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

[Clemens Eisserer]

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