[OpenJDK 2D-Dev] request for review: JDK-7179526 : xrender : closed/sun/java2d/volatileImage/LineClipTest.java failed since jdk8b36

[Clemens Eisserer]

Hi again,

I know this patch is cumbersome to review, however it would be great
if somebody could find the time to take a look at it.
Its basically only C-Code ported to java anyway ;)

It would be no problem for me to split the independent
performance-improvement for storing rectangles into a seperate patch
if it would help.

Thanks, Clemens

2013/8/24 Clemens Eisserer <linuxhippy at gmail.com>:
> Hello,
>
> Please review my fix for: JDK-7179526 : xrender :
> closed/sun/java2d/volatileImage/LineClipTest.java failed since jdk8b36
> at http://cr.openjdk.java.net/~ceisserer/7179526/webrev.00/
>
> Problem description: Lines weren't rendered in a consistent way when
> they were clipped.
> The issue originated from clipping being previously separated from
> line rasterization.
>
> Fix description:
> 1. After a few failed attempts, I decided to port the native line
> rendering algorithms from sun/java2d/loop/DrawLine.c and
> sun/java2d/loop/LoopMacros.h to Java.
> The original source consisted of quite a number of interdependent
> macros, I tried to split the code into smaller methods in XRDrawLine.
>
> 2. Also included is a small low-risk micro-optimization, by providing
> a GrowableRectArray.pushRectValues()-method, replacing the rather
> generically implemented MaskTile.addRect() method. This results in a
> 10-20% speedup for workloads consisting of many small rectangles, as
> this code is very often called.
>
> 3. Another change is a clean-up/removal of long-time unused member
> variables in MaskTileManager.java, from dates where line rendering was
> implemented in a different way.
>
> I could create separate patch-sets for the clean-up and the
> micro-optimization, as you prefer. However, I consider both no-risk.
>
>
> Thanks, Clemens
>
> PS: Performance for line-rendering workloads improved quite a bit:
>
> Options common across all tests:
>   graphics.opts.xormode=false
>   graphics.render.opts.paint=single
>   graphics.opts.renderhint=Default
>   graphics.opts.alpharule=SrcOver
>   graphics.opts.extraalpha=false
>   graphics.render.opts.alphacolor=false
>   global.dest=VolatileImg
>   graphics.render.opts.antialias=false
>   graphics.opts.clip=false
>   graphics.render.opts.stroke=width1
>   graphics.opts.transform=ident
>   graphics.opts.anim=2
>
> graphics.render.tests.drawLine,graphics.opts.sizes=20:
> baseline: 23234.32805 (var=18.95%) (100.0%)
> patch: 26042.31972 (var=6.28%) (112.09%)
> graphics.render.tests.drawLine,graphics.opts.sizes=250:
> baseline: 27573.53165 (var=30.54%) (100.0%)
> patch: 30530.53302 (var=7.46%) (110.72%)
> graphics.render.tests.drawLineHoriz,graphics.opts.sizes=20:
> baseline: 93574.96039 (var=21.09%) (100.0%)
> patch: 103011.66924 (var=3.92%) (110.08%)
> graphics.render.tests.drawLineHoriz,graphics.opts.sizes=250:
> baseline: 1129462.56050 (var=15.02%) (100.0%)
> patch: 1291397.82057 (var=1.53%) (114.34%)
> graphics.render.tests.drawOval,graphics.opts.sizes=20:
> baseline: 20958.84885 (var=18.79%) (100.0%)
> patch: 23018.13843 (var=3.44%) (109.83%)
> graphics.render.tests.drawOval,graphics.opts.sizes=250:
> baseline: 15263.36513 (var=19.22%) (100.0%)
> patch: 33692.11899 (var=1.29%) (220.74%)
> graphics.render.tests.drawPoly,graphics.opts.sizes=20:
> baseline: 33479.49456 (var=18.25%) (100.0%)
> patch: 37251.33485 (var=3.36%) (111.27%)
> graphics.render.tests.drawPoly,graphics.opts.sizes=250:
> baseline: 28618.54379 (var=22.98%) (100.0%)
> patch: 42345.48575 (var=4.03%) (147.97%)
> graphics.render.tests.shape.drawCubic,graphics.opts.sizes=20:
> baseline: 10687.11472 (var=13.72%) (100.0%)
> patch: 10538.90697 (var=33.91%) (98.61%)
> graphics.render.tests.shape.drawCubic,graphics.opts.sizes=250:
> baseline: 8458.942632 (var=18.26%) (100.0%)
> patch: 16690.96833 (var=2.67%) (197.32%)
>
> Summary:
>   baseline:
>     Number of tests:  10
>     Overall average:  139131.1690314054
>     Best spread:      13.72% variance
>     Worst spread:     30.54% variance
>     (Basis for results comparison)
>
>   patch:
>     Number of tests:  10
>     Overall average:  161451.9295901127
>     Best spread:      1.29% variance
>     Worst spread:     33.91% variance
>     Comparison to basis:
>       Best result:      220.74% of basis
>       Worst result:     98.61% of basis
>       Number of wins:   9
>       Number of ties:   1
>       Number of losses: 0