On Thu, 23 May 2024 21:51:55 GMT, Marius Hanl <mh...@openjdk.org> wrote:
> Alternative PR to https://github.com/openjdk/jfx/pull/1330 which does not > modify the layout of `VirtualFlow`. > > This PR fixes the glitching by removing the code in `NGNode.renderRectClip`, > which made many calculations leading to floating point errors. > Interestingly I found out, that `getClippedBounds(..)` is already returning > the correct bounds that just need to be intersected with the clip of the > `Graphics` object. > > So the following code is effectively doing the same: > > Old: > > BaseBounds newClip = clipNode.getShape().getBounds(); > if (!clipNode.getTransform().isIdentity()) { > newClip = clipNode.getTransform().transform(newClip, newClip); > } > final BaseTransform curXform = g.getTransformNoClone(); > final Rectangle curClip = g.getClipRectNoClone(); > newClip = curXform.transform(newClip, newClip); // <- The value of newClip > after the transform is what getClippedBounds(..) is returning > newClip.intersectWith(PrEffectHelper.getGraphicsClipNoClone(g)); > Rectangle clipRect = new Rectangle(newClip) > > > New: > > BaseTransform curXform = g.getTransformNoClone(); > BaseBounds clipBounds = getClippedBounds(new RectBounds(), curXform); > Rectangle clipRect = new Rectangle(clipBounds); > clipRect.intersectWith(PrEffectHelper.getGraphicsClipNoClone(g)); > > > As you can see, there are very similar, but `getClippedBounds` does a much > better job in calculating the bounds. > I also wrote a tests proving the bug. I took 100% of the setup and values > from a debugging session I did when reproducing this bug. > > I checked several scenarios and code and could not find any regressions. > Still, since this is change affects all nodes with rectangular clips, we > should be careful. > Performance wise I could not spot any difference, I do not expect any > difference. > **So I would like to have at least 2 reviewers.** > Note that I will do more testing as well soon on all JavaFX applications I > have access to. > > --- > > As written in the other PR, I have some interesting findings on this > particular problem. > > Copy&Paste from the other PR: > -- > > Ok, so I found out the following: > When a Rectangle is used as clip without any effect or opacity modification, > the rendering goes another (probably faster) route with rendering the clip. > That's why setting the `opacity` to `0.99` fixes the issue - another route > will be used for the rendering. > This happens at the low level (`NGNode`) side of JavaFX. > ... > I could track it down to be a typical floating point problem > ... > The bug always appears when I scroll and the clip RectBounds are somethi... I see a problem on Windows 11 at 125% scale: using the tester app in the ticket, the table focus rectangle's right edge is not visible at some width (i.e. appears and disappears when resizing the window width):  When it is visible, there is no jitter described in the ticket. Also, it can be reproduced at 100% scale. It may or may not be a separate issue. modules/javafx.graphics/src/test/java/test/com/sun/javafx/sg/prism/NGNodeTest.java line 626: > 624: @Override > 625: public void setClipNode(NGNode clipNode) { > 626: System.out.println(clipNode); should this println be removed? ------------- PR Comment: https://git.openjdk.org/jfx/pull/1462#issuecomment-2130095158 PR Review Comment: https://git.openjdk.org/jfx/pull/1462#discussion_r1613777480
