On Wed, Jan 13, 2010 at 06:03:41PM +1030, Ron wrote: > On Mon, Jan 11, 2010 at 03:59:26PM +0000, Przemysław Firszt wrote: > > Hi, > > I was looking for some kind of magic in those hardcoded tables, but > > after using brute force (generate all valuse, put them into table and > > see what we have here) I realised that it's just (x,y) -> (i, angle) > > conversion and we're using only the angle... > > > > I don't have Intuos4, so I need someone to test the patch. There are 2 > > questions: > > 1. Are todays PCs fast enough to use floating point calculations to > > convert tilt X and Y into rotation? (I think so, but again I can't test > > it). > > The floating point operations may be a killer on platforms like ARM, > that mostly don't have an FPU still. So it may be worth keeping both, > or adding a fixed-point version of it too.
> But it's always worth profiling these on modern systems now. There > are quite a few things that it is now cheaper to calculate than it is > to stall the pipeline and drag a table into cache. > > That can be quite unintuitive to people who remember just how many cycles > some of these operations do take to perform ;) I wonder how many ARM users use wacom tablets? Cheers, Peter ------------------------------------------------------------------------------ Throughout its 18-year history, RSA Conference consistently attracts the world's best and brightest in the field, creating opportunities for Conference attendees to learn about information security's most important issues through interactions with peers, luminaries and emerging and established companies. http://p.sf.net/sfu/rsaconf-dev2dev _______________________________________________ Linuxwacom-devel mailing list Linuxwacom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxwacom-devel
