setting right now, because the mouse will be either slow or imprecise.

The closest I got for being good for all mice has been to disable acceleration, and setting cursor speed to 0.25. Yet the cursor loses precision and jumps on the screen, noticeable if your mouse is high quality and the screen has high frame-rate.

So probably at some point we will need to ignore budget mice all together. Because higher resolutions, framerates and better mouse lens ask for adjustable dpi through hardware. Rendering non adjustable dpi mice eventually obsolete.

What I don't have clear is how to make this transition smooth. In my own distro, Zenned, I'm considering making it right now and optimizing for quality mice.

Maybe an alternative would be making a custom acceleration curve, different than the one provided by libinput, simulating those provided by gaming mice like: https://press.razer.com/product-news/razer-mouse-rotation-and-dynamic-sensitivity/