[OpenJDK 2D-Dev] Fwd: Various fixes to pisces stroke widening code

[Denis Lila]

----- Forwarded Message -----
From: "Denis Lila" <dlila at redhat.com>
To: "Jim Graham" <james.graham at oracle.com>
Sent: Monday, August 9, 2010 4:58:10 PM GMT -05:00 US/Canada Eastern
Subject: Re: [OpenJDK 2D-Dev] Various fixes to pisces stroke widening code

Hi Jim.

Good idea. I've implemented it. I also noticed the quicksort 
method wasn't very friendly to 0 length arrays. I fixed that.
I ran Java2Demo and a few of my tests, and everything looks good.
http://icedtea.classpath.org/~dlila/webrevs/fpBetterAAv2/webrev/

Everything, except the joins demo, that is. The interior of the
star's right arm (our left) and left leg is not drawn exactly like
in proprietary java or openjdk6. I am not sure if this is a bug
since I don't know exactly how the results of a bs.createStrokedShape
are supposed to look. However, I am almost certain that this
isn't my fault, since I can reproduce the behaviour with an only 
slightly changed version of openjdk7 with completely different
changes than what's in this patch. I'll run it next morning with
a fresh build of openjdk7 to be completely sure.

Can I push it?

Thanks,
Denis.

----- "Jim Graham" <james.graham at oracle.com> wrote:

> To the end of getting rid of "flips" - all they are used for is to 
> resize the crossings array, right?  This is not a huge array that
> costs 
> a lot to resize - why not simply use a default array of, say, 30 
> elements and then resize it if we ever have more crossings than that?
> 
> Only very complicated paths would have more than 30 crossings to
> track. 
>   The check for array length is only needed once per scanline since we
> 
> know how many active edges are on each scan line (hi-lo) and you can 
> only have 1 crossing per active edge so with one test per scanline we
> 
> can keep the crossings array within range...
> 
> 			...jim
> 
> Jim Graham wrote:
> > Hi Denis,
> > 
> > Well, I guess it's a good thing that Java2Demo had a path like that
> in 
> > it - not a very common case, so it's good we found it!
> > 
> > The fix looks fine.  It still seems like there is way more logic
> there 
> > than is needed - hopefully if we can get rid of flips at some point,
> 
> > much of it will go away.
> > 
> > Fixes look good to go to me...
> > 
> >             ...jim
> > 
> > On 8/5/2010 3:58 PM, Denis Lila wrote:
> >> Hi Jim.
> >>
> >> I didn't know about Java2Demo. If I did I would have run it
> sooner.
> >> But I ran it a few hours ago, and everything looked fine
> (surprisingly
> >> high fps too) until I got to the append test.
> >>
> >> Apparently I introduced a bug when solving the "2 consecutive
> moveTos 
> >> bug".
> >> Basically, when there's a close() after a horizontal lineTo(), the
> lineTo
> >> in close() won't be executed because it's inside the if 
> >> (firstOrientation != 0)
> >> test. So instead of going back to the starting point, close will
> stay 
> >> where
> >> it is, which will draw a triangle above the rectangle.
> >>
> >> I fixed this by introducing a variable that keeps track of the last
> 
> >> method
> >> called (lineTo, moveTo, or close), and instead of checking for 
> >> firstOrientation != 0
> >> in close(), I check for (last == LINE_TO).
> >>
> >> webrev (hopefully final):
> >> http://icedtea.classpath.org/~dlila/webrevs/fpBetterAAv2/webrev/
> >>
> >> I'm sorry about this. I wish I had known about Java2Demo sooner.
> >>
> >> Thanks,
> >> Denis.
> >>
> >> ----- "Jim Graham"<james.graham at oracle.com>  wrote:
> >>
> >>> Hi Denis,
> >>>
> >>> That's great!  I just did a last minute double-check of your last
> >>> (final) webrevs to be sure.
> >>>
> >>> Have you tested Java2Demo with these changes?  I'd also run any
> >>> regression tests you can find with the changes.  If there are no
> >>> problems there, then you are good to go to push it...
> >>>
> >>>             ...jim
> >>>
> >>> On 8/5/2010 8:08 AM, Denis Lila wrote:
> >>>> Hello.
> >>>>
> >>>>> Are you a registered OpenJDK developer?
> >>>> I am now.
> >>>> Can I go ahead and push it?
> >>>>
> >>>> Regards,
> >>>> Denis.