Maciej Pilichowski wrote: > > So there is obstacle, indeed. And till now I have no idea how to solve > this. > Might be a bit of a wild branch on this topic, but I'm wondering if all the effects described here could be implemented as a /subtractive/ process. I haven't looked at gimp's implementation, but generally speaking colors combine as Cr = Ce * ( 1- o) + Cb * o, where Cr is the resultant color (clamped full saturation of each of it's components), Ce is the existing color, Cb is the brush color, and a is the opacity. What if, instead, you made Cr = Ce * (1 - o) - Cb * o, with Cr clamped at 0? All this doesn't fiddle with the alpha channel at all, but might get the desired effect. > Kind regards, > _______________________________________________ > Gimp-developer mailing list > Gimp-developer@xxxxxxxxxxxxxxxxxxxxxx > https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer > > -- Moller Software Development Services *Christian H. L. Moller* /President/ *Moller Software Development Services, LLC* ** moller@xxxxxxxxxxxxxx 919.367.8689 (Voice) www.mollerware.com <http://www.mollerware.com> 919.367.9097 (Fax) ** ** _______________________________________________ Gimp-developer mailing list Gimp-developer@xxxxxxxxxxxxxxxxxxxxxx https://lists.XCF.Berkeley.EDU/mailman/listinfo/gimp-developer
