[OpenJDK 2D-Dev] X11 uniform scaled wide lines and dashed lines; STROKE_CONTROL in Pisces
dlila at redhat.com
Mon Nov 1 15:13:50 PDT 2010
I implemented your bucket sort idea. I'm not just using the buckets
to remove the y-sort. I use them in the iteration through the scanlines
too. What happens is that on any iteration, the active list is the
doubly linked list buckets[nextY-boundsMinY]. I did this because I thought
less memory would need to be moved around compared to when we just kept
the active list "pointers" in an array. For example, with doubly linked
lists we can implement insertion sort with O(1) writes. With arrays we
have to use O(n) writes. This also allows us to get rid of the the edgePtrs
I ran some benchmarks, and unfortunately I was wrong, somehwere. All the tests
are at least 10% slower than the insertion sort version of what we have now.
I can't immediately see why this is. The only thing I can think of is that
there are a lot of float -> int casts, but then again, I don't know how
slow this operation is. It would be good if it's because of the casts because
it would no longer be an issue when we convert to native.
I alo made an unrelated change: I now find the orientation and update x0,y0
much earlier than we used to. The way I was doing it before was silly.
----- "Jim Graham" <james.graham at oracle.com> wrote:
> Hi Denis,
> Good news!
> On 10/28/2010 3:27 PM, Denis Lila wrote:
> >> If we moved to a Curve class or some other way to
> >> consolidate the 3 lists (may be easier in native code), this might
> >> in more cases...
> > Does that mean you no longer think we should flatten every curve as
> > as we get it?
> No, I was just discussion the feasibility of that one suggestion in
> context of all of the possibilities of whether or not we took the
> choices. If you think that flattening will pay off then we don't have
> to worry about the 3 lists. It was just that when I hacked it in, I
> still had your 3 lists and so the pros and cons of horizontal edge
> sorting were relative to that version of the renderer...
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