[OpenJDK 2D-Dev] 8214481 is actually a regression?

[Mario Torre]

Hi Phil and all,

I was working on backporting this to 11:

https://bugs.openjdk.java.net/browse/JDK-8214481

When I realised this is actually a regression in that it makes
rendering on OpenJDK worse in some cases.

I've been testing with 8, 11, 13 and 15 and 11 patched and comparing
those the fonts rendering becomes blurry when fractional rendering is
used:

http://cr.openjdk.java.net/~neugens/JDK-8214481/1.png
http://cr.openjdk.java.net/~neugens/JDK-8214481/2.png

A you can see the rendering in all cases is cleaner, the font is both
blurry and thicker with the patched version.

This is not the case, however, with the font provided by original bug
report:

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

In this case indeed the rendering is better at lower sizes (but not at
higher, where the same blurring is apparent).

I filed a new bug to track this with a reproducer that is derived from
all the various test cases floating around 8214481:

https://bugs.openjdk.java.net/browse/JDK-8242285

Cheers,
Mario

-- 
Mario Torre
Associate Manager, Software Engineering
Red Hat GmbH <https://www.redhat.com>
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