[PD] Gem: Change blending mode ?

[james tittle]

On May 8, 2006, at 3:03 PM, Alexandre Quessy wrote:
>
> The default blending mode between geos is "add". I would like to set
> it to "multiply" in some cases and "mask", so that when we are viewing
> a geo with a pix texture on it, we don't see the other geos' pix
> textures behind it ? I am sure this is possible. How ?

...actually the default mode is "modulate", where it the texture is  
modulated by the surface color of the geo...the I recently added  
support for this (ie. glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE,  
m_env) )in gem cvs (and the pix_texture.pd help patch covers it):   
basically you just send an [env $1< to [pix_texture], with the  
following supported values:

0=GL_REPLACE
1=GL_DECAL
2=GL_BLEND
3=GL_ADD
4=GL_COMBINE
 >4=GL_MODULATE (default)

...alternatively, if yr just looking to play with blending, you could  
use [GEMglBlendFunc] and [GEMglBlendEquation]...looks like we need to  
add wrappers for glBlendFuncSeparate(), glBlendColor(), and  
glBlendEquationSeparate() (putting it on the to-do.91)...

jamie