UI long term development perspective: physics engine

Johan Prinsloo johan.a.prinsloo at gmail.com
Thu Mar 22 20:44:09 CET 2007

This is interesting - even if you just want a smooth scroll action you still
need to relate it somehow to machine time (bad approximation of real time)
and some time constant. It might be most efficient to group all those
functions into a library rather than have lots of apps each doing these
calcs independently each using the time system calls.

If you start a project I will help - I am a simulation engineer used to
modeling fluid dynamics, chemistry and electricity.


-----Original Message-----
From: community-bounces at lists.openmoko.org
[mailto:community-bounces at lists.openmoko.org] On Behalf Of Florent THIERY
Sent: Thursday, March 22, 2007 6:39 AM
To: OpenMoko Community List
Subject: UI long term development perspective: physics engine


I know it's not gonna come in the priority list before at least a year
(or ever), but if we want to add eye candy & (possibly) useability to
the UI (such as smooth realistic list scrolling, as seen in apple's
iphone demo on contacts lists), we'll need a physics engine, so that
moves & animations aren't all linear.

All i found so far is the akamaru lib, needs just GLib:


If you want to take a quick look at the code:
svn co http://svn.kiba-dock.org/akamaru/ akamaru

It's a verlet integration implementation;  modelization includes
elasticity, friction, gravity, geometrical objects...

The only (AFAIK) implementation using this model is kiba-dock, a *fun*
app launcher, but we may find another use to it in the future.

For instance, it may be useful to gesture recognition (i'm not aware
if existing gesture recognition engines measure speed, acceleration,

There's an undergoing verlet integration into the e17 project (by rephorm)
see http://rephorm.com/news/tag/physics , so we may see some UI
physics integration into e17 someday.

Such early projects mainly show "rope-like" animations, but maybe the
API wil spare some time for different usages.

Well, that was just a useless thought, but i'd be happy to know if
other people are wondering about improving the user experience
regarding physics-model-based UI animation.


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