[cairo] Re: Using ADD operator to prevent seams (newbe question)

[Adib Taraben]

does all this things mean that there is no api to get the bounding box 
of a number of graphical elements ? Lets say a polygon and a 
transformation to that.

Sorry for this dump question, just a yes or no is ok for me.

Grazie,

Adib.

Robert O'Callahan schrieb:
> Thanks for this thread. It was well written, very educating and
> directly addresses my questions and needs.
> 
> Gecko's in the same boat as Inkscape. Web authors also write documents
> that induce the adjoining edge problem, e.g., something as simple as a
> sequence of line boxes with a background color. (But lots of more
> complicated scenarios exist.) Currently this causes us problems
> because we simply don't round correctly (e.g.
> https://bugzilla.mozilla.org/show_bug.cgi?id=173051) but even if we
> fix that, we're still going to have problems on antialiased devices.
> 
> Like Inkscape, figuring out adjoining edges in general is going to be
> prohibitively complex and probably too slow also ... speed is
> incredibly important to us. That also rules out compositing with lots
> of temporary buffers. The dilation approach will cause artifacts with
> transparent fills. So my guess is we'll want to go with the Flash-like
> supersampling approach. I think we could automatically tune the system
> to use supersampling only when rendering is keeping up with the
> document's demands, given the available resources.
> 
> A few questions:
> -- Does this conclusion sound reasonable, or have I misunderstood something?
> -- Should I expect Glitz to make the supersampling approach really
> fast for users with sufficient VRAM?
> -- Given that we don't want coverage-based antialiasing, does that
> mean to maximise performance we really want something other than the
> current Cairo rasterizer?
> 
> Rob