protection masks and selections

[Casper Boemann]

Hi

I' have some things we need to discuss about selections and masks

I have changed soem code so that we now has selections (as we know them) and 
the bennings of protection masks. This is how we decided on irc some months 
ago.

http://wiki.koffice.org/index.php?title=Krita/SelectionsMasks

Thomas Zander asked today on irc: if this cool technical ability has been 
thought through with regards that the user will actually understand the user 
interface for it.  It seems a bit too complex to show to the user.

I tried photoshop to see what they do and they don't have the concept of 
protection masks. They only have:
- global selection
- opacity masks
- effect masks

Wheras we decided to have:
- global selection
- layer specific selection
- protection masks
- opacity masks
- effect masks

Now I wonder if we are indeed going overboard in complexity here. Do we really 
need protection masks AND per layer selections. To me they kind of fill the 
same gap.

Personally i would be happy to just do like Photoshop and only have global 
selection, but at the very least i think we should forget about either layer 
specific selection or protection mask.

One thing about having both a global selection and a local selection we havn't 
discussed is how to combine those. Is it AND or OR (I don't imagine other 
boolean ops are worth considering) of the selected areas

If we keep protection masks we would need to change the iterators from having 
a selectedness() method to having readabillity() and writabillity() methods 
as those values could be different. That would mean some porting though we 
could do it in steps by just deprecating selectedness().

-- 
best regards / venlig hilsen
Casper Boemann