[MPlayer-dev-eng] [PATCH] GUI: Implement a true rotary potmeter

[Hans-Dieter Kosch]

Ingo Brückl wrote:

> Hans-Dieter Kosch wrote on Tue, 08 Apr 2014 01:56:39 +0200:

>> I see, floating point precision issue.
> 
> Yes, but why is it if x0,y0 == x1,y1?
> 
>   item->zeropoint = appRadian(item, x0, y0);
>   item->arclength = appRadian(item, x1, y1) - item->zeropoint;
> 
> results in item->arclength not being zero (for the same call with same
> arguments)? I could understand for *different* points lying on the same axis,
> but for identical points?

Mhm, that's in deed strange. Probably still a precision issue when building the 
difference, eventually system dependent, if floating point calculations are done 
in hardware or software?

Hans-Dieter