[OpenJDK 2D-Dev] RFR: 8171303 sun/java2d/pipe/InterpolationQualityTest.java fails on Windows & Linux

[Ajit Ghaisas]

> On 02-Sep-2020, at 10:46 AM, Sergey Bylokhov <Sergey.Bylokhov at oracle.com> wrote:
> 
> On 01.09.2020 03:42, Ajit Ghaisas wrote:
>>> 
>>> In the HiDPI mode the VolatileImage internally have twice more pixels than BufferedImage, so when we draw the data to
>>> the VolatileImage and then scale it back to the size of the BufferedImage for comparison, the test fails.
>> This looks good. I checked with OGL and Metal (project Lanai) on macOS.
>> One question is - do we need to support this test in HiDPI mode?
> 
> The difference between HiDPI and non-HiDPI mode is that  VolatileImage has more
> pixels and every draw operation use scaled blits. The test in question scales
> the graphics ourselves. To eliminate the "sun.java2d.uiScale=1" we will need to
> apply the scale to the BufferedImage size, then we should skip the usage of
> "getSnapshot", and then we will need to scale all rendering to the
> BufferedImage(simulating the HiDPI in VolatileImage), but in the end, the same
> scaled blit will be tested.

OK. Thanks for the explanation.
Test fix looks good. +1. (not a ‘R’ reviewer)

Regards,
Ajit

> -- 
> Best regards, Sergey.