[PD] GEM / pix objects : limiting colours

IOhannes m zmoelnig zmoelnig at iem.at
Mon Mar 12 09:00:45 CET 2007


chris clepper wrote:
> On 3/11/07, *Sciss* <contact at sciss.de <mailto:contact at sciss.de>> wrote:
> 
>     mac intel. however the pix_offset help file says "When adding an
>     offset to each color-channel, no clipping is done. Thus you can wrap
>     around the color-space", so probably it behaves right, only in my
>     case i want to prevent wrapping ... 
> 
> 
> The PPC code does not wrap around since Altivec has saturating
> addition.  Maybe MMX lacks that.  I'll check when I have the time.


yes i think the mmx/sse2 code does overwrap.
however, i also think that there is a switch to turn that
on....wait...no ehm there is only a switch in the [pix_gain] object to
turn this on/off: it is [saturate 1/0(

though saturation is the logical usage, i would like to provide both
ways, for legacy reasons and for freedom of choice.

mfa.sdr
IOhannes




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