On Thu, 11 Jun 2020 13:30:00 GMT, Johan Vos <j...@openjdk.org> wrote:
>> modules/javafx.graphics/src/main/java/com/sun/javafx/font/freetype/PangoGlyphLayout.java
>> line 87:
>>
>>> 86:
>>> 87: private Map<TextRun, Long> runUtf8 = new HashMap<>();
>>> 88: public void layout(TextRun run, PGFont font, FontStrike strike,
>>> char[] text) {
>>
>> In order for this to work, each TextRun would need to be immutable (at least
>> during the life of this PangoGlyphLayout)
>> and there would need to be a 1-1 mapping between the TextRun and the string
>> pointer, independent of anything else. Is
>> this the case? I'm seeing some crashes in OSPango.g_utf8_offset_to_pointer
>> when testing. I don't know if they are
>> related to this or not.
>
> I would assume that once the layout method is called, the TextRun won't
> change anymore. If it would change, the current
> code might break as well, as the string pointer is currently cached. I agree
> though that this is a brittle approach.
> What I'm basically doing here is store additional information (the number of
> unicode codepoints rather than the number
> of UTF 16 chars, which can then be mapped to the string pointer pointing to
> the relevant substring) on the TextRun, but
> since I didn't want to modify TextRun, that additional info is stored in this
> Map. I'd prefer modifying TextRun though.
I think I see what you are trying to do, but there are a couple of problems it
is causing. I attached a new test
program to the JBS bug report, UnicodeTextTest2.java, which avoids any null (0)
characters. That test runs fine today,
and with the first version of your fix (the one without the Map), but causes
assertion failures with the current
version of the patch:
(java:32761): Pango-CRITICAL **: 10:37:09.535: pango_itemize: assertion 'length
>= 0' failed
(java:32761): Pango-CRITICAL **: 10:37:09.963: pango_itemize: assertion 'length
>= 0' failed
I also sometimes get this:
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x00007f00456c2d78, pid=32761, tid=32778
#
# JRE version: Java(TM) SE Runtime Environment (14.0+36) (build 14+36-1461)
# Java VM: Java HotSpot(TM) 64-Bit Server VM (14+36-1461, mixed mode, sharing,
tiered, compressed oops, serial gc,
linux-amd64) # Problematic frame:
# C [libglib-2.0.so.0+0x84d78] g_utf8_offset_to_pointer+0x28
Phil is the expert here, so I'd like him to weigh in.
-------------
PR: https://git.openjdk.java.net/jfx/pull/249
