[PD] pd/gem per-pixel image manipulation

[IOhannes m zmoelnig]

Martin Leopold Grödl wrote:
> hi marius & others,
> thanks for pointing me to glsl, i will have a look!
> 
> but for now i think i found what's causing the trouble:
> actually i want to apply per pixel manips continuously on a stream of 
> pixes. eg. video from pix_film. so i was constantly triggering pix_dump 
> with the gemhead. when triggering pix_dump manually it works fine.
> (see attached test-patch)


the problem you are experiencing is, that [pix_dump] will output an 
empty list (aka "bang") the first time it is called (no image yet at its 
input)

the bang will be distributed down your "processing" chain, and 
eventually, in [* 0.5] it will be converted into a number "0" which will 
be the first element in your [repack 100], thus introducing an offset.

the most naive workaround is to filter the bang with a [route bang].

apart from that: why do you manually unwrap the lists? [repack 1] will 
do just as well.
and for scalability, you should dynamically size the [repack 100]


(see attached patch)



> 
> i know it's not very efficient to do it like that in the first place 

indeed, it is not...:-)


fgmasdrö
IOhannes
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