[cairo] Re: Notes on cairo/win32

[Dimitrie O. Paun]

> 2. Implement it on top of GDI+. The GDI+ model is somewhat richer
>    than the GDI model... it adds antialiased primitives, and "Over"
>    compositing of those primitives, though considerable amounts of
>    the Cairo API would have to be done manually.

Speaking of which, being able to implement GDI+ on top of Cairo
easily and efficiently could be very helpful to Wine (http://winehq.org).

>From my 10,000 foot view, it looks like Cairo has a more powerful
model then GDI+, but it's good to keep this in mind, especially
given the track record for Microsoft for throwing weird stuff in
their interfaces.

Currently Wine uses Xlib to implement GDI, and that works well most
of the time, with DIBs being the notable exception. These are a very
popular feature that we need to support well. 

Theoretically, we would need a software renderer to implement them
properly, but that's a lot of work, and we don't have the resources 
to do it currently. So we have to play all sorts of silly games with 
the X server, bouncing the image back an forth (GDI operations must 
coherently modify the DIB with any direct memory modification 
performed by the application). This is both rather nasty and slow.

My hope is that we would be able to use Cairo to do the rendering.

-- 
Dimi.