RFR: 8326027: [TEST_BUG]Comparing buffered images of white background frame fails in Mac

[Phil Race]

On Thu, 29 Aug 2024 04:38:29 GMT, Tejesh R <tr at openjdk.org> wrote:

> On analysis of captured image, it is observed that there are few pixels which vary slightly w.r.t to expected color. Hence tolerance is included in color comparison. 
> Tested in mach5 multiple time and its green.

What makes it intermittent ? Does it fail on a non-retina ? or a retina ? or both ?
The test systems should all be set up with sRGB color profile, so that ought not to be the issue.
Have you seen it fail locally on a retina laptop screen  (with sRGB profile of course) ?
Mac these days doesn't always do the simple 2x scale they used to .. my macbook is natively 3072x1920 but
1792 x 1120 is the default virtual size. That's a scale of 1.71 .. I would have to change to 1536x960 to get the 2x scale.

Still interpolating white and white ought to result in white ...  but the hardware could be inaccurate ...

If you can reproduce it locally check your scale vs the native.

You could use -Dsun.java2d.uiScale=1 but I suspect that in this case it isn't going to help

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PR Comment: https://git.openjdk.org/jdk/pull/20760#issuecomment-2430384374