Hi! 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 ;) Cheers, Ron ------------------------------------------------------------------------------ This SF.Net email is sponsored by the Verizon Developer Community Take advantage of Verizon's best-in-class app development support A streamlined, 14 day to market process makes app distribution fast and easy Join now and get one step closer to millions of Verizon customers http://p.sf.net/sfu/verizon-dev2dev _______________________________________________ Linuxwacom-devel mailing list Linuxwacom-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxwacom-devel
