[PD] Image from shader back to Gem

[cyrille henry]

Le 15/02/2021 à 10:46, oliver a écrit :
> cyrille henry wrote:
>> What I understand from the original question was how to feed an image generated with a shader to pix_movement.
>> So one need an image, not a texture.
>> I'm afraid pix_snap is the only solution.
> 
> on a more general note:
> 
> it would be great to have something like a public [GEM-shader] archive, probably something like pdpatchrepo.info
> 
> should we open a new category there ?
> or maybe that already exists and i missed it ?
> anybody else on this list that has some GEM shaders to share ?

lot's have already been send on this list!

> 
> i have the feeling that a lot of people using GEM "roll their own" shaders  (i, for one, did) and it would be a great thing to join forces, so one doesn't have to reinvent the wheel when looking for a simple "brightness/contrast" shader ...
funny, this one can be found in pd/help/browser/Gem/exemples/10.glsl/01.simple_texture.pd


> 
> my own technical knowledge about shader scripting is close to non-existant, but i succeeded in adapting stuff found on the net, so that it loads as a shader in GEM. basic stuff only, mixers etc ...

it's quite easy to use shader from shadertoy, at least when it's a single pass rendering.


> 
> since csaba's original post talks about cropping/rotating a texture created from a MATLAB shader (would be also great to share !), one possibility could be to feed this texture into another shader.
or modify the curent shader!

> 
> i tried my clumsy hands on a quick and dirty adaption of MAX's [rota] shader, and even though it loads succesfully, it's obviously wrong as the resulting texture seems to be 1x1 dimension. i'm sure the error is somewhere in the .vert part.
or texturing mode (rectangular or not)

cheers
c

> 
> as i said, i got no deep insight into shader scripting, but maybe this can help somebody who has
> 
> best
> 
> oliver
> 
>>
>> Cheers
>> c
>>
>> Le 15/02/2021 à 08:39, IOhannes m zmoelnig a écrit :
>>> On 2/14/21 9:52 PM, Miller Puckette via Pd-list wrote:
>>>> I think the question is - within a shader, can you 'snap' an image to
>>>> a texture so that it doesn't have to go back and forth between the
>>>> GPU and CPU?  I'm curious too... I guess there must be a way to do this...
>>>
>>>
>>> [pix_snap2tex]
>>> or, preferably [gemframebuffer].
>>>
>>> gfamsdr
>>> IOhannes
>>>
>>>
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> 
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