[PD] GEM / pix objects : limiting colours

Sciss contact at sciss.de
Mon Mar 12 09:14:21 CET 2007

ok, but let me know if there's any kind of work around ... i guess  
internally everything is int8 not float32? because if float32 (-- i  
don't want to degrade the bit-resolution... --), i could do pix_gain  
0.5 before the colourization, then afterwards a pix_gain 2.0 with  
saturation ...

ciao, -sciss-

Am 12.03.2007 um 09:00 schrieb IOhannes m zmoelnig:

> 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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