[OpenJDK 2D-Dev] <Swing Dev>  Review Request 8187367: Numerous swing display problems with scaled displays on Windows
philip.race at oracle.com
Tue Nov 7 22:08:34 UTC 2017
I think we should push this fix, although there are concerns we can't
that Math.ceil may be wrong in some theoretical case.
Also Sergey, please add a comment in the bug report about the
alternative fix you mentioned
that was discussed previously so that can be re-visited if we
subsequently find problems as a result of this fix.
On 09/19/2017 07:58 AM, Semyon Sadetsky wrote:
> On 09/18/2017 12:01 PM, Sergey Bylokhov wrote:
>> Hi, Semyon.
>> Is it possible to write a test case for this issue? It will be
>> helpful to understand the bug and a fix.
> Writing the test is hard because those inner interfaces are too deep
> inside. You can use SwingSet2 demo to see the described artifacts at
> fractional scales before the fix.
>> On 9/18/17 09:36, Semyon Sadetsky wrote:
>>> Please review fix for JDK10 (in Swing and Java2D):
>>> bug: https://bugs.openjdk.java.net/browse/JDK-8187367
>>> webrev: http://cr.openjdk.java.net/~ssadetsky/8187367/webrev.00/
>>> Swing apps may have artifacts on HiDPI screens with fractional
>>> scales. There are several issues which may cause various artifacts
>>> but the current fix only eliminates one type of artifacts the
>>> vertical and horizontal lines on painted surfaces (other issues are
>>> addressed by  and ). This issue was introduced after 8073320
>>> and then incorrectly fixed in 8163193.
>>> The root cause is the painter pattern is drawn on a wrongly sized
>>> and scaled image in case the image is an off-screen volatile image.
>>> The painter doesn't take into account the volatile image inner scale
>>> transformation which is not an identity in case of HiDPI , so the
>>> resulting image is drawn on of off-screen surface that in the scale
>>> times bigger than it is actually necessary. Since such images are
>>> cached this was waste of RAM. Also, the bounds sent to the painter
>>> class don't take into account the transformation rounding error the
>>> latter caused artifacts on the drawing edges.
>>>  https://bugs.openjdk.java.net/browse/JDK-8187585
>>>  https://bugs.openjdk.java.net/browse/JDK-8187586
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