Graphics2D.drawPolyline performance on JDK 8 vs. JDK 11 (repost)

[Kevin Rushforth]

I suggest posting this on the 2d-dev at openjdk.java.net mailing list.

-- Kevin

On 10/9/2018 2:00 AM, Peter Hull wrote:
> I've recently started using Java 11 and noticed that drawPolyline is
> much slower on my PC than it was on Java 8.
> Example, simplified code:
>      @Override
>      protected void paintComponent(Graphics g) {
>          super.paintComponent(g);
>          Graphics2D graphics = (Graphics2D) g;
>          long starttime = System.nanoTime();
>          graphics.drawPolyline(xs, ys, xs.length);
>          long endtime = System.nanoTime();
>          Logger.getLogger(this.getClass().getName()).log(Level.INFO,
> "Paint Time: {0}s", (double)(endtime-starttime) / 1.0e9);
>      }
> where xs[] and ys[] are large (65536 points) integer arrays. On
> OpenJDK8_x64_Win_jdk8u172-b11 I get a paint time of 0.025s and on
> openjdk-11+28_windows-x64 it is 25s, i.e. factor of 1000.
> This may be related to JEP263 (HiDPI)
>
> I've got a recent Core i7 processor with Intel graphics, running Windows 10.
>
> Is this a bug do you think and if so, where to report it?
>
> Thanks,
> Peter