Re: transparent cairo rendering

[Jose Hevia <jose francisco hevia gmail com>]

Seems to me that when I say:
 Draw me a rectangle that is (0,0,0(black),0(and transparent)...

he says

oh, is transparent, so I don't need to paint it,

But the problem appears if there was something out there (not
transparent) and want to make it transparent, you can't, unless you
make a function to make it pixel by pixel.

That would explain why it works the first renderings and can't paint
over something already painted, although destroyed and recreated.