On Thu, 17 Aug 2023 20:43:59 GMT, Alexey Ivanov <[email protected]> wrote:
> **Problem** > > Glyphs aren't stretched by applying an affine transform `scale(2, 1)` to a > font. Instead, the space between glyphs increases. > > **Root Cause** > > Bitmaps embedded in the font are used to render the glyphs; the bitmaps > aren't transformed, so white-space is seen which fills the requested > horizontal size. > > **Fix** > > Disable using embedded bitmaps if horizontal transform is different from the > vertical one. > > It's similar to [JDK-8204929](https://bugs.openjdk.org/browse/JDK-8204929) > and [JDK-8255387](https://bugs.openjdk.org/browse/JDK-8255387). > > **Test** > > When embedded bitmaps are used, the right half of the image remains filled > with the background colour. The test looks for non-white pixels in the right > half of the image. If there are only white pixels in the right half of the > image, the test fails; if there are other colours, the test passes. > > I can reproduce the problem on Windows only. Without the fix, the test > reports 6 failures for "MS Gothic", "MS PGothic" and "MS UI Gothic" fonts > when text antialiasing is off and when LCD antialiasing is enabled. If > greyscale antialiasing is enabled, the glyphs are stretched as expected, this > case was handled in JDK-8204929; it can be used as a workaround. > > All client tests pass. > > The test could be *headless*, but headless systems, especially with Linux, > don't have fonts installed. Without fonts, the test is useless, therefore I > made it *headful*. test/jdk/java/awt/font/FontScaling/StretchedFontTest.java line 107: > 105: final Dimension size = getTextSize(font); > 106: final BufferedImage image = > 107: new BufferedImage(size.width, size.height, > TYPE_3BYTE_BGR); t might not be related but we can test the image with alpha as well, in that case I think the aa might be always disabled and/or some other code path will be executed. The test for JDK-8204929 uses the "Locale.ENGLISH" and this one "Locale.US", does it matter which one is used to reproduce this bug? ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/15335#discussion_r1297755681
