As you can do
relative masks, you can also do absolute ones, the only problem being that you
can't do so with picture bigger than 256x256.
The advantage is that you can sometimes see better what you are doing. I have done a mosaic-like picture once using absolute mask. (With modulos to make "stairs", to have the coordinate remain the same if we remain on one "step"...)
As you would have guessed, you use expressions like r(0,r(1,x,y),g(1,x,y)).
I let you explore this if you want :-)
Okay. We reached here the end of the tutorial.
I hope you enjoyed reading and experimenting this. Please do not hesitate to mail me if you have a query, if you made a cool picture (eg, to put it into the gallery)... If you would like to make an effect but do not know how to make it... If you found some cool mathematic formula that does pretty drawings...
I would really be pleased to recieve such feed back :-)
Concerning myself, I will continue updating this tutorial every time I find something new... I will maybe write more 'raw' mathematical theory, to help you build two-vars implicit functions [f(x,y)=0] and two-vars explicit functions ([r,g,b]=f(x,y)), as I think these are the areas were we find the most power for creating/modifying images.
It was a pleasure for me to write this tutorial, and again, I hope you enojoyed it :-)
5.1: Selection masks
5.2: Translation masks
5.3: Absolute masks
End Of Tutorial