I also found https://github.com/apache/netbeans/blob/master/platform/o.n.swing.plaf/src/org/netbeans/swing/plaf/windows8/DPIUnscaledBorder.java through that OpenJDK thread that I was reading yesterday, which looks to be taking a similar approach.
Probably in a world of 4x+ monitors, I would indeed want to go from 1-pixel to 2+ pixel "hairlines" as otherwise they would be almost invisible. As for the 0 meaning hairline, I was mostly thinking of SkPaint::setStrokeWidth in Skia. https://bugs.openjdk.java.net/browse/JDK-8090551 has been open for quite some time now on JDK. On Fri, May 27, 2022 at 2:00 PM Philip Race <philip.r...@oracle.com> wrote: > Indeed .. something very close to that is what is being proposed in a > current PR here : > https://github.com/openjdk/jdk/pull/7449/files > > Just bear in mind some of the same constraints and that if printed on a > 1200dpi printer > with a scale of 16.67 .. your one pixel line might be too thin to be > seen at all. > > I suggest you should have an upper limit on the unscaling. > > I don't remember why the change a long time ago was backed out .. indeed I > am not sure I remember it will enough for it to be more than a figment > of my imagination > but "0" used to have a special meaning in some graphics systems - X11 > took it to > mean "draw a line the fastest way you can, I do not care about accuracy". > > -phil. > > On 5/26/22 2:47 PM, Kirill Grouchnikov wrote: > > Haven't heard anything here, but in the meanwhile I got great pointers > from > > Karl, the developer of JFormDesigner and FlatLaf over at > > > https://github.com/kirill-grouchnikov/radiance/issues/39#issuecomment-1137649208 > > and subsequent comments. > > > > The core of the idea is to force scale factor of 1.0 on the graphics > > context, compute new origin and bounding box similar to how it's done in > > the internals of Java2D, and then strokes with width of 1.0f will be > > treated as full pixels (if no VALUE_STROKE_PURE hint is set). > > > > On Tue, May 24, 2022 at 7:48 PM Kirill Grouchnikov < > > kirill.grouchni...@gmail.com> wrote: > > > >> I'm trying to figure out what is the right way to draw paths such > >> rectangles or rounded rectangles, such that horizontal and vertical > parts > >> always fall on a full pixel and are displayed at hairline stroke width. > >> > >> A long time ago there was an option to specify stroke width of 0 for > that, > >> but then it was quickly reverted. > >> > >> My understanding is that I need to query scale x and scale y of the > >> device's config's transform, and use that to compute the stroke width. > >> Here's my code - > >> > https://github.com/kirill-grouchnikov/radiance/blob/sunshine/demos/theming-demo/src/main/java/org/pushingpixels/radiance/demo/theming/main/Hairlines.java > >> (no dependency on anything from Radiance, just the core Swing / AWT > stuff). > >> > >> Now, running this on a Windows 10 laptop with recommended / default 250% > >> scale factor gets the correct value of 2.5 as scale. But the visuals > switch > >> between hairline and "smudged" as I horizontally resize the frame one > pixel > >> at a time and the component shifts horizontally - > >> > https://raw.githubusercontent.com/kirill-grouchnikov/radiance/sunshine/docs/images/hairlines.png > >> (and the horizontal lines are also not hairline) > >> > >> How do I make this work in Java2D across all display scale factors so > that > >> I get consistent hairlines? I see the same behavior on Java 9 and Java > 17 > >> > >> Thanks > >> Kirill > >> > >
