Not an issue: How are the trackball/touch motion events handled

[GoogleCodeExporter]

Can someone help me understand this code:

In trackballMouse/touchEvent handlers:

    dx = dx * dx * dx;
    dy = dy * dy * dy;

and 
        int dx = (int) (evt.getX() * 6.01);
    int dy = (int) (evt.getY() * 6.01);

Why is the 6.01 and cube funtions used here?

Thanks!

Original issue reported on code.google.com by puneet.y...@gmail.com on 23 Jun 2010 at 6:45

[GoogleCodeExporter]

These numbers are to scale the motion events that are delivered to the 
onTrackballEvent methods by the Android system (at least with G1 and Nexus One, 
which are the trackball-equipped models I have).  They basically come in a few 
sizes: 

0.16666, 0.33333, 1

Where 1 comes from a very fast scroll.

The multiply by 6 just changes the scale so the smallest increment represents 1 
pixel.

The cubing (actually it is 1/2 cubing now) is a dumb way to do mouse 
acceleration-- so a very fast mouse spin goes much farther than a small scroll, 
instead of linearly farther, which makes the mouse way too slow.

The mouse acceleration could probably be tweaked so it acts more naturally if I 
added a timer for how long it was continuously scrolling to the same quadrant-- 
it's not bad (for me, at least) the way it is now.

Hope this clears things up.

Original comment by googlec...@antlersoft.com on 1 Jul 2010 at 7:03

• Changed state: Done
• Added labels: Type-Other
• Removed labels: Type-Defect