Darkening the crop area impossible?

[Adrian Page]

Bart Coppens wrote:
> I thought the big part of it would have been simple: make a region of the 
> cropped parts, paint over them with half-transparent black, and done (minus 
> some other things, updating the part that get un-darkened again and so). But 
> I got stuck at the first part.
> 
> The current code (see bottom) has even different effects with OpenGL verus 
> regular QPainter! OpenGL draws the entire thing in NotROP even though I 
> create a _new_ painter, whereas the QPainter just makes it black...

As far as I know this won't work with a non-OpenGL canvas because you 
can't paint with alpha like this with Qt 3. I think Qt 4 adds this ability.

The OpenGL painter paints with NotROP simply because I only implemented 
that mode since that was all that was needed at the time. There is a lot 
that isn't implemented yet, for that reason. I'll add anything that is 
needed when the need arises, like now.

> So for archival purposes (and because somebody might now how to fix it for at 
> least one KisCanvasPainter, that would really be enough to add it), here is 
> the small patch that doesn't work;

I'll add the required op.

Adrian