On Thu, 18 Jan 2024 11:09:12 GMT, Prasanta Sadhukhan <[email protected]> wrote:
> Lines are left behind when moving the scrollbar in the positive direction. > but are cleaned up on mouse release. > Additonally, with right arrow clicks too, the lines are left behind. > Seems like for mouseDragged and scrollByUnit, the dirty region of the > scrollbar is not repainted leading to artifacts > which is being done in this fix.. > > Because float scale results in fractional pixels? > > If the scale is 1.25, then 1 pixel is 1.25 physical pixels; 2 pixels are > > 2.5 physical pixels and so on. > > Initially this issue looked similar to fractional scaling issues such as > border rendering issues observed on windows previously but it seems to happen > only on non-standard fractional UI scales such as 2.3, 2.7 and not on > standard fractional scales supported on windows (1.25,1.75,2.25 ..) [#17484 > (review)](https://github.com/openjdk/jdk/pull/17484#pullrequestreview-1834275178). The underlying problem is still the same: there are fractional pixels. I haven't run the test case myself. The attached screenshot has a pattern… not every pixel remains visible. Likely, these pixels are where the fractional pixels add up to produce a new full pixel. ------------- PR Comment: https://git.openjdk.org/jdk/pull/17484#issuecomment-1908921963
