[cairo] potential bug in cairo relative to intel drivers

[Bill Spitzak]

Carl Worth wrote:

>> I still think Cairo could be changed to do EXTEND_REPEAT and clip with 
>> an antialiased polygon and everybody would be happier.
> 
> Certainly you mean EXTEND_PAD here, not EXTEND_REPEAT, (since
> EXTEND_REPEAT will give you discontinuities unless your image happens to
> be periodic).

Yes I did mean EXTEND_PAD. Sorry I was confused by other software that 
calls this "repeat" because it is repeating the edge pixels (it calls 
EXTEND_REPEAT "tiling").

> But still, adding an additional stage of compositing to all operations
> would not make me happy at all, (nor anybody else who cares about
> performance).

My complaint is that I think a solution built into cairo/pixman would be 
a faster than the solution required by multiple cairo calls now. The 
built-in one should be able to take advantage of knowing that the clip 
is exactly 4 straight lines that are parallel with particular features 
of the source surface.