<html> <head> <base href="https://bugs.freedesktop.org/" /> </head> <body> <div> <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - Touchpad does not feel "right", acceleration issue" href="https://bugs.freedesktop.org/show_bug.cgi?id=90735#c19">Comment # 19</a> on <a class="bz_bug_link bz_status_ASSIGNED " title="ASSIGNED - Touchpad does not feel "right", acceleration issue" href="https://bugs.freedesktop.org/show_bug.cgi?id=90735">bug 90735</a> from <a class="email" href="mailto:peter.hutterer@who-t.net" title="Peter Hutterer <peter.hutterer@who-t.net>"> Peter Hutterer</a> <pre>(In reply to Britt Yazel from <a href="show_bug.cgi?id=90735#c16">comment #16</a>) > It's getting better, though not quite there yet. I am noticing that really > minute touch movements are not registering as movements under libinput, > whereas the same minute movements (I'm talking 1-2mm) do register under > synaptic drivers. That might be a reason for a lack of perceived precision, > or it could all be in my head. libinput has a function to drop tiny movements (which I think is broken in synaptics, or at least not as consistent across devices). but that's in the sub-mm scale with libinput 0.18, on your device it should be 0.5mm. the last patch, when applied to master doesn't have deceleration so the pointer movement is what the touchpad sends. > Also, it feels like the acceleration ramps up too quickly. There is a point > right between the transition from slow movements and quick movements where > the acceleration seems to take a jump, and it is a bit jarring. The only way > to describe it is as if I am losing control of the cursor for a second. This > leads you to a state where mentally the cursor is not where my mind thinks > it should be, and I need to then cognitively reasses its location. hmm, interesting. for me it's almost too slow here and I feel the accel doesn't kick in when I think it does. You can play around with the parameters if you feel like it. the curve is a simple step of baseline, then linear up to max_accel. the parameters are: baseline: basic speed of the device w/o accel threshold: speed when accel starts kicking in max_accel: maximum accel factor, will be relative to baseline (2 * baseline == twice as fast) incline: the incline, the lower the longer it takes to reach max_accel. In your case I guess you either need a smaller incline or a higher threshold. (In reply to Britt Yazel from <a href="show_bug.cgi?id=90735#c18">comment #18</a>) > For the cursor to move 100% across the screen, at a maximum touchpad > velocity threshold that should equal 100% across the length of the touchpad. > And, at the lowest velocity threshold, the distance moved on the screen > should equal that of the distance moved on the touchpad. we don't know the screen size in libinput and tbh I don't think this approach works anyway. I'm using my laptop with an external monitor connected (LVDS off), touchpads like the T650 are external, touchpads on the x220 was significantly smaller at roughly the same screen resolution of the T440, etc.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the assignee for the bug.</li> </ul> </body> </html>