[Development] Painting an image onto itself

[Thiago Macieira]

On terça-feira, 10 de abril de 2012 23.08.26, André Pönitz wrote:
> But I am not sure that kind of guarantee needs to be given.
> 
> Would it be really needed in practice? How many occurences of such
> code are there in Qt/Qt Creator?

The guarantees we give change how we can optimise this code. I'll be satisfied 
if we require that no single pixel is both source and destination. 

I can't think anymore of a case where adjacency would cause a problem. The 
source loads never cause a write back and bytes off limits must not be used. 
The destination stores, if they write off-limits, they need to ensure that they 
store the same value that was there before in any case.

-- 
Thiago Macieira - thiago.macieira (AT) intel.com
  Software Architect - Intel Open Source Technology Center
     Intel Sweden AB - Registration Number: 556189-6027
     Knarrarnäsgatan 15, 164 40 Kista, Stockholm, Sweden
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 190 bytes
Desc: This is a digitally signed message part.
URL: <http://lists.qt-project.org/pipermail/development/attachments/20120410/011c47c4/attachment.sig>