From philip.race at oracle.com  Fri Apr 23 20:10:46 2021
From: philip.race at oracle.com (Philip Race)
Date: Fri, 23 Apr 2021 13:10:46 -0700
Subject: Heads up : JDK 17 b19 through b22 will use Metal instead of OpenGL
 for Java 2D rendering on macOS.
Message-ID: <9826c9ab-273e-b387-a5f1-f44f855007f7@oracle.com>


Heads up to anyone who is testing JDK 17 for running apps on macOS.
Starting with build 19 [1], JDK 17 for macOS is *temporarily* switched 
from using OpenGL
to using Apple's Metal API for Java 2D rendering. This should be 
invisible to applications.
We expect to revert this temporary switch in JDK 17 build 23,meaning b22 
will be the last build with Metal as default.

See JEP 382 [2] for more information about how Metal is used by JDK.

If you are running any kind of 2D / Swing/ AWT UI application on macOS, 
and see any rendering related problems
starting with JDK 17 b19, please do report them to us at either the 
usual bug submission channel [3],
or on the 2d-dev at openjdk.java.net OpenJDK mailing list [4]
Please be ready to provide us with a test case and screen shots.

You may also set "-Dsun.java2d.opengl=true" to re-enable OpenGL - which? 
implicitly disables Metal -
to confirm that any problem you see is a Metal related rendering glitch.

I will also forward this email to jdk-dev at openjdk.java.net

-Phil.

[1] https://jdk.java.net/17/
[2] https://openjdk.java.net/jeps/382 <https://openjdk.java.net/jeps/382>
[3] https://bugreport.java.com/bugreport/
[4] https://mail.openjdk.java.net/mailman/listinfo/2d-dev