Re: [E-devel] evas and shape mask calc

[Jose O G. <jos...@ju...>]

On Sun, 11 Dec 2005 13:59:10 +0900 Carsten writes:
> On Sat, 10 Dec 2005 20:47:56 -0600 Brian Mattern 
> <bri...@gm...>
> babbled:
> 
> > Some recent commit (after the 2nd but before the 8th) broke evas 
> shape 
> > mask calculations. I'm going to go out on a limb and blame Jose's 
> > gradient patch :)
> 
> correct. found it. the destination alpha math definitely gets things 
> wrong..
> like forgetting in 2's compliment binary math on single 32bit values 
> that
> values can overflow... into the next, etc. unlike mmx/'sse where the 
> simd ops
> protect the values form eachother... i ended up backign out all the 
> blend
> changes as it just woudl take too long to debug it all.
> 
> > For some reason regions that have transparent images blended onto 
> opaque 
> > ones get shaped out now.
> > 
> > For an example, see: http://rephorm.com/files/shots/icky.png
> > 
> > The AA parts of the text are shaped out, as is the window icon.
> > This isn't noticeable in the default theme, since it doesn't use 
> shaping.
> > 
> > I'll try to take a look, bu this isn't really my area of 
> expertise, so I 
> > wanted to let everyone else know about the issue (Raster and Jose 
> > especially).
> > 
> > Take care,
> > Brian
> > 

	Ummmm.... It's likely that some of the blend routines
have bugs -- they were written very quickly, and went basically
unchecked and untested. But it's also likely that most of them
are fine.. they do need to be checked and tested. I'll see if I
can get to that later -- but if you know of particular routines
that are incorrect, let me know and I can look at them first :)

	Moving to pre-mul alpha is a good idea, but is *far*
more radical in several respects, especially in relation to
programs that have been getting/setting image data.

	Right now I was thinking of sending a small patch to add
"rounded rectangles" to evas, but we'll see..


	Jose.