[PD] Gem: color to pix

[james tittle]

On Mar 8, 2006, at 12:36 AM, chris clepper wrote:

> Do you want to do something like add more red to an image?   
> pix_gain will multiply each channel (R G B or Y U V) by a  
> coefficient and pix_offset will add to the channel.  You can also  
> try the colorRGB object to modulate the color value in hardware,  
> but the coefficients are limited to 0..1.

...GL_MODULATE is the standard texture mode in gem:  I added  
switchable options via an [env $1< sent to [pix_texture] to cvs last  
week, so now you can also switch texture environment mode to GL_ADD,  
GL_BLEND, or GL_COMBINE, too...there's also an updated help patch in  
gem's cvs that shows this in action...

> On 3/7/06, Alexandre Quessy <listes at sourcelibre.com> wrote: Hi,
>
> Its been a little while since I am trying to _add_ a color to a  
> pix. Is
> there a way to do so ? The thing is that if I put a colored rectangle
> over a pix_textured reactangle, it kind of desaturate the picture.

...the benefit of the [env $1< is that all processing takes place on  
the gpu (ie. no extra cpu cost) ;-)

> I know such a thing is much easy in Gridflow, but I got to use Gem on
> OSX for this time again. If it is the only, though, I might try to
> compile Gridflow with its new export_pix and import_pix on OSX...

...yeh, time for us all to try that!

james