Box2D Forums

I listened to this interesting post here from kavaler.
15 secs for the TestBed/pyramide example Thats what I'm dreaming on...
Could fixed point math increase the box2d speed for slow processors ?
Should I give a try to kaveler's fixpoint math for my HTC touch cruise ?
(windows mobile 6 running on a 400 MHz Qualcomm Processor)

regards,
nimodo

ps: somebody knows a working patch-utility, running on windows ?

Fixed point math is used on processors that do not have a floating point unit (FPU). If an FPU is not present, floating point operations are emulated in software, which is very slow. In this case it is a lot faster to use fixed point math. Have a look at the specs of your processor to find out if it has an FPU. If it does, you are probably better off with the floating point implementation, because our fixed point changes are still unstable, and you will not see a speed improvement on a CPU with FPU.

It makes sense, what you are saying. It is the qualcomm msm 7200 chipset, if i interpret http://www.pdadb.net/index.php?m=cpu&id=a7200 correctly the chipset has a floating point unit.

But i will try and compare anyway testbed/pyramide ....

saludos - nimodo

Actually, if I remember correctly back to the dark ages of gaming, sometimes even if you have an FPU you'll get a speed boost from fixed point because the lower end FPUs still don't do stuff as quickly as you can do integer math. These days on desktops the speed difference has evaporated (on some PCs integer divides are even slower than floating point ones), but on some handhelds it's probably worth checking the difference.