JDK-8242285 : Font rendering regression after 8214481
  • Type: Bug
  • Component: client-libs
  • Affected Version: 14,15
  • Priority: P4
  • Status: Closed
  • Resolution: Not an Issue
  • Submitted: 2020-04-07
  • Updated: 2020-04-09
  • Resolved: 2020-04-07
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JDK 15
15Resolved
Related Reports
Relates :  
JDK-8214481 - freetype path does not disable TrueType hinting with AA+FM hints
Description
https://bugs.openjdk.java.net/browse/JDK-8214481 seems to be a regression in that it makes rendering on OpenJDK blurry as opposed to previous versions where the fonts are rendered correctly. 

Unfortunately, this doesn't seem to be the case always, for example the original bug has a test with the cambria.ttc font and this indeed has a better rendering with the patch. This maybe a difference between serif and non serif fonts but I've not tracked this down yet.

Here's a screenshot with the 11u with patch and without that shows the difference clearly  (left side is patched, right side is clean OpenJDK11), but you can see this same with latest jdk just by reverting 8214481:

http://cr.openjdk.java.net/~neugens/JDK-8214481/3.png

Attached a test case that helps a bit, this is a mesh of all the various tests floating around 8214481.
Comments
Unhinted text *will* be more blurry. That's because we are asking the rasteriser to turn off snapping to the pixel grid. So this is just an expected consequence. The results aren't always to everyone's liking, but this is what Oracle JDK had been doing for many, many years and users had come to expect.
07-04-2020