[OpenJDK 2D-Dev] HiDPI support issues on Windows

[Anton Tarasov]

Hi all,

On 04 Oct 2016, at 23:28, Jim Graham <james.graham at oracle.com> wrote:
> 
> On 10/4/16 1:01 PM, Anton Tarasov wrote:
>> Anyway, I roughly tried your approach mentioned in the previous e-mail, but forcing RM to paint via offscreen
>> BufferedImage, not volatile (just for a quick check).
>> It solved the shift issue of the demo listed in 8162350, which is cool. It also solved the traces of InternalFrame and
>> menu in SwingSet2. Scrolling still traces (I suppose it should be resolved in JViewport/blitting).
>> Also, the problem with primitives rendering (http://cr.openjdk.java.net/%7Eant/hidpi_pics/Scaling-150-percent.png) is
>> still there. But it seems to relate to line-thikness (border-thickness) rounding inaccuracy. What we can do with that?...
> 
> Yes, blitting is a separate, but related case where pixel-exactness matters.  When we scroll a pane we need to scroll it by a precise number of pixels and then paint the newly visible information at a precise pixel location.  Solving this aspect might require events to have higher precision data available.
> 
> We should probably take detailed conversations about the solutions to the bug reports…


What do you think, is it possible to address the mentioned issues in jdk9, not deferring them? The new HiDPI support will affect all the users having fractional scale screens...

Thanks,
Anton.