Re: Signed colour values and clamping

I guess what you need is a combiner with GL_ADD_SIGNED_ARB operation
check OpenGL 1.4 Specs Table 3.24 for equation details

Lo.

Robin Charlton wrote:
> I'd like to use signed vertex colour values in the range -0.5 to 0.5 
> with an additive texture stage to create high-lights and low-lights. 
> Unfortunately it seems that the colour values are clamped in the range 0 
> to 1 before input to the register-combiner.
>  
> The documentation says /Neither floating-point nor signed integer values 
> are clamped to the range [0,1] before updating the current color. 
> However, color components are clamped to this range before they are 
> interpolated or written into a color buffer./
>  
> Is what I'm seeing consistent with the docs and expected behavour?
>  
> Thanks
> __________________________________________________________
> Robin E. Charlton                   [email protected] 
> <mailto:[email protected]>
>  
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